| 1 | This is gnugo.info, produced by makeinfo version 4.11 from gnugo.texi. |
| 2 | |
| 3 | INFO-DIR-SECTION GNU games |
| 4 | START-INFO-DIR-ENTRY |
| 5 | * GNU Go: (gnugo). The GNU Go program |
| 6 | END-INFO-DIR-ENTRY |
| 7 | |
| 8 | \1f |
| 9 | File: gnugo.info, Node: The Owl Code, Next: Combinations, Up: Pattern Based Reading |
| 10 | |
| 11 | 12.1 The Owl Code |
| 12 | ================= |
| 13 | |
| 14 | The life and death code in `optics.c', described elsewhere (*note |
| 15 | Eyes::), works reasonably well as long as the position is in a |
| 16 | "terminal position", which we define to be one where there are no moves |
| 17 | left which can expand the eye space, or limit it. In situations where |
| 18 | the dragon is surrounded, yet has room to thrash around a bit making |
| 19 | eyes, a simple application of the graph-based analysis will not work. |
| 20 | Instead, a bit of reading is needed to reach a terminal position. |
| 21 | |
| 22 | The defender tries to expand his eyespace, the attacker to limit it, |
| 23 | and when neither finds an effective move, the position is evaluated. We |
| 24 | call this type of life and death reading "Optics With |
| 25 | Limit-negotiation" (OWL). The module which implements it is in |
| 26 | `engine/owl.c'. |
| 27 | |
| 28 | There are two reasonably small databases |
| 29 | `patterns/owl_defendpats.db' and `patterns/owl_attackpats.db' of |
| 30 | expanding and limiting moves. The code in `owl.c' generates a small |
| 31 | move tree, allowing the attacker only moves from `owl_attackpats.db', |
| 32 | and the defender only moves from `owl_defendpats.db'. In addition to |
| 33 | the moves suggested by patterns, vital moves from the eye space |
| 34 | analysis are also tested. |
| 35 | |
| 36 | A third database, `owl_vital_apats.db' includes patterns which |
| 37 | override the eyespace analysis done by the optics code. Since the |
| 38 | eyeshape graphs ignore the complications of shortage of liberties and |
| 39 | cutting points in the surrounding chains, the static analysis of |
| 40 | eyespace is sometimes wrong. The problem is when the optics code says |
| 41 | that a dragon definitely has 2 eyes, but it isn't true due to shortage |
| 42 | of liberties, so the ordinary owl patterns never get into play. In |
| 43 | such situations `owl_vital_apats.db' is the only available measure to |
| 44 | correct mistakes by the optics. Currently the patterns in |
| 45 | `owl_vital_apats.db' are only matched when the level is 9 or greater. |
| 46 | |
| 47 | The owl code is tuned by editing these three pattern databases, |
| 48 | principally the first two. |
| 49 | |
| 50 | A node of the move tree is considered `terminal' if no further moves |
| 51 | are found from `owl_attackpats.db' or `owl_defendpats.db', or if the |
| 52 | function `compute_eyes_pessimistic()' reports that the group is |
| 53 | definitely alive. At this point, the status of the group is evaluated. |
| 54 | The functions `owl_attack()' and `owl_defend()', with usage similar to |
| 55 | `attack()' and `find_defense()', make use of the owl pattern databases |
| 56 | to generate the move tree and decide the status of the group. |
| 57 | |
| 58 | The function `compute_eyes_pessimistic()' used by the owl code is |
| 59 | very conservative and only feels certain about eyes if the eyespace is |
| 60 | completely closed (i.e. no marginal vertices). |
| 61 | |
| 62 | The maximum number of moves tried at each node is limited by the |
| 63 | parameter `MAX_MOVES' defined at the beginning of `engine/owl.c'. The |
| 64 | most most valuable moves are tried first, with the following |
| 65 | restrictions: |
| 66 | |
| 67 | * If `stackp > owl_branch_depth' then only one move is tried per |
| 68 | variation. |
| 69 | |
| 70 | * If `stackp > owl_reading_depth' then the reading terminates, and |
| 71 | the situation is declared a win for the defender (since deep |
| 72 | reading may be a sign of escape). |
| 73 | |
| 74 | * If the node count exceeds `owl_node_limit', the reading also |
| 75 | terminates with a win for the defender. |
| 76 | |
| 77 | * Any pattern with value 99 is considered a forced move: no other |
| 78 | move is tried, and if two such moves are found, the function |
| 79 | returns false. This is only relevant for the attacker. |
| 80 | |
| 81 | * Any pattern in `patterns/owl_attackpats.db' and |
| 82 | `patterns/owl_defendpats.db' with value 100 is considered a win: if |
| 83 | such a pattern is found by `owl_attack' or `owl_defend', the |
| 84 | function returns true. This feature must be used most carefully. |
| 85 | |
| 86 | The functions `owl_attack()' and `owl_defend()' may, like `attack()' |
| 87 | and `find_defense()', return an attacking or defending move through |
| 88 | their pointer arguments. If the position is already won, `owl_attack()' |
| 89 | may or may not return an attacking move. If it finds no move of |
| 90 | interest, it will return `PASS', that is, `0'. The same goes for |
| 91 | `owl_defend()'. |
| 92 | |
| 93 | When `owl_attack()' or `owl_defend()' is called, the dragon under |
| 94 | attack is marked in the array `goal'. The stones of the dragon |
| 95 | originally on the board are marked with goal=1; those added by |
| 96 | `owl_defend()' are marked with goal=2. If all the original strings of |
| 97 | the original dragon are captured, `owl_attack()' considers the dragon |
| 98 | to be defeated, even if some stones added later can make a live group. |
| 99 | |
| 100 | Only dragons with small escape route are studied when the functions |
| 101 | are called from `make_dragons()'. |
| 102 | |
| 103 | The owl code can be conveniently tested using the `--decide-owl |
| 104 | LOCATION' option. This should be used with `-t' to produce a useful |
| 105 | trace, `-o' to produce an SGF file of variations produced when the life |
| 106 | and death of the dragon at LOCATION is checked, or both. |
| 107 | `--decide-position' performs the same analysis for all dragons with |
| 108 | small escape route. |
| 109 | |
| 110 | \1f |
| 111 | File: gnugo.info, Node: Combinations, Prev: The Owl Code, Up: Pattern Based Reading |
| 112 | |
| 113 | 12.2 Combination reading |
| 114 | ======================== |
| 115 | |
| 116 | It may happen that no single one of a set of worms can be killed, yet |
| 117 | there is a move that guarantees that at least one can be captured. The |
| 118 | simplest example is a double atari. The purpose of the code in |
| 119 | `combination.c' is to find such moves. |
| 120 | |
| 121 | For example, consider the following situation: |
| 122 | |
| 123 | |
| 124 | +--------- |
| 125 | |....OOOOX |
| 126 | |....OOXXX |
| 127 | |..O.OXX.. |
| 128 | |.OXO.OX.. |
| 129 | |.OX..OO.. |
| 130 | |.XXOOOXO. |
| 131 | |..*XXOX.. |
| 132 | |....XOX.. |
| 133 | |.XX..X... |
| 134 | |X........ |
| 135 | |
| 136 | Every `X' stone in this position is alive. However the move at `*' |
| 137 | produces a position in which at least one of four strings will get |
| 138 | captured. This is a _combination_. |
| 139 | |
| 140 | The driving function is called `atari_atari' because typically a |
| 141 | combination involves a sequence of ataris culminating in a capture, |
| 142 | though sometimes the moves involved are not ataris. For example in the |
| 143 | above example, the first move at `*' is _not_ an atari, though after |
| 144 | `O' defends the four stones above, a sequence of ataris ensues |
| 145 | resulting in the capture of some string. |
| 146 | |
| 147 | Like the owl functions `atari_atari' does pattern-based reading. The |
| 148 | database generating the attacking moves is `aa_attackpats.db'. One |
| 149 | danger with this function is that the first atari tried might be |
| 150 | irrelevant to the actual combination. To detect this possibility, once |
| 151 | we've found a combination, we mark that first move as forbidden, then |
| 152 | try again. If no combination of the same size or larger turns up, then |
| 153 | the first move was indeed essential. |
| 154 | |
| 155 | * `void combinations(int color)' |
| 156 | |
| 157 | Generate move reasons for combination attacks and defenses |
| 158 | against them. This is one of the move generators called from |
| 159 | genmove(). |
| 160 | |
| 161 | * `int atari_atari(int color, int *attack_move, char |
| 162 | defense_moves[BOARDMAX], int save_verbose)' |
| 163 | |
| 164 | Look for a combination for `color'. For the purpose of the |
| 165 | move generation, returns the size of the smallest of the |
| 166 | worms under attack. |
| 167 | |
| 168 | * `int atari_atari_confirm_safety(int color, int move, int *defense, |
| 169 | int minsize, const char saved_dragons[BOARDMAX], const char |
| 170 | saved_worms[BOARDMAX])' |
| 171 | |
| 172 | Tries to determine whether a move is a blunder. Wrapper |
| 173 | around atari_atari_blunder_size. Check whether a combination |
| 174 | attack of size at least `minsize' appears after move at |
| 175 | `move' has been made. The arrays `saved_dragons[]' and |
| 176 | `saved_worms[]' should be one for stones belonging to dragons |
| 177 | or worms respectively, which are supposedly saved by `move'. |
| 178 | |
| 179 | * `int atari_atari_blunder_size(int color, int move, int *defense, |
| 180 | const char safe_stones[BOARDMAX])' |
| 181 | |
| 182 | This function checks whether any new combination attack |
| 183 | appears after move at (move) has been made, and returns its |
| 184 | size (in points). `safe_stones' marks which of our stones |
| 185 | are supposedly safe after this move. |
| 186 | |
| 187 | \1f |
| 188 | File: gnugo.info, Node: Influence, Next: Monte Carlo Go, Prev: Pattern Based Reading, Up: Top |
| 189 | |
| 190 | 13 Influence Function |
| 191 | ********************* |
| 192 | |
| 193 | * Menu: |
| 194 | |
| 195 | * Influential Concepts:: Conceptual Outline of Influence |
| 196 | * Territory and Moyo:: Territory, Moyo and Area |
| 197 | * Influence Usage:: Where influence gets used in the engine |
| 198 | * Influence and Territory:: Influence and Territory |
| 199 | * Territorial Details:: Details of the Territory Valuation |
| 200 | * The Influence Core:: The Core of the Influence Function |
| 201 | * The Influence Algorithm:: The algorithm of `accumlate_influence()' |
| 202 | * Permeability:: Permeability |
| 203 | * Escape:: Escape |
| 204 | * Break Ins:: Break Ins |
| 205 | * Surrounded Dragons:: Surrounded Dragons |
| 206 | * Influential Patterns:: Patterns used by the Influence module |
| 207 | * Influential Display:: Colored display and debugging of influence |
| 208 | * Influence Tuning:: Influence tuning with view.pike |
| 209 | |
| 210 | \1f |
| 211 | File: gnugo.info, Node: Influential Concepts, Next: Territory and Moyo, Up: Influence |
| 212 | |
| 213 | 13.1 Conceptual Outline of Influence |
| 214 | ==================================== |
| 215 | |
| 216 | We define call stones "lively" if they cannot be tactically attacked, |
| 217 | or if they have a tactical defense and belong to the player whose turn |
| 218 | it is. Similarly, stones that cannot be strategically attacked (in the |
| 219 | sense of the life-and-death analysis), or that have a strategical |
| 220 | defense and belong to the player to move, are called "alive". If we |
| 221 | want to use the influence function before deciding the strategical |
| 222 | status, all lively stones count as alive. |
| 223 | |
| 224 | Every alive stone on the board works as an influence source, with |
| 225 | influence of its color radiating outwards in all directions. The |
| 226 | strength of the influence declines exponentially with the distance from |
| 227 | the source. |
| 228 | |
| 229 | Influence can only flow unhindered if the board is empty, however. |
| 230 | All lively stones (regardless of color) act as influence barriers, as do |
| 231 | connections between enemy stones that can't be broken through. For |
| 232 | example the one space jump counts as a barrier unless either of the |
| 233 | stones can be captured. Notice that it doesn't matter much if the |
| 234 | connection between the two stones can be broken, since in that case |
| 235 | there would come influence from both directions anyway. |
| 236 | |
| 237 | From the influence of both colors we compute a territorial value |
| 238 | between -1.0 and +1.0 for each intersection, which can be seen as the |
| 239 | likely hood of it becoming territory for either color. |
| 240 | |
| 241 | In order to avoid finding bogus territory, we add extra influence |
| 242 | sources at places where an invasion can be launched, e.g. at 3-3 under |
| 243 | a handicap stone, in the middle of wide edge extensions and in the |
| 244 | center of large open spaces anywhere. Similarly we add extra influence |
| 245 | sources where intrusions can be made into what otherwise looks as solid |
| 246 | territory, e.g. monkey jumps. These intrusions depend on whose turn we |
| 247 | assume it to be. |
| 248 | |
| 249 | All these extra influence sources, as well as connections, are |
| 250 | controlled by a pattern database, which consists of the two files |
| 251 | patterns/influence.db and patterns/barriers.db. The details are |
| 252 | explained in *note Influential Patterns::. |
| 253 | |
| 254 | \1f |
| 255 | File: gnugo.info, Node: Territory and Moyo, Next: Influence Usage, Prev: Influential Concepts, Up: Influence |
| 256 | |
| 257 | 13.2 Territory, Moyo and Area |
| 258 | ============================= |
| 259 | |
| 260 | Using the influence code, empty regions of the board are partitioned in |
| 261 | three ways. A vertex may be described as White or Black's "territory", |
| 262 | "moyo" or "area". The functions `whose_territory()', `whose_moyo()' and |
| 263 | `whose_area()' will return a color, or EMPTY if it belongs to one |
| 264 | player or the other in one of these classifications. |
| 265 | |
| 266 | * Territory |
| 267 | |
| 268 | Those parts of the board which are expected to materialize as |
| 269 | actual points for one player or the other at the end of the |
| 270 | game are considered "territory". |
| 271 | |
| 272 | * Moyo |
| 273 | |
| 274 | Those parts of the board which are either already territory |
| 275 | or more generally places where a territory can easily |
| 276 | materialize if the opponent neglects to reduce are considered |
| 277 | "moyo". "moyo". |
| 278 | |
| 279 | * Area |
| 280 | |
| 281 | Those parts of the board where one player or the other has a |
| 282 | stronger influence than his opponent are considered "area". |
| 283 | |
| 284 | Generally territory is moyo and moyo is area. To get a feeling for |
| 285 | these concepts, load an sgf file in a middle game position with the |
| 286 | option `-m 0x0180' and examine the resulting diagrams (*note |
| 287 | Influential Display::). |
| 288 | |
| 289 | \1f |
| 290 | File: gnugo.info, Node: Influence Usage, Next: Influence and Territory, Prev: Territory and Moyo, Up: Influence |
| 291 | |
| 292 | 13.3 Where influence gets used in the engine |
| 293 | ============================================ |
| 294 | |
| 295 | The information obtained from the influence computation is used in a |
| 296 | variety of places in the engine, and the influence module is called |
| 297 | several times in the process of the move generation. The details of the |
| 298 | influence computation vary according to the needs of the calling |
| 299 | function. |
| 300 | |
| 301 | After GNU Go has decided about the tactical stability of strings, the |
| 302 | influence module gets called the first time. Here all lively stones act |
| 303 | as an influence source of default strength 100. The result is stored in |
| 304 | the variables `initial_influence' and `initial_opposite_influence', and |
| 305 | it is used as an important information for guessing the strength of |
| 306 | dragons. For example, a dragon that is part of a moyo of size 25 is |
| 307 | immediately considered alive. For dragons with a smaller moyo size, a |
| 308 | life-and-death analysis will be done by the owl code (see *note Pattern |
| 309 | Based Reading::). A dragon with a moyo size of only 5 will be |
| 310 | considered weak, even if the owl code has decided that it cannot be |
| 311 | killed. |
| 312 | |
| 313 | As a tool for both the owl code and the strength estimate of dragons, |
| 314 | an "escape" influence gets computed for each dragon (*note Escape::). |
| 315 | |
| 316 | Once all dragons have been evaluated, the influence module is called |
| 317 | again and the variables `initial_influence' and |
| 318 | `initial_opposite_influence' get overwritten. Of course, the dragon |
| 319 | status', which are available now, are taken into account. Stones |
| 320 | belonging to a dead dragon will not serve as an influence source, and |
| 321 | the strengths of other stones get adjusted according to the strength of |
| 322 | their respective dragon. |
| 323 | |
| 324 | The result of this run is the most important tool for move |
| 325 | evaluation. All helper functions of patterns as explained in *note |
| 326 | Patterns:: that refer to influence results (e. g. `olib(*)' etc.) |
| 327 | actually use these results. Further, `initial_influence' serves as the |
| 328 | reference for computing the territorial value of a move. That is, from |
| 329 | the influence strengths stored in `initial_influence', a territory |
| 330 | value is assigned to each intersection. This value is supposed to |
| 331 | estimate the likelyhood that this intersection will become white or |
| 332 | black territory. |
| 333 | |
| 334 | Then, for each move that gets considered in the function |
| 335 | `value_moves', the influence module is called again via the function |
| 336 | `compute_move_influence' to assess the likely territorial balance after |
| 337 | this move, and the result is compared with the state before that move. |
| 338 | |
| 339 | An additional influence computation is done in order to compute the |
| 340 | followup value of a move. Some explainations are in *note Territorial |
| 341 | Details::. |
| 342 | |
| 343 | Some of the public functions from `influence.c' which are used |
| 344 | throughout the engine are listed in *note Influence Utilities::. |
| 345 | |
| 346 | \1f |
| 347 | File: gnugo.info, Node: Influence and Territory, Next: Territorial Details, Prev: Influence Usage, Up: Influence |
| 348 | |
| 349 | 13.4 Influence and Territory |
| 350 | ============================ |
| 351 | |
| 352 | In this section we consider how the influence function is used to |
| 353 | estimate territory in the function `estimate_territorial_value()'. |
| 354 | |
| 355 | A move like `*' by `O' below is worth one point: |
| 356 | |
| 357 | OXXX. |
| 358 | OX.XX |
| 359 | O*a.X |
| 360 | OX.XX |
| 361 | OXXX. |
| 362 | |
| 363 | This is evaluated by the influence function in the following way: We |
| 364 | first assign territory under the assumption that X moves first in all |
| 365 | local positions in the original position; then we reassing territory, |
| 366 | again under the assumption that `X' moves first in all local positions, |
| 367 | but after we let `O' make the move at `*'. These two territory |
| 368 | assignments are compared and the difference gives the territorial value |
| 369 | of the move. |
| 370 | |
| 371 | Technically, the assumption that `X' plays first everywhere is |
| 372 | implemented via an asymmetric pattern database in `barriers.db'. What |
| 373 | exactly is a safe connection that stops hostile influence from passing |
| 374 | through is different for `O' and `X'; of course such a connection has |
| 375 | to be tighter for stones with color `O'. Also, additional intrusion |
| 376 | influence sources are added for `X' in places where `X' stones have |
| 377 | natural followup moves. |
| 378 | |
| 379 | In this specific example above, the asymmetry (before any move has |
| 380 | been made) would turn out as follows: If `X' is in turn to move, the |
| 381 | white influence would get stopped by a barrier at `*', leaving 4 points |
| 382 | of territory for `X'. However, if `O' was next to move, then a |
| 383 | followup move for the white stones at the left would be assumed in the |
| 384 | form of an extra ("intrusion") influence source at `*'. This would get |
| 385 | stopped at `a', leaving three points of territory. |
| 386 | |
| 387 | Returning to the valuation of a move by `O' at `*', we get a value |
| 388 | of 1 for the move at `*'. However, of course this move is sente once |
| 389 | it is worth playing, and should therefore (in miai counting) be awarded |
| 390 | an effective value of 2. Hence we need to recognize the followup value |
| 391 | of a move. GNU Go 3.0 took care of this by using patterns in |
| 392 | `patterns.db' that enforced an explicit followup value. Versions from |
| 393 | 3.2 on instead compute a seperate followup influence to each move |
| 394 | considered. In the above example, an intrusion source will be added at |
| 395 | `a' as a followup move to `*'. This destroys all of Black's territory |
| 396 | and hence gives a followup value of 3. |
| 397 | |
| 398 | The pattern based followup value are still needed at some places, |
| 399 | however. |
| 400 | |
| 401 | To give another example, consider this position where we want to |
| 402 | estimate the value of an `O' move at `*': |
| 403 | |
| 404 | OOOXXX |
| 405 | ..OX.. |
| 406 | ..OX.. |
| 407 | ...*.. |
| 408 | ------ |
| 409 | |
| 410 | Before the move we assume `X' moves first in the local position (and |
| 411 | that `O' has to connect), which gives territory like this (lower case |
| 412 | letter identify territory for each player): |
| 413 | |
| 414 | OOOXXX |
| 415 | ooOXxx |
| 416 | o.OXxx |
| 417 | o...xx |
| 418 | ------ |
| 419 | |
| 420 | Then we let `O' make the move at `*' and assume `X' moves first |
| 421 | again next. The territory then becomes (`X' is also assumed to have to |
| 422 | connect): |
| 423 | |
| 424 | OOOXXX |
| 425 | ooOXxx |
| 426 | ooOX.x |
| 427 | oo.O.x |
| 428 | ------ |
| 429 | |
| 430 | We see that this makes a difference in territory of 4, which is what |
| 431 | influence_delta_territory() should report. Then again, we have followup |
| 432 | value, and here also a reverse followup value. The reverse followup |
| 433 | value, which in this case will be so high that the move is treated as |
| 434 | reverse sente, is added by an explicit pattern. Other sources for |
| 435 | followup or reverse followup values are threats to capture a rescue a |
| 436 | string of stones. See the code and comments in the function |
| 437 | `value_move_reaons' for how followup and reverse followup values are |
| 438 | used to adjust the effective move value. |
| 439 | |
| 440 | To give an example of territorial value where something is captured, |
| 441 | consider the `O' move at `*' here, |
| 442 | |
| 443 | XXXXXXXO |
| 444 | X.OOOOXO |
| 445 | X.O..O*O |
| 446 | -------- |
| 447 | |
| 448 | As before we first let the influence function determine territory |
| 449 | assuming X moves first, i.e. with a captured group: |
| 450 | |
| 451 | XXXXXXXO |
| 452 | XxyyyyXO |
| 453 | Xxyxxy.O |
| 454 | -------- |
| 455 | |
| 456 | Here `y' indicates `X' territory + captured stone, i.e. these count |
| 457 | for two points. After the `O' move at `*' we instead get |
| 458 | |
| 459 | XXXXXXXO |
| 460 | X.OOOOXO |
| 461 | X.OooOOO |
| 462 | -------- |
| 463 | |
| 464 | and we see that `X' has 16 territory fewer and `O' has two territory |
| 465 | more, for a total difference of 18 points. |
| 466 | |
| 467 | That the influence function counts the value of captured stones was |
| 468 | introduced in GNU Go 3.2. Previously this was instead done using the |
| 469 | effective_size heuristic. The effective size is the number of stones |
| 470 | plus the surrounding empty spaces which are closer to this string or |
| 471 | dragon than to any other stones. Here the `O' string would thus have |
| 472 | effective size 6 (number of stones) + 2 (interior eye) + 2*0.5 (the two |
| 473 | empty vertices to the left of the string, split half each with the |
| 474 | surrounding X string) + 1*0.33 (the connection point, split between |
| 475 | three strings) = 9.33. As noted this value was doubled, giving 18.67 |
| 476 | which is reasonably close to the correct value of 18. The effective size |
| 477 | heuristic is still used in certain parts of the move valuation where we |
| 478 | can't easily get a more accurate value from the influence function (e. |
| 479 | g. attacks depending on a ko, attack threats). |
| 480 | |
| 481 | Note that this section only describes the territorial valuation of a |
| 482 | move. Apart from that, GNU Go uses various heuristics in assigning a |
| 483 | strategical value (weakening and strengthening of other stones on the |
| 484 | board) to a move. Also, the influence function isn't quite as well |
| 485 | tuned as the examples above may seem to claim. But it should give a |
| 486 | fairly good idea of how the design is intended. |
| 487 | |
| 488 | Another matter is that so far we have only considered the change in |
| 489 | secure territory. GNU Go 3.2 and later versions use a revised |
| 490 | heuristic, which is explained in the next section, to assign probable |
| 491 | territory to each player. |
| 492 | |
| 493 | \1f |
| 494 | File: gnugo.info, Node: Territorial Details, Next: The Influence Core, Prev: Influence and Territory, Up: Influence |
| 495 | |
| 496 | 13.5 Details of the Territory Valuation |
| 497 | ======================================= |
| 498 | |
| 499 | This section explains how GNU Go assigns a territorial value to an |
| 500 | intersection once the white and black influence have been computed. |
| 501 | The intention is that an intersection that has a chance of xx% of |
| 502 | becoming white territory is counted as 0.xx points of territory for |
| 503 | white, and similar for black. |
| 504 | |
| 505 | The algorithm in the function `new_value_territory' goes roughly as |
| 506 | follows: |
| 507 | |
| 508 | If `wi' is the white influence at a point, and `bi' the black |
| 509 | influence, then ` value = ( (wi-bi)/ (wi+bi) )^3' (positive values |
| 510 | indicates likley white territory, negative stand for black territory) |
| 511 | turns out to be very simple first guess that is still far off, but |
| 512 | reasonable enough to be useful. |
| 513 | |
| 514 | This value is then suspect a number of corrections. Assume that this |
| 515 | first guess resulted in a positive value. |
| 516 | |
| 517 | If both `bi' and `wi' are small, it gets reduced. What exactly is |
| 518 | "small" depends on whether the intersection is close to a corner or an |
| 519 | edge of the board, since it is easier to claim territory in the corner |
| 520 | than in the center. |
| 521 | |
| 522 | Then the value at each intersection is degraded to the minimum value |
| 523 | of its neighbors. This can be seen as a second implementation of the |
| 524 | proverb saying that there is no territory in the center of the board. |
| 525 | This step substantially reduces the size of spheres of territory that |
| 526 | are open at several sides. |
| 527 | |
| 528 | Finally, there are a number of patterns that explicitly forbid GNU |
| 529 | Go to count territory at some intersections. This is used e. g. for |
| 530 | false eyes that will eventually have to be filled in. Also, points for |
| 531 | prisoners are added. |
| 532 | |
| 533 | To fine tune this scheme, some revisions have been made to the |
| 534 | influence computations that are relevant for territorial evaluation. |
| 535 | This includes a reduced default attenuation and some revised pattern |
| 536 | handling. |
| 537 | |
| 538 | \1f |
| 539 | File: gnugo.info, Node: The Influence Core, Next: The Influence Algorithm, Prev: Territorial Details, Up: Influence |
| 540 | |
| 541 | 13.6 The Core of the Influence Function |
| 542 | ======================================= |
| 543 | |
| 544 | The basic influence radiation process can efficiently be implemented as |
| 545 | a breadth first search for adjacent and more distant points, using a |
| 546 | queue structure. |
| 547 | |
| 548 | Influence barriers can be found by pattern matching, assisted by |
| 549 | reading through constraints and/or helpers. Wall structures, invasion |
| 550 | points and intrusion points can be found by pattern matching as well. |
| 551 | |
| 552 | When influence is computed, the basic idea is that there are a number |
| 553 | of influence sources on the board, whose contributions are summed to |
| 554 | produce the influence values. For the time being we can assume that the |
| 555 | living stones on the board are the influence sources, although this is |
| 556 | not the whole story. |
| 557 | |
| 558 | The function `compute_influence()' contains a loop over the board, |
| 559 | and for each influence source on the board, the function |
| 560 | `accumulate_influence()' is called. This is the core of the influence |
| 561 | function. Before we get into the details, this is how the influence |
| 562 | field from a single isolated influence source of strength 100 turns out |
| 563 | (with an attenuation of 3.0): |
| 564 | |
| 565 | 0 0 0 0 0 0 0 0 0 0 0 |
| 566 | 0 0 0 0 1 1 1 0 0 0 0 |
| 567 | 0 0 0 1 2 3 2 1 0 0 0 |
| 568 | 0 0 1 3 5 11 5 3 1 0 0 |
| 569 | 0 1 2 5 16 33 16 5 2 1 0 |
| 570 | 0 1 3 11 33 X 33 11 3 1 0 |
| 571 | 0 1 2 5 16 33 16 5 2 1 0 |
| 572 | 0 0 1 3 5 11 5 3 1 0 0 |
| 573 | 0 0 0 1 2 3 2 1 0 0 0 |
| 574 | 0 0 0 0 1 1 1 0 0 0 0 |
| 575 | 0 0 0 0 0 0 0 0 0 0 0 |
| 576 | |
| 577 | These values are in reality floating point numbers but have been |
| 578 | rounded down to the nearest integer for presentation. This means that |
| 579 | the influence field does not stop when the numbers become zeroes. |
| 580 | |
| 581 | Internally `accumulate_influence()' starts at the influence source |
| 582 | and spreads influence outwards by means of a breadth first propagation, |
| 583 | implemented in the form of a queue. The order of propagation and the |
| 584 | condition that influence only is spread outwards guarantee that no |
| 585 | intersection is visited more than once and that the process terminates. |
| 586 | In the example above, the intersections are visited in the following |
| 587 | order: |
| 588 | |
| 589 | + + + + + + + + + + + |
| 590 | + 78 68 66 64 63 65 67 69 79 + |
| 591 | + 62 46 38 36 35 37 39 47 75 + |
| 592 | + 60 34 22 16 15 17 23 43 73 + |
| 593 | + 58 32 14 6 3 7 19 41 71 + |
| 594 | + 56 30 12 2 0 4 18 40 70 + |
| 595 | + 57 31 13 5 1 8 20 42 72 + |
| 596 | + 59 33 21 10 9 11 24 44 74 + |
| 597 | + 61 45 28 26 25 27 29 48 76 + |
| 598 | + 77 54 52 50 49 51 53 55 80 + |
| 599 | + + + + + + + + + + + |
| 600 | |
| 601 | The visitation of intersections continues in the same way on the |
| 602 | intersections marked '`+' and further outwards. In a real position |
| 603 | there will be stones and tight connections stopping the influence from |
| 604 | spreading to certain intersections. This will disrupt the diagram |
| 605 | above, but the main property of the propagation still remains, i.e. no |
| 606 | intersection is visited more than once and after being visited no more |
| 607 | influence will be propagated to the intersection. |
| 608 | |
| 609 | \1f |
| 610 | File: gnugo.info, Node: The Influence Algorithm, Next: Permeability, Prev: The Influence Core, Up: Influence |
| 611 | |
| 612 | 13.7 The Influence Algorithm |
| 613 | ============================ |
| 614 | |
| 615 | Let `(m, n)' be the coordinates of the influence source and `(i, j)' |
| 616 | the coordinates of a an intersection being visited during propagation, |
| 617 | using the same notation as in the `accumulate_influence()' function. |
| 618 | Influence is now propagated to its eight closest neighbors, including |
| 619 | the diagonal ones, according to the follow scheme: |
| 620 | |
| 621 | For each of the eight directions `(di, dj)', do: |
| 622 | |
| 623 | 1. Compute the scalar product `di*(i-m) + dj*(j-n)' between the |
| 624 | vectors `(di,dj)' and `(i,j) - (m,n)' |
| 625 | |
| 626 | 2. If this is negative or zero, the direction is not outwards and we |
| 627 | continue with the next direction. The exception is when we are |
| 628 | visiting the influence source, i.e. the first intersection, when |
| 629 | we spread influence in all directions anyway. |
| 630 | |
| 631 | 3. If `(i+di, j+dj)' is outside the board or occupied we also |
| 632 | continue with the next direction. |
| 633 | |
| 634 | 4. Let S be the strength of the influence at `(i, j)'. The influence |
| 635 | propagated to `(i+di, j+dj)' from this intersection is given by |
| 636 | `P*(1/A)*D*S', where the three different kinds of damping are: |
| 637 | |
| 638 | * The permeability `P', which is a property of the board |
| 639 | intersections. Normally this is one, i.e. unrestricted |
| 640 | propagation, but to stop propagation through e.g. one step |
| 641 | jumps, the permeability is set to zero at such intersections |
| 642 | through pattern matching. This is further discussed below. |
| 643 | |
| 644 | * The attenuation `A', which is a property of the influence |
| 645 | source and different in different directions. By default this |
| 646 | has the value 3 except diagonally where the number is twice |
| 647 | as much. By modifying the attenuation value it is possible to |
| 648 | obtain influence sources with a larger or a smaller effective |
| 649 | range. |
| 650 | |
| 651 | * The directional damping `D', which is the squared cosine of |
| 652 | the angle between `(di,dj)' and `(i,j) - (m,n)'. The idea is |
| 653 | to stop influence from "bending" around an interfering stone |
| 654 | and get a continuous behavior at the right angle cutoff. The |
| 655 | choice of the squared cosine for this purpose is rather |
| 656 | arbitrary, but has the advantage that it can be expressed as a |
| 657 | rational function of `m', `n', `i', `j', `di', and `dj', |
| 658 | without involving any trigonometric or square root |
| 659 | computations. When we are visiting the influence source we |
| 660 | let by convention this factor be one. |
| 661 | |
| 662 | Influence is typically contributed from up to three neighbors |
| 663 | "between" this intersection and the influence source. These values are |
| 664 | simply added together. As pointed out before, all contributions will |
| 665 | automatically have been made before the intersection itself is visited. |
| 666 | |
| 667 | When the total influence for the whole board is computed by |
| 668 | `compute_influence()', `accumulate_influence()' is called once for each |
| 669 | influence source. These invocations are totally independent and the |
| 670 | influence contributions from the different sources are added together. |
| 671 | |
| 672 | \1f |
| 673 | File: gnugo.info, Node: Permeability, Next: Escape, Prev: The Influence Algorithm, Up: Influence |
| 674 | |
| 675 | 13.8 Permeability |
| 676 | ================= |
| 677 | |
| 678 | The permeability at the different points is initially one at all empty |
| 679 | intersections and zero at occupied intersections. To get a useful |
| 680 | influence function we need to modify this, however. Consider the |
| 681 | following position: |
| 682 | |
| 683 | |...... |
| 684 | |OOOO.. |
| 685 | |...O.. |
| 686 | |...a.X ('a' empty intersection) |
| 687 | |...O.. |
| 688 | |...OOO |
| 689 | |.....O |
| 690 | +------ |
| 691 | |
| 692 | The corner is of course secure territory for `O' and clearly the `X' |
| 693 | stone has negligible effect inside this position. To stop `X' influence |
| 694 | from leaking into the corner we use pattern matching (pattern |
| 695 | Barrier1/Barrier2 in `barriers.db') to modify the permeability for `X' |
| 696 | at this intersection to zero. `O' can still spread influence through |
| 697 | this connection. |
| 698 | |
| 699 | Another case that needs to be mentioned is how the permeability |
| 700 | damping is computed for diagonal influence radiation. For horizontal |
| 701 | and vertical radiation we just use the permeability (for the relevant |
| 702 | color) at the intersection we are radiating from. In the diagonal case |
| 703 | we additionally multiply with the maximum permeability at the two |
| 704 | intersections we are trying to squeeze between. The reason for this can |
| 705 | be found in the diagram below: |
| 706 | |
| 707 | |...X |...X |
| 708 | |OO.. |Oda. |
| 709 | |..O. |.bc. |
| 710 | |..O. |..O. |
| 711 | +---- +---- |
| 712 | |
| 713 | We don't want `X' influence to be spread from `a' to `b', and since |
| 714 | the permeability at both c and d is zero, the rule above stops this. |
| 715 | |
| 716 | \1f |
| 717 | File: gnugo.info, Node: Escape, Next: Break Ins, Prev: Permeability, Up: Influence |
| 718 | |
| 719 | 13.9 Escape |
| 720 | =========== |
| 721 | |
| 722 | One application of the influence code is in computing the |
| 723 | `dragon.escape_route' field. This is computed by the function |
| 724 | `compute_escape()' as follows. First, every intersection is assigned |
| 725 | an escape value, ranging between 0 and 4, depending on the influence |
| 726 | value of the opposite color. |
| 727 | |
| 728 | The `escape_route' field is modified by the code in `surround.c' |
| 729 | (*note Surrounded Dragons::). It is divided by two for weakly surrounded |
| 730 | dragons, and set to zero for surrounded ones. |
| 731 | |
| 732 | In addition to assiging an escape value to empty vertices, we also |
| 733 | assign an escape value to friendly dragons. This value can range from 0 |
| 734 | to 6 depending on the status of the dragon, with live dragons having |
| 735 | value 6. |
| 736 | |
| 737 | Then we sum the values of the resulting influence escape values over |
| 738 | the intersections (including friendly dragons) at distance 4, that is, |
| 739 | over those intersections which can be joined to the dragon by a path of |
| 740 | length 4 (and no shorter path) not passing adjacent to any unfriendly |
| 741 | dragon. In the following example, we sum the influence escape value |
| 742 | over the four vertices labelled '4'. |
| 743 | |
| 744 | |
| 745 | . . . . . . . . . . . . . . . . . . |
| 746 | . . . . . X . . O . . . . . X . . O |
| 747 | . . X . . . . . O . . X . 2 . 4 . O |
| 748 | X . . . . . . . . X . . 1 1 2 3 4 . |
| 749 | X O . O . . . . O X O 1 O 1 2 3 4 O |
| 750 | X O . O . . . . . X O 1 O 1 . 4 . . |
| 751 | X O . . . X . O O X O 1 . . X . . O |
| 752 | . . . X . . . . . . 1 . X . . . . . |
| 753 | X . . . . X . . . X . . . . X . . . |
| 754 | . . . . . . . . . . . . . . . . . . |
| 755 | |
| 756 | Since the dragon is trying to reach safety, the reader might wonder |
| 757 | why `compute_influence()' is called with the opposite color of the |
| 758 | dragon contemplating escape. To explain this point, we first remind |
| 759 | the reader why there is a color parameter to `compute_influence()'. |
| 760 | Consider the following example position: |
| 761 | |
| 762 | ...XX... |
| 763 | OOO..OOO |
| 764 | O......O |
| 765 | O......O |
| 766 | -------- |
| 767 | |
| 768 | Whether the bottom will become O territory depends on who is in turn |
| 769 | to play. This is implemented with the help of patterns in barriers.db, |
| 770 | so that X influence is allowed to leak into the bottom if X is in turn |
| 771 | to move but not if O is. There are also "invade" patterns which add |
| 772 | influence sources in sufficiently open parts of the board which are |
| 773 | handled differently depending on who is in turn to move. |
| 774 | |
| 775 | In order to decide the territorial value of an O move in the third |
| 776 | line gap above, influence is first computed in the original position |
| 777 | with the opponent (i.e. X) in turn to move. Then the O stone is played |
| 778 | to give: |
| 779 | |
| 780 | |
| 781 | ...XX... |
| 782 | OOO.OOOO |
| 783 | O......O |
| 784 | O......O |
| 785 | -------- |
| 786 | |
| 787 | Now influence is computed once more, also this time with X in turn to |
| 788 | move. The difference in territory (as computed from the influence |
| 789 | values) gives the territorial value of the move. |
| 790 | |
| 791 | Exactly how influence is computed for use in the escape route |
| 792 | estimation is all ad hoc. But it makes sense to assume the opponent |
| 793 | color in turn to move so that the escape possibilities aren't |
| 794 | overestimated. After we have made a move in the escape direction it is |
| 795 | after all the opponent's turn. |
| 796 | |
| 797 | The current escape route mechanism seems good enough to be useful |
| 798 | but is not completely reliable. Mostly it seems to err on the side of |
| 799 | being too optimistic. |
| 800 | |
| 801 | \1f |
| 802 | File: gnugo.info, Node: Break Ins, Next: Surrounded Dragons, Prev: Escape, Up: Influence |
| 803 | |
| 804 | 13.10 Break Ins |
| 805 | =============== |
| 806 | |
| 807 | The code in `breakin.c' break-ins into territories that require deeper |
| 808 | tactical reading and are thus impossible to detect for the influence |
| 809 | module. It gets run after the influence module and revises its |
| 810 | territory valuations. |
| 811 | |
| 812 | The break-in code makes use of two public functions in |
| 813 | `readconnect.c', |
| 814 | |
| 815 | * int break_in(int str, const char goal[BOARDMAX], int *move) |
| 816 | |
| 817 | Returns WIN if `str' can connect to the area `goal[]' (which |
| 818 | may or may not contain stones), if the string's owner gets |
| 819 | the first move. |
| 820 | |
| 821 | * int block_off(int str, const char goal[BOARDMAX], int *move) |
| 822 | |
| 823 | Returns WIN if `str' cannot connect to the area `goal[]' |
| 824 | (which may or may not contain stones), if the other color |
| 825 | moves first. |
| 826 | |
| 827 | These functions are public front ends to their counterparts |
| 828 | `recursive_break_in' and `recursive_block_off', which call each other |
| 829 | recursively. |
| 830 | |
| 831 | The procedure is as follows: We look at all big (>= 10) territory |
| 832 | regions as detected by the influence code. Using the computation of |
| 833 | connection distances from readconnect.c, we compute all nearby vertices |
| 834 | of this territory. We look for the closest safe stones belonging to the |
| 835 | opponent. |
| 836 | |
| 837 | For each such string `str' we call |
| 838 | |
| 839 | * `break_in(str, territory)' if the opponent is assumed to be next |
| 840 | to move, |
| 841 | |
| 842 | * `block_off(str, territory)' if the territory owner is next. |
| 843 | |
| 844 | If the break in is successful resp. the blocking unsuccessful, we |
| 845 | shrink the territory, and see whether the opponent can still break in. |
| 846 | We repeat this until the territory is shrunk so much that the opponent |
| 847 | can no longer reach it. |
| 848 | |
| 849 | To see the break in code in action run GNU Go on the file |
| 850 | `regression/games/break_in.sgf' with the option `-d0x102000'. Among the |
| 851 | traces you will find: |
| 852 | |
| 853 | Trying to break in from D7 to: |
| 854 | E9 (1) F9 (1) G9 (1) E8 (1) F8 (1) G8 (1) |
| 855 | H8 (1) G7 (1) H7 (1) J7 (1) H6 (1) J6 (1) |
| 856 | H5 (1) J5 (1) H4 (1) J4 (1) H3 (1) J3 (1) |
| 857 | H2 (1) J2 (1) |
| 858 | block_off D7, result 0 PASS (355, 41952 nodes, 0.73 seconds) |
| 859 | E9 (1) F9 (1) G9 (1) E8 (1) F8 (1) G8 (1) |
| 860 | H8 (1) G7 (1) H7 (1) J7 (1) H6 (1) J6 (1) |
| 861 | H5 (1) J5 (1) H4 (1) J4 (1) H3 (1) J3 (1) |
| 862 | H2 (1) J2 (1) |
| 863 | B:F4 |
| 864 | Erasing territory at E8 -b. |
| 865 | Erasing territory at G3 -b. |
| 866 | Now trying to break to smaller goal: |
| 867 | F9 (1) G9 (1) F8 (1) G8 (1) H8 (1) G7 (1) |
| 868 | H7 (1) J7 (1) H6 (1) J6 (1) H5 (1) J5 (1) |
| 869 | H4 (1) J4 (1) H3 (1) J3 (1) H2 (1) J2 (1) |
| 870 | |
| 871 | This means that the function `break_in' is called with the goal |
| 872 | marked 'a' in the following diagram. The code attempts to find out |
| 873 | whether it is possible to connect into this area from the string at |
| 874 | `D7'. |
| 875 | |
| 876 | A B C D E F G H J |
| 877 | 9 . . . . a a a . . 9 |
| 878 | 8 . . . . a a a a . 8 |
| 879 | 7 . . . X O O a a a 7 |
| 880 | 6 . . . X X X O a a 6 |
| 881 | 5 . . . . + . . a a 5 |
| 882 | 4 . . . X . . O a a 4 |
| 883 | 3 . . . . X . . a a 3 |
| 884 | 2 . . . . . . O a a 2 |
| 885 | 1 . . . . . . . . . 1 |
| 886 | A B C D E F G H J |
| 887 | |
| 888 | A breakin is found, so the goal is shrunk by removing `E9' and `J2', |
| 889 | then break_in is called again. |
| 890 | |
| 891 | In order to see what reading is actually done in order to do this |
| 892 | break in, you may load GNU Go in gtp mode, then issue the commands: |
| 893 | |
| 894 | loadsgf break_in.sgf |
| 895 | = black |
| 896 | |
| 897 | start_sgftrace |
| 898 | = |
| 899 | |
| 900 | break_in D7 E9 F9 G9 E8 F8 G8 H8 G7 H7 J7 H6 J6 H5 J5 H4 J4 H3 J3 H2 J2 |
| 901 | = 1 E8 |
| 902 | |
| 903 | finish_sgftrace vars.sgf |
| 904 | = |
| 905 | |
| 906 | start_sgftrace |
| 907 | = |
| 908 | |
| 909 | break_in D7 F9 G9 F8 G8 H8 G7 H7 J7 H6 J6 H5 J5 H4 J4 H3 J3 H2 J2 |
| 910 | = 1 G7 |
| 911 | |
| 912 | finish_sgftrace vars1.sgf |
| 913 | |
| 914 | This will produce two sgf files containing the variations caused by |
| 915 | these calls to the breakin code. The second file, `vars1.sgf' will |
| 916 | contain quite a few variations. |
| 917 | |
| 918 | The break in code makes a list of break ins which are found. When |
| 919 | it is finished, the function `add_expand_territory_move' is called for |
| 920 | each break in, adding a move reason. |
| 921 | |
| 922 | The break in code is slow, and only changes a few moves by the engine |
| 923 | per game. Nevertheless we believe that it contributes substantially to |
| 924 | the strength of the program. The break in code is enabled by default in |
| 925 | GNU Go 3.6 at level 10, and disabled at level 9. In fact, this is the |
| 926 | *only* difference between levels 9 and 10 in GNU Go 3.6. |
| 927 | |
| 928 | \1f |
| 929 | File: gnugo.info, Node: Surrounded Dragons, Next: Influential Patterns, Prev: Break Ins, Up: Influence |
| 930 | |
| 931 | 13.11 Surrounded Dragons |
| 932 | ======================== |
| 933 | |
| 934 | When is a dragon surrounded? |
| 935 | |
| 936 | As has been pointed out by Bruce Wilcox, the geometric lines |
| 937 | connecting groups of the opposite color are often important. It is very |
| 938 | hard to prevent the escape of this `O' dragon: |
| 939 | |
| 940 | .......... |
| 941 | .....O.... |
| 942 | .X.......X |
| 943 | .X...O...X |
| 944 | .......... |
| 945 | .......... |
| 946 | ---------- |
| 947 | |
| 948 | On the other hand, this dragon is in grave danger: |
| 949 | |
| 950 | .......... |
| 951 | .......... |
| 952 | .X.......X |
| 953 | .....O.... |
| 954 | .X.......X |
| 955 | .X...O...X |
| 956 | .......... |
| 957 | .......... |
| 958 | ---------- |
| 959 | |
| 960 | The difference between these two positions is that in the first, the |
| 961 | `O' dragon crosses the line connecting the top two `X' stones. |
| 962 | |
| 963 | Code in `surround.c' implements a test for when a dragon is |
| 964 | surrounded. The idea is to compute the convex hull of the _surround |
| 965 | set_, that is, the set stones belonging to unfriendly neighbor dragons. |
| 966 | If the dragon is contained within that hull. If it is, it is said to be |
| 967 | _surrounded_. |
| 968 | |
| 969 | In practice this scheme is modified slightly. The implementation |
| 970 | uses various algorithms to compute distances and hostile stones are |
| 971 | discarded from the surround set when a pair other hostile ones can be |
| 972 | found which makes the considered one useless. For example, in the |
| 973 | following position the bottom `O' stone would get discarded. |
| 974 | |
| 975 | O.X.O |
| 976 | ..... |
| 977 | .O.O. |
| 978 | ..... |
| 979 | ..O.. |
| 980 | |
| 981 | Also, points are added to the surround set below stones on the |
| 982 | second and third lines. This should account for the edge being a |
| 983 | natural barrier. |
| 984 | |
| 985 | In order to compute distances between corners of the convex hull a |
| 986 | sorting by angle algorithm has been implemented. If the distance |
| 987 | between a pair enclosing stones is large, the surround status gets |
| 988 | decreased to `WEAKLY_SURROUNDED', or even 0 for very large ones. |
| 989 | |
| 990 | The sorting by angle must be explained. A small diagram will |
| 991 | probably help : |
| 992 | |
| 993 | .O.O. |
| 994 | O...O |
| 995 | ..X.. |
| 996 | O...O |
| 997 | .O.O. |
| 998 | |
| 999 | The sorting algorithm will generate this: |
| 1000 | |
| 1001 | .4.5. |
| 1002 | 3...6 |
| 1003 | ..X.. |
| 1004 | 2...7 |
| 1005 | .1.8. |
| 1006 | |
| 1007 | That is, the points are sorted by ascending order of the measure of |
| 1008 | the angle S-G-O, where S is SOUTH, G the (approximated) gravity center |
| 1009 | of the goal, and O the position of the considered hostile stones. |
| 1010 | |
| 1011 | The necessity of such sorting appears when one tries to measure |
| 1012 | distances between enclosing stones without sorting them, just by using |
| 1013 | directly the existing left and right corners arrays. In some positions, |
| 1014 | the results will be inconsistent. Imagine, for example a position where |
| 1015 | for instance the points 1,2,3,4,6 and 7 were in the left arrary, |
| 1016 | leaving only 5 and 8 in the right array. Because of the large distance |
| 1017 | between 5 and 8, the dragon would have declared weak surrounded or not |
| 1018 | surrounded at all. Such cases are rare but frequent enough to require |
| 1019 | the angle sorting. |
| 1020 | |
| 1021 | The following position: |
| 1022 | |
| 1023 | O.X.O |
| 1024 | ..... |
| 1025 | .O.O. |
| 1026 | |
| 1027 | This is "more" surrounded than the following position: |
| 1028 | |
| 1029 | O.XXXXXX.O |
| 1030 | .......... |
| 1031 | .O......O. |
| 1032 | |
| 1033 | In the second case, the surround status would be lowered to |
| 1034 | `WEAKLY_SURROUNDED'. |
| 1035 | |
| 1036 | The surround code is used to modify the escape_route field in the |
| 1037 | dragon2 data array. When a dragon is WEAKLY_SURROUNDED, the |
| 1038 | escape_route is divided by 2. If the dragon is SURROUNDED, escape_route |
| 1039 | is simply set to 0. |
| 1040 | |
| 1041 | \1f |
| 1042 | File: gnugo.info, Node: Influential Patterns, Next: Influential Display, Prev: Surrounded Dragons, Up: Influence |
| 1043 | |
| 1044 | 13.12 Patterns used by the Influence module |
| 1045 | =========================================== |
| 1046 | |
| 1047 | This section explains the details of the pattern databases used for the |
| 1048 | influence computation. |
| 1049 | |
| 1050 | First, we have the patterns in `influence.db', which get matched |
| 1051 | symmetrically for both colors. |
| 1052 | |
| 1053 | * `E' |
| 1054 | |
| 1055 | These patterns add extra influence sources close to some |
| 1056 | shapes like walls. This tries to reflect their extra |
| 1057 | strength. These patterns are not used in the influence |
| 1058 | computations relevant for territory valuations, but they are |
| 1059 | useful for getting a better estimate of strengths of groups. |
| 1060 | |
| 1061 | * `I' |
| 1062 | |
| 1063 | These patterns add extra influence sources at typical |
| 1064 | invasion points. Usually they are of small strength. If they |
| 1065 | additionally have the class `s', the extra influence source |
| 1066 | is added for both colors. Otherwise, only the player assumed |
| 1067 | to be next to move gets the benefit. |
| 1068 | |
| 1069 | The patterns in `barriers.db' get matched only for `O' being the |
| 1070 | player next to move. |
| 1071 | |
| 1072 | * `A' |
| 1073 | |
| 1074 | Connections between `X' stones that stop influence of `O'. |
| 1075 | They have to be tight enough that `O' cannot break through, |
| 1076 | even though he is allowed to move first. |
| 1077 | |
| 1078 | * `D' |
| 1079 | |
| 1080 | Connections between `O' stones that stop influence of `X'. The |
| 1081 | stones involved can be more loosely connected than those in |
| 1082 | `A' patterns. |
| 1083 | |
| 1084 | * `B' |
| 1085 | |
| 1086 | These indicate positions of followup moves for the `O' stone |
| 1087 | marked with `Q' in the pattern. They are used to reduce the |
| 1088 | territory e. g. where a monkey jump is possible. Also, they |
| 1089 | are used in the computation of the followup influence, if the |
| 1090 | `Q' stone was the move played (or a stone saved by the move |
| 1091 | played). |
| 1092 | |
| 1093 | * `t' |
| 1094 | |
| 1095 | These patterns indicate intersections where one color will |
| 1096 | not be able to get territory, for example in a false eye. The |
| 1097 | points are set with a call to the helper non_oterritory or |
| 1098 | non_xterritory in the action of the pattern. |
| 1099 | |
| 1100 | The intrusion patterns (`B') are more powerful than the description |
| 1101 | above might suggest. They can be very helpful in identifying weak shapes |
| 1102 | (by adding an intrusion source for the opponent where he can break |
| 1103 | through). A negative inference for this is that a single bad `B' |
| 1104 | pattern, e. g. one that has a wrong constraint, typically causes 5 to |
| 1105 | 10 `FAIL's in the regression test suite. |
| 1106 | |
| 1107 | Influence Patterns can have autohelper constraints as usual. As for |
| 1108 | the constraint attributes, there are (additionally to the usual ones |
| 1109 | `O', `o', `X' and `x'), attributes `Y' and `FY'. A pattern marked with |
| 1110 | `Y' will only be used in the influence computations relevant for the |
| 1111 | territory valuation, while `FY' patterns only get used in the other |
| 1112 | influence computations. |
| 1113 | |
| 1114 | The action of an influence pattern is at the moment only used for |
| 1115 | non-territory patterns as mentioned above, and as a workaround for a |
| 1116 | problem with `B' patterns in the followup influence. |
| 1117 | |
| 1118 | To see why this workaround is necessary, consider the follwoing |
| 1119 | situation: |
| 1120 | |
| 1121 | |
| 1122 | ..XXX |
| 1123 | .a*.O |
| 1124 | .X.O. |
| 1125 | ..XXO |
| 1126 | |
| 1127 | (Imagine that there is `X' territory on the left.) |
| 1128 | |
| 1129 | The move by `O' at `*' has a natural followup move at `a'. So, in |
| 1130 | the computation of the followup influence for `*', there would be an |
| 1131 | extra influence source for `O' at `a' which would destroy a lot of |
| 1132 | black territory on the left. This would give a big followup value, and |
| 1133 | in effect the move `*' would be treated as sente. |
| 1134 | |
| 1135 | But of course it is gote, since `X' will answer at `a', which both |
| 1136 | stops the possible intrusion and threatens to capture `*'. This |
| 1137 | situation is in fact quite common. |
| 1138 | |
| 1139 | Hence we need an additional constraint that can tell when an |
| 1140 | intrusion pattern can be used in followup influence. This is done by |
| 1141 | misusing the action line: An additional line |
| 1142 | |
| 1143 | >return <condition>; |
| 1144 | |
| 1145 | gets added to the pattern. The `condition' should be true if the |
| 1146 | intrusion cannot be stopped in sente. In the above example, the relevant |
| 1147 | intrusion pattern will have an action line of the form |
| 1148 | |
| 1149 | >return (!xplay_attack(a,b)); |
| 1150 | |
| 1151 | where `b' refers to the stone at `*'. In fact, almost all |
| 1152 | followup-specific constraints look similar to this. |
| 1153 | |
| 1154 | \1f |
| 1155 | File: gnugo.info, Node: Influential Display, Next: Influence Tuning, Prev: Influential Patterns, Up: Influence |
| 1156 | |
| 1157 | 13.13 Colored display and debugging of influence |
| 1158 | ================================================ |
| 1159 | |
| 1160 | There are various ways to obtain detailed information about the |
| 1161 | influence computations. Colored diagrams showing influence are possible |
| 1162 | from a colored xterm or rxvt window. |
| 1163 | |
| 1164 | There are two options controlling when to generate diagrams: |
| 1165 | |
| 1166 | * `-m 0x08' or `-m 8' |
| 1167 | |
| 1168 | Show diagrams for the initial influence computation. This is |
| 1169 | done twice, the first time before `make_dragons()' is run and |
| 1170 | the second time after. The difference is that dead dragons |
| 1171 | are taken into account the second time. Tactically captured |
| 1172 | worms are taken into account both times. |
| 1173 | |
| 1174 | * `--debug-influence LOCATION' |
| 1175 | |
| 1176 | Show influence diagrams after the move at the given location. |
| 1177 | An important limitation of this option is that it's only |
| 1178 | effective for moves that the move generation is considering. |
| 1179 | |
| 1180 | The other options control which diagrams should be generated in these |
| 1181 | situations. You have to specify at least one of the options above and |
| 1182 | at least one of the options below to generate any output. |
| 1183 | |
| 1184 | * The options below must be combined with one of the two previous |
| 1185 | ones, or the diagram will not be printed. For example to print the |
| 1186 | influence diagram, you may combine 0x08 and 0x010, and use the option |
| 1187 | `-m 0x018'.* |
| 1188 | |
| 1189 | * `-m 0x010' or `-m 16' |
| 1190 | |
| 1191 | Show colored display of territory/moyo/area regions. |
| 1192 | - territory: cyan |
| 1193 | |
| 1194 | - moyo: yellow |
| 1195 | |
| 1196 | - area: red |
| 1197 | This feature is very useful to get an immediate impression of |
| 1198 | the influence regions as GNU Go sees them. |
| 1199 | |
| 1200 | * `-m 0x20' or `-m 32' |
| 1201 | |
| 1202 | Show numerical influence values for white and black. These |
| 1203 | come in two separate diagrams, the first one for white, the |
| 1204 | second one for black. Notice that the influence values are |
| 1205 | represented by floats and thus have been rounded in these |
| 1206 | diagrams. |
| 1207 | |
| 1208 | * `-m 0x40' or `-m 64' |
| 1209 | |
| 1210 | This generates two diagrams showing the permeability for |
| 1211 | black and white influence on the board. |
| 1212 | |
| 1213 | * `-m 0x80' or `-m 128' |
| 1214 | |
| 1215 | This shows the strength of the influence sources for black |
| 1216 | and white across the board. You will see sources at each |
| 1217 | lively stone (with strength depending on the strength of this |
| 1218 | stone), and sources contributed by patterns. |
| 1219 | |
| 1220 | * `-m 0x100' or `-m 256' |
| 1221 | |
| 1222 | This shows the attenuation with which the influence sources |
| 1223 | spread influence across the board. Low attenuation indicates |
| 1224 | far-reaching influence sources. |
| 1225 | |
| 1226 | * `-m 0x200' or `-m 512' |
| 1227 | |
| 1228 | This shows the territory valuation of GNU Go. Each |
| 1229 | intersection is shown with a value between -1.0 and +1.0 (or |
| 1230 | -2 resp. +2 if there is a dead stone on this intersection). |
| 1231 | Positive values indicate territory for white. A value of -0.5 |
| 1232 | thus indicates a point where black has a 50% chance of |
| 1233 | getting territory. |
| 1234 | |
| 1235 | Finally, there is the debug option `-d 0x1' which turns on on |
| 1236 | `DEBUG_INFLUENCE'. This gives a message for each influence pattern that |
| 1237 | gets matched. Unfortunately, these are way too many messages making it |
| 1238 | tedious to navigate the output. However, if you discover an influence |
| 1239 | source with `-m 0x80' that looks wrong, the debug output can help you |
| 1240 | to quickly find out the responsible pattern. |
| 1241 | |
| 1242 | \1f |
| 1243 | File: gnugo.info, Node: Influence Tuning, Prev: Influential Display, Up: Influence |
| 1244 | |
| 1245 | 13.14 Influence Tuning with `view.pike' |
| 1246 | ======================================= |
| 1247 | |
| 1248 | A useful program in the regression directory is `view.pike'. To run |
| 1249 | it, you need Pike, which you may download from |
| 1250 | `http://pike.ida.liu.se/'. |
| 1251 | |
| 1252 | The test case `endgame:920' fails in GNU Go 3.6. We will explain how |
| 1253 | to fix it. |
| 1254 | |
| 1255 | Start by firing up view.pike on testcase endgame:920, e.g. by running |
| 1256 | `pike view.pike endgame:920' in the regression directory. |
| 1257 | |
| 1258 | We see from the first view of move values that filling dame at P15 is |
| 1259 | valued highest with 0.17 points while the correct move at C4 is valued |
| 1260 | slightly lower with 0.16. The real problem is of course that C4 is |
| 1261 | worth a full point and thus should be valued about 1.0. |
| 1262 | |
| 1263 | Now click on C4 to get a list of move reasons and move valuation |
| 1264 | information. Everything looks okay except that change in territory is |
| 1265 | 0.00 rather than 1.00 as it ought to be. |
| 1266 | |
| 1267 | We can confirm this by choosing the "delta territory for..." button |
| 1268 | and again clicking C4. Now B5 should have been marked as one point of |
| 1269 | change in territory, but it's not. |
| 1270 | |
| 1271 | Next step is to enter the influence debug tool. Press the "influence" |
| 1272 | button, followed by "black influence, dragons known," and "territory |
| 1273 | value." This shows the expected territory if black locally moves first |
| 1274 | everywhere (thus "black influence"). Here we can see that B5 is |
| 1275 | incorrectly considered as 1.0 points of white territory. |
| 1276 | |
| 1277 | We can compare this with the territory after a white move at C4 |
| 1278 | (still assuming that black locally moves first everywhere after that) by |
| 1279 | pressing "after move influence for..." and clicking C4. This looks |
| 1280 | identical, as expected since delta territory was 0, but here it is |
| 1281 | correct that B5 is 1.0 points of territory for white. |
| 1282 | |
| 1283 | The most straightforward solution to this problem is to add a |
| 1284 | non-territory pattern, saying that white can't get territory on B5 if |
| 1285 | black moves first. The nonterritory patterns are in `barriers.db'. |
| 1286 | |
| 1287 | Pattern Nonterritory56 |
| 1288 | |
| 1289 | ... |
| 1290 | X.O |
| 1291 | ?O. |
| 1292 | |
| 1293 | :8,t |
| 1294 | |
| 1295 | eac |
| 1296 | XbO |
| 1297 | ?Od |
| 1298 | |
| 1299 | ;oplay_attack(a,b,c,d,d) |
| 1300 | |
| 1301 | >non_xterritory(e); |
| 1302 | |
| 1303 | In these patterns it's always assumed that `O' moves first and thus |
| 1304 | it says that `X' can't get territory at `B5' (`e' in the pattern). Now |
| 1305 | we need to be a bit careful however since after `O' plays at `a' and |
| 1306 | `X' cuts in at `b', it may well happen that `O' needs to defend around |
| 1307 | `d', allowing `X' to cut at `c', possibly making the nonterritory |
| 1308 | assumption invalid. It's difficult to do this entirely accurate, but |
| 1309 | the constraint above is fairly conservative and should guarantee that |
| 1310 | `a' is safe in most, although not all, cases. |
| 1311 | |
| 1312 | \1f |
| 1313 | File: gnugo.info, Node: Monte Carlo Go, Next: Libboard, Prev: Influence, Up: Top |
| 1314 | |
| 1315 | 14 Monte Carlo Go |
| 1316 | ***************** |
| 1317 | |
| 1318 | In Monte Carlo Go the engine plays random games to the end, generating |
| 1319 | moves from a pattern database within the context of the algorithm UCT |
| 1320 | (upper confidence bounds applied to trees). This algorithm allowed the |
| 1321 | program MoGo (`http://www.lri.fr/~gelly/MoGo.htm', to become the first |
| 1322 | computer program to defeat a professional while taking a 9 stone |
| 1323 | handicap (`http://senseis.xmp.net/?MoGo'). |
| 1324 | |
| 1325 | GNU Go 3.8 can play 9x9 Go with the option `--monte-carlo' using the |
| 1326 | UCT algorithm. For command line options, see *Note Invoking GNU Go::. |
| 1327 | |
| 1328 | During reading, the engine makes incremental updates of local 3x3 |
| 1329 | neighborhood, suicide status, self-atari status, and number of stones |
| 1330 | captured, for each move. |
| 1331 | |
| 1332 | GNU Go's simulations (Monte Carlo games) are pattern generated. The |
| 1333 | random playout move generation is distributed strictly proportional to |
| 1334 | move values computed by table lookup from a local context consisting of |
| 1335 | 3x3 neighborhood, opponent suicide status, own and opponent self-atari |
| 1336 | status, number of stones captured by own and opponent move, and |
| 1337 | closeness to the previous move. Let's call this local context simply "a |
| 1338 | pattern" and the table "pattern values" or simply "patterns". |
| 1339 | |
| 1340 | There are three built-in databases that you can select using the |
| 1341 | option `--mc-patterns <name>', where `<name>' is one of |
| 1342 | |
| 1343 | * `mc_montegnu_classic' |
| 1344 | |
| 1345 | * `mc_mogo_classic' |
| 1346 | |
| 1347 | * `mc_uniform' |
| 1348 | |
| 1349 | The first of these is an approximation of the previous random move |
| 1350 | generation algorithm. The `mogo_classic' pattern values is an |
| 1351 | approximation of the simulation policy used by early versions of MoGo, |
| 1352 | as published in the report odification of UCT with Patterns in |
| 1353 | Monte-Carlo Go (http://hal.inria.fr/inria-00117266) RR-6062, by Sylvain |
| 1354 | Gelly, Yizao Wang, Rémi Munos, and Olivier Teytaud. The uniform pattern |
| 1355 | values is the so called "light" playout which chooses uniformly between |
| 1356 | all legal moves except single point proper eyes. |
| 1357 | |
| 1358 | If you're not satisfied with these you can also tune your own |
| 1359 | pattern values with a pattern database file and load it at runtime with |
| 1360 | `--mc-load-patterns <name>' adding your own pattern database. |
| 1361 | |
| 1362 | Let's start with the uniform pattern values. Those are defined by the |
| 1363 | file `patterns/mc_uniform.db', which looks like this: |
| 1364 | |
| 1365 | |
| 1366 | oOo |
| 1367 | O*O |
| 1368 | oO? |
| 1369 | |
| 1370 | :0 |
| 1371 | |
| 1372 | oOo |
| 1373 | O*O |
| 1374 | --- |
| 1375 | |
| 1376 | :0 |
| 1377 | |
| 1378 | |Oo |
| 1379 | |*O |
| 1380 | +-- |
| 1381 | |
| 1382 | :0 |
| 1383 | |
| 1384 | Patterns are always exactly 3x3 in size with the move at the center |
| 1385 | point. The symbols are the usual for GNU Go pattern databases: |
| 1386 | |
| 1387 | * move |
| 1388 | O own stone (i.e. the same color as the color to move) |
| 1389 | o own stone or empty |
| 1390 | X opponent stone |
| 1391 | x opponent stone or empty |
| 1392 | ? own stone, opponent stone, or empty |
| 1393 | | vertical edge |
| 1394 | - horizontal edge |
| 1395 | + corner |
| 1396 | |
| 1397 | There's also a new symbol: |
| 1398 | |
| 1399 | % own stone, opponent stone, empty, or edge |
| 1400 | |
| 1401 | After the pattern comes a line starting with a colon. In all these |
| 1402 | patterns it says that the pattern has a move value of 0, i.e. must not |
| 1403 | be played. Unmatched patterns have a default value of 1. When all move |
| 1404 | values are zero for both players, the playout will stop. Including the |
| 1405 | three patterns above is important because otherwise the playouts would |
| 1406 | be likely to go on indefinitely, or as it actually happens be |
| 1407 | terminated at a hard-coded limit of 600 moves. Also place these |
| 1408 | patterns at the top of the database because when multiple patterns |
| 1409 | match, the first one is used, regardless of the values. |
| 1410 | |
| 1411 | When using only these patterns you will probably notice that it plays |
| 1412 | rather heavy, trying hard to be solidly connected. This is because |
| 1413 | uniform playouts are badly biased with a high probability of non-solid |
| 1414 | connections being cut apart. To counter this you could try a pattern |
| 1415 | like |
| 1416 | |
| 1417 | ?X? |
| 1418 | O*O |
| 1419 | x.? |
| 1420 | |
| 1421 | :20,near |
| 1422 | |
| 1423 | to increase the probability that the one-point jump is reinforced |
| 1424 | when threatened. Here we added the property "near", which means that the |
| 1425 | pattern only applies if the previous move was played "near" this move. |
| 1426 | Primarily "near" means within the surrounding 3x3 neighborhood but it |
| 1427 | also includes certain cases of liberties of low-liberty strings |
| 1428 | adjacent to the previous move, e.g. the move to extend out of an atari |
| 1429 | created by the previous move. You have to read the source to find out |
| 1430 | the exact rules for nearness. |
| 1431 | |
| 1432 | We could also be even more specific and say |
| 1433 | |
| 1434 | ?X? |
| 1435 | O*O |
| 1436 | x.? |
| 1437 | |
| 1438 | :20,near,osafe,xsafe |
| 1439 | |
| 1440 | to exclude the cases where this move is a self atari (osafe) or would |
| 1441 | be a self-atari for the opponent (xsafe). |
| 1442 | |
| 1443 | It may also be interesting to see the effect of capturing stones. A |
| 1444 | catch-all pattern for captures would be |
| 1445 | |
| 1446 | ?X% |
| 1447 | ?*% |
| 1448 | %%% |
| 1449 | |
| 1450 | :10,ocap1,osafe |
| 1451 | :20,ocap2 |
| 1452 | :30,ocap3 |
| 1453 | |
| 1454 | where we have used multiple colon lines to specify different move |
| 1455 | values depending on the number of captured stones; value 10 for a |
| 1456 | single captured stone, value 20 for two captured stones, and value 30 |
| 1457 | for three or more captured stones. Here we also excluded self-atari |
| 1458 | moves in the case of 1 captured stone in order to avoid getting stuck |
| 1459 | in triple-ko in the playouts (there's no superko detection in the |
| 1460 | playouts). |
| 1461 | |
| 1462 | The full set of pattern properties is as follows: |
| 1463 | |
| 1464 | `near' |
| 1465 | The move is "near" the previous move. |
| 1466 | |
| 1467 | `far' |
| 1468 | The move is not "near" the previous move. |
| 1469 | |
| 1470 | `osafe' |
| 1471 | The move is not a self-atari. |
| 1472 | |
| 1473 | `ounsafe' |
| 1474 | The move is a self-atari. |
| 1475 | |
| 1476 | `xsafe' |
| 1477 | The move would not be a self-atari for the opponent. |
| 1478 | |
| 1479 | `xunsafe' |
| 1480 | The move would be a self-atari for the opponent. |
| 1481 | |
| 1482 | `xsuicide' |
| 1483 | The move would be suicide for the opponent |
| 1484 | |
| 1485 | `xnosuicide' |
| 1486 | The move would not be suicide for the opponent. |
| 1487 | |
| 1488 | `ocap0' |
| 1489 | The move captures zero stones. |
| 1490 | |
| 1491 | `ocap1' |
| 1492 | The move captures one stone. |
| 1493 | |
| 1494 | `ocap2' |
| 1495 | The move captures two stones. |
| 1496 | |
| 1497 | `ocap3' |
| 1498 | The move captures three or more stones. |
| 1499 | |
| 1500 | `ocap1+' |
| 1501 | The move captures one or more stones. |
| 1502 | |
| 1503 | `ocap1-' |
| 1504 | The move captures at most one stone. |
| 1505 | |
| 1506 | `ocap2+' |
| 1507 | The move captures two or more stones. |
| 1508 | |
| 1509 | `ocap2-' |
| 1510 | The move captures at most two stones. |
| 1511 | |
| 1512 | `xcap0' |
| 1513 | An opponent move would capture zero stones. |
| 1514 | |
| 1515 | `xcap1' |
| 1516 | An opponent move would capture one stone. |
| 1517 | |
| 1518 | `xcap2' |
| 1519 | An opponent move would capture two stones. |
| 1520 | |
| 1521 | `xcap3' |
| 1522 | An opponent move would capture three or more stones. |
| 1523 | |
| 1524 | `xcap1+' |
| 1525 | An opponent move would capture one or more stones. |
| 1526 | |
| 1527 | `xcap1-' |
| 1528 | An opponent move would capture at most one stone. |
| 1529 | |
| 1530 | `xcap2+' |
| 1531 | An opponent move would capture two or more stones. |
| 1532 | |
| 1533 | `xcap2-' |
| 1534 | An opponent move would capture at most two stones. |
| 1535 | |
| 1536 | These can be combined arbitrarily but all must be satisfied for the |
| 1537 | pattern to take effect. If contradictory properties are combined, the |
| 1538 | pattern will never match. |
| 1539 | |
| 1540 | 14.0.1 Final Remarks |
| 1541 | -------------------- |
| 1542 | |
| 1543 | * Move values are unsigned 32-bit integers. To avoid overflow in |
| 1544 | computations it is highly recommended to keep the values below |
| 1545 | 10000000 or so. |
| 1546 | |
| 1547 | * There is no speed penalty for having lots of patterns in the |
| 1548 | database. The average time per move is approximately constant |
| 1549 | (slightly dependent on how often stones are captured or become low |
| 1550 | on liberties) and the time per game mostly depends on the average |
| 1551 | game length. |
| 1552 | |
| 1553 | * For more complex pattern databases, see |
| 1554 | `patterns/mc_montegnu_classic.db' and |
| 1555 | `patterns/mc_mogo_classic.db'. |
| 1556 | |
| 1557 | Nobody really knows how to tune the random playouts to get as strong |
| 1558 | engine as possible. Please play with this and report any interesting |
| 1559 | findings, especially if you're able to make it substantially stronger |
| 1560 | than the `montegnu_classic' patterns. |
| 1561 | |
| 1562 | \1f |
| 1563 | File: gnugo.info, Node: Libboard, Next: SGF, Prev: Monte Carlo Go, Up: Top |
| 1564 | |
| 1565 | 15 The Board Library |
| 1566 | ******************** |
| 1567 | |
| 1568 | * Menu: |
| 1569 | |
| 1570 | * Board Data Structures:: Board Data Structures |
| 1571 | * The Board Array:: One-dimensional board array |
| 1572 | * Incremental Board:: Incremental board data structures |
| 1573 | * Some Board Functions:: Explanation of some board functions |
| 1574 | |
| 1575 | The foundation of the GNU Go engine is a library of very efficient |
| 1576 | routines for handling go boards. This board library, called |
| 1577 | `libboard', can be used for those programs that only need a basic go |
| 1578 | board but no AI capability. One such program is `patterns/joseki.c', |
| 1579 | which compiles joseki pattern databases from SGF files. |
| 1580 | |
| 1581 | If you want to use the board library in your own program, you need |
| 1582 | all the .c-files listed under libboard_SOURCES in engine/Makefile.am, |
| 1583 | and the files in the directories sgf/ and utils/. Then you should |
| 1584 | include engine/board.h in your code. |
| 1585 | |
| 1586 | The library consists of the following files: |
| 1587 | |
| 1588 | * `board.h' |
| 1589 | |
| 1590 | The public interface to the board library. |
| 1591 | |
| 1592 | * `board.c' |
| 1593 | |
| 1594 | The basic board code. It uses incremental algorithms for |
| 1595 | keeping track of strings and liberties on the go board. |
| 1596 | |
| 1597 | * `boardlib.c' |
| 1598 | |
| 1599 | This contains all global variable of the board library. |
| 1600 | |
| 1601 | * `hash.c' |
| 1602 | |
| 1603 | Code for hashing go positions. |
| 1604 | |
| 1605 | * `sgffile.c' |
| 1606 | |
| 1607 | Implementation of output file in SGF format. |
| 1608 | |
| 1609 | * `printutils.c' |
| 1610 | |
| 1611 | Utilities for printing go boards and other things. |
| 1612 | |
| 1613 | |
| 1614 | To use the board library, you must include `liberty.h' just like |
| 1615 | when you use the whole engine, but of course you cannot use all the |
| 1616 | functions declared in it, i.e. the functions that are part of the |
| 1617 | engine, but not part of the board library. You must link your |
| 1618 | application with `libboard.a'. |
| 1619 | |
| 1620 | \1f |
| 1621 | File: gnugo.info, Node: Board Data Structures, Next: The Board Array, Up: Libboard |
| 1622 | |
| 1623 | 15.1 Board Data structures |
| 1624 | ========================== |
| 1625 | |
| 1626 | The basic data structures of the board correspond tightly to the |
| 1627 | `board_state' struct described in *Note The Board State::. They are all |
| 1628 | stored in global variables for efficiency reasons, the most important |
| 1629 | of which are: |
| 1630 | |
| 1631 | |
| 1632 | int board_size; |
| 1633 | Intersection board[MAXSIZE]; |
| 1634 | int board_ko_pos; |
| 1635 | |
| 1636 | float komi; |
| 1637 | int white_captured; |
| 1638 | int black_captured; |
| 1639 | |
| 1640 | Hash_data hashdata; |
| 1641 | |
| 1642 | The description of the `Position' struct is applicable to these |
| 1643 | variables also, so we won't duplicate it here. All these variables are |
| 1644 | globals for performance reasons. Behind these variables, there are a |
| 1645 | number of other private data structures. These implement incremental |
| 1646 | handling of strings, liberties and other properties (*note Incremental |
| 1647 | Board::). The variable `hashdata' contains information about the hash |
| 1648 | value for the current position (*note Hashing::). |
| 1649 | |
| 1650 | These variables should never be manipulated directly, since they are |
| 1651 | only the front end for the incremental machinery. They can be read, but |
| 1652 | should only be written by using the functions described in the next |
| 1653 | section. If you write directly to them, the incremental data structures |
| 1654 | will become out of sync with each other, and a crash is the likely |
| 1655 | result. |
| 1656 | |
| 1657 | \1f |
| 1658 | File: gnugo.info, Node: The Board Array, Next: Incremental Board, Prev: Board Data Structures, Up: Libboard |
| 1659 | |
| 1660 | 15.2 The Board Array |
| 1661 | ==================== |
| 1662 | |
| 1663 | GNU Go represents the board in a one-dimensional array called `board'. |
| 1664 | For some purposes a two dimensional indexing of the board by parameters |
| 1665 | `(i,j)' might be used. |
| 1666 | |
| 1667 | The `board' array includes out-of-board markers around the board. To |
| 1668 | make the relation to the old two-dimensional board representation |
| 1669 | clear, this figure shows how the 1D indices correspond to the 2D |
| 1670 | indices when MAX_BOARD is 7. |
| 1671 | |
| 1672 | j -1 0 1 2 3 4 5 6 |
| 1673 | i +---------------------------------- |
| 1674 | -1| 0 1 2 3 4 5 6 7 |
| 1675 | 0| 8 9 10 11 12 13 14 15 |
| 1676 | 1| 16 17 18 19 20 21 22 23 |
| 1677 | 2| 24 25 26 27 28 29 30 31 |
| 1678 | 3| 32 33 34 35 36 37 38 39 |
| 1679 | 4| 40 41 42 43 44 45 46 47 |
| 1680 | 5| 48 49 50 51 52 53 54 55 |
| 1681 | 6| 56 57 58 59 60 61 62 63 |
| 1682 | 7| 64 65 66 67 68 69 70 71 72 |
| 1683 | |
| 1684 | To convert between a 1D index `pos' and a 2D index `(i,j)', the |
| 1685 | macros `POS', `I', and `J' are provided, defined as below: |
| 1686 | |
| 1687 | #define POS(i, j) ((MAX_BOARD + 2) + (i) * (MAX_BOARD + 1) + (j)) |
| 1688 | #define I(pos) ((pos) / (MAX_BOARD + 1) - 1) |
| 1689 | #define J(pos) ((pos) % (MAX_BOARD + 1) - 1) |
| 1690 | |
| 1691 | All 1D indices not corresponding to points on the board have the out |
| 1692 | of board marker value `GRAY'. Thus if `board_size' and `MAX_BOARD' both |
| 1693 | are 7, this looks like |
| 1694 | |
| 1695 | j -1 0 1 2 3 4 5 6 |
| 1696 | i +---------------------------------- |
| 1697 | -1| # # # # # # # # |
| 1698 | 0| # . . . . . . . |
| 1699 | 1| # . . . . . . . |
| 1700 | 2| # . . . . . . . |
| 1701 | 3| # . . . . . . . |
| 1702 | 4| # . . . . . . . |
| 1703 | 5| # . . . . . . . |
| 1704 | 6| # . . . . . . . |
| 1705 | 7| # # # # # # # # # |
| 1706 | |
| 1707 | The indices marked `#' have value `GRAY'. If `MAX_BOARD' is 7 and |
| 1708 | `board_size' is only 5: |
| 1709 | |
| 1710 | j -1 0 1 2 3 4 5 6 |
| 1711 | i +---------------------------------- |
| 1712 | -1| # # # # # # # # |
| 1713 | 0| # . . . . . # # |
| 1714 | 1| # . . . . . # # |
| 1715 | 2| # . . . . . # # |
| 1716 | 3| # . . . . . # # |
| 1717 | 4| # . . . . . # # |
| 1718 | 5| # # # # # # # # |
| 1719 | 6| # # # # # # # # |
| 1720 | 7| # # # # # # # # # |
| 1721 | |
| 1722 | Navigation on the board is done by the `SOUTH', `WEST', `NORTH', and |
| 1723 | `EAST' macros, |
| 1724 | |
| 1725 | #define NS (MAX_BOARD + 1) |
| 1726 | #define WE 1 |
| 1727 | #define SOUTH(pos) ((pos) + NS) |
| 1728 | #define WEST(pos) ((pos) - 1) |
| 1729 | #define NORTH(pos) ((pos) - NS) |
| 1730 | #define EAST(pos) ((pos) + 1) |
| 1731 | |
| 1732 | There are also shorthand macros `SW', `NW', `NE', `SE', `SS', `WW', |
| 1733 | `NN', `EE' for two step movements. |
| 1734 | |
| 1735 | Any movement from a point on the board to an adjacent or diagonal |
| 1736 | vertex is guaranteed to produce a valid index into the board array, and |
| 1737 | the color found is GRAY if it is not on the board. To do explicit tests |
| 1738 | for out of board there are two macros |
| 1739 | |
| 1740 | #define ON_BOARD(pos) (board[pos] != GRAY) |
| 1741 | #define ON_BOARD1(pos) (((unsigned) (pos) < BOARDSIZE) && board[pos] != GRAY) |
| 1742 | |
| 1743 | where the first one should be used in the algorithms and the second |
| 1744 | one is useful for assertion tests. |
| 1745 | |
| 1746 | The advantage of a one-dimensional board array is that it gives a |
| 1747 | significant performance advantage. We need only one variable to |
| 1748 | determine a board position, which means that many functions need less |
| 1749 | arguments. Also, often one computation is sufficient for 1D-coordinate |
| 1750 | where we would need two with two 2D-coordinates: If we, for example, |
| 1751 | want to have the coordinate of the upper right of `pos', we can do this |
| 1752 | with `NORTH(EAST(pos))' instead of `(i+1, j-1)'. |
| 1753 | |
| 1754 | *Important*: The 2D coordinate `(-1,-1)', which is used for pass and |
| 1755 | sometimes to indicate no point, maps to the 1D coordinate `0', not to |
| 1756 | `-1'. Instead of a plain `0', use one of the macros `NO_MOVE' or |
| 1757 | `PASS_MOVE'. |
| 1758 | |
| 1759 | A loop over multiple directions is straightforwardly written: |
| 1760 | |
| 1761 | for (k = 0; k < 4; k++) { |
| 1762 | int d = delta[k]; |
| 1763 | do_something(pos + d); |
| 1764 | } |
| 1765 | |
| 1766 | The following constants are useful for loops over the entire board |
| 1767 | and allocation of arrays with a 1-1 mapping to the board. |
| 1768 | |
| 1769 | #define BOARDSIZE ((MAX_BOARD + 2) * (MAX_BOARD + 1) + 1) |
| 1770 | #define BOARDMIN (MAX_BOARD + 2) |
| 1771 | #define BOARDMAX (MAX_BOARD + 1) * (MAX_BOARD + 1) |
| 1772 | |
| 1773 | `BOARDSIZE' is the actual size of the 1D board array, `BOARDMIN' is |
| 1774 | the first index corresponding to a point on the board, and `BOARDMAX' |
| 1775 | is one larger than the last index corresponding to a point on the board. |
| 1776 | |
| 1777 | Often one wants to traverse the board, carrying out some function at |
| 1778 | every vertex. Here are two possible ways of doing this: |
| 1779 | |
| 1780 | int m, n; |
| 1781 | for (m = 0; m < board_size; m++) |
| 1782 | for (n = 0; n < board_size; n++) { |
| 1783 | do_something(POS(m, n)); |
| 1784 | } |
| 1785 | |
| 1786 | Or: |
| 1787 | |
| 1788 | int pos; |
| 1789 | for (pos = BOARDMIN; pos < BOARDMAX; pos++) { |
| 1790 | if (ON_BOARD(pos)) |
| 1791 | do_something(pos); |
| 1792 | } |
| 1793 | |
| 1794 | \1f |
| 1795 | File: gnugo.info, Node: Incremental Board, Next: Some Board Functions, Prev: The Board Array, Up: Libboard |
| 1796 | |
| 1797 | 15.3 Incremental Board data structures |
| 1798 | ====================================== |
| 1799 | |
| 1800 | In addition to the global board state, the algorithms in `board.c' |
| 1801 | implement a method of incremental updates that keeps track of the |
| 1802 | following information for each string: |
| 1803 | |
| 1804 | * The color of the string. |
| 1805 | |
| 1806 | * Number of stones in the string. |
| 1807 | |
| 1808 | * Origin of the string, i.e. a canonical reference point, defined to |
| 1809 | be the stone with smallest 1D board coordinate. |
| 1810 | |
| 1811 | * A list of the stones in the string. |
| 1812 | |
| 1813 | * Number of liberties. |
| 1814 | |
| 1815 | * A list of the liberties. If there are too many liberties the list |
| 1816 | is truncated. |
| 1817 | |
| 1818 | * The number of neighbor strings. |
| 1819 | |
| 1820 | * A list of the neighbor strings. |
| 1821 | |
| 1822 | The basic data structure is |
| 1823 | |
| 1824 | struct string_data { |
| 1825 | int color; /* Color of string, BLACK or WHITE */ |
| 1826 | int size; /* Number of stones in string. */ |
| 1827 | int origin; /* Coordinates of "origin", i.e. */ |
| 1828 | /* "upper left" stone. */ |
| 1829 | int liberties; /* Number of liberties. */ |
| 1830 | int libs[MAX_LIBERTIES]; /* Coordinates of liberties. */ |
| 1831 | int neighbors; /* Number of neighbor strings */ |
| 1832 | int neighborlist[MAXCHAIN]; /* List of neighbor string numbers. */ |
| 1833 | int mark; /* General purpose mark. */ |
| 1834 | }; |
| 1835 | |
| 1836 | struct string_data string[MAX_STRINGS]; |
| 1837 | |
| 1838 | It should be clear that almost all information is stored in the |
| 1839 | `string' array. To get a mapping from the board coordinates to the |
| 1840 | `string' array we have |
| 1841 | |
| 1842 | static int string_number[BOARDMAX]; |
| 1843 | |
| 1844 | which contains indices into the `string' array. This information is only |
| 1845 | valid at nonempty vertices, however, so it is necessary to first verify |
| 1846 | that `board[pos] != EMPTY'. |
| 1847 | |
| 1848 | The `string_data' structure does not include an array of the stone |
| 1849 | coordinates. This information is stored in a separate array: |
| 1850 | |
| 1851 | static int next_stone[BOARDMAX]; |
| 1852 | |
| 1853 | This array implements cyclic linked lists of stones. Each vertex |
| 1854 | contains a pointer to another (possibly the same) vertex. Starting at |
| 1855 | an arbitrary stone on the board, following these pointers should |
| 1856 | traverse the entire string in an arbitrary order before coming back to |
| 1857 | the starting point. As for the 'string_number' array, this information |
| 1858 | is invalid at empty points on the board. This data structure has the |
| 1859 | good properties of requiring fixed space (regardless of the number of |
| 1860 | strings) and making it easy to add a new stone or join two strings. |
| 1861 | |
| 1862 | Additionally the code makes use of some work variables: |
| 1863 | |
| 1864 | static int ml[BOARDMAX]; |
| 1865 | static int liberty_mark; |
| 1866 | static int string_mark; |
| 1867 | static int next_string; |
| 1868 | static int strings_initialized = 0; |
| 1869 | |
| 1870 | The `ml' array and `liberty_mark' are used to "mark" liberties on |
| 1871 | the board, e.g. to avoid counting the same liberty twice. The |
| 1872 | convention is that if `ml[pos]' has the same value as `liberty_mark', |
| 1873 | then `pos' is marked. To clear all marks it suffices to increase the |
| 1874 | value of `liberty_mark', since it is never allowed to decrease. |
| 1875 | |
| 1876 | The same relation holds between the `mark' field of the `string_data' |
| 1877 | structure and `string_mark'. Of course these are used for marking |
| 1878 | individual strings. |
| 1879 | |
| 1880 | `next_string' gives the number of the next available entry in the |
| 1881 | `string' array. Then `strings_initialized' is set to one when all data |
| 1882 | structures are known to be up to date. Given an arbitrary board |
| 1883 | position in the `board' array, this is done by calling |
| 1884 | `incremental_board_init()'. It is not necessary to call this function |
| 1885 | explicitly since any other function that needs the information does |
| 1886 | this if it has not been done. |
| 1887 | |
| 1888 | The interesting part of the code is the incremental update of the |
| 1889 | data structures when a stone is played and subsequently removed. To |
| 1890 | understand the strategies involved in adding a stone it is necessary to |
| 1891 | first know how undoing a move works. The idea is that as soon as some |
| 1892 | piece of information is about to be changed, the old value is pushed |
| 1893 | onto a stack which stores the value and its address. The stack is built |
| 1894 | from the following structures: |
| 1895 | |
| 1896 | struct change_stack_entry { |
| 1897 | int *address; |
| 1898 | int value; |
| 1899 | }; |
| 1900 | |
| 1901 | struct change_stack_entry change_stack[STACK_SIZE]; |
| 1902 | int change_stack_index; |
| 1903 | |
| 1904 | and manipulated with the macros |
| 1905 | |
| 1906 | BEGIN_CHANGE_RECORD() |
| 1907 | PUSH_VALUE(v) |
| 1908 | POP_MOVE() |
| 1909 | |
| 1910 | Calling `BEGIN_CHANGE_RECORD()' stores a null pointer in the address |
| 1911 | field to indicate the start of changes for a new move. As mentioned |
| 1912 | earlier `PUSH_VALUE()' stores a value and its corresponding address. |
| 1913 | Assuming that all changed information has been duly pushed onto the |
| 1914 | stack, undoing the move is only a matter of calling `POP_MOVE()', which |
| 1915 | simply assigns the values to the addresses in the reverse order until |
| 1916 | the null pointer is reached. This description is slightly simplified |
| 1917 | because this stack can only store 'int' values and we need to also |
| 1918 | store changes to the board. Thus we have two parallel stacks where one |
| 1919 | stores `int' values and the other one stores `Intersection' values. |
| 1920 | |
| 1921 | When a new stone is played on the board, first captured opponent |
| 1922 | strings, if any, are removed. In this step we have to push the board |
| 1923 | values and the `next_stone' pointers for the removed stones, and update |
| 1924 | the liberties and neighbor lists for the neighbors of the removed |
| 1925 | strings. We do not have to push all information in the 'string' entries |
| 1926 | of the removed strings however. As we do not reuse the entries they |
| 1927 | will remain intact until the move is pushed and they are back in use. |
| 1928 | |
| 1929 | After this we put down the new stone and get three distinct cases: |
| 1930 | |
| 1931 | 1. The new stone is isolated, i.e. it has no friendly neighbor. |
| 1932 | |
| 1933 | 2. The new stone has exactly one friendly neighbor. |
| 1934 | |
| 1935 | 3. The new stone has at least two friendly neighbors. |
| 1936 | |
| 1937 | The first case is easiest. Then we create a new string by using the |
| 1938 | number given by `next_string' and increasing this variable. The string |
| 1939 | will have size one, `next_stone' points directly back on itself, the |
| 1940 | liberties can be found by looking for empty points in the four |
| 1941 | directions, possible neighbor strings are found in the same way, and |
| 1942 | those need also to remove one liberty and add one neighbor. |
| 1943 | |
| 1944 | In the second case we do not create a new string but extend the |
| 1945 | neighbor with the new stone. This involves linking the new stone into |
| 1946 | the cyclic chain, if needed moving the origin, and updating liberties |
| 1947 | and neighbors. Liberty and neighbor information also needs updating for |
| 1948 | the neighbors of the new stone. |
| 1949 | |
| 1950 | In the third case finally, we need to join already existing strings. |
| 1951 | In order not to have to store excessive amounts of information, we |
| 1952 | create a new string for the new stone and let it assimilate the |
| 1953 | neighbor strings. Thus all information about those can simply be left |
| 1954 | around in the 'string' array, exactly as for removed strings. Here it |
| 1955 | becomes a little more complex to keep track of liberties and neighbors |
| 1956 | since those may have been shared by more than one of the joined |
| 1957 | strings. Making good use of marks it all becomes rather straightforward |
| 1958 | anyway. |
| 1959 | |
| 1960 | The often used construction |
| 1961 | |
| 1962 | pos = FIRST_STONE(s); |
| 1963 | do { |
| 1964 | ... |
| 1965 | pos = NEXT_STONE(pos); |
| 1966 | } while (!BACK_TO_FIRST_STONE(s, pos)); |
| 1967 | |
| 1968 | traverses the stones of the string with number `s' exactly once, with |
| 1969 | `pos' holding the coordinates. In general `pos' is used as board |
| 1970 | coordinate and `s' as an index into the `string' array or sometimes a |
| 1971 | pointer to an entry in the `string' array. |
| 1972 | |
| 1973 | \1f |
| 1974 | File: gnugo.info, Node: Some Board Functions, Prev: Incremental Board, Up: Libboard |
| 1975 | |
| 1976 | 15.4 Some Board Functions |
| 1977 | ========================= |
| 1978 | |
| 1979 | *Reading*, often called *search* in computer game theory, is a |
| 1980 | fundamental process in GNU Go. This is the process of generating |
| 1981 | hypothetical future boards in order to determine the answer to some |
| 1982 | question, for example "can these stones live." Since these are |
| 1983 | hypothetical future positions, it is important to be able to undo them, |
| 1984 | ultimately returning to the present board. Thus a move stack is |
| 1985 | maintained during reading. When a move is tried, by the function |
| 1986 | `trymove', or its variant `tryko'. This function pushes the current |
| 1987 | board on the stack and plays a move. The stack pointer `stackp', which |
| 1988 | keeps track of the position, is incremented. The function `popgo()' |
| 1989 | pops the move stack, decrementing `stackp' and undoing the last move |
| 1990 | made. |
| 1991 | |
| 1992 | Every successful `trymove()' must be matched with a `popgo()'. Thus |
| 1993 | the correct way of using this function is: |
| 1994 | |
| 1995 | |
| 1996 | if (trymove(pos, color, ... )) { |
| 1997 | ... [potentially lots of code here] |
| 1998 | popgo(); |
| 1999 | } |
| 2000 | |
| 2001 | In case the move is a ko capture, the legality of the capture is |
| 2002 | subject to the komaster scheme (*note Ko::). |
| 2003 | |
| 2004 | * `int trymove(int pos, int color, const char *message)' |
| 2005 | |
| 2006 | Returns true if `(pos)' is a legal move for `color'. In that |
| 2007 | case, it pushes the board on the stack and makes the move, |
| 2008 | incrementing `stackp'. If the reading code is recording |
| 2009 | reading variations (as with `--decide-string' or with `-o'), |
| 2010 | the string `*message' will be inserted in the SGF file as a |
| 2011 | comment. The comment will also refer to the string at `str' |
| 2012 | if this is not `0'. The value of `str' can be NO_MOVE if it |
| 2013 | is not needed but otherwise the location of `str' is included |
| 2014 | in the comment. |
| 2015 | |
| 2016 | * `int tryko(int pos, int color, const char *message)' |
| 2017 | |
| 2018 | `tryko()' pushes the position onto the stack, and makes a move |
| 2019 | `pos' of `color'. The move is allowed even if it is an |
| 2020 | illegal ko capture. It is to be imagined that `color' has |
| 2021 | made an intervening ko threat which was answered and now the |
| 2022 | continuation is to be explored. Return 1 if the move is legal |
| 2023 | with the above caveat. Returns zero if it is not legal |
| 2024 | because of suicide. |
| 2025 | |
| 2026 | * `void popgo()' |
| 2027 | |
| 2028 | Pops the move stack. This function must (eventually) be |
| 2029 | called after a succesful `trymove' or `tryko' to restore the |
| 2030 | board position. It undoes all the changes done by the call to |
| 2031 | `trymove/tryko' and leaves the board in the same state as it |
| 2032 | was before the call. |
| 2033 | |
| 2034 | *NOTE*: If `trymove/tryko' returns `0', i.e. the tried move |
| 2035 | was not legal, you must *not* call `popgo'. |
| 2036 | |
| 2037 | * `int komaster_trymove(int pos, int color, const char *message, int |
| 2038 | str, int *is_conditional_ko, int consider_conditional_ko)' |
| 2039 | |
| 2040 | Variation of `trymove'/`tryko' where ko captures (both |
| 2041 | conditional and unconditional) must follow a komaster scheme |
| 2042 | (*note Ko::). |
| 2043 | |
| 2044 | |
| 2045 | As you see, `trymove()' plays a move which can be easily retracted |
| 2046 | (with `popgo()') and it is call thousands of times per actual game move |
| 2047 | as GNU Go analyzes the board position. By contrast the function |
| 2048 | `play_move()' plays a move which is intended to be permanent, though it |
| 2049 | is still possible to undo it if, for example, the opponent retracts a |
| 2050 | move. |
| 2051 | |
| 2052 | * `void play_move(int pos, int color)' |
| 2053 | |
| 2054 | Play a move. If you want to test for legality you should |
| 2055 | first call `is_legal()'. This function strictly follows the |
| 2056 | algorithm: |
| 2057 | 1. Place a stone of given color on the board. |
| 2058 | |
| 2059 | 2. If there are any adjacent opponent strings without |
| 2060 | liberties, remove them and increase the prisoner count. |
| 2061 | |
| 2062 | 3. If the newly placed stone is part of a string without |
| 2063 | liberties, remove it and increase the prisoner count. |
| 2064 | In spite of the name "permanent move", this move can |
| 2065 | (usually) be unplayed by `undo_move()', but it is |
| 2066 | significantly more costly than unplaying a temporary move. |
| 2067 | There are limitations on the available move history, so under |
| 2068 | certain circumstances the move may not be possible to unplay |
| 2069 | at a later time. |
| 2070 | |
| 2071 | * `int undo_move(int n)' |
| 2072 | |
| 2073 | Undo `n' permanent moves. Returns 1 if successful and 0 if it |
| 2074 | fails. If `n' moves cannot be undone, no move is undone. |
| 2075 | |
| 2076 | Other board functions are documented in *Note Board Utilities::. |
| 2077 | |
| 2078 | \1f |
| 2079 | File: gnugo.info, Node: SGF, Next: DFA, Prev: Libboard, Up: Top |
| 2080 | |
| 2081 | 16 Handling SGF trees in memory |
| 2082 | ******************************* |
| 2083 | |
| 2084 | "SGF" - Smart Game Format - is a file format which is used for storing |
| 2085 | game records for a number of different games, among them chess and go. |
| 2086 | The format is a framework with special adaptions to each game. This is |
| 2087 | not a description of the file format standard. Too see the exact |
| 2088 | definition of the file format, see `http://www.red-bean.com/sgf/'. |
| 2089 | |
| 2090 | GNU Go contains a library to handle go game records in the SGF |
| 2091 | format in memory and to read and write SGF files. This library - |
| 2092 | `libsgf.a' - is in the `sgf' subdirectory. To use the SGF routines, |
| 2093 | include the file `sgftree.h'. |
| 2094 | |
| 2095 | Each game record is stored as a tree of "nodes", where each node |
| 2096 | represents a state of the game, often after some move is made. Each node |
| 2097 | contains zero or more "properties", which gives meaning to the node. |
| 2098 | There can also be a number of "child nodes" which are different |
| 2099 | variations of the game tree. The first child node is the main variation. |
| 2100 | |
| 2101 | Here is the definition of `SGFNode', and `SGFProperty', the data |
| 2102 | structures which are used to encode the game tree. |
| 2103 | |
| 2104 | |
| 2105 | typedef struct SGFProperty_t { |
| 2106 | struct SGFProperty_t *next; |
| 2107 | short name; |
| 2108 | char value[1]; |
| 2109 | } SGFProperty; |
| 2110 | |
| 2111 | typedef struct SGFNode_t { |
| 2112 | SGFProperty *props; |
| 2113 | struct SGFNode_t *parent; |
| 2114 | struct SGFNode_t *child; |
| 2115 | struct SGFNode_t *next; |
| 2116 | } SGFNode; |
| 2117 | |
| 2118 | Each node of the SGF tree is stored in an `SGFNode' struct. It has a |
| 2119 | pointer to a linked list of properties (see below) called `props'. It |
| 2120 | also has a pointer to a linked list of children, where each child is a |
| 2121 | variation which starts at this node. The variations are linked through |
| 2122 | the `next' pointer and each variation continues through the `child' |
| 2123 | pointer. Each and every node also has a pointer to its parent node (the |
| 2124 | `parent' field), except the top node whose parent pointer is `NULL'. |
| 2125 | |
| 2126 | An SGF property is encoded in the `SGFPoperty' struct. It is linked |
| 2127 | in a list through the `next' field. A property has a `name' which is |
| 2128 | encoded in a short int. Symbolic names of properties can be found in |
| 2129 | `sgf_properties.h'. |
| 2130 | |
| 2131 | Some properties also have a value, which could be an integer, a |
| 2132 | floating point value, a character or a string. These values can be |
| 2133 | accessed or set through special functions. |
| 2134 | |
| 2135 | 16.1 The SGFTree datatype |
| 2136 | ========================= |
| 2137 | |
| 2138 | Sometimes we just want to record an ongoing game or something similarly |
| 2139 | simple and not do any sofisticated tree manipulation. In that case we |
| 2140 | can use the simplified interface provided by `SGFTree' below. |
| 2141 | |
| 2142 | |
| 2143 | typedef struct SGFTree_t { |
| 2144 | SGFNode *root; |
| 2145 | SGFNode *lastnode; |
| 2146 | } SGFTree; |
| 2147 | |
| 2148 | An `SGFTree' contains a pointer to the root node of an SGF tree and |
| 2149 | a pointer to the node that we last accessed. Most of the time this will |
| 2150 | be the last move of an ongoing game. |
| 2151 | |
| 2152 | Most of the functions which manipulate an `SGFTree' work exactly |
| 2153 | like their `SGFNode' counterparts, except that they work on the current |
| 2154 | node of the tree. |
| 2155 | |
| 2156 | All the functions below that take arguments `tree' and `node' will |
| 2157 | work on: |
| 2158 | |
| 2159 | 1. `node' if non-`NULL' |
| 2160 | |
| 2161 | 2. `tree->lastnode' if non-`NULL' |
| 2162 | |
| 2163 | 3. The current end of the game tree. |
| 2164 | in that order. |
| 2165 | |
| 2166 | \1f |
| 2167 | File: gnugo.info, Node: API, Next: GTP, Prev: Utility Functions, Up: Top |
| 2168 | |
| 2169 | 17 Application Programmers Interface to GNU Go |
| 2170 | ********************************************** |
| 2171 | |
| 2172 | If you want to write your own interface to GNU Go, or if you want to |
| 2173 | create a go application using the GNU Go engine, this chapter is of |
| 2174 | interest to you. |
| 2175 | |
| 2176 | First an overview: GNU Go consists of two parts: the GNU Go engine |
| 2177 | and a program (user interface) which uses this engine. These are linked |
| 2178 | together into one binary. The current program implements the following |
| 2179 | user modes: |
| 2180 | |
| 2181 | * An interactive board playable on ASCII terminals |
| 2182 | |
| 2183 | * solo play - GNU Go plays against itself |
| 2184 | |
| 2185 | * replay - a mode which lets the user investigate moves in an |
| 2186 | existing SGF file. |
| 2187 | |
| 2188 | * GMP - Go Modem Protocol, a protocol for automatic play between two |
| 2189 | computers. |
| 2190 | |
| 2191 | * GTP - Go Text Protocol, a more general go protocol, *note GTP::. |
| 2192 | |
| 2193 | The GNU Go engine can be used in other applications. For example, |
| 2194 | supplied with GNU Go is another program using the engine, called |
| 2195 | `debugboard', in the directory `interface/debugboard/'. The program |
| 2196 | debugboard lets the user load SGF files and can then interactively look |
| 2197 | at different properties of the position such as group status and eye |
| 2198 | status. |
| 2199 | |
| 2200 | The purpose of this Chapter is to show how to interface your own |
| 2201 | program such as `debugboard' with the GNU Go engine. |
| 2202 | |
| 2203 | Figure 1 describes the structure of a program using the GNU Go |
| 2204 | engine. |
| 2205 | |
| 2206 | +-----------------------------------+ |
| 2207 | | | |
| 2208 | | Go application | |
| 2209 | | | |
| 2210 | +-----+----------+------+ | |
| 2211 | | | | | | |
| 2212 | | | Game | | | |
| 2213 | | | handling | | | |
| 2214 | | | | | | |
| 2215 | | +----+-----+ | | |
| 2216 | | SGF | Move | | |
| 2217 | | handling | generation | | |
| 2218 | | | | | |
| 2219 | +----------+------------+-----------+ |
| 2220 | | | |
| 2221 | | Board handling | |
| 2222 | | | |
| 2223 | +-----------------------------------+ |
| 2224 | |
| 2225 | Figure 1: The structure of a program using the GNU Go engine |
| 2226 | |
| 2227 | The foundation is a library called `libboard.a' which provides |
| 2228 | efficient handling of a go board with rule checks for moves, with |
| 2229 | incremental handling of connected strings of stones and with methods to |
| 2230 | efficiently hash go positions. |
| 2231 | |
| 2232 | On top of this, there is a library which helps the application use |
| 2233 | Smart Game Format (SGF) files, with complete handling of game trees in |
| 2234 | memory and in files. This library is called `libsgf.a' |
| 2235 | |
| 2236 | The main part of the code within GNU Go is the move generation |
| 2237 | library which given a position generates a move. This part of the |
| 2238 | engine can also be used to manipulate a go position, add or remove |
| 2239 | stones, do tactical and strategic reading and to query the engine for |
| 2240 | legal moves. These functions are collected into `libengine.a'. |
| 2241 | |
| 2242 | The game handling code helps the application programmer keep tracks |
| 2243 | of the moves in a game. Games can be saved to SGF files and then later |
| 2244 | be read back again. These are also within `libengine.a'. |
| 2245 | |
| 2246 | The responsibility of the application is to provide the user with a |
| 2247 | user interface, graphical or not, and let the user interact with the |
| 2248 | engine. |
| 2249 | |
| 2250 | * Menu: |
| 2251 | |
| 2252 | * Getting Started:: How to use the engine in your program |
| 2253 | * Basic Data Structures:: Basic Data Structures in the Engine |
| 2254 | * The Board State:: The board_state `struct' |
| 2255 | * Positional Functions:: Functions which manipulate a Position |
| 2256 | |
| 2257 | \1f |
| 2258 | File: gnugo.info, Node: Getting Started, Next: Basic Data Structures, Up: API |
| 2259 | |
| 2260 | 17.1 How to use the engine in your own program: getting started |
| 2261 | =============================================================== |
| 2262 | |
| 2263 | To use the GNU Go engine in your own program you must include the file |
| 2264 | `gnugo.h'. This file describes the whole public API. There is another |
| 2265 | file, `liberty.h', which describes the internal interface within the |
| 2266 | engine. If you want to make a new module within the engine, e.g. for |
| 2267 | suggesting moves you will have to include this file also. In this |
| 2268 | section we will only describe the public interface. |
| 2269 | |
| 2270 | Before you do anything else, you have to call the function |
| 2271 | `init_gnugo()'. This function initializes everything within the engine. |
| 2272 | It takes one parameter: the number of megabytes the engine can use for |
| 2273 | the internal hash table. In addition to this the engine will use a few |
| 2274 | megabytes for other purposes such as data describing groups (liberties, |
| 2275 | life status, etc), eyes and so on. |
| 2276 | |
| 2277 | \1f |
| 2278 | File: gnugo.info, Node: Basic Data Structures, Next: The Board State, Prev: Getting Started, Up: API |
| 2279 | |
| 2280 | 17.2 Basic Data Structures in the Engine |
| 2281 | ======================================== |
| 2282 | |
| 2283 | There are some basic definitions in gnugo.h which are used everywhere. |
| 2284 | The most important of these are the numeric declarations of colors. |
| 2285 | Each intersection on the board is represented by one of these: |
| 2286 | |
| 2287 | |
| 2288 | color value |
| 2289 | EMPTY 0 |
| 2290 | WHITE 1 |
| 2291 | BLACK 2 |
| 2292 | |
| 2293 | There is a macro, `OTHER_COLOR(color)' which can be used to get the |
| 2294 | other color than the parameter. This macro can only be used on `WHITE' |
| 2295 | or `BLACK', but not on `EMPTY'. |
| 2296 | |
| 2297 | GNU Go uses two different representations of the board, for most |
| 2298 | purposes a one-dimensional one, but for a few purposes a two |
| 2299 | dimensional one (*note Libboard::). The one-dimensional board was |
| 2300 | introduced before GNU Go 3.2, while the two-dimensional board dates |
| 2301 | back to the ancestral program written by Man Lung Li before 1995. The |
| 2302 | API still uses the two-dimensional board, so the API functions have not |
| 2303 | changed much since GNU Go 3.0. |
| 2304 | |
| 2305 | \1f |
| 2306 | File: gnugo.info, Node: The Board State, Next: Positional Functions, Prev: Basic Data Structures, Up: API |
| 2307 | |
| 2308 | 17.3 The board_state struct |
| 2309 | =========================== |
| 2310 | |
| 2311 | A basic data structure in the engine is the `board_state' struct. This |
| 2312 | structure is internal to the engine and is defined in `liberty.h'. |
| 2313 | |
| 2314 | |
| 2315 | typedef unsigned char Intersection; |
| 2316 | |
| 2317 | struct board_state { |
| 2318 | int board_size; |
| 2319 | |
| 2320 | Intersection board[BOARDSIZE]; |
| 2321 | int board_ko_pos; |
| 2322 | int black_captured; |
| 2323 | int white_captured; |
| 2324 | |
| 2325 | Intersection initial_board[BOARDSIZE]; |
| 2326 | int initial_board_ko_pos; |
| 2327 | int initial_white_captured; |
| 2328 | int initial_black_captured; |
| 2329 | int move_history_color[MAX_MOVE_HISTORY]; |
| 2330 | int move_history_pos[MAX_MOVE_HISTORY]; |
| 2331 | int move_history_pointer; |
| 2332 | |
| 2333 | float komi; |
| 2334 | int move_number; |
| 2335 | }; |
| 2336 | |
| 2337 | Here `Intersection' stores `EMPTY', `WHITE' or `BLACK'. It is |
| 2338 | currently defined as an `unsigned char' to make it reasonably efficient |
| 2339 | in both storage and access time. The board state contains an array of |
| 2340 | `Intersection''s representing the board. The move history is contained |
| 2341 | in the struct. Also contained in the struct is the location of a ko |
| 2342 | (`EMPTY') if the last move was not a ko capture, the komi, the number |
| 2343 | of captures, and corresponding data for the initial position at the |
| 2344 | beginning of the move history. |
| 2345 | |
| 2346 | \1f |
| 2347 | File: gnugo.info, Node: Positional Functions, Prev: The Board State, Up: API |
| 2348 | |
| 2349 | 17.4 Functions which manipulate a Position |
| 2350 | ========================================== |
| 2351 | |
| 2352 | All the functions in the engine that manipulate Positions have names |
| 2353 | prefixed by `gnugo_'. These functions still use the two-dimensional |
| 2354 | representation of the board (*note The Board Array::). Here is a |
| 2355 | complete list, as prototyped in `gnugo.h': |
| 2356 | |
| 2357 | * `void init_gnugo(float memory)' |
| 2358 | |
| 2359 | Initialize the gnugo engine. This needs to be called once |
| 2360 | only. |
| 2361 | |
| 2362 | * `void gnugo_clear_board(int boardsize)' |
| 2363 | |
| 2364 | Clear the board. |
| 2365 | |
| 2366 | * `void gnugo_set_komi(float new_komi)' |
| 2367 | |
| 2368 | Set the komi. |
| 2369 | |
| 2370 | * `void gnugo_add_stone(int i, int j, int color)' |
| 2371 | |
| 2372 | Place a stone on the board |
| 2373 | |
| 2374 | * `void gnugo_remove_stone(int i, int j)' |
| 2375 | |
| 2376 | Remove a stone from the board |
| 2377 | |
| 2378 | * `int gnugo_is_pass(int i, int j)' |
| 2379 | |
| 2380 | Return true if (i,j) is PASS_MOVE |
| 2381 | |
| 2382 | * `void gnugo_play_move(int i, int j, int color)' |
| 2383 | |
| 2384 | Play a move and start the clock |
| 2385 | |
| 2386 | * `int gnugo_undo_move(int n)' |
| 2387 | |
| 2388 | Undo n permanent moves. Returns 1 if successful and 0 if it |
| 2389 | fails. If n moves cannot be undone, no move is undone. |
| 2390 | |
| 2391 | * `int gnugo_play_sgfnode(SGFNode *node, int to_move)' |
| 2392 | |
| 2393 | Perform the moves and place the stones from the SGF node on |
| 2394 | the board. Return the color of the player whose turn it is to |
| 2395 | move. |
| 2396 | |
| 2397 | * `int gnugo_play_sgftree(SGFNode *root, int *until, SGFNode |
| 2398 | **curnode)' |
| 2399 | |
| 2400 | Play the moves in ROOT UNTIL movenumber is reached. Return |
| 2401 | the color of the player whose turn it is to move. |
| 2402 | |
| 2403 | * `int gnugo_is_legal(int i, int j, int color)' |
| 2404 | |
| 2405 | Interface to `is_legal()'. |
| 2406 | |
| 2407 | * `int gnugo_is_suicide(int i, int j, int color)' |
| 2408 | |
| 2409 | Interface to `is_suicide()'. |
| 2410 | |
| 2411 | * `int gnugo_placehand(int handicap)' |
| 2412 | |
| 2413 | Interface to placehand. Sets up handicap pieces and returns |
| 2414 | the number of placed handicap stones. |
| 2415 | |
| 2416 | * `void gnugo_recordboard(SGFNode *root)' |
| 2417 | |
| 2418 | Interface to `sgffile_recordboard()' |
| 2419 | |
| 2420 | * `int gnugo_sethand(int handicap, SGFNode *node)' |
| 2421 | |
| 2422 | Interface to placehand. Sets up handicap stones and returns |
| 2423 | the number of placed handicap stones, updating the sgf file |
| 2424 | |
| 2425 | * `float gnugo_genmove(int *i, int *j, int color, int *resign)' |
| 2426 | |
| 2427 | Interface to `genmove()'. |
| 2428 | |
| 2429 | * `int gnugo_attack(int m, int n, int *i, int *j)' |
| 2430 | |
| 2431 | Interface to `attack()'. |
| 2432 | |
| 2433 | * `int gnugo_find_defense(int m, int n, int *i, int *j)' |
| 2434 | |
| 2435 | Interface to `find_defense()'. |
| 2436 | |
| 2437 | * `void gnugo_who_wins(int color, FILE *outfile)' |
| 2438 | |
| 2439 | Interface to `who_wins()'. |
| 2440 | |
| 2441 | * `float gnugo_estimate_score(float *upper, float *lower)' |
| 2442 | |
| 2443 | Put upper and lower score estimates into `*upper', `*lower' |
| 2444 | and return the average. A positive score favors white. In |
| 2445 | computing the upper bound, `CRITICAL' dragons are awarded to |
| 2446 | white; in computing the lower bound, they are awarded to |
| 2447 | black. |
| 2448 | |
| 2449 | * `void gnugo_examine_position(int color, int how_much)' |
| 2450 | |
| 2451 | Interface to `examine_position'. |
| 2452 | |
| 2453 | * `int gnugo_get_komi()' |
| 2454 | |
| 2455 | Report the komi. |
| 2456 | |
| 2457 | * `void gnugo_get_board(int b[MAX_BOARD][MAX_BOARD])' |
| 2458 | |
| 2459 | Place the board into the `b' array. |
| 2460 | |
| 2461 | * `int gnugo_get_boardsize()' |
| 2462 | |
| 2463 | Report the board size. |
| 2464 | |
| 2465 | * `int gnugo_get_move_number()' |
| 2466 | |
| 2467 | Report the move number. |
| 2468 | |
| 2469 | 17.5 Game handling |
| 2470 | ================== |
| 2471 | |
| 2472 | The functions (in *note Positional Functions::) are all that are needed |
| 2473 | to create a fully functional go program. But to make the life easier |
| 2474 | for the programmer, there is a small set of functions specially |
| 2475 | designed for handling ongoing games. |
| 2476 | |
| 2477 | The data structure describing an ongoing game is the `Gameinfo'. It |
| 2478 | is defined as follows: |
| 2479 | |
| 2480 | |
| 2481 | typedef struct { |
| 2482 | int handicap; |
| 2483 | |
| 2484 | int to_move; /* whose move it currently is */ |
| 2485 | SGFTree game_record; /* Game record in sgf format. */ |
| 2486 | |
| 2487 | int computer_player; /* BLACK, WHITE, or EMPTY (used as BOTH) */ |
| 2488 | |
| 2489 | char outfilename[128]; /* Trickle file */ |
| 2490 | FILE *outfile; |
| 2491 | } Gameinfo; |
| 2492 | |
| 2493 | The meaning of `handicap' should be obvious. `to_move' is the color |
| 2494 | of the side whose turn it is to move. |
| 2495 | |
| 2496 | The SGF tree `game_record' is used to store all the moves in the |
| 2497 | entire game, including a header node which contains, among other |
| 2498 | things, komi and handicap. |
| 2499 | |
| 2500 | If one or both of the opponents is the computer, the field |
| 2501 | `computer_player' is used. Otherwise it can be ignored. |
| 2502 | |
| 2503 | GNU Go can use a trickle file to continuously save all the moves of |
| 2504 | an ongoing game. This file can also contain information about internal |
| 2505 | state of the engine such as move reasons for various locations or move |
| 2506 | valuations. The name of this file should be stored in `outfilename' and |
| 2507 | the file pointer to the open file is stored in `outfile'. If no trickle |
| 2508 | file is used, `outfilename[0]' will contain a null character and |
| 2509 | `outfile' will be set to `NULL'. |
| 2510 | |
| 2511 | 17.5.1 Functions which manipulate a Gameinfo |
| 2512 | -------------------------------------------- |
| 2513 | |
| 2514 | All the functions in the engine that manipulate Gameinfos have names |
| 2515 | prefixed by `gameinfo_'. Here is a complete list, as prototyped in |
| 2516 | `gnugo.h': |
| 2517 | |
| 2518 | * `void gameinfo_clear(Gameinfo *ginfo, int boardsize, float komi)' |
| 2519 | |
| 2520 | Initialize the `Gameinfo' structure. |
| 2521 | |
| 2522 | * `void gameinfo_print(Gameinfo *ginfo)' |
| 2523 | |
| 2524 | Print a gameinfo. |
| 2525 | |
| 2526 | * `void gameinfo_load_sgfheader(Gameinfo *gameinfo, SGFNode *head)' |
| 2527 | |
| 2528 | Reads header info from sgf structure and sets the appropriate |
| 2529 | variables. |
| 2530 | |
| 2531 | * `void gameinfo_play_move(Gameinfo *ginfo, int i, int j, int color)' |
| 2532 | |
| 2533 | Make a move in the game. Return 1 if the move was legal. In |
| 2534 | that case the move is actually done. Otherwise return 0. |
| 2535 | |
| 2536 | * `int gameinfo_play_sgftree_rot(Gameinfo *gameinfo, SGFNode *head, |
| 2537 | const char *untilstr, int orientation)' |
| 2538 | |
| 2539 | Play the moves in an SGF tree. Walk the main variation, |
| 2540 | actioning the properties into the playing board. Returns the |
| 2541 | color of the next move to be made. Head is an sgf tree. |
| 2542 | Untilstr is an optional string of the form either 'L12' or |
| 2543 | '120' which tells it to stop playing at that move or move |
| 2544 | number. When debugging, this is the location of the move |
| 2545 | being examined. |
| 2546 | |
| 2547 | * `int gameinfo_play_sgftree(Gameinfo *gameinfo, SGFNode *head, |
| 2548 | const char *untilstr)' |
| 2549 | |
| 2550 | Same as previous function, using standard orientation. |
| 2551 | |
| 2552 | \1f |
| 2553 | File: gnugo.info, Node: Utility Functions, Next: API, Prev: DFA, Up: Top |
| 2554 | |
| 2555 | 18 Utility Functions |
| 2556 | ******************** |
| 2557 | |
| 2558 | In this Chapter, we document some of the utilities which may be called |
| 2559 | from the GNU Go engine. |
| 2560 | |
| 2561 | * Menu: |
| 2562 | |
| 2563 | * General Utilities:: Utilities from `engine/utils.c' |
| 2564 | * Print Utilities:: Utilities from `engine/printutils.c' |
| 2565 | * Board Utilities:: Utilities from `engine/board.c' |
| 2566 | * Influence Utilities:: Utilities from `engine/influence.c' |
| 2567 | |
| 2568 | \1f |
| 2569 | File: gnugo.info, Node: General Utilities, Next: Print Utilities, Up: Utility Functions |
| 2570 | |
| 2571 | 18.1 General Utilities |
| 2572 | ====================== |
| 2573 | |
| 2574 | Utility functions from `engine/utils.c'. Many of these functions |
| 2575 | underlie autohelper functions (*note Autohelper Functions::). |
| 2576 | |
| 2577 | * `void change_dragon_status(int dr, int status)' |
| 2578 | |
| 2579 | Change the status of all the stones in the dragon at `dr'. |
| 2580 | |
| 2581 | * `int defend_against(int move, int color, int apos)' |
| 2582 | |
| 2583 | Check whether a move at `move' stops the enemy from playing |
| 2584 | at (apos). |
| 2585 | |
| 2586 | * `int cut_possible(int pos, int color)' |
| 2587 | |
| 2588 | Returns true if `color' can cut at `pos', or if connection |
| 2589 | through `pos' is inhibited. This information is collected by |
| 2590 | `find_cuts()', using the B patterns in the connections |
| 2591 | database. |
| 2592 | |
| 2593 | * `int does_attack(int move, int str)' |
| 2594 | |
| 2595 | returns true if the move at `move' attacks `str'. This means |
| 2596 | that it captures the string, and that `str' is not already |
| 2597 | dead. |
| 2598 | |
| 2599 | * `int does_defend(int move, int str)' |
| 2600 | |
| 2601 | `does_defend(move, str)' returns true if the move at `move' |
| 2602 | defends `str'. This means that it defends the string, and that |
| 2603 | `str' can be captured if no defense is made. |
| 2604 | |
| 2605 | * `int somewhere(int color, int last_move, ...)' |
| 2606 | |
| 2607 | Example: `somewhere(WHITE, 2, apos, bpos, cpos)'. Returns |
| 2608 | true if one of the vertices listed satisfies |
| 2609 | `board[pos]==color'. Here num_moves is the number of moves |
| 2610 | minus one. If the check is true the dragon is not allowed to |
| 2611 | be dead. This check is only valid if `stackp==0'. |
| 2612 | |
| 2613 | * `int visible_along_edge(int color, int apos, int bpos)' |
| 2614 | |
| 2615 | Search along the edge for the first visible stone. Start at |
| 2616 | apos and move in the direction of bpos. Return 1 if the first |
| 2617 | visible stone is of the given color. It is required that apos |
| 2618 | and bpos are at the same distance from the edge. |
| 2619 | |
| 2620 | * `int test_symmetry_after_move(int move, int color, int strict)' |
| 2621 | |
| 2622 | Is the board symmetric (or rather antisymmetric) with respect |
| 2623 | to mirroring in tengen after a specific move has been played? |
| 2624 | If the move is PASS_MOVE, check the current board. If strict |
| 2625 | is set we require that each stone is matched by a stone of |
| 2626 | the opposite color at the mirrored vertex. Otherwise we only |
| 2627 | require that each stone is matched by a stone of either color. |
| 2628 | |
| 2629 | * `int play_break_through_n(int color, int num_moves, ...)' |
| 2630 | |
| 2631 | The function `play_break_through_n()' plays a sequence of |
| 2632 | moves, alternating between the players and starting with |
| 2633 | color. After having played through the sequence, the three |
| 2634 | last coordinate pairs gives a position to be analyzed by |
| 2635 | `break_through()', to see whether either color has managed to |
| 2636 | enclose some stones and/or connected his own stones. If any |
| 2637 | of the three last positions is empty, it's assumed that the |
| 2638 | enclosure has failed, as well as the attempt to connect. If |
| 2639 | one or more of the moves to play turns out to be illegal for |
| 2640 | some reason, the rest of the sequence is played anyway, and |
| 2641 | `break_through()' is called as if nothing special happened. |
| 2642 | Like `break_through()', this function returns 1 if the |
| 2643 | attempt to break through was succesful and 2 if it only |
| 2644 | managed to cut through. |
| 2645 | |
| 2646 | * `int play_attack_defend_n(int color, int do_attack, int num_moves, |
| 2647 | ...)' |
| 2648 | |
| 2649 | * `int play_attack_defend2_n(int color, int do_attack, int |
| 2650 | num_moves, ...)' |
| 2651 | |
| 2652 | The function `play_attack_defend_n()' plays a sequence of |
| 2653 | moves, alternating between the players and starting with |
| 2654 | `color'. After having played through the sequence, the last |
| 2655 | coordinate pair gives a target to attack or defend, depending |
| 2656 | on the value of do_attack. If there is no stone present to |
| 2657 | attack or defend, it is assumed that it has already been |
| 2658 | captured. If one or more of the moves to play turns out to be |
| 2659 | illegal for some reason, the rest of the sequence is played |
| 2660 | anyway, and attack/defense is tested as if nothing special |
| 2661 | happened. Conversely, `play_attack_defend2_n()' plays a |
| 2662 | sequence of moves, alternating between the players and |
| 2663 | starting with `color'. After having played through the |
| 2664 | sequence, the two last coordinate pairs give two targets to |
| 2665 | simultaneously attack or defend, depending on the value of |
| 2666 | do_attack. If there is no stone present to attack or defend, |
| 2667 | it is assumed that it has already been captured. If one or |
| 2668 | more of the moves to play turns out to be illegal for some |
| 2669 | reason, the rest of the sequence is played anyway, and |
| 2670 | attack/defense is tested as if nothing special happened. A |
| 2671 | typical use of these functions is to set up a ladder in an |
| 2672 | autohelper and see whether it works or not. |
| 2673 | |
| 2674 | * `int play_connect_n(int color, int do_connect, int num_moves, ...)' |
| 2675 | |
| 2676 | Plays a sequence of moves, alternating between the players |
| 2677 | and starting with `color'. After having played through the |
| 2678 | sequence, the two last coordinates give two targets that |
| 2679 | should be connected or disconnected, depending on the value |
| 2680 | of do_connect. If there is no stone present to connect or |
| 2681 | disconnect, it is assumed that the connection has failed. If |
| 2682 | one or more of the moves to play turns out to be illegal for |
| 2683 | some reason, the rest of the sequence is played anyway, and |
| 2684 | connection/disconnection is tested as if nothing special |
| 2685 | happened. Ultimately the connection is decided by the |
| 2686 | functions `string_connect' and `disconnect' (*note Connection |
| 2687 | Reading::). |
| 2688 | |
| 2689 | * `void set_depth_values(int level)' |
| 2690 | |
| 2691 | It is assumed in reading a ladder if `stackp >= depth' that |
| 2692 | as soon as a bounding stone is in atari, the string is safe. |
| 2693 | Similar uses are made of the other depth parameters such as |
| 2694 | `backfill_depth' and so forth. In short, simplifying |
| 2695 | assumptions are made when `stackp' is large. Unfortunately |
| 2696 | any such scheme invites the "horizon effect," in which a |
| 2697 | stalling move is perceived as a win, by pushing the |
| 2698 | refutation past the "horizon"--the value of `stackp' in which |
| 2699 | the reading assumptions are relaxed. To avoid the depth it is |
| 2700 | sometimes necessary to increase the depth parameters. This |
| 2701 | function can be used to set the various reading depth |
| 2702 | parameters. If `mandated_depth_value' is not -1 that value is |
| 2703 | used; otherwise the depth values are set as a function of |
| 2704 | level. The parameter `mandated_depth_value' can be set at the |
| 2705 | command line to force a particular value of depth; normally |
| 2706 | it is -1. |
| 2707 | |
| 2708 | * `void modify_depth_values(int n)' |
| 2709 | |
| 2710 | Modify the various tactical reading depth parameters. This is |
| 2711 | typically used to avoid horizon effects. By temporarily |
| 2712 | increasing the depth values when trying some move, one can |
| 2713 | avoid that an irrelevant move seems effective just because |
| 2714 | the reading hits a depth limit earlier than it did when |
| 2715 | reading only on relevant moves. |
| 2716 | |
| 2717 | * `void increase_depth_values(void)' |
| 2718 | |
| 2719 | `modify_depth_values(1)'. |
| 2720 | |
| 2721 | * `void decrease_depth_values(void)' |
| 2722 | |
| 2723 | `modify_depth_values(-1)'. |
| 2724 | |
| 2725 | * `void restore_depth_values()' |
| 2726 | |
| 2727 | Sets `depth' and so forth to their saved values. |
| 2728 | |
| 2729 | * `void set_temporary_depth_values(int d, int b, int b2, int bc, int |
| 2730 | ss, int br, int f, int k)' |
| 2731 | |
| 2732 | Explicitly set the depth values. This function is currently |
| 2733 | never called. |
| 2734 | |
| 2735 | * `int confirm_safety(int move, int color, int *defense_point, char |
| 2736 | safe_stones[BOARDMAX])' |
| 2737 | |
| 2738 | Check that the move at color doesn't involve any kind of |
| 2739 | blunder, regardless of size. |
| 2740 | |
| 2741 | * `float blunder_size(int move, int color, int *defense_point, char |
| 2742 | safe_stones[BOARDMAX])' |
| 2743 | |
| 2744 | This function will detect some blunders. If the move reduces |
| 2745 | the number of liberties of an adjacent friendly string, there |
| 2746 | is a danger that the move could backfire, so the function |
| 2747 | checks that no friendly worm which was formerly not |
| 2748 | attackable becomes attackable, and it checks that no opposing |
| 2749 | worm which was not defendable becomes defendable. It returns |
| 2750 | the estimated size of the blunder, or 0.0 if nothing bad has |
| 2751 | happened. The array `safe_stones[]' contains the stones that |
| 2752 | are supposedly safe after `move'. It may be `NULL'. For use |
| 2753 | when called from `fill_liberty()', this function may |
| 2754 | optionally return a point of defense, which, if taken, will |
| 2755 | presumably make the move at `move' safe on a subsequent turn. |
| 2756 | |
| 2757 | * `int double_atari(int move, int color, float *value, char |
| 2758 | safe_stones[BOARDMAX])' |
| 2759 | |
| 2760 | Returns true if a move by (color) fits the following shape: |
| 2761 | X* (O=color) |
| 2762 | OX |
| 2763 | capturing one of the two `X' strings. The name is a slight |
| 2764 | misnomer since this includes attacks which are not |
| 2765 | necessarily double ataris, though the common double atari is |
| 2766 | the most important special case. If `safe_stones != NULL', |
| 2767 | then only attacks on stones marked as safe are tried. The |
| 2768 | value of the double atari attack is returned in value (unless |
| 2769 | value is `NULL'), and the attacked stones are marked unsafe. |
| 2770 | |
| 2771 | * `void unconditional_life(int unconditional_territory[BOARDMAX], |
| 2772 | int color)' |
| 2773 | |
| 2774 | Find those worms of the given color that can never be |
| 2775 | captured, even if the opponent is allowed an arbitrary number |
| 2776 | of consecutive moves. The coordinates of the origins of these |
| 2777 | worms are written to the worm arrays and the number of |
| 2778 | non-capturable worms is returned. The algorithm is to cycle |
| 2779 | through the worms until none remains or no more can be |
| 2780 | captured. A worm is removed when it is found to be |
| 2781 | capturable, by letting the opponent try to play on all its |
| 2782 | liberties. If the attack fails, the moves are undone. When no |
| 2783 | more worm can be removed in this way, the remaining ones are |
| 2784 | unconditionally alive. After this, unconditionally dead |
| 2785 | opponent worms and unconditional territory are identified. To |
| 2786 | find these, we continue from the position obtained at the end |
| 2787 | of the previous operation (only unconditionally alive strings |
| 2788 | remain for color) with the following steps: |
| 2789 | |
| 2790 | 1. Play opponent stones on all liberties of the |
| 2791 | unconditionally alive strings except where illegal. |
| 2792 | (That the move order may determine exactly which |
| 2793 | liberties can be played legally is not important. Just |
| 2794 | pick an arbitrary order). |
| 2795 | |
| 2796 | 2. Recursively extend opponent strings in atari, except |
| 2797 | where this would be suicide. |
| 2798 | |
| 2799 | 3. Play an opponent stone anywhere it can get two empty |
| 2800 | neighbors. (I.e. split big eyes into small ones). |
| 2801 | |
| 2802 | 4. an opponent stone anywhere it can get one empty |
| 2803 | neighbor. (I.e. reduce two space eyes to one space eyes.) |
| 2804 | Remaining opponent strings in atari and remaining |
| 2805 | liberties of the unconditionally alive strings |
| 2806 | constitute the unconditional territory. Opponent |
| 2807 | strings from the initial position placed on |
| 2808 | unconditional territory are unconditionally dead. On |
| 2809 | return, `unconditional_territory[][]' is 1 where color |
| 2810 | has unconditionally alive stones, 2 where it has |
| 2811 | unconditional territory, and 0 otherwise. |
| 2812 | |
| 2813 | * `void who_wins(int color, FILE *outfile)' |
| 2814 | |
| 2815 | Score the game and determine the winner |
| 2816 | |
| 2817 | * `void find_superstring(int str, int *num_stones, int *stones)' |
| 2818 | |
| 2819 | Find the stones of an extended string, where the extensions |
| 2820 | are through the following kinds of connections: |
| 2821 | 1. Solid connections (just like ordinary string). |
| 2822 | OO |
| 2823 | |
| 2824 | 2. Diagonal connection or one space jump through an |
| 2825 | intersection where an opponent move would be suicide or |
| 2826 | self-atari. |
| 2827 | ... |
| 2828 | O.O |
| 2829 | XOX |
| 2830 | X.X |
| 2831 | |
| 2832 | 3. Bamboo joint. |
| 2833 | OO |
| 2834 | .. |
| 2835 | OO |
| 2836 | |
| 2837 | 4. Diagonal connection where both adjacent intersections |
| 2838 | are empty. |
| 2839 | .O |
| 2840 | O. |
| 2841 | |
| 2842 | 5. Connection through adjacent or diagonal tactically |
| 2843 | captured stones. Connections of this type are omitted |
| 2844 | when the superstring code is called from reading.c, but |
| 2845 | included when the superstring code is called from owl.c |
| 2846 | |
| 2847 | * `void find_superstring_liberties(int str, int *num_libs, int |
| 2848 | *libs, int liberty_cap)' |
| 2849 | |
| 2850 | This function computes the superstring at `str' as described |
| 2851 | above, but omitting connections of type 5. Then it constructs |
| 2852 | a list of liberties of the superstring which are not already |
| 2853 | liberties of `str'. If `liberty_cap' is nonzero, only |
| 2854 | liberties of substrings of the superstring which have fewer |
| 2855 | than `liberty_cap' liberties are generated. |
| 2856 | |
| 2857 | * `void find_proper_superstring_liberties(int str, int *num_libs, |
| 2858 | int *libs, int liberty_cap)' |
| 2859 | |
| 2860 | This function is the same as find_superstring_liberties, but |
| 2861 | it omits those liberties of the string `str', presumably |
| 2862 | since those have already been treated elsewhere. If |
| 2863 | `liberty_cap' is nonzero, only liberties of substrings of the |
| 2864 | superstring which have at most `liberty_cap' liberties are |
| 2865 | generated. |
| 2866 | |
| 2867 | * `void find_superstring_stones_and_liberties(int str, int |
| 2868 | *num_stones, int *stones, int *num_libs, int *libs, int |
| 2869 | liberty_cap)' |
| 2870 | |
| 2871 | This function computes the superstring at `str' as described |
| 2872 | above, but omitting connections of type 5. Then it constructs |
| 2873 | a list of liberties of the superstring which are not already |
| 2874 | liberties of `str'. If liberty_cap is nonzero, only liberties |
| 2875 | of substrings of the superstring which have fewer than |
| 2876 | liberty_cap liberties are generated. |
| 2877 | |
| 2878 | * `void superstring_chainlinks(int str, int *num_adj, int |
| 2879 | adjs[MAXCHAIN], int liberty_cap)' |
| 2880 | |
| 2881 | analogous to chainlinks, this function finds boundary chains |
| 2882 | of the superstring at `str', including those which are |
| 2883 | boundary chains of `str' itself. If `liberty_cap != 0', only |
| 2884 | those boundary chains with `<= liberty_cap' liberties are |
| 2885 | reported. |
| 2886 | |
| 2887 | * `void proper_superstring_chainlinks(int str, int *num_adj, int |
| 2888 | adjs[MAXCHAIN], int liberty_cap)' |
| 2889 | |
| 2890 | analogous to chainlinks, this function finds boundary chains |
| 2891 | of the superstring at `str', omitting those which are |
| 2892 | boundary chains of `str' itself. If `liberty_cap != 0', only |
| 2893 | those boundary chains with `<= liberty_cap' liberties are |
| 2894 | reported. |
| 2895 | |
| 2896 | * `void start_timer(int n)' |
| 2897 | |
| 2898 | Start a timer. GNU Go has four internal timers available for |
| 2899 | assessing the time spent on various tasks. |
| 2900 | |
| 2901 | * `double time_report(int n, const char *occupation, int move, |
| 2902 | double mintime)' |
| 2903 | |
| 2904 | Report time spent and restart the timer. Make no report if |
| 2905 | elapsed time is less than mintime. |
| 2906 | |
| 2907 | \1f |
| 2908 | File: gnugo.info, Node: Print Utilities, Next: Board Utilities, Prev: General Utilities, Up: Utility Functions |
| 2909 | |
| 2910 | 18.2 Print Utilities |
| 2911 | ==================== |
| 2912 | |
| 2913 | Functions in `engine/printutils.c' do formatted printing similar to |
| 2914 | `printf' and its allies. The following formats are recognized: |
| 2915 | |
| 2916 | * `%c', `%d', `%f', `%s', `%x' |
| 2917 | |
| 2918 | These have their usual meaning in formatted output, printing |
| 2919 | a character, integer, float, string or hexadecimal, |
| 2920 | respectively. |
| 2921 | |
| 2922 | * `%o' |
| 2923 | |
| 2924 | `Outdent.' Normally output is indented by `2*stackp' spaces, |
| 2925 | so that the depth can be seen at a glance in traces. At the |
| 2926 | beginning of a format, this `%o' inhibits the indentation. |
| 2927 | |
| 2928 | * `%H' |
| 2929 | |
| 2930 | Print a hashvalue. |
| 2931 | |
| 2932 | * `%C' |
| 2933 | |
| 2934 | Print a color as a string. |
| 2935 | |
| 2936 | * `%m', `%2m' (synonyms) |
| 2937 | |
| 2938 | Takes 2 integers and writes a move, using the two dimensional |
| 2939 | board representation (*note The Board Array::) |
| 2940 | |
| 2941 | * `%1m' |
| 2942 | |
| 2943 | Takes 1 integers and writes a move, using the one dimensional |
| 2944 | board representation (*note The Board Array::) |
| 2945 | |
| 2946 | We list the non statically declared functions in `printutils.c'. |
| 2947 | |
| 2948 | * `void gfprintf(FILE *outfile, const char *fmt, ...)' |
| 2949 | |
| 2950 | Formatted output to `outfile'. |
| 2951 | |
| 2952 | * `int gprintf(const char *fmt, ...)' |
| 2953 | |
| 2954 | Formatted output to stderr. Always returns 1 to allow use in |
| 2955 | short-circuit logical expressions. |
| 2956 | |
| 2957 | * `int mprintf(const char *fmt, ...)' |
| 2958 | |
| 2959 | Formatted output to stdout. |
| 2960 | |
| 2961 | * `DEBUG(level, fmt, args...)' |
| 2962 | |
| 2963 | If `level & debug', do formatted output to stderr. Otherwise, |
| 2964 | ignore. |
| 2965 | |
| 2966 | * `void abortgo(const char *file, int line, const char *msg, int |
| 2967 | pos)' |
| 2968 | |
| 2969 | Print debugging output in an error situation, then exit. |
| 2970 | |
| 2971 | * `const char * color_to_string(int color)' |
| 2972 | |
| 2973 | Convert a color value to a string |
| 2974 | |
| 2975 | * `const char * location_to_string(int pos)' |
| 2976 | |
| 2977 | Convert a location to a string |
| 2978 | |
| 2979 | * `void location_to_buffer(int pos, char *buf)' |
| 2980 | |
| 2981 | Convert a location to a string, writing to a buffer. |
| 2982 | |
| 2983 | * `int string_to_location(int boardsize, char *str, int *m, int *n)' |
| 2984 | |
| 2985 | Get the `(m, n)' coordinates in the standard GNU Go |
| 2986 | coordinate system from the string `str'. This means that `m' |
| 2987 | is the nth row from the top and `n' is the column. Both |
| 2988 | coordinates are between 0 and `boardsize-1', inclusive. |
| 2989 | Return 1 if ok, otherwise return 0; |
| 2990 | |
| 2991 | * `int is_hoshi_point(int m, int n)' True if the coordinate is a |
| 2992 | hoshi point. |
| 2993 | |
| 2994 | * `void draw_letter_coordinates(FILE *outfile)' Print a line with |
| 2995 | coordinate letters above the board. |
| 2996 | |
| 2997 | * `void simple_showboard(FILE *outfile)' |
| 2998 | |
| 2999 | Bare bones version of `showboard(0)'. No fancy options, no |
| 3000 | hint of color, and you can choose where to write it. |
| 3001 | |
| 3002 | The following functions are in `showbord.c'. Not all public |
| 3003 | functions in that file are listed here. |
| 3004 | |
| 3005 | * `void showboard(int xo)' |
| 3006 | |
| 3007 | Show go board. |
| 3008 | xo=0: black and white XO board for ascii game |
| 3009 | xo=1: colored dragon display |
| 3010 | xo=2: colored eye display |
| 3011 | xo=3: colored owl display |
| 3012 | xo=4: colored matcher status display |
| 3013 | |
| 3014 | * `const char * status_to_string(int status)' |
| 3015 | |
| 3016 | Convert a status value to a string. |
| 3017 | |
| 3018 | * `const char * safety_to_string(int status)' |
| 3019 | |
| 3020 | Convert a safety value to a string. |
| 3021 | |
| 3022 | * `const char * result_to_string(int result)' |
| 3023 | |
| 3024 | Convert a read result to a string |
| 3025 | |
| 3026 | \1f |
| 3027 | File: gnugo.info, Node: Board Utilities, Next: Influence Utilities, Prev: Print Utilities, Up: Utility Functions |
| 3028 | |
| 3029 | 18.3 Board Utilities |
| 3030 | ==================== |
| 3031 | |
| 3032 | The functions documented in this section are from `board.c'. Other |
| 3033 | functions in `board.c' are described in *Note Some Board Functions::. |
| 3034 | |
| 3035 | * `void store_board(struct board_state *state)' |
| 3036 | |
| 3037 | Save board state. |
| 3038 | |
| 3039 | * `void restore_board(struct board_state *state)' |
| 3040 | |
| 3041 | Restore a saved board state. |
| 3042 | |
| 3043 | * `void clear_board(void)' |
| 3044 | |
| 3045 | Clear the internal board. |
| 3046 | |
| 3047 | * `void dump_stack(void)' |
| 3048 | |
| 3049 | for use under GDB prints the move stack. |
| 3050 | |
| 3051 | * `void add_stone(int pos, int color)' |
| 3052 | |
| 3053 | Place a stone on the board and update the board_hash. This |
| 3054 | operation destroys all move history. |
| 3055 | |
| 3056 | * `void remove_stone(int pos)' |
| 3057 | |
| 3058 | Remove a stone from the board and update the board_hash. This |
| 3059 | operation destroys the move history. |
| 3060 | |
| 3061 | * `int is_pass(int pos)' |
| 3062 | |
| 3063 | Test if the move is a pass or not. Return 1 if it is. |
| 3064 | |
| 3065 | * `int is_legal(int pos, int color)' |
| 3066 | |
| 3067 | Determines whether the move `color' at `pos' is legal. |
| 3068 | |
| 3069 | * `int is_suicide(int pos, int color)' |
| 3070 | |
| 3071 | Determines whether the move `color' at `pos' would be a |
| 3072 | suicide. This is the case if |
| 3073 | 1. There is no neighboring empty intersection. |
| 3074 | |
| 3075 | 2. There is no neighboring opponent string with exactly one |
| 3076 | liberty. |
| 3077 | |
| 3078 | 3. There is no neighboring friendly string with more than |
| 3079 | one liberty. |
| 3080 | |
| 3081 | * `int is_illegal_ko_capture(int pos, int color)' |
| 3082 | |
| 3083 | Determines whether the move `color' at `pos' would be an |
| 3084 | illegal ko capture. |
| 3085 | |
| 3086 | * `int is_edge_vertex(int pos)' |
| 3087 | |
| 3088 | Determine whether vertex is on the edge. |
| 3089 | |
| 3090 | * `int edge_distance(int pos)' |
| 3091 | |
| 3092 | Distance to the edge. |
| 3093 | |
| 3094 | * `int is_corner_vertex(int pos)' |
| 3095 | |
| 3096 | Determine whether vertex is a corner. |
| 3097 | |
| 3098 | * `int get_komaster()' |
| 3099 | |
| 3100 | * `int get_kom_pos()' |
| 3101 | |
| 3102 | Public functions to access the variable `komaster' and |
| 3103 | `kom_pos', which are static in `board.c'. |
| 3104 | |
| 3105 | Next we come to `countlib()' and its allies, which address the |
| 3106 | problem of determining how many liberties a string has. Although |
| 3107 | `countlib()' addresses this basic question, other functions can often |
| 3108 | get the needed information more quickly, so there are a number of |
| 3109 | different functions in this family. |
| 3110 | |
| 3111 | * `int countlib(int str)' |
| 3112 | |
| 3113 | Count the number of liberties of the string at `pos'. There |
| 3114 | must be a stone at this location. |
| 3115 | |
| 3116 | * `int findlib(int str, int maxlib, int *libs)' |
| 3117 | |
| 3118 | Find the liberties of the string at `str'. This location must |
| 3119 | not be empty. The locations of up to maxlib liberties are |
| 3120 | written into `libs[]'. The full number of liberties is |
| 3121 | returned. If you want the locations of all liberties, |
| 3122 | whatever their number, you should pass `MAXLIBS' as the value |
| 3123 | for `maxlib' and allocate space for `libs[]' accordingly. |
| 3124 | |
| 3125 | * `int fastlib(int pos, int color, int ignore_captures)' |
| 3126 | |
| 3127 | Count the liberties a stone of the given color would get if |
| 3128 | played at `pos'. The intent of this function is to be as fast |
| 3129 | as possible, not necessarily complete. But if it returns a |
| 3130 | positive value (meaning it has succeeded), the value is |
| 3131 | guaranteed to be correct. Captures are ignored based if the |
| 3132 | `ignore_captures' field is nonzero. The location `pos' must |
| 3133 | be empty. The function fails if there are more than two |
| 3134 | neighbor strings of the same color. In this case, the return |
| 3135 | value is -1. Captures are handled in a very limited way, so |
| 3136 | if ignore_capture is 0, and a capture is required, it will |
| 3137 | often return -1. |
| 3138 | |
| 3139 | * `int approxlib(int pos, int color, int maxlib, int *libs)' |
| 3140 | |
| 3141 | Find the liberties a stone of the given color would get if |
| 3142 | played at `pos', ignoring possible captures of opponent |
| 3143 | stones. The location `pos' must be empty. If `libs != NULL', |
| 3144 | the locations of up to `maxlib' liberties are written into |
| 3145 | `libs[]'. The counting of liberties may or may not be halted |
| 3146 | when `maxlib' is reached. The number of liberties found is |
| 3147 | returned, which may be less than the total number of |
| 3148 | liberties if `maxlib' is small. If you want the number or the |
| 3149 | locations of all liberties, however many they are, you should |
| 3150 | pass `MAXLIBS' as the value for maxlib and allocate space for |
| 3151 | `libs[]' accordingly. |
| 3152 | |
| 3153 | * `int accuratelib(int pos, int color, int maxlib, int *libs)' |
| 3154 | |
| 3155 | Find the liberties a stone of the given color would get if |
| 3156 | played at `pos'. This function takes into consideration all |
| 3157 | captures. Its return value is exact in that sense it counts |
| 3158 | all the liberties, unless `maxlib' allows it to stop earlier. |
| 3159 | The location `pos' must be empty. If `libs != NULL', the |
| 3160 | locations of up to `maxlib' liberties are written into |
| 3161 | `libs[]'. The counting of liberties may or may not be halted |
| 3162 | when `maxlib' is reached. The number of found liberties is |
| 3163 | returned. This function guarantees that liberties which are |
| 3164 | not results of captures come first in `libs[]' array. To find |
| 3165 | whether all the liberties starting from a given one are |
| 3166 | results of captures, one may use `if (board[libs[k]] != |
| 3167 | EMPTY)' construction. If you want the number or the |
| 3168 | locations of all liberties, however many they are, you should |
| 3169 | pass `MAXLIBS' as the value for `maxlib' and allocate space |
| 3170 | for `libs[]' accordingly. |
| 3171 | |
| 3172 | Next we have some general utility functions. |
| 3173 | |
| 3174 | * `int count_common_libs(int str1, int str2)' |
| 3175 | |
| 3176 | Find the number of common liberties of the two strings. |
| 3177 | |
| 3178 | * `int find_common_libs(int str1, int str2, int maxlib, int *libs)' |
| 3179 | |
| 3180 | Find the common liberties of the two strings. The locations |
| 3181 | of up to `maxlib' common liberties are written into `libs[]'. |
| 3182 | The full number of common liberties is returned. If you want |
| 3183 | the locations of all common liberties, whatever their number, |
| 3184 | you should pass `MAXLIBS' as the value for `maxlib' and |
| 3185 | allocate space for `libs[]' accordingly. |
| 3186 | |
| 3187 | * `int have_common_lib(int str1, int str2, int *lib)' |
| 3188 | |
| 3189 | Determine whether two strings have at least one common |
| 3190 | liberty. If they do and `lib != NULL', one common liberty is |
| 3191 | returned in `*lib'. |
| 3192 | |
| 3193 | * `int countstones(int str)' |
| 3194 | |
| 3195 | Report the number of stones in a string. |
| 3196 | |
| 3197 | * `int findstones(int str, int maxstones, int *stones)' |
| 3198 | |
| 3199 | Find the stones of the string at `str'. The location must not |
| 3200 | be empty. The locations of up to maxstones stones are written |
| 3201 | into `stones[]'. The full number of stones is returned. |
| 3202 | |
| 3203 | * `int chainlinks(int str, int adj[MAXCHAIN])' |
| 3204 | |
| 3205 | This very useful function returns (in the `adj' array) the |
| 3206 | chains surrounding the string at `str'. The number of chains |
| 3207 | is returned. |
| 3208 | |
| 3209 | * `int chainlinks2(int str, int adj[MAXCHAIN], int lib)' |
| 3210 | |
| 3211 | Returns (in `adj' array) those chains surrounding the string |
| 3212 | at `str', which has exactly `lib' liberties. The number of |
| 3213 | such chains is returned. |
| 3214 | |
| 3215 | * `int chainlinks3(int str, int adj[MAXCHAIN], int lib)' |
| 3216 | |
| 3217 | Returns (in `adj' array) the chains surrounding the string at |
| 3218 | `str', which have less or equal `lib' liberties. The number |
| 3219 | of such chains is returned. |
| 3220 | |
| 3221 | * `int extended_chainlinks(int str, int adj[MAXCHAIN], int |
| 3222 | both_colors)' |
| 3223 | |
| 3224 | Returns (in the `adj' array) the opponent strings being |
| 3225 | directly adjacent to `str' or having a common liberty with |
| 3226 | `str'. The number of such strings is returned. If the |
| 3227 | both_colors parameter is true, also own strings sharing a |
| 3228 | liberty are returned. |
| 3229 | |
| 3230 | * `int find_origin(int str)' |
| 3231 | |
| 3232 | Find the origin of a string, i.e. the point with the smallest |
| 3233 | 1D board coordinate. The idea is to have a canonical |
| 3234 | reference point for a string. |
| 3235 | |
| 3236 | * `int is_self_atari(int pos, int color)' |
| 3237 | |
| 3238 | Determine whether a move by color at `pos' would be a self |
| 3239 | atari, i.e. whether it would get more than one liberty. This |
| 3240 | function returns true also for the case of a suicide move. |
| 3241 | |
| 3242 | * `int liberty_of_string(int pos, int str)' |
| 3243 | |
| 3244 | Returns true if `pos' is a liberty of the string at `str'. |
| 3245 | |
| 3246 | * `int second_order_liberty_of_string(int pos, int str)' |
| 3247 | |
| 3248 | Returns true if `pos' is a second order liberty of the string |
| 3249 | at str. |
| 3250 | |
| 3251 | * `int neighbor_of_string(int pos, int str)' |
| 3252 | |
| 3253 | Returns true if `pos' is adjacent to the string at `str'. |
| 3254 | |
| 3255 | * `int has_neighbor(int pos, int color)' |
| 3256 | |
| 3257 | Returns true if `pos' has a neighbor of `color'. |
| 3258 | |
| 3259 | * `int same_string(int str1, int str2)' |
| 3260 | |
| 3261 | Returns true if `str1' and `str2' belong to the same string. |
| 3262 | |
| 3263 | * `int adjacent_strings(int str1, int str2)' |
| 3264 | |
| 3265 | Returns true if the strings at `str1' and `str2' are adjacent. |
| 3266 | |
| 3267 | * `int is_ko(int pos, int color, int *ko_pos)' |
| 3268 | |
| 3269 | Return true if the move `pos' by `color' is a ko capture |
| 3270 | (whether capture is legal on this move or not). If so, and if |
| 3271 | `ko_pos' is not a `NULL' pointer, then `*ko_pos' returns the |
| 3272 | location of the captured ko stone. If the move is not a ko |
| 3273 | capture, `*ko_pos' is set to 0. A move is a ko capture if |
| 3274 | and only if |
| 3275 | 1. All neighbors are opponent stones. |
| 3276 | |
| 3277 | 2. The number of captured stones is exactly one. |
| 3278 | |
| 3279 | * `int is_ko_point(int pos)' |
| 3280 | |
| 3281 | Return true if `pos' is either a stone, which if captured |
| 3282 | would give ko, or if `pos' is an empty intersection adjacent |
| 3283 | to a ko stone. |
| 3284 | |
| 3285 | * `int does_capture_something(int pos, int color)' |
| 3286 | |
| 3287 | Returns 1 if at least one string is captured when color plays |
| 3288 | at `pos'. |
| 3289 | |
| 3290 | * `void mark_string(int str, char mx[BOARDMAX], char mark)' |
| 3291 | |
| 3292 | For each stone in the string at pos, set `mx' to value mark. |
| 3293 | If some of the stones in the string are marked prior to |
| 3294 | calling this function, only the connected unmarked stones |
| 3295 | starting from pos are guaranteed to become marked. The rest |
| 3296 | of the string may or may not become marked. (In the current |
| 3297 | implementation, it will.) |
| 3298 | |
| 3299 | * `int move_in_stack(int pos, int cutoff)' |
| 3300 | |
| 3301 | Returns true if at least one move has been played at pos at |
| 3302 | deeper than level `cutoff' in the reading tree. |
| 3303 | |
| 3304 | * `int stones_on_board(int color)' |
| 3305 | |
| 3306 | Return the number of stones of the indicated color(s) on the |
| 3307 | board. This only counts stones in the permanent position, |
| 3308 | not stones placed by `trymove()' or `tryko()'. Use |
| 3309 | `stones_on_board(BLACK | WHITE)' to get the total number of |
| 3310 | stones on the board. |
| 3311 | |
| 3312 | \1f |
| 3313 | File: gnugo.info, Node: Influence Utilities, Prev: Board Utilities, Up: Utility Functions |
| 3314 | |
| 3315 | 18.4 Utilities from `engine/influence.c' |
| 3316 | ======================================== |
| 3317 | |
| 3318 | We will only list here a portion of the public functions in |
| 3319 | `influence.c'. The influence code is invoked through the function |
| 3320 | `compute_influence' (*note Influence Usage::). It is invoked as follows. |
| 3321 | |
| 3322 | * `void compute_influence(int color, const char |
| 3323 | safe_stones[BOARDMAX], const float strength[BOARDMAX], struct |
| 3324 | influence_data *q, int move, const char *trace_message)' |
| 3325 | |
| 3326 | Compute the influence values for both colors. The caller must |
| 3327 | - set up the `board[]' state |
| 3328 | |
| 3329 | - mark safe stones with `INFLUENCE_SAFE_STONE', dead |
| 3330 | stones with 0 |
| 3331 | |
| 3332 | - mark stones newly saved by a move with |
| 3333 | `INFLUENCE_SAVED_STONE' (this is relevant if the |
| 3334 | influence_data *q is reused to compute a followup value |
| 3335 | for this move). |
| 3336 | Results will be stored in q. `move' has no effects except |
| 3337 | toggling debugging. Set it to -1 for no debug output at all |
| 3338 | (otherwise it will be controlled by the `-m' command line |
| 3339 | option). It is assumed that `color' is in turn to move. (This |
| 3340 | affects the barrier patterns (class A, D) and intrusions |
| 3341 | (class B)). Color |
| 3342 | |
| 3343 | Other functions in `influence.c' are of the nature of utilities |
| 3344 | which may be useful throughout the engine. We list the most useful ones |
| 3345 | here. |
| 3346 | |
| 3347 | * `void influence_mark_non_territory(int pos, int color)' |
| 3348 | |
| 3349 | Called from actions for `t' patterns in `barriers.db'. Marks |
| 3350 | `pos' as not being territory for `color'. |
| 3351 | |
| 3352 | * `int whose_territory(const struct influence_data *q, int pos)' |
| 3353 | |
| 3354 | Return the color of the territory at `pos'. If it's territory |
| 3355 | for neither color, `EMPTY' is returned. |
| 3356 | |
| 3357 | * `int whose_moyo(const struct influence_data *q, int pos)' |
| 3358 | |
| 3359 | Return the color who has a moyo at `pos'. If neither color |
| 3360 | has a moyo there, `EMPTY' is returned. The definition of moyo |
| 3361 | in terms of the influences is totally ad hoc. |
| 3362 | |
| 3363 | * `int whose_area(const struct influence_data *q, int pos)' |
| 3364 | |
| 3365 | Return the color who has dominating influence ("area") at |
| 3366 | `pos'. If neither color dominates the influence there, EMPTY |
| 3367 | is returned. The definition of area in terms of the |
| 3368 | influences is totally ad hoc. |
| 3369 | |
| 3370 | \1f |
| 3371 | File: gnugo.info, Node: GTP, Next: Regression, Prev: API, Up: Top |
| 3372 | |
| 3373 | 19 The Go Text Protocol |
| 3374 | *********************** |
| 3375 | |
| 3376 | * Menu: |
| 3377 | |
| 3378 | * The Go Text Protocol:: The Go Text Protocol |
| 3379 | * Running in GTP mode:: Running GNU Go in GTP mode |
| 3380 | * GTP applications:: GTP applications |
| 3381 | * The Metamachine:: The Metamachine |
| 3382 | * Adding new GTP commands:: Adding new GTP commands |
| 3383 | * GTP command reference:: Details on every GTP command |
| 3384 | |
| 3385 | \1f |
| 3386 | File: gnugo.info, Node: The Go Text Protocol, Next: Running in GTP mode, Up: GTP |
| 3387 | |
| 3388 | 19.1 The Go Text Protocol |
| 3389 | ========================= |
| 3390 | |
| 3391 | GNU Go 3.0 introduced a new interface, the Go Text Protocol, abbreviated |
| 3392 | GTP. The intention was to make an interface that is better suited for |
| 3393 | machine-machine communication than the ascii interface and simpler, more |
| 3394 | powerful, and more flexible than the Go Modem Protocol. |
| 3395 | |
| 3396 | There are two versions of the protocol. Version 1 was used with GNU |
| 3397 | Go 3.0 and 3.2. GNU Go 3.4 and later versions use protocol version 2. |
| 3398 | The specification of GTP version 2 is available at |
| 3399 | `http://www.lysator.liu.se/~gunnar/gtp/'. GNU Go 3.4 is the reference |
| 3400 | implementation for GTP version 2, but all but the most common commands |
| 3401 | are to be regarded as private extensions of the protocol. |
| 3402 | |
| 3403 | The GTP has a variety of applications. For GNU Go the first use was |
| 3404 | in regression testing (*note Regression::), followed by communication |
| 3405 | with the NNGS go server and for automated test games against itself and |
| 3406 | other programs. Now there are also many graphical user interfaces |
| 3407 | available supporting GTP, as well as bridges to other Go servers than |
| 3408 | NNGS. |
| 3409 | |
| 3410 | \1f |
| 3411 | File: gnugo.info, Node: Running in GTP mode, Next: GTP applications, Prev: The Go Text Protocol, Up: GTP |
| 3412 | |
| 3413 | 19.2 Running GNU Go in GTP mode |
| 3414 | =============================== |
| 3415 | |
| 3416 | To start GNU Go in GTP mode, simply invoke it with the option `--mode |
| 3417 | gtp'. You will not get a prompt or any other output to start with but |
| 3418 | GNU Go is silently waiting for GTP commands. |
| 3419 | |
| 3420 | A sample GTP session may look as follows: |
| 3421 | |
| 3422 | virihaure 462% ./gnugo --mode gtp |
| 3423 | 1 boardsize 7 |
| 3424 | =1 |
| 3425 | |
| 3426 | 2 clear_board |
| 3427 | =2 |
| 3428 | |
| 3429 | 3 play black D5 |
| 3430 | =3 |
| 3431 | |
| 3432 | 4 genmove white |
| 3433 | =4 C3 |
| 3434 | |
| 3435 | 5 play black C3 |
| 3436 | ?5 illegal move |
| 3437 | |
| 3438 | 6 play black E3 |
| 3439 | =6 |
| 3440 | |
| 3441 | 7 showboard |
| 3442 | =7 |
| 3443 | A B C D E F G |
| 3444 | 7 . . . . . . . 7 |
| 3445 | 6 . . . . . . . 6 |
| 3446 | 5 . . + X + . . 5 |
| 3447 | 4 . . . + . . . 4 |
| 3448 | 3 . . O . X . . 3 |
| 3449 | 2 . . . . . . . 2 WHITE (O) has captured 0 stones |
| 3450 | 1 . . . . . . . 1 BLACK (X) has captured 0 stones |
| 3451 | A B C D E F G |
| 3452 | |
| 3453 | 8 quit |
| 3454 | =8 |
| 3455 | |
| 3456 | Commands are given on a single line, starting by an optional identity |
| 3457 | number, followed by the command name and its arguments. |
| 3458 | |
| 3459 | If the command is successful, the response starts by an equals sign |
| 3460 | (`='), followed by the identity number of the command (if any) and then |
| 3461 | the result. In this example all results were empty strings except for |
| 3462 | command 4 where the answer was the white move at C3, and command 7 |
| 3463 | where the result was a diagram of the current board position. The |
| 3464 | response ends by two consecutive newlines. |
| 3465 | |
| 3466 | Failing commands are signified by a question mark (`?') instead of |
| 3467 | an equals sign, as in the response to command 5. |
| 3468 | |
| 3469 | The detailed specification of the protocol can be found at |
| 3470 | `http://www.lysator.liu.se/~gunnar/gtp/'. The available commands in GNU |
| 3471 | Go may always be listed using the command `list_commands'. They are |
| 3472 | also documented in *Note GTP command reference::. |
| 3473 | |
| 3474 | \1f |
| 3475 | File: gnugo.info, Node: GTP applications, Next: The Metamachine, Prev: Running in GTP mode, Up: GTP |
| 3476 | |
| 3477 | 19.3 GTP applications |
| 3478 | ===================== |
| 3479 | |
| 3480 | GTP is an asymmetric protocol involving two parties which we call |
| 3481 | controller and engine. The controller sends all commands and the engine |
| 3482 | only responds to these commands. GNU Go implements the engine end of the |
| 3483 | protocol. |
| 3484 | |
| 3485 | With the source code of GNU Go is also distributed a number of |
| 3486 | applications implementing the controller end. Among the most |
| 3487 | interesting of these are: |
| 3488 | |
| 3489 | * `regression/regress.awk' |
| 3490 | |
| 3491 | Script to run regressions. The script sends GTP commands to |
| 3492 | set up and evaluate positions to the engine and then analyzes |
| 3493 | the responses from the engine. More information about GTP |
| 3494 | based regression testing can be found in the regression |
| 3495 | chapter (*note Regression::). |
| 3496 | |
| 3497 | * `regression/regress.pl' |
| 3498 | |
| 3499 | Perl script to run regressions, giving output which together |
| 3500 | with the CGI script `regression/regress.plx' generates HTML |
| 3501 | views of the regressions. |
| 3502 | |
| 3503 | * `regression/regress.pike' |
| 3504 | |
| 3505 | Pike script to run regressions. More feature-rich and |
| 3506 | powerful than `regress.awk'. |
| 3507 | |
| 3508 | * `regression/view.pike' |
| 3509 | |
| 3510 | Pike script to examine a single regression testcase through a |
| 3511 | graphical board. This gives an easy way to inspect many of |
| 3512 | the GNU Go internals. |
| 3513 | |
| 3514 | * `interface/gtp_examples/twogtp' |
| 3515 | |
| 3516 | Perl script to play two engines against each other. The script |
| 3517 | essentially sets up both engines with desired boardsize, |
| 3518 | handicap, and komi, then relays moves back and forth between |
| 3519 | the engines. |
| 3520 | |
| 3521 | * `interface/gtp_examples/twogtp-a' |
| 3522 | |
| 3523 | An alternative Perl implementation of twogtp. |
| 3524 | |
| 3525 | * `interface/gtp_examples/twogtp.py' |
| 3526 | |
| 3527 | Implementation of twogtp in Python. Has more features than |
| 3528 | the Perl variants. |
| 3529 | |
| 3530 | * `interface/gtp_examples/twogtp.pike' |
| 3531 | |
| 3532 | Implementation of twogtp in Pike. Has even more features than |
| 3533 | the Python variant. |
| 3534 | |
| 3535 | * `interface/gtp_examples/2ptkgo.pl' |
| 3536 | |
| 3537 | Variation of twogtp which includes a graphical board. |
| 3538 | |
| 3539 | More GTP applications, including bridges to go servers and graphical |
| 3540 | user interfaces, are listed at `http://www.lysator.liu.se/~gunnar/gtp/'. |
| 3541 | |
| 3542 | \1f |
| 3543 | File: gnugo.info, Node: The Metamachine, Next: Adding new GTP commands, Prev: GTP applications, Up: GTP |
| 3544 | |
| 3545 | 19.4 The Metamachine |
| 3546 | ==================== |
| 3547 | |
| 3548 | An interesting application of the GTP is the concept of using GNU Go as |
| 3549 | an "Oracle" that can be consulted by another process. This could be |
| 3550 | another computer program that asks GNU Go to generate future board |
| 3551 | positions, then evaluate them. |
| 3552 | |
| 3553 | David Doshay at the University of California at Santa Cruz has done |
| 3554 | interesting experiments with a parallel engine, known as SlugGo, that |
| 3555 | is based on GNU Go. These are described in |
| 3556 | `http://lists.gnu.org/archive/html/gnugo-devel/2004-08/msg00060.html'. |
| 3557 | |
| 3558 | The "Metamachine" experiment is a more modest approach using the GTP |
| 3559 | to communicate with a GNU Go process that is used as an oracle. The |
| 3560 | following scheme is used. |
| 3561 | |
| 3562 | * The GNU Go "oracle" is asked to generate its top moves using the |
| 3563 | GTP `top_moves' commands. |
| 3564 | |
| 3565 | * Both moves are tried and `estimate_score' is called from the |
| 3566 | resulting board position. |
| 3567 | |
| 3568 | * The higher scoring position is selected as the engine's move. |
| 3569 | |
| 3570 | This scheme does not produce a stronger engine, but it is |
| 3571 | suggestive, and the SlugGo experiment seems to show that a more |
| 3572 | elaborate scheme along the same lines could produce a stronger engine. |
| 3573 | |
| 3574 | Two implementations are distributed with GNU Go. Both make use of |
| 3575 | `fork' and `pipe' system calls, so they require a Unix-like |
| 3576 | environment. The Metamachine has been tested under GNU/Linux. |
| 3577 | |
| 3578 | *Important:* If the Metamachine terminates normally, the GNU Go |
| 3579 | process will be killed. However there is a danger that something will |
| 3580 | go wrong. When you are finished running the Metamachine, it is a good |
| 3581 | idea to run `ps -A|grep gnugo' or `ps -aux|grep gnugo' to make sure |
| 3582 | there are no unterminated processes. (If there are, just kill them.) |
| 3583 | |
| 3584 | 19.4.1 The Standalone Metamachine |
| 3585 | --------------------------------- |
| 3586 | |
| 3587 | In `interface/gtp_examples/metamachine.c' is a standalone |
| 3588 | implementation of the Metamachine. Compile it with `cc -o metamachine |
| 3589 | metamachine.c' and run it. It forks a `gnugo' process with which it |
| 3590 | communicates through the GTP, to use as an oracle. |
| 3591 | |
| 3592 | The following scheme is followed: |
| 3593 | |
| 3594 | stdin pipe a |
| 3595 | GTP client ----> Metamachine -----> GNU Go |
| 3596 | <---- <----- |
| 3597 | stdout pipe b |
| 3598 | |
| 3599 | Most commands issued by the client are passed along verbatim to GNU |
| 3600 | Go by the Metamachine. The exception is gg_genmove, which is |
| 3601 | intercepted then processed differently, as described above. The client |
| 3602 | is unaware of this, and only knows that it issued a gg_genmove command |
| 3603 | and received a reply. Thus to the the Metamachine appears as an |
| 3604 | ordinary GTP engine. |
| 3605 | |
| 3606 | Usage: no arguments gives normal GTP behavior. `metamachine |
| 3607 | --debug' sends diagnostics to stderr. |
| 3608 | |
| 3609 | 19.4.2 GNU Go as a Metamachine |
| 3610 | ------------------------------ |
| 3611 | |
| 3612 | Alternatively, you may compile GNU Go with the configure option |
| 3613 | `--enable-metamachine'. This causes the file `oracle.c' to be compiled, |
| 3614 | which contains the Metamachine code. This has no effect on the engine |
| 3615 | unless you run GNU Go with the runtime option `--metamachine'. Thus you |
| 3616 | must use both the configure and the runtime option to get the |
| 3617 | Metamachine. |
| 3618 | |
| 3619 | This method is better than the standalone program since you have |
| 3620 | access to GNU Go's facilities. For example, you can run the Metamachine |
| 3621 | with CGoban or in Ascii mode this way. |
| 3622 | |
| 3623 | You can get traces by adding the command line `-d0x1000000'. In |
| 3624 | debugging the Metamachine, a danger is that any small oversight in |
| 3625 | designing the program can cause the forked process and the controller |
| 3626 | to hang, each one waiting for a response from the other. If this seems |
| 3627 | to happen it is useful to know that you can attach `gdb' to a running |
| 3628 | process and find out what it is doing. |
| 3629 | |
| 3630 | \1f |
| 3631 | File: gnugo.info, Node: Adding new GTP commands, Next: GTP command reference, Prev: The Metamachine, Up: GTP |
| 3632 | |
| 3633 | 19.5 Adding new GTP commands |
| 3634 | ============================ |
| 3635 | |
| 3636 | The implementation of GTP in GNU Go is distributed over three files, |
| 3637 | `interface/gtp.h', `interface/gtp.c', and `interface/play_gtp.c'. The |
| 3638 | first two implement a small library of helper functions which can be |
| 3639 | used also by other programs. In the interest of promoting the GTP they |
| 3640 | are licensed with minimal restrictions (*note GTP License::). The |
| 3641 | actual GTP commands are implemented in `play_gtp.c', which has |
| 3642 | knowledge about the engine internals. |
| 3643 | |
| 3644 | To see how a simple but fairly typical command is implemented we |
| 3645 | look at `gtp_countlib()' (a GNU Go private extension command): |
| 3646 | |
| 3647 | static int |
| 3648 | gtp_countlib(char *s) |
| 3649 | { |
| 3650 | int i, j; |
| 3651 | if (!gtp_decode_coord(s, &i, &j)) |
| 3652 | return gtp_failure("invalid coordinate"); |
| 3653 | |
| 3654 | if (BOARD(i, j) == EMPTY) |
| 3655 | return gtp_failure("vertex must not be empty"); |
| 3656 | |
| 3657 | return gtp_success("%d", countlib(POS(i, j))); |
| 3658 | } |
| 3659 | |
| 3660 | The arguments to the command are passed in the string `s'. In this |
| 3661 | case we expect a vertex as argument and thus try to read it with |
| 3662 | `gtp_decode_coord()' from `gtp.c'. |
| 3663 | |
| 3664 | A correctly formatted response should start with either `=' or `?', |
| 3665 | followed by the identity number (if one was sent), the actual result, |
| 3666 | and finally two consecutive newlines. It is important to get this |
| 3667 | formatting correct since the controller in the other end relies on it. |
| 3668 | Naturally the result itself cannot contain two consecutive newlines but |
| 3669 | it may be split over several lines by single newlines. |
| 3670 | |
| 3671 | The easiest way to generate a correctly formatted response is with |
| 3672 | one of the functions `gtp_failure()' and `gtp_success()', assuming that |
| 3673 | their formatted output does not end with a newline. |
| 3674 | |
| 3675 | Sometimes the output is too complex for use with gtp_success, e.g. if |
| 3676 | we want to print vertices, which gtp_success() does not support. Then |
| 3677 | we have to fall back to the construction in e.g. `gtp_genmove()': |
| 3678 | |
| 3679 | static int |
| 3680 | gtp_genmove(char *s) |
| 3681 | { |
| 3682 | [...] |
| 3683 | gtp_start_response(GTP_SUCCESS); |
| 3684 | gtp_print_vertex(i, j); |
| 3685 | return gtp_finish_response(); |
| 3686 | } |
| 3687 | |
| 3688 | Here `gtp_start_response()' writes the equal sign and the identity |
| 3689 | number while `gtp_finish_response()' adds the final two newlines. The |
| 3690 | next example is from `gtp_list_commands()': |
| 3691 | |
| 3692 | static int |
| 3693 | gtp_list_commands(char *s) |
| 3694 | { |
| 3695 | int k; |
| 3696 | UNUSED(s); |
| 3697 | |
| 3698 | gtp_start_response(GTP_SUCCESS); |
| 3699 | |
| 3700 | for (k = 0; commands[k].name != NULL; k++) |
| 3701 | gtp_printf("%s\n", commands[k].name); |
| 3702 | |
| 3703 | gtp_printf("\n"); |
| 3704 | return GTP_OK; |
| 3705 | } |
| 3706 | |
| 3707 | As we have said, the response should be finished with two newlines. |
| 3708 | Here we have to finish up the response ourselves since we already have |
| 3709 | one newline in place from the last command printed in the loop. |
| 3710 | |
| 3711 | In order to add a new GTP command to GNU Go, the following pieces of |
| 3712 | code need to be inserted in `play_gtp.c': |
| 3713 | 1. A function declaration using the `DECLARE' macro in the list |
| 3714 | starting at line 68. |
| 3715 | |
| 3716 | 2. An entry in the `commands[]' array starting at line 200. |
| 3717 | |
| 3718 | 3. An implementation of the function handling the command. |
| 3719 | |
| 3720 | Useful helper functions in `gtp.c'/`gtp.h' are: |
| 3721 | * `gtp_printf()' for basic formatted printing. |
| 3722 | |
| 3723 | * `gtp_mprintf()' for printing with special format codes for |
| 3724 | vertices and colors. |
| 3725 | |
| 3726 | * `gtp_success()' and `gtp_failure()' for simple responses. |
| 3727 | |
| 3728 | * `gtp_start_response()' and `gtp_end_response()' for more complex |
| 3729 | responses. |
| 3730 | |
| 3731 | * `gtp_print_vertex()' and `gtp_print_vertices()' for printing one |
| 3732 | or multiple vertices. |
| 3733 | |
| 3734 | * `gtp_decode_color()' to read in a color from the command arguments. |
| 3735 | |
| 3736 | * `gtp_decode_coord()' to read in a vertex from the command |
| 3737 | arguments. |
| 3738 | |
| 3739 | * `gtp_decode_move()' to read in a move, i.e. color plus vertex, |
| 3740 | from the command arguments. |
| 3741 | |
| 3742 | \1f |
| 3743 | File: gnugo.info, Node: GTP command reference, Prev: Adding new GTP commands, Up: GTP |
| 3744 | |
| 3745 | 19.6 GTP command reference |
| 3746 | ========================== |
| 3747 | |
| 3748 | This section lists the GTP commands implemented in GNU Go along with |
| 3749 | some information about each command. Each entry in the list has the |
| 3750 | following fields: |
| 3751 | |
| 3752 | * Function: What this command does. |
| 3753 | |
| 3754 | * Arguments: What other information, if any, this command requires. |
| 3755 | Typical values include "none" or "vertex" or "integer" (there are |
| 3756 | others). |
| 3757 | |
| 3758 | * Fails: Circumstances which cause this command to fail. |
| 3759 | |
| 3760 | * Returns: What is displayed after the "=" and before the two |
| 3761 | newlines. Typical values include "nothing" or "a move coordinate" |
| 3762 | or some status string (there are others). |
| 3763 | |
| 3764 | * Status: How this command relates to the standard GTP version 2 |
| 3765 | commands. If nothing else is specified it is a GNU Go private |
| 3766 | extension. |
| 3767 | |
| 3768 | Without further ado, here is the big list (in no particular order). |
| 3769 | |
| 3770 | Note: if new commands are added by editing `interface/play_gtp.c' |
| 3771 | this list could become incomplete. You may rebuild this list in |
| 3772 | `doc/gtp-commands.texi' with the command `make gtp-commands' in the |
| 3773 | `doc/' directory. This may require GNU sed. |
| 3774 | |
| 3775 | * quit: Quit |
| 3776 | Arguments: none |
| 3777 | Fails: never |
| 3778 | Returns: nothing |
| 3779 | |
| 3780 | Status: GTP version 2 standard command. |
| 3781 | |
| 3782 | |
| 3783 | * protocol_version: Report protocol version. |
| 3784 | Arguments: none |
| 3785 | Fails: never |
| 3786 | Returns: protocol version number |
| 3787 | |
| 3788 | Status: GTP version 2 standard command. |
| 3789 | |
| 3790 | |
| 3791 | * name: Report the name of the program. |
| 3792 | Arguments: none |
| 3793 | Fails: never |
| 3794 | Returns: program name |
| 3795 | |
| 3796 | Status: GTP version 2 standard command. |
| 3797 | |
| 3798 | |
| 3799 | * version: Report the version number of the program. |
| 3800 | Arguments: none |
| 3801 | Fails: never |
| 3802 | Returns: version number |
| 3803 | |
| 3804 | Status: GTP version 2 standard command. |
| 3805 | |
| 3806 | |
| 3807 | * boardsize: Set the board size to NxN and clear the board. |
| 3808 | Arguments: integer |
| 3809 | Fails: board size outside engine's limits |
| 3810 | Returns: nothing |
| 3811 | |
| 3812 | Status: GTP version 2 standard command. |
| 3813 | |
| 3814 | |
| 3815 | * query_boardsize: Find the current boardsize |
| 3816 | Arguments: none |
| 3817 | Fails: never |
| 3818 | Returns: board_size |
| 3819 | |
| 3820 | |
| 3821 | * clear_board: Clear the board. |
| 3822 | Arguments: none |
| 3823 | Fails: never |
| 3824 | Returns: nothing |
| 3825 | |
| 3826 | Status: GTP version 2 standard command. |
| 3827 | |
| 3828 | |
| 3829 | * orientation: Set the orienation to N and clear the board |
| 3830 | Arguments: integer |
| 3831 | Fails: illegal orientation |
| 3832 | Returns: nothing |
| 3833 | |
| 3834 | |
| 3835 | * query_orientation: Find the current orientation |
| 3836 | Arguments: none |
| 3837 | Fails: never |
| 3838 | Returns: orientation |
| 3839 | |
| 3840 | |
| 3841 | * komi: Set the komi. |
| 3842 | Arguments: float |
| 3843 | Fails: incorrect argument |
| 3844 | Returns: nothing |
| 3845 | |
| 3846 | Status: GTP version 2 standard command. |
| 3847 | |
| 3848 | |
| 3849 | * get_komi: Get the komi |
| 3850 | Arguments: none |
| 3851 | Fails: never |
| 3852 | Returns: Komi |
| 3853 | |
| 3854 | |
| 3855 | * black: Play a black stone at the given vertex. |
| 3856 | Arguments: vertex |
| 3857 | Fails: invalid vertex, illegal move |
| 3858 | Returns: nothing |
| 3859 | |
| 3860 | Status: Obsolete GTP version 1 command. |
| 3861 | |
| 3862 | |
| 3863 | * playwhite: Play a white stone at the given vertex. |
| 3864 | Arguments: vertex |
| 3865 | Fails: invalid vertex, illegal move |
| 3866 | Returns: nothing |
| 3867 | |
| 3868 | Status: Obsolete GTP version 1 command. |
| 3869 | |
| 3870 | |
| 3871 | * play: Play a stone of the given color at the given vertex. |
| 3872 | Arguments: color, vertex |
| 3873 | Fails: invalid vertex, illegal move |
| 3874 | Returns: nothing |
| 3875 | |
| 3876 | Status: GTP version 2 standard command. |
| 3877 | |
| 3878 | |
| 3879 | * fixed_handicap: Set up fixed placement handicap stones. |
| 3880 | Arguments: number of handicap stones |
| 3881 | Fails: invalid number of stones for the current boardsize |
| 3882 | Returns: list of vertices with handicap stones |
| 3883 | |
| 3884 | Status: GTP version 2 standard command. |
| 3885 | |
| 3886 | |
| 3887 | * place_free_handicap: Choose free placement handicap stones and put |
| 3888 | them on the board. |
| 3889 | Arguments: number of handicap stones |
| 3890 | Fails: invalid number of stones |
| 3891 | Returns: list of vertices with handicap stones |
| 3892 | |
| 3893 | Status: GTP version 2 standard command. |
| 3894 | |
| 3895 | |
| 3896 | * set_free_handicap: Put free placement handicap stones on the board. |
| 3897 | Arguments: list of vertices with handicap stones |
| 3898 | Fails: board not empty, bad list of vertices |
| 3899 | Returns: nothing |
| 3900 | |
| 3901 | Status: GTP version 2 standard command. |
| 3902 | |
| 3903 | |
| 3904 | * get_handicap: Get the handicap |
| 3905 | Arguments: none |
| 3906 | Fails: never |
| 3907 | Returns: handicap |
| 3908 | |
| 3909 | |
| 3910 | * loadsgf: Load an sgf file, possibly up to a move number or the |
| 3911 | first occurence of a move. |
| 3912 | Arguments: filename + move number, vertex, or nothing |
| 3913 | Fails: missing filename or failure to open or parse file |
| 3914 | Returns: color to play |
| 3915 | |
| 3916 | Status: GTP version 2 standard command. |
| 3917 | |
| 3918 | |
| 3919 | * color: Return the color at a vertex. |
| 3920 | Arguments: vertex |
| 3921 | Fails: invalid vertex |
| 3922 | Returns: "black", "white", or "empty" |
| 3923 | |
| 3924 | |
| 3925 | * list_stones: List vertices with either black or white stones. |
| 3926 | Arguments: color |
| 3927 | Fails: invalid color |
| 3928 | Returns: list of vertices |
| 3929 | |
| 3930 | |
| 3931 | * countlib: Count number of liberties for the string at a vertex. |
| 3932 | Arguments: vertex |
| 3933 | Fails: invalid vertex, empty vertex |
| 3934 | Returns: Number of liberties. |
| 3935 | |
| 3936 | |
| 3937 | * findlib: Return the positions of the liberties for the string at a |
| 3938 | vertex. |
| 3939 | Arguments: vertex |
| 3940 | Fails: invalid vertex, empty vertex |
| 3941 | Returns: Sorted space separated list of vertices. |
| 3942 | |
| 3943 | |
| 3944 | * accuratelib: Determine which liberties a stone of given color will |
| 3945 | get if played at given vertex. |
| 3946 | Arguments: move (color + vertex) |
| 3947 | Fails: invalid color, invalid vertex, occupied vertex |
| 3948 | Returns: Sorted space separated list of liberties |
| 3949 | |
| 3950 | |
| 3951 | * accurate_approxlib: Determine which liberties a stone of given |
| 3952 | color will get if played at given vertex. |
| 3953 | Arguments: move (color + vertex) |
| 3954 | Fails: invalid color, invalid vertex, occupied vertex |
| 3955 | Returns: Sorted space separated list of liberties |
| 3956 | |
| 3957 | Supposedly identical in behavior to the above function and |
| 3958 | can be retired when this is confirmed. |
| 3959 | |
| 3960 | |
| 3961 | * is_legal: Tell whether a move is legal. |
| 3962 | Arguments: move |
| 3963 | Fails: invalid move |
| 3964 | Returns: 1 if the move is legal, 0 if it is not. |
| 3965 | |
| 3966 | |
| 3967 | * all_legal: List all legal moves for either color. |
| 3968 | Arguments: color |
| 3969 | Fails: invalid color |
| 3970 | Returns: Sorted space separated list of vertices. |
| 3971 | |
| 3972 | |
| 3973 | * captures: List the number of captures taken by either color. |
| 3974 | Arguments: color |
| 3975 | Fails: invalid color |
| 3976 | Returns: Number of captures. |
| 3977 | |
| 3978 | |
| 3979 | * last_move: Return the last move. |
| 3980 | Arguments: none |
| 3981 | Fails: no previous move known |
| 3982 | Returns: Color and vertex of last move. |
| 3983 | |
| 3984 | |
| 3985 | * move_history: Print the move history in reverse order |
| 3986 | Arguments: none |
| 3987 | Fails: never |
| 3988 | Returns: List of moves played in reverse order in format: |
| 3989 | color move (one move per line) |
| 3990 | |
| 3991 | |
| 3992 | * invariant_hash: Return the rotation/reflection invariant board |
| 3993 | hash. |
| 3994 | Arguments: none |
| 3995 | Fails: never |
| 3996 | Returns: Invariant hash for the board as a hexadecimal number. |
| 3997 | |
| 3998 | |
| 3999 | * invariant_hash_for_moves: Return the rotation/reflection invariant |
| 4000 | board hash obtained by playing all the possible moves for the |
| 4001 | given color. |
| 4002 | Arguments: color |
| 4003 | Fails: invalid color |
| 4004 | Returns: List of moves + invariant hash as a hexadecimal number, |
| 4005 | one pair of move + hash per line. |
| 4006 | |
| 4007 | |
| 4008 | * trymove: Play a stone of the given color at the given vertex. |
| 4009 | Arguments: move (color + vertex) |
| 4010 | Fails: invalid color, invalid vertex, illegal move |
| 4011 | Returns: nothing |
| 4012 | |
| 4013 | |
| 4014 | * tryko: Play a stone of the given color at the given vertex, |
| 4015 | allowing illegal ko capture. |
| 4016 | Arguments: move (color + vertex) |
| 4017 | Fails: invalid color, invalid vertex, illegal move |
| 4018 | Returns: nothing |
| 4019 | |
| 4020 | |
| 4021 | * popgo: Undo a trymove or tryko. |
| 4022 | Arguments: none |
| 4023 | Fails: stack empty |
| 4024 | Returns: nothing |
| 4025 | |
| 4026 | * clear_cache: clear the caches. |
| 4027 | Arguments: none. |
| 4028 | Fails: never. |
| 4029 | Returns: nothing. |
| 4030 | |
| 4031 | |
| 4032 | * attack: Try to attack a string. |
| 4033 | Arguments: vertex |
| 4034 | Fails: invalid vertex, empty vertex |
| 4035 | Returns: attack code followed by attack point if attack code nonzero. |
| 4036 | |
| 4037 | |
| 4038 | * attack_either: Try to attack either of two strings |
| 4039 | Arguments: two vertices |
| 4040 | Fails: invalid vertex, empty vertex |
| 4041 | Returns: attack code against the strings. Guarantees there |
| 4042 | exists a move which will attack one of the two |
| 4043 | with attack_code, but does not return the move. |
| 4044 | |
| 4045 | |
| 4046 | * defend: Try to defend a string. |
| 4047 | Arguments: vertex |
| 4048 | Fails: invalid vertex, empty vertex |
| 4049 | Returns: defense code followed by defense point if defense code nonzero. |
| 4050 | |
| 4051 | |
| 4052 | * does_attack: Examine whether a specific move attacks a string |
| 4053 | tactically. |
| 4054 | Arguments: vertex (move), vertex (dragon) |
| 4055 | Fails: invalid vertex, empty vertex |
| 4056 | Returns: attack code |
| 4057 | |
| 4058 | |
| 4059 | * does_defend: Examine whether a specific move defends a string |
| 4060 | tactically. |
| 4061 | Arguments: vertex (move), vertex (dragon) |
| 4062 | Fails: invalid vertex, empty vertex |
| 4063 | Returns: attack code |
| 4064 | |
| 4065 | |
| 4066 | * ladder_attack: Try to attack a string strictly in a ladder. |
| 4067 | Arguments: vertex |
| 4068 | Fails: invalid vertex, empty vertex |
| 4069 | Returns: attack code followed by attack point if attack code nonzero. |
| 4070 | |
| 4071 | |
| 4072 | * increase_depths: Increase depth values by one. |
| 4073 | Arguments: none |
| 4074 | Fails: never |
| 4075 | Returns: nothing |
| 4076 | |
| 4077 | |
| 4078 | * decrease_depths: Decrease depth values by one. |
| 4079 | Arguments: none |
| 4080 | Fails: never |
| 4081 | Returns: nothing |
| 4082 | |
| 4083 | |
| 4084 | * owl_attack: Try to attack a dragon. |
| 4085 | Arguments: vertex |
| 4086 | Fails: invalid vertex, empty vertex |
| 4087 | Returns: attack code followed by attack point if attack code nonzero. |
| 4088 | |
| 4089 | |
| 4090 | * owl_defend: Try to defend a dragon. |
| 4091 | Arguments: vertex |
| 4092 | Fails: invalid vertex, empty vertex |
| 4093 | Returns: defense code followed by defense point if defense code nonzero. |
| 4094 | |
| 4095 | |
| 4096 | * owl_threaten_attack: Try to attack a dragon in 2 moves. |
| 4097 | Arguments: vertex |
| 4098 | Fails: invalid vertex, empty vertex |
| 4099 | Returns: attack code followed by the two attack points if |
| 4100 | attack code nonzero. |
| 4101 | |
| 4102 | |
| 4103 | * owl_threaten_defense: Try to defend a dragon with 2 moves. |
| 4104 | Arguments: vertex |
| 4105 | Fails: invalid vertex, empty vertex |
| 4106 | Returns: defense code followed by the 2 defense points if |
| 4107 | defense code nonzero. |
| 4108 | |
| 4109 | |
| 4110 | * owl_does_attack: Examine whether a specific move attacks a dragon. |
| 4111 | Arguments: vertex (move), vertex (dragon) |
| 4112 | Fails: invalid vertex, empty vertex |
| 4113 | Returns: attack code |
| 4114 | |
| 4115 | |
| 4116 | * owl_does_defend: Examine whether a specific move defends a dragon. |
| 4117 | Arguments: vertex (move), vertex (dragon) |
| 4118 | Fails: invalid vertex, empty vertex |
| 4119 | Returns: defense code |
| 4120 | |
| 4121 | |
| 4122 | * owl_connection_defends: Examine whether a connection defends |
| 4123 | involved dragons. |
| 4124 | Arguments: vertex (move), vertex (dragon1), vertex (dragon2) |
| 4125 | Fails: invalid vertex, empty vertex |
| 4126 | Returns: defense code |
| 4127 | |
| 4128 | |
| 4129 | * defend_both: Try to defend both of two strings |
| 4130 | Arguments: two vertices |
| 4131 | Fails: invalid vertex, empty vertex |
| 4132 | Returns: defend code for the strings. Guarantees there |
| 4133 | exists a move which will defend both of the two |
| 4134 | with defend_code, but does not return the move. |
| 4135 | |
| 4136 | |
| 4137 | * owl_substantial: Determine whether capturing a string gives a |
| 4138 | living dragon |
| 4139 | Arguments: vertex |
| 4140 | Fails: invalid vertex, empty vertex |
| 4141 | Returns: 1 if dragon can live, 0 otherwise |
| 4142 | |
| 4143 | |
| 4144 | * analyze_semeai: Analyze a semeai |
| 4145 | Arguments: dragona, dragonb |
| 4146 | Fails: invalid vertices, empty vertices |
| 4147 | Returns: semeai defense result, semeai attack result, semeai move |
| 4148 | |
| 4149 | |
| 4150 | * analyze_semeai_after_move: Analyze a semeai after a move have been |
| 4151 | made. |
| 4152 | Arguments: color, vertex, dragona, dragonb |
| 4153 | Fails: invalid vertices |
| 4154 | Returns: semeai defense result, semeai attack result, semeai move |
| 4155 | |
| 4156 | |
| 4157 | * tactical_analyze_semeai: Analyze a semeai, not using owl |
| 4158 | Arguments: dragona, dragonb |
| 4159 | Fails: invalid vertices, empty vertices |
| 4160 | Returns: status of dragona, dragonb assuming dragona moves first |
| 4161 | |
| 4162 | |
| 4163 | * connect: Try to connect two strings. |
| 4164 | Arguments: vertex, vertex |
| 4165 | Fails: invalid vertex, empty vertex, vertices of different colors |
| 4166 | Returns: connect result followed by connect point if successful. |
| 4167 | |
| 4168 | |
| 4169 | * disconnect: Try to disconnect two strings. |
| 4170 | Arguments: vertex, vertex |
| 4171 | Fails: invalid vertex, empty vertex, vertices of different colors |
| 4172 | Returns: disconnect result followed by disconnect point if successful. |
| 4173 | |
| 4174 | |
| 4175 | * break_in: Try to break from string into area. |
| 4176 | Arguments: vertex, vertices |
| 4177 | Fails: invalid vertex, empty vertex. |
| 4178 | Returns: result followed by break in point if successful. |
| 4179 | |
| 4180 | |
| 4181 | * block_off: Try to block string from area. |
| 4182 | Arguments: vertex, vertices |
| 4183 | Fails: invalid vertex, empty vertex. |
| 4184 | Returns: result followed by block point if successful. |
| 4185 | |
| 4186 | * eval_eye: Evaluate an eye space |
| 4187 | Arguments: vertex |
| 4188 | Fails: invalid vertex |
| 4189 | Returns: Minimum and maximum number of eyes. If these differ an |
| 4190 | attack and a defense point are additionally returned. |
| 4191 | If the vertex is not an eye space or not of unique color, |
| 4192 | a single -1 is returned. |
| 4193 | |
| 4194 | * dragon_status: Determine status of a dragon. |
| 4195 | Arguments: optional vertex |
| 4196 | Fails: invalid vertex, empty vertex |
| 4197 | Returns: status ("alive", "critical", "dead", or "unknown"), |
| 4198 | attack point, defense point. Points of attack and |
| 4199 | defense are only given if the status is critical. |
| 4200 | If no vertex is given, the status is listed for all |
| 4201 | dragons, one per row in the format "A4: alive". |
| 4202 | |
| 4203 | FIXME: Should be able to distinguish between life in seki |
| 4204 | and independent life. Should also be able to identify ko. |
| 4205 | |
| 4206 | * same_dragon: Determine whether two stones belong to the same |
| 4207 | dragon. |
| 4208 | Arguments: vertex, vertex |
| 4209 | Fails: invalid vertex, empty vertex |
| 4210 | Returns: 1 if the vertices belong to the same dragon, 0 otherwise |
| 4211 | |
| 4212 | * unconditional_status: Determine the unconditional status of a |
| 4213 | vertex. |
| 4214 | Arguments: vertex |
| 4215 | Fails: invalid vertex |
| 4216 | Returns: unconditional status ("undecided", "alive", "dead", |
| 4217 | "white_territory", "black_territory"). Occupied vertices can |
| 4218 | be undecided, alive, or dead. Empty vertices can be |
| 4219 | undecided, white territory, or black territory. |
| 4220 | |
| 4221 | * combination_attack: Find a move by color capturing something |
| 4222 | through a combination attack. |
| 4223 | Arguments: color |
| 4224 | Fails: invalid color |
| 4225 | Returns: Recommended move, PASS if no move found |
| 4226 | |
| 4227 | * combination_defend: If color can capture something through a |
| 4228 | combination attack, list moves by the opponent of color |
| 4229 | to defend against this attack. |
| 4230 | Arguments: color |
| 4231 | Fails: invalid color |
| 4232 | Returns: Recommended moves, PASS if no combination attack found. |
| 4233 | |
| 4234 | * aa_confirm_safety: Run atari_atari_confirm_safety(). |
| 4235 | Arguments: move, optional int |
| 4236 | Fails: invalid move |
| 4237 | Returns: success code, if failure also defending move |
| 4238 | |
| 4239 | |
| 4240 | * genmove_black: Generate and play the supposedly best black move. |
| 4241 | Arguments: none |
| 4242 | Fails: never |
| 4243 | Returns: a move coordinate or "PASS" |
| 4244 | |
| 4245 | Status: Obsolete GTP version 1 command. |
| 4246 | |
| 4247 | |
| 4248 | * genmove_white: Generate and play the supposedly best white move. |
| 4249 | Arguments: none |
| 4250 | Fails: never |
| 4251 | Returns: a move coordinate or "PASS" |
| 4252 | |
| 4253 | Status: Obsolete GTP version 1 command. |
| 4254 | |
| 4255 | |
| 4256 | * genmove: Generate and play the supposedly best move for either |
| 4257 | color. |
| 4258 | Arguments: color to move |
| 4259 | Fails: invalid color |
| 4260 | Returns: a move coordinate or "PASS" (or "resign" if resignation_allowed) |
| 4261 | |
| 4262 | Status: GTP version 2 standard command. |
| 4263 | |
| 4264 | |
| 4265 | * reg_genmove: Generate the supposedly best move for either color. |
| 4266 | Arguments: color to move |
| 4267 | Fails: invalid color |
| 4268 | Returns: a move coordinate (or "PASS") |
| 4269 | |
| 4270 | Status: GTP version 2 standard command. |
| 4271 | |
| 4272 | |
| 4273 | * gg_genmove: Generate the supposedly best move for either color. |
| 4274 | Arguments: color to move, optionally a random seed |
| 4275 | Fails: invalid color |
| 4276 | Returns: a move coordinate (or "PASS") |
| 4277 | |
| 4278 | This differs from reg_genmove in the optional random seed. |
| 4279 | |
| 4280 | |
| 4281 | * restricted_genmove: Generate the supposedly best move for either |
| 4282 | color from a choice of allowed vertices. |
| 4283 | Arguments: color to move, allowed vertices |
| 4284 | Fails: invalid color, invalid vertex, no vertex listed |
| 4285 | Returns: a move coordinate (or "PASS") |
| 4286 | |
| 4287 | |
| 4288 | * kgs-genmove_cleanup: Generate and play the supposedly best move |
| 4289 | for either color, not passing until all dead opponent stones have |
| 4290 | been removed. |
| 4291 | Arguments: color to move |
| 4292 | Fails: invalid color |
| 4293 | Returns: a move coordinate (or "PASS") |
| 4294 | |
| 4295 | Status: KGS specific command. |
| 4296 | |
| 4297 | A similar command, but possibly somewhat different, will likely be added |
| 4298 | to GTP version 3 at a later time. |
| 4299 | |
| 4300 | |
| 4301 | * level: Set the playing level. |
| 4302 | Arguments: int |
| 4303 | Fails: incorrect argument |
| 4304 | Returns: nothing |
| 4305 | |
| 4306 | * undo: Undo one move |
| 4307 | Arguments: none |
| 4308 | Fails: If move history is too short. |
| 4309 | Returns: nothing |
| 4310 | |
| 4311 | Status: GTP version 2 standard command. |
| 4312 | |
| 4313 | * gg-undo: Undo a number of moves |
| 4314 | Arguments: optional int |
| 4315 | Fails: If move history is too short. |
| 4316 | Returns: nothing |
| 4317 | |
| 4318 | * time_settings: Set time allowance |
| 4319 | Arguments: int main_time, int byo_yomi_time, int byo_yomi_stones |
| 4320 | Fails: syntax error |
| 4321 | Returns: nothing |
| 4322 | |
| 4323 | Status: GTP version 2 standard command. |
| 4324 | |
| 4325 | * time_left: Report remaining time |
| 4326 | Arguments: color color, int time, int stones |
| 4327 | Fails: syntax error |
| 4328 | Returns: nothing |
| 4329 | |
| 4330 | Status: GTP version 2 standard command. |
| 4331 | |
| 4332 | |
| 4333 | * final_score: Compute the score of a finished game. |
| 4334 | Arguments: Optional random seed |
| 4335 | Fails: never |
| 4336 | Returns: Score in SGF format (RE property). |
| 4337 | |
| 4338 | Status: GTP version 2 standard command. |
| 4339 | |
| 4340 | |
| 4341 | * final_status: Report the final status of a vertex in a finished |
| 4342 | game. |
| 4343 | Arguments: Vertex, optional random seed |
| 4344 | Fails: invalid vertex |
| 4345 | Returns: Status in the form of one of the strings "alive", "dead", |
| 4346 | "seki", "white_territory", "black_territory", or "dame". |
| 4347 | |
| 4348 | |
| 4349 | * final_status_list: Report vertices with a specific final status in |
| 4350 | a finished game. |
| 4351 | Arguments: Status in the form of one of the strings "alive", "dead", |
| 4352 | "seki", "white_territory", "black_territory", or "dame". |
| 4353 | An optional random seed can be added. |
| 4354 | Fails: missing or invalid status string |
| 4355 | Returns: Vertices having the specified status. These are split with |
| 4356 | one string on each line if the vertices are nonempty (i.e. |
| 4357 | for "alive", "dead", and "seki"). |
| 4358 | |
| 4359 | Status: GTP version 2 standard command. |
| 4360 | However, "dame", "white_territory", and "black_territory" |
| 4361 | are private extensions. |
| 4362 | |
| 4363 | * estimate_score: Estimate the score |
| 4364 | Arguments: None |
| 4365 | Fails: never |
| 4366 | Returns: upper and lower bounds for the score |
| 4367 | |
| 4368 | * experimental_score: Estimate the score, taking into account which |
| 4369 | player moves next |
| 4370 | Arguments: Color to play |
| 4371 | Fails: Invalid color |
| 4372 | Returns: Score. |
| 4373 | |
| 4374 | This function generates a move for color, then adds the |
| 4375 | value of the move generated to the value of the position. |
| 4376 | Critical dragons are awarded to the opponent since the |
| 4377 | value of rescuing a critical dragon is taken into account |
| 4378 | in the value of the move generated. |
| 4379 | |
| 4380 | |
| 4381 | * reset_life_node_counter: Reset the count of life nodes. |
| 4382 | Arguments: none |
| 4383 | Fails: never |
| 4384 | Returns: nothing |
| 4385 | |
| 4386 | Note: This function is obsolete and only remains for backwards |
| 4387 | compatibility. |
| 4388 | |
| 4389 | |
| 4390 | * get_life_node_counter: Retrieve the count of life nodes. |
| 4391 | Arguments: none |
| 4392 | Fails: never |
| 4393 | Returns: number of life nodes |
| 4394 | |
| 4395 | Note: This function is obsolete and only remains for backwards |
| 4396 | compatibility. |
| 4397 | |
| 4398 | |
| 4399 | * reset_owl_node_counter: Reset the count of owl nodes. |
| 4400 | Arguments: none |
| 4401 | Fails: never |
| 4402 | Returns: nothing |
| 4403 | |
| 4404 | |
| 4405 | * get_owl_node_counter: Retrieve the count of owl nodes. |
| 4406 | Arguments: none |
| 4407 | Fails: never |
| 4408 | Returns: number of owl nodes |
| 4409 | |
| 4410 | |
| 4411 | * reset_reading_node_counter: Reset the count of reading nodes. |
| 4412 | Arguments: none |
| 4413 | Fails: never |
| 4414 | Returns: nothing |
| 4415 | |
| 4416 | |
| 4417 | * get_reading_node_counter: Retrieve the count of reading nodes. |
| 4418 | Arguments: none |
| 4419 | Fails: never |
| 4420 | Returns: number of reading nodes |
| 4421 | |
| 4422 | |
| 4423 | * reset_trymove_counter: Reset the count of trymoves/trykos. |
| 4424 | Arguments: none |
| 4425 | Fails: never |
| 4426 | Returns: nothing |
| 4427 | |
| 4428 | |
| 4429 | * get_trymove_counter: Retrieve the count of trymoves/trykos. |
| 4430 | Arguments: none |
| 4431 | Fails: never |
| 4432 | Returns: number of trymoves/trykos |
| 4433 | |
| 4434 | |
| 4435 | * reset_connection_node_counter: Reset the count of connection nodes. |
| 4436 | Arguments: none |
| 4437 | Fails: never |
| 4438 | Returns: nothing |
| 4439 | |
| 4440 | |
| 4441 | * get_connection_node_counter: Retrieve the count of connection |
| 4442 | nodes. |
| 4443 | Arguments: none |
| 4444 | Fails: never |
| 4445 | Returns: number of connection nodes |
| 4446 | |
| 4447 | |
| 4448 | * test_eyeshape: Test an eyeshape for inconsistent evaluations |
| 4449 | Arguments: Eyeshape vertices |
| 4450 | Fails: Bad vertices |
| 4451 | Returns: Failure reports on stderr. |
| 4452 | |
| 4453 | |
| 4454 | * analyze_eyegraph: Compute an eyevalue and vital points for an eye |
| 4455 | graph |
| 4456 | Arguments: Eyeshape encoded in string |
| 4457 | Fails: Bad eyeshape, analysis failed |
| 4458 | Returns: Eyevalue, vital points |
| 4459 | |
| 4460 | |
| 4461 | * cputime: Returns elapsed CPU time in seconds. |
| 4462 | Arguments: none |
| 4463 | Fails: never |
| 4464 | Returns: Total elapsed (user + system) CPU time in seconds. |
| 4465 | |
| 4466 | |
| 4467 | * showboard: Write the position to stdout. |
| 4468 | Arguments: none |
| 4469 | Fails: never |
| 4470 | Returns: nothing |
| 4471 | |
| 4472 | Status: GTP version 2 standard command. |
| 4473 | |
| 4474 | |
| 4475 | * dump_stack: Dump stack to stderr. |
| 4476 | Arguments: none |
| 4477 | Fails: never |
| 4478 | Returns: nothing |
| 4479 | |
| 4480 | |
| 4481 | * initial_influence: Return information about the initial influence |
| 4482 | function. |
| 4483 | Arguments: color to move, what information |
| 4484 | Fails: never |
| 4485 | Returns: Influence data formatted like: |
| 4486 | |
| 4487 | 0.51 1.34 3.20 6.60 9.09 8.06 1.96 0.00 0.00 |
| 4488 | 0.45 1.65 4.92 12.19 17.47 15.92 4.03 0.00 0.00 |
| 4489 | . |
| 4490 | . |
| 4491 | . |
| 4492 | 0.00 0.00 0.00 0.00 0.00 100.00 75.53 41.47 23.41 |
| 4493 | |
| 4494 | The available choices of information are: |
| 4495 | |
| 4496 | white_influence (float) |
| 4497 | black_influence (float) |
| 4498 | white_strength (float) |
| 4499 | black_strength (float) |
| 4500 | white_attenuation (float) |
| 4501 | black_attenuation (float) |
| 4502 | white_permeability (float) |
| 4503 | black_permeability (float) |
| 4504 | territory_value (float) |
| 4505 | influence_regions (int) |
| 4506 | non_territory (int) |
| 4507 | |
| 4508 | The encoding of influence_regions is as follows: |
| 4509 | 4 white stone |
| 4510 | 3 white territory |
| 4511 | 2 white moyo |
| 4512 | 1 white area |
| 4513 | 0 neutral |
| 4514 | -1 black area |
| 4515 | -2 black moyo |
| 4516 | -3 black territory |
| 4517 | -4 black stone |
| 4518 | |
| 4519 | |
| 4520 | * move_influence: Return information about the influence function |
| 4521 | after a move. |
| 4522 | Arguments: move, what information |
| 4523 | Fails: never |
| 4524 | Returns: Influence data formatted like for initial_influence. |
| 4525 | |
| 4526 | |
| 4527 | * move_probabilities: List probabilities of each move being played |
| 4528 | (when non-zero). If no previous genmove command has been issued, |
| 4529 | the result of this command will be meaningless. |
| 4530 | Arguments: none |
| 4531 | Fails: never |
| 4532 | Returns: Move, probabilty pairs, one per row. |
| 4533 | |
| 4534 | |
| 4535 | * move_uncertainty: Return the number of bits of uncertainty in the |
| 4536 | move. If no previous genmove command has been issued, the result |
| 4537 | of this command will be meaningless. |
| 4538 | Arguments: none |
| 4539 | Fails: never |
| 4540 | Returns: bits of uncertainty |
| 4541 | |
| 4542 | |
| 4543 | * followup_influence: Return information about the followup |
| 4544 | influence after a move. |
| 4545 | Arguments: move, what information |
| 4546 | Fails: never |
| 4547 | Returns: Influence data formatted like for initial_influence. |
| 4548 | |
| 4549 | |
| 4550 | * worm_data: Return the information in the worm data structure. |
| 4551 | Arguments: optional vertex |
| 4552 | Fails: never |
| 4553 | Returns: Worm data formatted like: |
| 4554 | |
| 4555 | A19: |
| 4556 | color black |
| 4557 | size 10 |
| 4558 | effective_size 17.83 |
| 4559 | origin A19 |
| 4560 | liberties 8 |
| 4561 | liberties2 15 |
| 4562 | liberties3 10 |
| 4563 | liberties4 8 |
| 4564 | attack PASS |
| 4565 | attack_code 0 |
| 4566 | lunch B19 |
| 4567 | defend PASS |
| 4568 | defend_code 0 |
| 4569 | cutstone 2 |
| 4570 | cutstone2 0 |
| 4571 | genus 0 |
| 4572 | inessential 0 |
| 4573 | B19: |
| 4574 | color white |
| 4575 | . |
| 4576 | . |
| 4577 | . |
| 4578 | inessential 0 |
| 4579 | C19: |
| 4580 | ... |
| 4581 | |
| 4582 | If an intersection is specified, only data for this one will be returned. |
| 4583 | |
| 4584 | |
| 4585 | * worm_stones: List the stones of a worm |
| 4586 | Arguments: the location, "BLACK" or "WHITE" |
| 4587 | Fails: if called on an empty or off-board location |
| 4588 | Returns: list of stones |
| 4589 | |
| 4590 | |
| 4591 | * worm_cutstone: Return the cutstone field in the worm data |
| 4592 | structure. |
| 4593 | Arguments: non-empty vertex |
| 4594 | Fails: never |
| 4595 | Returns: cutstone |
| 4596 | |
| 4597 | |
| 4598 | * dragon_data: Return the information in the dragon data structure. |
| 4599 | Arguments: optional intersection |
| 4600 | Fails: never |
| 4601 | Returns: Dragon data formatted in the corresponding way to worm_data. |
| 4602 | |
| 4603 | |
| 4604 | * dragon_stones: List the stones of a dragon |
| 4605 | Arguments: the location |
| 4606 | Fails: if called on an empty or off-board location |
| 4607 | Returns: list of stones |
| 4608 | |
| 4609 | |
| 4610 | * eye_data: Return the information in the eye data structure. |
| 4611 | Arguments: color, vertex |
| 4612 | Fails: never |
| 4613 | Returns: eye data fields and values, one pair per row |
| 4614 | |
| 4615 | |
| 4616 | * half_eye_data: Return the information in the half eye data |
| 4617 | structure. |
| 4618 | Arguments: vertex |
| 4619 | Fails: never |
| 4620 | Returns: half eye data fields and values, one pair per row |
| 4621 | |
| 4622 | |
| 4623 | * start_sgftrace: Start storing moves executed during reading in an |
| 4624 | sgf tree in memory. |
| 4625 | Arguments: none |
| 4626 | Fails: never |
| 4627 | Returns: nothing |
| 4628 | |
| 4629 | Warning: You had better know what you're doing if you try to use this |
| 4630 | command. |
| 4631 | |
| 4632 | |
| 4633 | * finish_sgftrace: Finish storing moves in an sgf tree and write it |
| 4634 | to file. |
| 4635 | Arguments: filename |
| 4636 | Fails: never |
| 4637 | Returns: nothing |
| 4638 | |
| 4639 | Warning: You had better know what you're doing if you try to use this |
| 4640 | command. |
| 4641 | |
| 4642 | |
| 4643 | * printsgf: Dump the current position as a static sgf file to |
| 4644 | filename, or as output if filename is missing or "-" |
| 4645 | Arguments: optional filename |
| 4646 | Fails: never |
| 4647 | Returns: nothing if filename, otherwise the sgf |
| 4648 | |
| 4649 | |
| 4650 | * tune_move_ordering: Tune the parameters for the move ordering in |
| 4651 | the tactical reading. |
| 4652 | Arguments: MOVE_ORDERING_PARAMETERS integers |
| 4653 | Fails: incorrect arguments |
| 4654 | Returns: nothing |
| 4655 | |
| 4656 | |
| 4657 | * echo: Echo the parameter |
| 4658 | Arguments: string |
| 4659 | Fails: never |
| 4660 | Returns: nothing |
| 4661 | |
| 4662 | |
| 4663 | * echo_err: Echo the parameter to stdout AND stderr |
| 4664 | Arguments: string |
| 4665 | Fails: never |
| 4666 | Returns: nothing |
| 4667 | |
| 4668 | |
| 4669 | * help: List all known commands |
| 4670 | Arguments: none |
| 4671 | Fails: never |
| 4672 | Returns: list of known commands, one per line |
| 4673 | |
| 4674 | Status: GTP version 2 standard command. |
| 4675 | |
| 4676 | |
| 4677 | * known_command: Tell whether a command is known. |
| 4678 | Arguments: command name |
| 4679 | Fails: never |
| 4680 | Returns: "true" if command exists, "false" if not |
| 4681 | |
| 4682 | Status: GTP version 2 standard command. |
| 4683 | |
| 4684 | |
| 4685 | * report_uncertainty: Turn uncertainty reports from owl_attack and |
| 4686 | owl_defend on or off. |
| 4687 | Arguments: "on" or "off" |
| 4688 | Fails: invalid argument |
| 4689 | Returns: nothing |
| 4690 | |
| 4691 | |
| 4692 | * get_random_seed: Get the random seed |
| 4693 | Arguments: none |
| 4694 | Fails: never |
| 4695 | Returns: random seed |
| 4696 | |
| 4697 | |
| 4698 | * set_random_seed: Set the random seed |
| 4699 | Arguments: integer |
| 4700 | Fails: invalid data |
| 4701 | Returns: nothing |
| 4702 | |
| 4703 | |
| 4704 | * advance_random_seed: Advance the random seed by a number of games. |
| 4705 | Arguments: integer |
| 4706 | Fails: invalid data |
| 4707 | Returns: New random seed. |
| 4708 | |
| 4709 | |
| 4710 | * is_surrounded: Determine if a dragon is surrounded |
| 4711 | Arguments: vertex (dragon) |
| 4712 | Fails: invalid vertex, empty vertex |
| 4713 | Returns: 1 if surrounded, 2 if weakly surrounded, 0 if not |
| 4714 | |
| 4715 | |
| 4716 | * does_surround: Determine if a move surrounds a dragon |
| 4717 | Arguments: vertex (move), vertex (dragon) |
| 4718 | Fails: invalid vertex, empty (dragon, nonempty (move) |
| 4719 | Returns: 1 if (move) surrounds (dragon) |
| 4720 | |
| 4721 | * surround_map: Report the surround map for dragon at a vertex |
| 4722 | Arguments: vertex (dragon), vertex (mapped location) |
| 4723 | Fails: invalid vertex, empty dragon |
| 4724 | Returns: value of surround map at (mapped location), or -1 if |
| 4725 | dragon not surrounded. |
| 4726 | |
| 4727 | |
| 4728 | * set_search_diamond: limit search, and establish a search diamond |
| 4729 | Arguments: pos |
| 4730 | Fails: invalid value |
| 4731 | Returns: nothing |
| 4732 | |
| 4733 | |
| 4734 | * reset_search_mask: unmark the entire board for limited search |
| 4735 | Arguments: none |
| 4736 | Fails: never |
| 4737 | Returns: nothing |
| 4738 | |
| 4739 | |
| 4740 | * limit_search: sets the global variable limit_search |
| 4741 | Arguments: value |
| 4742 | Fails: invalid arguments |
| 4743 | Returns: nothing |
| 4744 | |
| 4745 | |
| 4746 | * set_search_limit: mark a vertex for limited search |
| 4747 | Arguments: position |
| 4748 | Fails: invalid arguments |
| 4749 | Returns: nothing |
| 4750 | |
| 4751 | |
| 4752 | * draw_search_area: Draw search area. Writes to stderr. |
| 4753 | Arguments: none |
| 4754 | Fails: never |
| 4755 | Returns: nothing |
| 4756 | |
| 4757 | \1f |
| 4758 | File: gnugo.info, Node: Regression, Next: Copying, Prev: GTP, Up: Top |
| 4759 | |
| 4760 | 20 Regression testing |
| 4761 | ********************* |
| 4762 | |
| 4763 | The standard purpose of regression testing is to avoid getting the same |
| 4764 | bug twice. When a bug is found, the programmer fixes the bug and adds a |
| 4765 | test to the test suite. The test should fail before the fix and pass |
| 4766 | after the fix. When a new version is about to be released, all the tests |
| 4767 | in the regression test suite are run and if an old bug reappears, this |
| 4768 | will be seen quickly since the appropriate test will fail. |
| 4769 | |
| 4770 | The regression testing in GNU Go is slightly different. A typical |
| 4771 | test case involves specifying a position and asking the engine what |
| 4772 | move it would make. This is compared to one or more correct moves to |
| 4773 | decide whether the test case passes or fails. It is also stored whether |
| 4774 | a test case is expected to pass or fail, and deviations in this status |
| 4775 | signify whether a change has solved some problem and/or broken something |
| 4776 | else. Thus the regression tests both include positions highlighting some |
| 4777 | mistake being done by the engine, which are waiting to be fixed, and |
| 4778 | positions where the engine does the right thing, where we want to detect |
| 4779 | if a change breaks something. |
| 4780 | |
| 4781 | * Menu: |
| 4782 | |
| 4783 | * Regression Testing:: Regression Testing in GNU Go |
| 4784 | * Test Suites:: Test Suites |
| 4785 | * Running the Regressions:: Running the Regression Tests |
| 4786 | * Running regress.pike:: Running regress.pike |
| 4787 | * Viewing with Emacs:: Viewing tests with Emacs |
| 4788 | * HTML Views:: HTML Views |
| 4789 | |
| 4790 | \1f |
| 4791 | File: gnugo.info, Node: Regression Testing, Next: Test Suites, Up: Regression |
| 4792 | |
| 4793 | 20.1 Regression testing in GNU Go |
| 4794 | ================================= |
| 4795 | |
| 4796 | Regression testing is performed by the files in the `regression/' |
| 4797 | directory. The tests are specified as GTP commands in files with the |
| 4798 | suffix `.tst', with corresponding correct results and expected |
| 4799 | pass/fail status encoded in GTP comments following the test. To run a |
| 4800 | test suite the shell scripts `test.sh', `eval.sh', and `regress.sh' can |
| 4801 | be used. There are also Makefile targets to do this. If you `make |
| 4802 | all_batches' most of the tests are run. The Pike script `regress.pike' |
| 4803 | can also be used to run all tests or a subset of the tests. |
| 4804 | |
| 4805 | Game records used by the regression tests are stored in the |
| 4806 | directory `regression/games/' and its subdirectories. |
| 4807 | |
| 4808 | \1f |
| 4809 | File: gnugo.info, Node: Test Suites, Next: Running the Regressions, Prev: Regression Testing, Up: Regression |
| 4810 | |
| 4811 | 20.2 Test suites |
| 4812 | ================ |
| 4813 | |
| 4814 | The regression tests are grouped into suites and stored in files as GTP |
| 4815 | commands. A part of a test suite can look as follows: |
| 4816 | # Connecting with ko at B14 looks best. Cutting at D17 might be |
| 4817 | # considered. B17 (game move) is inferior. |
| 4818 | loadsgf games/strategy25.sgf 61 |
| 4819 | 90 gg_genmove black |
| 4820 | #? [B14|D17] |
| 4821 | |
| 4822 | # The game move at P13 is a suicidal blunder. |
| 4823 | loadsgf games/strategy25.sgf 249 |
| 4824 | 95 gg_genmove black |
| 4825 | #? [!P13] |
| 4826 | |
| 4827 | loadsgf games/strategy26.sgf 257 |
| 4828 | 100 gg_genmove black |
| 4829 | #? [M16]* |
| 4830 | |
| 4831 | Lines starting with a hash sign, or in general anything following a |
| 4832 | hash sign, are interpreted as comments by the GTP mode and thus ignored |
| 4833 | by the engine. GTP commands are executed in the order they appear, but |
| 4834 | only those on numbered lines are used for testing. The comment lines |
| 4835 | starting with `#?' are magical to the regression testing scripts and |
| 4836 | indicate correct results and expected pass/fail status. The string |
| 4837 | within brackets is matched as a regular expression against the response |
| 4838 | from the previous numbered GTP command. A particular useful feature of |
| 4839 | regular expressions is that by using `|' it is possible to specify |
| 4840 | alternatives. Thus `B14|D17' above means that if either `B14' or `D17' |
| 4841 | is the move generated in test case 90, it passes. There is one |
| 4842 | important special case to be aware of. If the correct result string |
| 4843 | starts with an exclamation mark, this is excluded from the regular |
| 4844 | expression but afterwards the result of the matching is negated. Thus |
| 4845 | `!P13' in test case 95 means that any move except `P13' is accepted as |
| 4846 | a correct result. |
| 4847 | |
| 4848 | In test case 100, the brackets on the `#?' line is followed by an |
| 4849 | asterisk. This means that the test is expected to fail. If there is no |
| 4850 | asterisk, the test is expected to pass. The brackets may also be |
| 4851 | followed by a `&', meaning that the result is ignored. This is |
| 4852 | primarily used to report statistics, e.g. how many tactical reading |
| 4853 | nodes were spent while running the test suite. |
| 4854 | |
| 4855 | \1f |
| 4856 | File: gnugo.info, Node: Running the Regressions, Next: Running regress.pike, Prev: Test Suites, Up: Regression |
| 4857 | |
| 4858 | 20.3 Running the Regression Tests |
| 4859 | ================================= |
| 4860 | |
| 4861 | `./test.sh blunder.tst' runs the tests in `blunder.tst' and prints the |
| 4862 | results of the commands on numbered lines, which may look like: |
| 4863 | |
| 4864 | 1 E5 |
| 4865 | 2 F9 |
| 4866 | 3 O18 |
| 4867 | 4 B7 |
| 4868 | 5 A4 |
| 4869 | 6 E4 |
| 4870 | 7 E3 |
| 4871 | 8 A3 |
| 4872 | 9 D9 |
| 4873 | 10 J9 |
| 4874 | 11 B3 |
| 4875 | 12 C6 |
| 4876 | 13 C6 |
| 4877 | |
| 4878 | This is usually not very informative, however. More interesting is |
| 4879 | `./eval.sh blunder.tst' which also compares the results above against |
| 4880 | the correct ones in the test file and prints a report for each test on |
| 4881 | the form: |
| 4882 | |
| 4883 | 1 failed: Correct '!E5', got 'E5' |
| 4884 | 2 failed: Correct 'C9|H9', got 'F9' |
| 4885 | 3 PASSED |
| 4886 | 4 failed: Correct 'B5|C5|C4|D4|E4|E3|F3', got 'B7' |
| 4887 | 5 PASSED |
| 4888 | 6 failed: Correct 'D4', got 'E4' |
| 4889 | 7 PASSED |
| 4890 | 8 failed: Correct 'B4', got 'A3' |
| 4891 | 9 failed: Correct 'G8|G9|H8', got 'D9' |
| 4892 | 10 failed: Correct 'G9|F9|C7', got 'J9' |
| 4893 | 11 failed: Correct 'D4|E4|E5|F4|C6', got 'B3' |
| 4894 | 12 failed: Correct 'D4', got 'C6' |
| 4895 | 13 failed: Correct 'D4|E4|E5|F4', got 'C6' |
| 4896 | |
| 4897 | The result of a test can be one of four different cases: |
| 4898 | |
| 4899 | * `passed': An expected pass |
| 4900 | |
| 4901 | This is the ideal result. |
| 4902 | |
| 4903 | * `PASSED': An unexpected pass |
| 4904 | |
| 4905 | This is a result that we are hoping for when we fix a bug. An old |
| 4906 | test case that used to fail is now passing. |
| 4907 | |
| 4908 | * `failed': An expected failure |
| 4909 | |
| 4910 | The test failed but this was also what we expected, unless we were |
| 4911 | trying to fix the particular mistake highlighted by the test case. |
| 4912 | These tests show weaknesses of the GNU Go engine and are good |
| 4913 | places to search if you want to detect an area which needs |
| 4914 | improvement. |
| 4915 | |
| 4916 | * `FAILED': An unexpected failure |
| 4917 | |
| 4918 | This should nominally only happen if something is broken by a |
| 4919 | change. However, sometimes GNU Go passes a test, but for the wrong |
| 4920 | reason or for a combination of wrong reasons. When one of these |
| 4921 | reasons is fixed, the other one may shine through so that the test |
| 4922 | suddenly fails. When a test case unexpectedly fails, it is |
| 4923 | necessary to make a closer examination in order to determine |
| 4924 | whether a change has broken something. |
| 4925 | |
| 4926 | |
| 4927 | If you want a less verbose report, `./regress.sh . blunder.tst' does |
| 4928 | the same thing as the previous command, but only reports unexpected |
| 4929 | results. The example above is compressed to |
| 4930 | |
| 4931 | 3 unexpected PASS! |
| 4932 | 5 unexpected PASS! |
| 4933 | 7 unexpected PASS! |
| 4934 | |
| 4935 | For convenience the tests are also available as makefile targets. For |
| 4936 | example, `make blunder' runs the tests in the blunder test suite by |
| 4937 | executing `eval.sh blunder.tst'. `make all_batches' runs all test |
| 4938 | suites in a sequence using the `regress.sh' script. |
| 4939 | |
| 4940 | \1f |
| 4941 | File: gnugo.info, Node: Running regress.pike, Next: Viewing with Emacs, Prev: Running the Regressions, Up: Regression |
| 4942 | |
| 4943 | 20.4 Running regress.pike |
| 4944 | ========================= |
| 4945 | |
| 4946 | A more powerful way to run regressions is with the script |
| 4947 | `regress.pike'. This requires that you have Pike |
| 4948 | (`http://pike.ida.liu.se') installed. |
| 4949 | |
| 4950 | Executing `./regress.pike' without arguments will run all testsuites |
| 4951 | that `make all_batches' would run. The difference is that unexpected |
| 4952 | results are reported immediately when they have been found (instead of |
| 4953 | after the whole file has been run) and that statistics of time |
| 4954 | consumption and node usage is presented for each test file and in total. |
| 4955 | |
| 4956 | To run a single test suite do e.g. `./regress.pike nicklas3.tst' or |
| 4957 | `./regress.pike nicklas3'. The result may look like: |
| 4958 | nicklas3 2.96 614772 3322 469 |
| 4959 | Total nodes: 614772 3322 469 |
| 4960 | Total time: 2.96 (3.22) |
| 4961 | Total uncertainty: 0.00 |
| 4962 | The numbers here mean that the test suite took 2.96 seconds of |
| 4963 | processor time and 3.22 seconds of real time. The consumption of |
| 4964 | reading nodes was 614772 for tactical reading, 3322 for owl reading, |
| 4965 | and 469 for connection reading. The last line relates to the |
| 4966 | variability of the generated moves in the test suite, and 0 means that |
| 4967 | none was decided by the randomness contribution to the move valuation. |
| 4968 | Multiple testsuites can be run by e.g. `./regress.pike owl ld_owl owl1'. |
| 4969 | |
| 4970 | It is also possible to run a single testcase, e.g. `./regress.pike |
| 4971 | strategy:6', a number of testcases, e.g. `./regress.pike |
| 4972 | strategy:6,23,45', a range of testcases, e.g. `./regress.pike |
| 4973 | strategy:13-15' or more complex combinations e.g. `./regress.pike |
| 4974 | strategy:6,13-15,23,45 nicklas3:602,1403'. |
| 4975 | |
| 4976 | There are also command line options to choose what engine to run, |
| 4977 | what options to send to the engine, to turn on verbose output, and to |
| 4978 | use a file to specify which testcases to run. Run `./regress.pike |
| 4979 | --help' for a complete and up to date list of options. |
| 4980 | |
| 4981 | \1f |
| 4982 | File: gnugo.info, Node: Viewing with Emacs, Next: HTML Views, Prev: Running regress.pike, Up: Regression |
| 4983 | |
| 4984 | 20.5 Viewing tests with Emacs |
| 4985 | ============================= |
| 4986 | |
| 4987 | To get a quick regression view, you may use the graphical display mode |
| 4988 | available with Emacs (*note Emacs::). You will want the cursor in the |
| 4989 | regression buffer when you enter `M-x gnugo', so that GNU Go opens in |
| 4990 | the correct directory. A good way to be in the right directory is to |
| 4991 | open the window of the test you want to investigate. Then you can cut |
| 4992 | and past GTP commands directly from the test to the minibuffer, using |
| 4993 | the `:' command from Emacs. Although Emacs mode does not have a |
| 4994 | coordinate grid, you may get an ascii board with the coordinate grid |
| 4995 | using `: showboard' command. |
| 4996 | |
| 4997 | \1f |
| 4998 | File: gnugo.info, Node: HTML Views, Prev: Viewing with Emacs, Up: Regression |
| 4999 | |
| 5000 | 20.6 HTML Regression Views |
| 5001 | ========================== |
| 5002 | |
| 5003 | Extremely useful HTML Views of the regression tests may be produced |
| 5004 | using two perl scripts `regression/regress.pl' and |
| 5005 | `regression/regress.plx'. |
| 5006 | |
| 5007 | 1. The driver program (regress.pl) which: |
| 5008 | * Runs the regression tests, invoking GNU Go. |
| 5009 | |
| 5010 | * Captures the trace output, board position, and pass/fail |
| 5011 | status, sgf output, and dragon status information. |
| 5012 | |
| 5013 | 2. The interface to view the captured output (regress.plx) which: |
| 5014 | * Never invokes GNU Go. |
| 5015 | |
| 5016 | * Displays the captured output in helpful formats (i.e. HTML). |
| 5017 | |
| 5018 | 20.6.1 Setting up the HTML regression Views |
| 5019 | ------------------------------------------- |
| 5020 | |
| 5021 | There are many ways configuring Apache to permit CGI scripts, all of |
| 5022 | them are featured in Apache documentation, which can be found at |
| 5023 | `http://httpd.apache.org/docs/2.0/howto/cgi.html' |
| 5024 | |
| 5025 | Below you will find one example. |
| 5026 | |
| 5027 | This documentation assumes an Apache 2.0 included in Fedora Core |
| 5028 | distribution, but it should be fairly close to the config for other |
| 5029 | distributions. |
| 5030 | |
| 5031 | First, you will need to configure Apache to run CGI scripts in the |
| 5032 | directory you wish to serve the html views from. In |
| 5033 | `/etc/httpd/conf/httpd.conf' there should be a line: |
| 5034 | |
| 5035 | `DocumentRoot "/var/www/html"' |
| 5036 | |
| 5037 | Search for a line `<Directory "/path/to/directory">', where |
| 5038 | `/path/to/directory' is the same as provided in `DocumentRoot', then |
| 5039 | add `ExecCGI' to list of `Options'. The whole section should look like: |
| 5040 | |
| 5041 | <Directory "/var/www/html"> |
| 5042 | ... |
| 5043 | Options ... ExecCGI |
| 5044 | ... |
| 5045 | </Directory> |
| 5046 | |
| 5047 | This allows CGI scripts to be executed in the directory used by |
| 5048 | regress.plx. Next, you need to tell Apache that `.plx' is a CGI script |
| 5049 | ending. Your `httpd.conf' file should contain a line: |
| 5050 | |
| 5051 | `AddHandler cgi-script ...' |
| 5052 | |
| 5053 | If there isn't already, add it; add `.plx' to the list of extensions, |
| 5054 | so line should look like: |
| 5055 | |
| 5056 | `AddHandler cgi-script ... .plx' |
| 5057 | |
| 5058 | You will also need to make sure you have the necessary modules |
| 5059 | loaded to run CGI scripts; mod_cgi and mod_mime should be sufficient. |
| 5060 | Your `httpd.conf' should have the relevant `LoadModule cgi_module |
| 5061 | modules/mod_cgi.so' and `LoadModule mime_module modules/mod_mime.so' |
| 5062 | lines; uncomment them if necessary. |
| 5063 | |
| 5064 | Next, you need to put a copy of `regress.plx' in the `DocumentRoot' |
| 5065 | directory `/var/www/html' or it subdirectories where you plan to serve |
| 5066 | the html views from. |
| 5067 | |
| 5068 | You will also need to install the Perl module GD |
| 5069 | (`http://search.cpan.org/dist/GD/'), available from CPAN. |
| 5070 | |
| 5071 | Finally, run `regression/regress.pl' to create the xml data used to |
| 5072 | generate the html views (to do all regression tests run |
| 5073 | `regression/regress.pl -a 1'); then, copy the `html/' directory to the |
| 5074 | same directory as `regress.plx' resides in. |
| 5075 | |
| 5076 | At this point, you should have a working copy of the html regression |
| 5077 | views. |
| 5078 | |
| 5079 | Additional notes for Debian users: The Perl GD module can be |
| 5080 | installed by `apt-get install libgd-perl'. It may suffice to add this to |
| 5081 | the apache2 configuration: |
| 5082 | |
| 5083 | <Directory "/var/www/regression"> |
| 5084 | Options +ExecCGI |
| 5085 | AddHandler cgi-script .plx |
| 5086 | RedirectMatch ^/regression$ /regression/regress.plx |
| 5087 | </Directory> |
| 5088 | |
| 5089 | and then make a link from `/var/www/regression' to the GNU Go |
| 5090 | regression directory. The `RedirectMatch' statement is only needed to |
| 5091 | set up a shorter entry URL. |
| 5092 | |
| 5093 | \1f |
| 5094 | File: gnugo.info, Node: Copying, Next: Concept Index, Prev: Regression, Up: Top |
| 5095 | |
| 5096 | Appendix A Copying |
| 5097 | ****************** |
| 5098 | |
| 5099 | The program GNU Go is distributed under the terms of the GNU General |
| 5100 | Public License (GPL). Its documentation is distributed under the terms |
| 5101 | of the GNU Free Documentation License (GFDL). |
| 5102 | |
| 5103 | * Menu: |
| 5104 | |
| 5105 | * GPL:: The GNU General Public License |
| 5106 | * GFDL:: The GNU Free Documentation License |
| 5107 | * GTP License:: The Go Text Protocol License |
| 5108 | |
| 5109 | \1f |
| 5110 | File: gnugo.info, Node: GPL, Next: GFDL, Prev: Copying, Up: Copying |
| 5111 | |
| 5112 | A.1 GNU GENERAL PUBLIC LICENSE |
| 5113 | ============================== |
| 5114 | |
| 5115 | Version 3, 29 June 2007 |
| 5116 | |
| 5117 | Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/> |
| 5118 | Everyone is permitted to copy and distribute verbatim copies |
| 5119 | of this license document, but changing it is not allowed. |
| 5120 | |
| 5121 | Preamble |
| 5122 | ======== |
| 5123 | |
| 5124 | The GNU General Public License is a free, copyleft license for software |
| 5125 | and other kinds of works. |
| 5126 | |
| 5127 | The licenses for most software and other practical works are designed |
| 5128 | to take away your freedom to share and change the works. By contrast, |
| 5129 | the GNU General Public License is intended to guarantee your freedom to |
| 5130 | share and change all versions of a program-to make sure it remains free |
| 5131 | software for all its users. We, the Free Software Foundation, use the |
| 5132 | GNU General Public License for most of our software; it applies also to |
| 5133 | any other work released this way by its authors. You can apply it to |
| 5134 | your programs, too. |
| 5135 | |
| 5136 | When we speak of free software, we are referring to freedom, not |
| 5137 | price. Our General Public Licenses are designed to make sure that you |
| 5138 | have the freedom to distribute copies of free software (and charge for |
| 5139 | them if you wish), that you receive source code or can get it if you |
| 5140 | want it, that you can change the software or use pieces of it in new |
| 5141 | free programs, and that you know you can do these things. |
| 5142 | |
| 5143 | To protect your rights, we need to prevent others from denying you |
| 5144 | these rights or asking you to surrender the rights. Therefore, you have |
| 5145 | certain responsibilities if you distribute copies of the software, or if |
| 5146 | you modify it: responsibilities to respect the freedom of others. |
| 5147 | |
| 5148 | For example, if you distribute copies of such a program, whether |
| 5149 | gratis or for a fee, you must pass on to the recipients the same |
| 5150 | freedoms that you received. You must make sure that they, too, receive |
| 5151 | or can get the source code. And you must show them these terms so they |
| 5152 | know their rights. |
| 5153 | |
| 5154 | Developers that use the GNU GPL protect your rights with two steps: |
| 5155 | (1) assert copyright on the software, and (2) offer you this License |
| 5156 | giving you legal permission to copy, distribute and/or modify it. |
| 5157 | |
| 5158 | For the developers' and authors' protection, the GPL clearly explains |
| 5159 | that there is no warranty for this free software. For both users' and |
| 5160 | authors' sake, the GPL requires that modified versions be marked as |
| 5161 | changed, so that their problems will not be attributed erroneously to |
| 5162 | authors of previous versions. |
| 5163 | |
| 5164 | Some devices are designed to deny users access to install or run |
| 5165 | modified versions of the software inside them, although the manufacturer |
| 5166 | can do so. This is fundamentally incompatible with the aim of |
| 5167 | protecting users' freedom to change the software. The systematic |
| 5168 | pattern of such abuse occurs in the area of products for individuals to |
| 5169 | use, which is precisely where it is most unacceptable. Therefore, we |
| 5170 | have designed this version of the GPL to prohibit the practice for those |
| 5171 | products. If such problems arise substantially in other domains, we |
| 5172 | stand ready to extend this provision to those domains in future versions |
| 5173 | of the GPL, as needed to protect the freedom of users. |
| 5174 | |
| 5175 | Finally, every program is threatened constantly by software patents. |
| 5176 | States should not allow patents to restrict development and use of |
| 5177 | software on general-purpose computers, but in those that do, we wish to |
| 5178 | avoid the special danger that patents applied to a free program could |
| 5179 | make it effectively proprietary. To prevent this, the GPL assures that |
| 5180 | patents cannot be used to render the program non-free. |
| 5181 | |
| 5182 | The precise terms and conditions for copying, distribution and |
| 5183 | modification follow. |
| 5184 | |
| 5185 | TERMS AND CONDITIONS |
| 5186 | 0. DEFINITIONS |
| 5187 | |
| 5188 | "This License" refers to version 3 of the GNU General Public |
| 5189 | License. |
| 5190 | |
| 5191 | "Copyright" also means copyright-like laws that apply to other |
| 5192 | kinds of works, such as semiconductor masks. |
| 5193 | |
| 5194 | "The Program" refers to any copyrightable work licensed under this |
| 5195 | License. Each licensee is addressed as "you". "Licensees" and |
| 5196 | "recipients" may be individuals or organizations. |
| 5197 | |
| 5198 | To "modify" a work means to copy from or adapt all or part of the |
| 5199 | work in a fashion requiring copyright permission, other than the |
| 5200 | making of an exact copy. The resulting work is called a "modified |
| 5201 | version" of the earlier work or a work "based on" the earlier work. |
| 5202 | |
| 5203 | A "covered work" means either the unmodified Program or a work |
| 5204 | based on the Program. |
| 5205 | |
| 5206 | To "propagate" a work means to do anything with it that, without |
| 5207 | permission, would make you directly or secondarily liable for |
| 5208 | infringement under applicable copyright law, except executing it |
| 5209 | on a computer or modifying a private copy. Propagation includes |
| 5210 | copying, distribution (with or without modification), making |
| 5211 | available to the public, and in some countries other activities as |
| 5212 | well. |
| 5213 | |
| 5214 | To "convey" a work means any kind of propagation that enables other |
| 5215 | parties to make or receive copies. Mere interaction with a user |
| 5216 | through a computer network, with no transfer of a copy, is not |
| 5217 | conveying. |
| 5218 | |
| 5219 | An interactive user interface displays "Appropriate Legal Notices" |
| 5220 | to the extent that it includes a convenient and prominently visible |
| 5221 | feature that (1) displays an appropriate copyright notice, and (2) |
| 5222 | tells the user that there is no warranty for the work (except to |
| 5223 | the extent that warranties are provided), that licensees may |
| 5224 | convey the work under this License, and how to view a copy of this |
| 5225 | License. If the interface presents a list of user commands or |
| 5226 | options, such as a menu, a prominent item in the list meets this |
| 5227 | criterion. |
| 5228 | |
| 5229 | |
| 5230 | 1. SOURCE CODE |
| 5231 | |
| 5232 | The "source code" for a work means the preferred form of the work |
| 5233 | for making modifications to it. "Object code" means any non-source |
| 5234 | form of a work. |
| 5235 | |
| 5236 | A "Standard Interface" means an interface that either is an |
| 5237 | official standard defined by a recognized standards body, or, in |
| 5238 | the case of interfaces specified for a particular programming |
| 5239 | language, one that is widely used among developers working in that |
| 5240 | language. |
| 5241 | |
| 5242 | The "System Libraries" of an executable work include anything, |
| 5243 | other than the work as a whole, that (a) is included in the normal |
| 5244 | form of packaging a Major Component, but which is not part of that |
| 5245 | Major Component, and (b) serves only to enable use of the work |
| 5246 | with that Major Component, or to implement a Standard Interface |
| 5247 | for which an implementation is available to the public in source |
| 5248 | code form. A "Major Component", in this context, means a major |
| 5249 | essential component (kernel, window system, and so on) of the |
| 5250 | specific operating system (if any) on which the executable work |
| 5251 | runs, or a compiler used to produce the work, or an object code |
| 5252 | interpreter used to run it. |
| 5253 | |
| 5254 | The "Corresponding Source" for a work in object code form means all |
| 5255 | the source code needed to generate, install, and (for an executable |
| 5256 | work) run the object code and to modify the work, including |
| 5257 | scripts to control those activities. However, it does not include |
| 5258 | the work's System Libraries, or general-purpose tools or generally |
| 5259 | available free programs which are used unmodified in performing |
| 5260 | those activities but which are not part of the work. For example, |
| 5261 | Corresponding Source includes interface definition files |
| 5262 | associated with source files for the work, and the source code for |
| 5263 | shared libraries and dynamically linked subprograms that the work |
| 5264 | is specifically designed to require, such as by intimate data |
| 5265 | communication or control flow between those subprograms and other |
| 5266 | parts of the work. |
| 5267 | |
| 5268 | The Corresponding Source need not include anything that users can |
| 5269 | regenerate automatically from other parts of the Corresponding |
| 5270 | Source. |
| 5271 | |
| 5272 | The Corresponding Source for a work in source code form is that |
| 5273 | same work. |
| 5274 | |
| 5275 | |
| 5276 | 2. BASIC PERMISSIONS |
| 5277 | |
| 5278 | All rights granted under this License are granted for the term of |
| 5279 | copyright on the Program, and are irrevocable provided the stated |
| 5280 | conditions are met. This License explicitly affirms your unlimited |
| 5281 | permission to run the unmodified Program. The output from running |
| 5282 | a covered work is covered by this License only if the output, |
| 5283 | given its content, constitutes a covered work. This License |
| 5284 | acknowledges your rights of fair use or other equivalent, as |
| 5285 | provided by copyright law. |
| 5286 | |
| 5287 | You may make, run and propagate covered works that you do not |
| 5288 | convey, without conditions so long as your license otherwise |
| 5289 | remains in force. You may convey covered works to others for the |
| 5290 | sole purpose of having them make modifications exclusively for |
| 5291 | you, or provide you with facilities for running those works, |
| 5292 | provided that you comply with the terms of this License in |
| 5293 | conveying all material for which you do not control copyright. |
| 5294 | Those thus making or running the covered works for you must do so |
| 5295 | exclusively on your behalf, under your direction and control, on |
| 5296 | terms that prohibit them from making any copies of your |
| 5297 | copyrighted material outside their relationship with you. |
| 5298 | |
| 5299 | Conveying under any other circumstances is permitted solely under |
| 5300 | the conditions stated below. Sublicensing is not allowed; section |
| 5301 | 10 makes it unnecessary. |
| 5302 | |
| 5303 | |
| 5304 | 3. PROTECTING USERS' LEGAL RIGHTS FROM ANTI-CIRCUMVENTION LAW |
| 5305 | |
| 5306 | No covered work shall be deemed part of an effective technological |
| 5307 | measure under any applicable law fulfilling obligations under |
| 5308 | article 11 of the WIPO copyright treaty adopted on 20 December |
| 5309 | 1996, or similar laws prohibiting or restricting circumvention of |
| 5310 | such measures. |
| 5311 | |
| 5312 | When you convey a covered work, you waive any legal power to forbid |
| 5313 | circumvention of technological measures to the extent such |
| 5314 | circumvention is effected by exercising rights under this License |
| 5315 | with respect to the covered work, and you disclaim any intention |
| 5316 | to limit operation or modification of the work as a means of |
| 5317 | enforcing, against the work's users, your or third parties' legal |
| 5318 | rights to forbid circumvention of technological measures. |
| 5319 | |
| 5320 | |
| 5321 | 4. CONVEYING VERBATIM COPIES |
| 5322 | |
| 5323 | You may convey verbatim copies of the Program's source code as you |
| 5324 | receive it, in any medium, provided that you conspicuously and |
| 5325 | appropriately publish on each copy an appropriate copyright notice; |
| 5326 | keep intact all notices stating that this License and any |
| 5327 | non-permissive terms added in accord with section 7 apply to the |
| 5328 | code; keep intact all notices of the absence of any warranty; and |
| 5329 | give all recipients a copy of this License along with the Program. |
| 5330 | |
| 5331 | You may charge any price or no price for each copy that you convey, |
| 5332 | and you may offer support or warranty protection for a fee. |
| 5333 | |
| 5334 | |
| 5335 | 5. CONVEYING MODIFIED SOURCE VERSIONS |
| 5336 | |
| 5337 | You may convey a work based on the Program, or the modifications to |
| 5338 | produce it from the Program, in the form of source code under the |
| 5339 | terms of section 4, provided that you also meet all of these |
| 5340 | conditions: |
| 5341 | |
| 5342 | a) The work must carry prominent notices stating that you modified |
| 5343 | it, and giving a relevant date. |
| 5344 | |
| 5345 | b) The work must carry prominent notices stating that it is |
| 5346 | released under this License and any conditions added under section |
| 5347 | 7. This requirement modifies the requirement in section 4 to |
| 5348 | "keep intact all notices". |
| 5349 | |
| 5350 | c) You must license the entire work, as a whole, under this |
| 5351 | License to anyone who comes into possession of a copy. This |
| 5352 | License will therefore apply, along with any applicable section 7 |
| 5353 | additional terms, to the whole of the work, and all its parts, |
| 5354 | regardless of how they are packaged. This License gives no |
| 5355 | permission to license the work in any other way, but it does not |
| 5356 | invalidate such permission if you have separately received it. |
| 5357 | |
| 5358 | d) If the work has interactive user interfaces, each must display |
| 5359 | Appropriate Legal Notices; however, if the Program has |
| 5360 | interactive interfaces that do not display Appropriate Legal |
| 5361 | Notices, your work need not make them do so. |
| 5362 | |
| 5363 | A compilation of a covered work with other separate and independent |
| 5364 | works, which are not by their nature extensions of the covered |
| 5365 | work, and which are not combined with it such as to form a larger |
| 5366 | program, in or on a volume of a storage or distribution medium, is |
| 5367 | called an "aggregate" if the compilation and its resulting |
| 5368 | copyright are not used to limit the access or legal rights of the |
| 5369 | compilation's users beyond what the individual works permit. |
| 5370 | Inclusion of a covered work in an aggregate does not cause this |
| 5371 | License to apply to the other parts of the aggregate. |
| 5372 | |
| 5373 | |
| 5374 | 6. CONVEYING NON-SOURCE FORMS |
| 5375 | |
| 5376 | You may convey a covered work in object code form under the terms |
| 5377 | of sections 4 and 5, provided that you also convey the |
| 5378 | machine-readable Corresponding Source under the terms of this |
| 5379 | License, in one of these ways: |
| 5380 | |
| 5381 | a) Convey the object code in, or embodied in, a physical product |
| 5382 | (including a physical distribution medium), accompanied by the |
| 5383 | Corresponding Source fixed on a durable physical medium |
| 5384 | customarily used for software interchange. |
| 5385 | |
| 5386 | b) Convey the object code in, or embodied in, a physical product |
| 5387 | (including a physical distribution medium), accompanied by a |
| 5388 | written offer, valid for at least three years and valid for as |
| 5389 | long as you offer spare parts or customer support for that product |
| 5390 | model, to give anyone who possesses the object code either (1) a |
| 5391 | copy of the Corresponding Source for all the software in the |
| 5392 | product that is covered by this License, on a durable physical |
| 5393 | medium customarily used for software interchange, for a price no |
| 5394 | more than your reasonable cost of physically performing this |
| 5395 | conveying of source, or (2) access to copy the Corresponding |
| 5396 | Source from a network server at no charge. |
| 5397 | |
| 5398 | c) Convey individual copies of the object code with a copy of the |
| 5399 | written offer to provide the Corresponding Source. This |
| 5400 | alternative is allowed only occasionally and noncommercially, and |
| 5401 | only if you received the object code with such an offer, in |
| 5402 | accord with subsection 6b. |
| 5403 | |
| 5404 | d) Convey the object code by offering access from a designated |
| 5405 | place (gratis or for a charge), and offer equivalent access to the |
| 5406 | Corresponding Source in the same way through the same place at |
| 5407 | no further charge. You need not require recipients to copy the |
| 5408 | Corresponding Source along with the object code. If the place |
| 5409 | to copy the object code is a network server, the Corresponding |
| 5410 | Source may be on a different server (operated by you or a |
| 5411 | third party) that supports equivalent copying facilities, |
| 5412 | provided you maintain clear directions next to the object code |
| 5413 | saying where to find the Corresponding Source. Regardless of |
| 5414 | what server hosts the Corresponding Source, you remain |
| 5415 | obligated to ensure that it is available for as long as needed |
| 5416 | to satisfy these requirements. |
| 5417 | |
| 5418 | e) Convey the object code using peer-to-peer transmission, provided |
| 5419 | you inform other peers where the object code and Corresponding |
| 5420 | Source of the work are being offered to the general public at no |
| 5421 | charge under subsection 6d. |
| 5422 | |
| 5423 | A separable portion of the object code, whose source code is |
| 5424 | excluded from the Corresponding Source as a System Library, need |
| 5425 | not be included in conveying the object code work. |
| 5426 | |
| 5427 | A "User Product" is either (1) a "consumer product", which means |
| 5428 | any tangible personal property which is normally used for |
| 5429 | personal, family, or household purposes, or (2) anything designed |
| 5430 | or sold for incorporation into a dwelling. In determining whether |
| 5431 | a product is a consumer product, doubtful cases shall be resolved |
| 5432 | in favor of coverage. For a particular product received by a |
| 5433 | particular user, "normally used" refers to a typical or common use |
| 5434 | of that class of product, regardless of the status of the |
| 5435 | particular user or of the way in which the particular user |
| 5436 | actually uses, or expects or is expected to use, the product. A |
| 5437 | product is a consumer product regardless of whether the product |
| 5438 | has substantial commercial, industrial or non-consumer uses, |
| 5439 | unless such uses represent the only significant mode of use of the |
| 5440 | product. |
| 5441 | |
| 5442 | "Installation Information" for a User Product means any methods, |
| 5443 | procedures, authorization keys, or other information required to |
| 5444 | install and execute modified versions of a covered work in that |
| 5445 | User Product from a modified version of its Corresponding Source. |
| 5446 | The information must suffice to ensure that the continued |
| 5447 | functioning of the modified object code is in no case prevented or |
| 5448 | interfered with solely because modification has been made. |
| 5449 | |
| 5450 | If you convey an object code work under this section in, or with, |
| 5451 | or specifically for use in, a User Product, and the conveying |
| 5452 | occurs as part of a transaction in which the right of possession |
| 5453 | and use of the User Product is transferred to the recipient in |
| 5454 | perpetuity or for a fixed term (regardless of how the transaction |
| 5455 | is characterized), the Corresponding Source conveyed under this |
| 5456 | section must be accompanied by the Installation Information. But |
| 5457 | this requirement does not apply if neither you nor any third party |
| 5458 | retains the ability to install modified object code on the User |
| 5459 | Product (for example, the work has been installed in ROM). |
| 5460 | |
| 5461 | The requirement to provide Installation Information does not |
| 5462 | include a requirement to continue to provide support service, |
| 5463 | warranty, or updates for a work that has been modified or |
| 5464 | installed by the recipient, or for the User Product in which it |
| 5465 | has been modified or installed. Access to a network may be denied |
| 5466 | when the modification itself materially and adversely affects the |
| 5467 | operation of the network or violates the rules and protocols for |
| 5468 | communication across the network. |
| 5469 | |
| 5470 | Corresponding Source conveyed, and Installation Information |
| 5471 | provided, in accord with this section must be in a format that is |
| 5472 | publicly documented (and with an implementation available to the |
| 5473 | public in source code form), and must require no special password |
| 5474 | or key for unpacking, reading or copying. |
| 5475 | |
| 5476 | |
| 5477 | 7. ADDITIONAL TERMS |
| 5478 | |
| 5479 | "Additional permissions" are terms that supplement the terms of |
| 5480 | this License by making exceptions from one or more of its |
| 5481 | conditions. Additional permissions that are applicable to the |
| 5482 | entire Program shall be treated as though they were included in |
| 5483 | this License, to the extent that they are valid under applicable |
| 5484 | law. If additional permissions apply only to part of the Program, |
| 5485 | that part may be used separately under those permissions, but the |
| 5486 | entire Program remains governed by this License without regard to |
| 5487 | the additional permissions. |
| 5488 | |
| 5489 | When you convey a copy of a covered work, you may at your option |
| 5490 | remove any additional permissions from that copy, or from any part |
| 5491 | of it. (Additional permissions may be written to require their own |
| 5492 | removal in certain cases when you modify the work.) You may place |
| 5493 | additional permissions on material, added by you to a covered work, |
| 5494 | for which you have or can give appropriate copyright permission. |
| 5495 | |
| 5496 | Notwithstanding any other provision of this License, for material |
| 5497 | you add to a covered work, you may (if authorized by the copyright |
| 5498 | holders of that material) supplement the terms of this License |
| 5499 | with terms: |
| 5500 | |
| 5501 | a) Disclaiming warranty or limiting liability differently from the |
| 5502 | terms of sections 15 and 16 of this License; or |
| 5503 | |
| 5504 | b) Requiring preservation of specified reasonable legal notices or |
| 5505 | author attributions in that material or in the Appropriate Legal |
| 5506 | Notices displayed by works containing it; or |
| 5507 | |
| 5508 | c) Prohibiting misrepresentation of the origin of that material, or |
| 5509 | requiring that modified versions of such material be marked in |
| 5510 | reasonable ways as different from the original version; or |
| 5511 | |
| 5512 | d) Limiting the use for publicity purposes of names of licensors or |
| 5513 | authors of the material; or |
| 5514 | |
| 5515 | e) Declining to grant rights under trademark law for use of some |
| 5516 | trade names, trademarks, or service marks; or |
| 5517 | |
| 5518 | f) Requiring indemnification of licensors and authors of that |
| 5519 | material by anyone who conveys the material (or modified versions |
| 5520 | of it) with contractual assumptions of liability to the |
| 5521 | recipient, for any liability that these contractual |
| 5522 | assumptions directly impose on those licensors and authors. |
| 5523 | |
| 5524 | All other non-permissive additional terms are considered "further |
| 5525 | restrictions" within the meaning of section 10. If the Program as |
| 5526 | you received it, or any part of it, contains a notice stating that |
| 5527 | it is governed by this License along with a term that is a further |
| 5528 | restriction, you may remove that term. If a license document |
| 5529 | contains a further restriction but permits relicensing or |
| 5530 | conveying under this License, you may add to a covered work |
| 5531 | material governed by the terms of that license document, provided |
| 5532 | that the further restriction does not survive such relicensing or |
| 5533 | conveying. |
| 5534 | |
| 5535 | If you add terms to a covered work in accord with this section, you |
| 5536 | must place, in the relevant source files, a statement of the |
| 5537 | additional terms that apply to those files, or a notice indicating |
| 5538 | where to find the applicable terms. |
| 5539 | |
| 5540 | Additional terms, permissive or non-permissive, may be stated in |
| 5541 | the form of a separately written license, or stated as exceptions; |
| 5542 | the above requirements apply either way. |
| 5543 | |
| 5544 | |
| 5545 | 8. TERMINATION |
| 5546 | |
| 5547 | You may not propagate or modify a covered work except as expressly |
| 5548 | provided under this License. Any attempt otherwise to propagate or |
| 5549 | modify it is void, and will automatically terminate your rights |
| 5550 | under this License (including any patent licenses granted under |
| 5551 | the third paragraph of section 11). |
| 5552 | |
| 5553 | However, if you cease all violation of this License, then your |
| 5554 | license from a particular copyright holder is reinstated (a) |
| 5555 | provisionally, unless and until the copyright holder explicitly and |
| 5556 | finally terminates your license, and (b) permanently, if the |
| 5557 | copyright holder fails to notify you of the violation by some |
| 5558 | reasonable means prior to 60 days after the cessation. |
| 5559 | |
| 5560 | Moreover, your license from a particular copyright holder is |
| 5561 | reinstated permanently if the copyright holder notifies you of the |
| 5562 | violation by some reasonable means, this is the first time you have |
| 5563 | received notice of violation of this License (for any work) from |
| 5564 | that copyright holder, and you cure the violation prior to 30 days |
| 5565 | after your receipt of the notice. |
| 5566 | |
| 5567 | Termination of your rights under this section does not terminate |
| 5568 | the licenses of parties who have received copies or rights from |
| 5569 | you under this License. If your rights have been terminated and |
| 5570 | not permanently reinstated, you do not qualify to receive new |
| 5571 | licenses for the same material under section 10. |
| 5572 | |
| 5573 | |
| 5574 | 9. ACCEPTANCE NOT REQUIRED FOR HAVING COPIES |
| 5575 | |
| 5576 | You are not required to accept this License in order to receive or |
| 5577 | run a copy of the Program. Ancillary propagation of a covered work |
| 5578 | occurring solely as a consequence of using peer-to-peer |
| 5579 | transmission to receive a copy likewise does not require |
| 5580 | acceptance. However, nothing other than this License grants you |
| 5581 | permission to propagate or modify any covered work. These actions |
| 5582 | infringe copyright if you do not accept this License. Therefore, |
| 5583 | by modifying or propagating a covered work, you indicate your |
| 5584 | acceptance of this License to do so. |
| 5585 | |
| 5586 | |
| 5587 | 10. AUTOMATIC LICENSING OF DOWNSTREAM RECIPIENTS |
| 5588 | |
| 5589 | Each time you convey a covered work, the recipient automatically |
| 5590 | receives a license from the original licensors, to run, modify and |
| 5591 | propagate that work, subject to this License. You are not |
| 5592 | responsible for enforcing compliance by third parties with this |
| 5593 | License. |
| 5594 | |
| 5595 | An "entity transaction" is a transaction transferring control of an |
| 5596 | organization, or substantially all assets of one, or subdividing an |
| 5597 | organization, or merging organizations. If propagation of a |
| 5598 | covered work results from an entity transaction, each party to that |
| 5599 | transaction who receives a copy of the work also receives whatever |
| 5600 | licenses to the work the party's predecessor in interest had or |
| 5601 | could give under the previous paragraph, plus a right to |
| 5602 | possession of the Corresponding Source of the work from the |
| 5603 | predecessor in interest, if the predecessor has it or can get it |
| 5604 | with reasonable efforts. |
| 5605 | |
| 5606 | You may not impose any further restrictions on the exercise of the |
| 5607 | rights granted or affirmed under this License. For example, you |
| 5608 | may not impose a license fee, royalty, or other charge for |
| 5609 | exercise of rights granted under this License, and you may not |
| 5610 | initiate litigation (including a cross-claim or counterclaim in a |
| 5611 | lawsuit) alleging that any patent claim is infringed by making, |
| 5612 | using, selling, offering for sale, or importing the Program or any |
| 5613 | portion of it. |
| 5614 | |
| 5615 | |
| 5616 | 11. PATENTS |
| 5617 | |
| 5618 | A "contributor" is a copyright holder who authorizes use under this |
| 5619 | License of the Program or a work on which the Program is based. |
| 5620 | The work thus licensed is called the contributor's "contributor |
| 5621 | version". |
| 5622 | |
| 5623 | A contributor's "essential patent claims" are all patent claims |
| 5624 | owned or controlled by the contributor, whether already acquired or |
| 5625 | hereafter acquired, that would be infringed by some manner, |
| 5626 | permitted by this License, of making, using, or selling its |
| 5627 | contributor version, but do not include claims that would be |
| 5628 | infringed only as a consequence of further modification of the |
| 5629 | contributor version. For purposes of this definition, "control" |
| 5630 | includes the right to grant patent sublicenses in a manner |
| 5631 | consistent with the requirements of this License. |
| 5632 | |
| 5633 | Each contributor grants you a non-exclusive, worldwide, |
| 5634 | royalty-free patent license under the contributor's essential |
| 5635 | patent claims, to make, use, sell, offer for sale, import and |
| 5636 | otherwise run, modify and propagate the contents of its |
| 5637 | contributor version. |
| 5638 | |
| 5639 | In the following three paragraphs, a "patent license" is any |
| 5640 | express agreement or commitment, however denominated, not to |
| 5641 | enforce a patent (such as an express permission to practice a |
| 5642 | patent or covenant not to sue for patent infringement). To |
| 5643 | "grant" such a patent license to a party means to make such an |
| 5644 | agreement or commitment not to enforce a patent against the party. |
| 5645 | |
| 5646 | If you convey a covered work, knowingly relying on a patent |
| 5647 | license, and the Corresponding Source of the work is not available |
| 5648 | for anyone to copy, free of charge and under the terms of this |
| 5649 | License, through a publicly available network server or other |
| 5650 | readily accessible means, then you must either (1) cause the |
| 5651 | Corresponding Source to be so available, or (2) arrange to deprive |
| 5652 | yourself of the benefit of the patent license for this particular |
| 5653 | work, or (3) arrange, in a manner consistent with the requirements |
| 5654 | of this License, to extend the patent license to downstream |
| 5655 | recipients. "Knowingly relying" means you have actual knowledge |
| 5656 | that, but for the patent license, your conveying the covered work |
| 5657 | in a country, or your recipient's use of the covered work in a |
| 5658 | country, would infringe one or more identifiable patents in that |
| 5659 | country that you have reason to believe are valid. |
| 5660 | |
| 5661 | If, pursuant to or in connection with a single transaction or |
| 5662 | arrangement, you convey, or propagate by procuring conveyance of, a |
| 5663 | covered work, and grant a patent license to some of the parties |
| 5664 | receiving the covered work authorizing them to use, propagate, |
| 5665 | modify or convey a specific copy of the covered work, then the |
| 5666 | patent license you grant is automatically extended to all |
| 5667 | recipients of the covered work and works based on it. |
| 5668 | |
| 5669 | A patent license is "discriminatory" if it does not include within |
| 5670 | the scope of its coverage, prohibits the exercise of, or is |
| 5671 | conditioned on the non-exercise of one or more of the rights that |
| 5672 | are specifically granted under this License. You may not convey a |
| 5673 | covered work if you are a party to an arrangement with a third |
| 5674 | party that is in the business of distributing software, under |
| 5675 | which you make payment to the third party based on the extent of |
| 5676 | your activity of conveying the work, and under which the third |
| 5677 | party grants, to any of the parties who would receive the covered |
| 5678 | work from you, a discriminatory patent license (a) in connection |
| 5679 | with copies of the covered work conveyed by you (or copies made |
| 5680 | from those copies), or (b) primarily for and in connection with |
| 5681 | specific products or compilations that contain the covered work, |
| 5682 | unless you entered into that arrangement, or that patent license |
| 5683 | was granted, prior to 28 March 2007. |
| 5684 | |
| 5685 | Nothing in this License shall be construed as excluding or limiting |
| 5686 | any implied license or other defenses to infringement that may |
| 5687 | otherwise be available to you under applicable patent law. |
| 5688 | |
| 5689 | |
| 5690 | 12. NO SURRENDER OF OTHERS' FREEDOM |
| 5691 | |
| 5692 | If conditions are imposed on you (whether by court order, |
| 5693 | agreement or otherwise) that contradict the conditions of this |
| 5694 | License, they do not excuse you from the conditions of this |
| 5695 | License. If you cannot convey a covered work so as to satisfy |
| 5696 | simultaneously your obligations under this License and any other |
| 5697 | pertinent obligations, then as a consequence you may not convey it |
| 5698 | at all. For example, if you agree to terms that obligate you to |
| 5699 | collect a royalty for further conveying from those to whom you |
| 5700 | convey the Program, the only way you could satisfy both those |
| 5701 | terms and this License would be to refrain entirely from conveying |
| 5702 | the Program. |
| 5703 | |
| 5704 | |
| 5705 | 13. USE WITH THE GNU AFFERO GENERAL PUBLIC LICENSE |
| 5706 | |
| 5707 | Notwithstanding any other provision of this License, you have |
| 5708 | permission to link or combine any covered work with a work licensed |
| 5709 | under version 3 of the GNU Affero General Public License into a |
| 5710 | single combined work, and to convey the resulting work. The terms |
| 5711 | of this License will continue to apply to the part which is the |
| 5712 | covered work, but the special requirements of the GNU Affero |
| 5713 | General Public License, section 13, concerning interaction through |
| 5714 | a network will apply to the combination as such. |
| 5715 | |
| 5716 | |
| 5717 | 14. REVISED VERSIONS OF THIS LICENSE |
| 5718 | |
| 5719 | The Free Software Foundation may publish revised and/or new |
| 5720 | versions of the GNU General Public License from time to time. |
| 5721 | Such new versions will be similar in spirit to the present |
| 5722 | version, but may differ in detail to address new problems or |
| 5723 | concerns. |
| 5724 | |
| 5725 | Each version is given a distinguishing version number. If the |
| 5726 | Program specifies that a certain numbered version of the GNU |
| 5727 | General Public License "or any later version" applies to it, you |
| 5728 | have the option of following the terms and conditions either of |
| 5729 | that numbered version or of any later version published by the |
| 5730 | Free Software Foundation. If the Program does not specify a |
| 5731 | version number of the GNU General Public License, you may choose |
| 5732 | any version ever published by the Free Software Foundation. |
| 5733 | |
| 5734 | If the Program specifies that a proxy can decide which future |
| 5735 | versions of the GNU General Public License can be used, that |
| 5736 | proxy's public statement of acceptance of a version permanently |
| 5737 | authorizes you to choose that version for the Program. |
| 5738 | |
| 5739 | Later license versions may give you additional or different |
| 5740 | permissions. However, no additional obligations are imposed on any |
| 5741 | author or copyright holder as a result of your choosing to follow a |
| 5742 | later version. |
| 5743 | |
| 5744 | |
| 5745 | 15. DISCLAIMER OF WARRANTY |
| 5746 | |
| 5747 | THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY |
| 5748 | APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE |
| 5749 | COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" |
| 5750 | WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, |
| 5751 | INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
| 5752 | MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE |
| 5753 | RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. |
| 5754 | SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL |
| 5755 | NECESSARY SERVICING, REPAIR OR CORRECTION. |
| 5756 | |
| 5757 | |
| 5758 | 16. LIMITATION OF LIABILITY. |
| 5759 | |
| 5760 | IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN |
| 5761 | WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES |
| 5762 | AND/OR CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU |
| 5763 | FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR |
| 5764 | CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE |
| 5765 | THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA |
| 5766 | BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD |
| 5767 | PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER |
| 5768 | PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF |
| 5769 | THE POSSIBILITY OF SUCH DAMAGES. |
| 5770 | |
| 5771 | |
| 5772 | 17. INTERPRETATION OF SECTIONS 15 AND 16 |
| 5773 | |
| 5774 | If the disclaimer of warranty and limitation of liability provided |
| 5775 | above cannot be given local legal effect according to their terms, |
| 5776 | reviewing courts shall apply local law that most closely |
| 5777 | approximates an absolute waiver of all civil liability in |
| 5778 | connection with the Program, unless a warranty or assumption of |
| 5779 | liability accompanies a copy of the Program in return for a fee. |
| 5780 | |
| 5781 | |
| 5782 | How to Apply These Terms to your New Programs |
| 5783 | ============================================= |
| 5784 | |
| 5785 | If you develop a new program, and you want it to be of the greatest |
| 5786 | possible use to the public, the best way to achieve this is to make it |
| 5787 | free software which everyone can redistribute and change under these |
| 5788 | terms. |
| 5789 | |
| 5790 | To do so, attach the following notices to the program. It is safest |
| 5791 | to attach them to the start of each source file to most effectively |
| 5792 | state the exclusion of warranty; and each file should have at least the |
| 5793 | "copyright" line and a pointer to where the full notice is found. |
| 5794 | |
| 5795 | <one line to give the program's name and a brief idea of what it |
| 5796 | does.> Copyright (C) <year> <name of author> |
| 5797 | |
| 5798 | This program is free software: you can redistribute it and/or modify |
| 5799 | it under the terms of the GNU General Public License as published by |
| 5800 | the Free Software Foundation, either version 3 of the License, or |
| 5801 | (at your option) any later version. |
| 5802 | |
| 5803 | This program is distributed in the hope that it will be useful, |
| 5804 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 5805 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 5806 | General Public License for more details. |
| 5807 | |
| 5808 | You should have received a copy of the GNU General Public License |
| 5809 | along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 5810 | |
| 5811 | Also add information on how to contact you by electronic and paper |
| 5812 | mail. |
| 5813 | |
| 5814 | If the program does terminal interaction, make it output a short |
| 5815 | notice like this when it starts in an interactive mode: |
| 5816 | |
| 5817 | <program> Copyright (C) <year> <name of author> This program |
| 5818 | comes with ABSOLUTELY NO WARRANTY; for details type `show w'. This |
| 5819 | is free software, and you are welcome to redistribute it under |
| 5820 | certain conditions; type `show c' for details. |
| 5821 | |
| 5822 | The hypothetical commands `show w' and `show c' should show the |
| 5823 | appropriate parts of the General Public License. Of course, your |
| 5824 | program's commands might be different; for a GUI interface, you would |
| 5825 | use an "about box". |
| 5826 | |
| 5827 | You should also get your employer (if you work as a programmer) or |
| 5828 | school, if any, to sign a "copyright disclaimer" for the program, if |
| 5829 | necessary. For more information on this, and how to apply and follow |
| 5830 | the GNU GPL, see <http://www.gnu.org/licenses/>. |
| 5831 | |
| 5832 | The GNU General Public License does not permit incorporating your |
| 5833 | program into proprietary programs. If your program is a subroutine |
| 5834 | library, you may consider it more useful to permit linking proprietary |
| 5835 | applications with the library. If this is what you want to do, use the |
| 5836 | GNU Lesser General Public License instead of this License. But first, |
| 5837 | please read <http://www.gnu.org/philosophy/why-not-lgpl.html>. |
| 5838 | |
| 5839 | \1f |
| 5840 | File: gnugo.info, Node: GFDL, Next: GTP License, Prev: GPL, Up: Copying |
| 5841 | |
| 5842 | A.2 GNU FREE DOCUMENTATION LICENSE |
| 5843 | ================================== |
| 5844 | |
| 5845 | Version 1.3, 3 November 2008 |
| 5846 | |
| 5847 | Copyright (C) 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc. |
| 5848 | `http://fsf.org/' |
| 5849 | |
| 5850 | Everyone is permitted to copy and distribute verbatim copies |
| 5851 | of this license document, but changing it is not allowed. |
| 5852 | |
| 5853 | 0. PREAMBLE |
| 5854 | |
| 5855 | The purpose of this License is to make a manual, textbook, or other |
| 5856 | functional and useful document "free" in the sense of freedom: to |
| 5857 | assure everyone the effective freedom to copy and redistribute it, |
| 5858 | with or without modifying it, either commercially or |
| 5859 | noncommercially. Secondarily, this License preserves for the |
| 5860 | author and publisher a way to get credit for their work, while not |
| 5861 | being considered responsible for modifications made by others. |
| 5862 | |
| 5863 | This License is a kind of "copyleft", which means that derivative |
| 5864 | works of the document must themselves be free in the same sense. |
| 5865 | It complements the GNU General Public License, which is a copyleft |
| 5866 | license designed for free software. |
| 5867 | |
| 5868 | We have designed this License in order to use it for manuals for |
| 5869 | free software, because free software needs free documentation: a |
| 5870 | free program should come with manuals providing the same freedoms |
| 5871 | that the software does. But this License is not limited to |
| 5872 | software manuals; it can be used for any textual work, regardless |
| 5873 | of subject matter or whether it is published as a printed book. |
| 5874 | We recommend this License principally for works whose purpose is |
| 5875 | instruction or reference. |
| 5876 | |
| 5877 | 1. APPLICABILITY AND DEFINITIONS |
| 5878 | |
| 5879 | This License applies to any manual or other work, in any medium, |
| 5880 | that contains a notice placed by the copyright holder saying it |
| 5881 | can be distributed under the terms of this License. Such a notice |
| 5882 | grants a world-wide, royalty-free license, unlimited in duration, |
| 5883 | to use that work under the conditions stated herein. The |
| 5884 | "Document", below, refers to any such manual or work. Any member |
| 5885 | of the public is a licensee, and is addressed as "you". You |
| 5886 | accept the license if you copy, modify or distribute the work in a |
| 5887 | way requiring permission under copyright law. |
| 5888 | |
| 5889 | A "Modified Version" of the Document means any work containing the |
| 5890 | Document or a portion of it, either copied verbatim, or with |
| 5891 | modifications and/or translated into another language. |
| 5892 | |
| 5893 | A "Secondary Section" is a named appendix or a front-matter section |
| 5894 | of the Document that deals exclusively with the relationship of the |
| 5895 | publishers or authors of the Document to the Document's overall |
| 5896 | subject (or to related matters) and contains nothing that could |
| 5897 | fall directly within that overall subject. (Thus, if the Document |
| 5898 | is in part a textbook of mathematics, a Secondary Section may not |
| 5899 | explain any mathematics.) The relationship could be a matter of |
| 5900 | historical connection with the subject or with related matters, or |
| 5901 | of legal, commercial, philosophical, ethical or political position |
| 5902 | regarding them. |
| 5903 | |
| 5904 | The "Invariant Sections" are certain Secondary Sections whose |
| 5905 | titles are designated, as being those of Invariant Sections, in |
| 5906 | the notice that says that the Document is released under this |
| 5907 | License. If a section does not fit the above definition of |
| 5908 | Secondary then it is not allowed to be designated as Invariant. |
| 5909 | The Document may contain zero Invariant Sections. If the Document |
| 5910 | does not identify any Invariant Sections then there are none. |
| 5911 | |
| 5912 | The "Cover Texts" are certain short passages of text that are |
| 5913 | listed, as Front-Cover Texts or Back-Cover Texts, in the notice |
| 5914 | that says that the Document is released under this License. A |
| 5915 | Front-Cover Text may be at most 5 words, and a Back-Cover Text may |
| 5916 | be at most 25 words. |
| 5917 | |
| 5918 | A "Transparent" copy of the Document means a machine-readable copy, |
| 5919 | represented in a format whose specification is available to the |
| 5920 | general public, that is suitable for revising the document |
| 5921 | straightforwardly with generic text editors or (for images |
| 5922 | composed of pixels) generic paint programs or (for drawings) some |
| 5923 | widely available drawing editor, and that is suitable for input to |
| 5924 | text formatters or for automatic translation to a variety of |
| 5925 | formats suitable for input to text formatters. A copy made in an |
| 5926 | otherwise Transparent file format whose markup, or absence of |
| 5927 | markup, has been arranged to thwart or discourage subsequent |
| 5928 | modification by readers is not Transparent. An image format is |
| 5929 | not Transparent if used for any substantial amount of text. A |
| 5930 | copy that is not "Transparent" is called "Opaque". |
| 5931 | |
| 5932 | Examples of suitable formats for Transparent copies include plain |
| 5933 | ASCII without markup, Texinfo input format, LaTeX input format, |
| 5934 | SGML or XML using a publicly available DTD, and |
| 5935 | standard-conforming simple HTML, PostScript or PDF designed for |
| 5936 | human modification. Examples of transparent image formats include |
| 5937 | PNG, XCF and JPG. Opaque formats include proprietary formats that |
| 5938 | can be read and edited only by proprietary word processors, SGML or |
| 5939 | XML for which the DTD and/or processing tools are not generally |
| 5940 | available, and the machine-generated HTML, PostScript or PDF |
| 5941 | produced by some word processors for output purposes only. |
| 5942 | |
| 5943 | The "Title Page" means, for a printed book, the title page itself, |
| 5944 | plus such following pages as are needed to hold, legibly, the |
| 5945 | material this License requires to appear in the title page. For |
| 5946 | works in formats which do not have any title page as such, "Title |
| 5947 | Page" means the text near the most prominent appearance of the |
| 5948 | work's title, preceding the beginning of the body of the text. |
| 5949 | |
| 5950 | The "publisher" means any person or entity that distributes copies |
| 5951 | of the Document to the public. |
| 5952 | |
| 5953 | A section "Entitled XYZ" means a named subunit of the Document |
| 5954 | whose title either is precisely XYZ or contains XYZ in parentheses |
| 5955 | following text that translates XYZ in another language. (Here XYZ |
| 5956 | stands for a specific section name mentioned below, such as |
| 5957 | "Acknowledgements", "Dedications", "Endorsements", or "History".) |
| 5958 | To "Preserve the Title" of such a section when you modify the |
| 5959 | Document means that it remains a section "Entitled XYZ" according |
| 5960 | to this definition. |
| 5961 | |
| 5962 | The Document may include Warranty Disclaimers next to the notice |
| 5963 | which states that this License applies to the Document. These |
| 5964 | Warranty Disclaimers are considered to be included by reference in |
| 5965 | this License, but only as regards disclaiming warranties: any other |
| 5966 | implication that these Warranty Disclaimers may have is void and |
| 5967 | has no effect on the meaning of this License. |
| 5968 | |
| 5969 | 2. VERBATIM COPYING |
| 5970 | |
| 5971 | You may copy and distribute the Document in any medium, either |
| 5972 | commercially or noncommercially, provided that this License, the |
| 5973 | copyright notices, and the license notice saying this License |
| 5974 | applies to the Document are reproduced in all copies, and that you |
| 5975 | add no other conditions whatsoever to those of this License. You |
| 5976 | may not use technical measures to obstruct or control the reading |
| 5977 | or further copying of the copies you make or distribute. However, |
| 5978 | you may accept compensation in exchange for copies. If you |
| 5979 | distribute a large enough number of copies you must also follow |
| 5980 | the conditions in section 3. |
| 5981 | |
| 5982 | You may also lend copies, under the same conditions stated above, |
| 5983 | and you may publicly display copies. |
| 5984 | |
| 5985 | 3. COPYING IN QUANTITY |
| 5986 | |
| 5987 | If you publish printed copies (or copies in media that commonly |
| 5988 | have printed covers) of the Document, numbering more than 100, and |
| 5989 | the Document's license notice requires Cover Texts, you must |
| 5990 | enclose the copies in covers that carry, clearly and legibly, all |
| 5991 | these Cover Texts: Front-Cover Texts on the front cover, and |
| 5992 | Back-Cover Texts on the back cover. Both covers must also clearly |
| 5993 | and legibly identify you as the publisher of these copies. The |
| 5994 | front cover must present the full title with all words of the |
| 5995 | title equally prominent and visible. You may add other material |
| 5996 | on the covers in addition. Copying with changes limited to the |
| 5997 | covers, as long as they preserve the title of the Document and |
| 5998 | satisfy these conditions, can be treated as verbatim copying in |
| 5999 | other respects. |
| 6000 | |
| 6001 | If the required texts for either cover are too voluminous to fit |
| 6002 | legibly, you should put the first ones listed (as many as fit |
| 6003 | reasonably) on the actual cover, and continue the rest onto |
| 6004 | adjacent pages. |
| 6005 | |
| 6006 | If you publish or distribute Opaque copies of the Document |
| 6007 | numbering more than 100, you must either include a |
| 6008 | machine-readable Transparent copy along with each Opaque copy, or |
| 6009 | state in or with each Opaque copy a computer-network location from |
| 6010 | which the general network-using public has access to download |
| 6011 | using public-standard network protocols a complete Transparent |
| 6012 | copy of the Document, free of added material. If you use the |
| 6013 | latter option, you must take reasonably prudent steps, when you |
| 6014 | begin distribution of Opaque copies in quantity, to ensure that |
| 6015 | this Transparent copy will remain thus accessible at the stated |
| 6016 | location until at least one year after the last time you |
| 6017 | distribute an Opaque copy (directly or through your agents or |
| 6018 | retailers) of that edition to the public. |
| 6019 | |
| 6020 | It is requested, but not required, that you contact the authors of |
| 6021 | the Document well before redistributing any large number of |
| 6022 | copies, to give them a chance to provide you with an updated |
| 6023 | version of the Document. |
| 6024 | |
| 6025 | 4. MODIFICATIONS |
| 6026 | |
| 6027 | You may copy and distribute a Modified Version of the Document |
| 6028 | under the conditions of sections 2 and 3 above, provided that you |
| 6029 | release the Modified Version under precisely this License, with |
| 6030 | the Modified Version filling the role of the Document, thus |
| 6031 | licensing distribution and modification of the Modified Version to |
| 6032 | whoever possesses a copy of it. In addition, you must do these |
| 6033 | things in the Modified Version: |
| 6034 | |
| 6035 | A. Use in the Title Page (and on the covers, if any) a title |
| 6036 | distinct from that of the Document, and from those of |
| 6037 | previous versions (which should, if there were any, be listed |
| 6038 | in the History section of the Document). You may use the |
| 6039 | same title as a previous version if the original publisher of |
| 6040 | that version gives permission. |
| 6041 | |
| 6042 | B. List on the Title Page, as authors, one or more persons or |
| 6043 | entities responsible for authorship of the modifications in |
| 6044 | the Modified Version, together with at least five of the |
| 6045 | principal authors of the Document (all of its principal |
| 6046 | authors, if it has fewer than five), unless they release you |
| 6047 | from this requirement. |
| 6048 | |
| 6049 | C. State on the Title page the name of the publisher of the |
| 6050 | Modified Version, as the publisher. |
| 6051 | |
| 6052 | D. Preserve all the copyright notices of the Document. |
| 6053 | |
| 6054 | E. Add an appropriate copyright notice for your modifications |
| 6055 | adjacent to the other copyright notices. |
| 6056 | |
| 6057 | F. Include, immediately after the copyright notices, a license |
| 6058 | notice giving the public permission to use the Modified |
| 6059 | Version under the terms of this License, in the form shown in |
| 6060 | the Addendum below. |
| 6061 | |
| 6062 | G. Preserve in that license notice the full lists of Invariant |
| 6063 | Sections and required Cover Texts given in the Document's |
| 6064 | license notice. |
| 6065 | |
| 6066 | H. Include an unaltered copy of this License. |
| 6067 | |
| 6068 | I. Preserve the section Entitled "History", Preserve its Title, |
| 6069 | and add to it an item stating at least the title, year, new |
| 6070 | authors, and publisher of the Modified Version as given on |
| 6071 | the Title Page. If there is no section Entitled "History" in |
| 6072 | the Document, create one stating the title, year, authors, |
| 6073 | and publisher of the Document as given on its Title Page, |
| 6074 | then add an item describing the Modified Version as stated in |
| 6075 | the previous sentence. |
| 6076 | |
| 6077 | J. Preserve the network location, if any, given in the Document |
| 6078 | for public access to a Transparent copy of the Document, and |
| 6079 | likewise the network locations given in the Document for |
| 6080 | previous versions it was based on. These may be placed in |
| 6081 | the "History" section. You may omit a network location for a |
| 6082 | work that was published at least four years before the |
| 6083 | Document itself, or if the original publisher of the version |
| 6084 | it refers to gives permission. |
| 6085 | |
| 6086 | K. For any section Entitled "Acknowledgements" or "Dedications", |
| 6087 | Preserve the Title of the section, and preserve in the |
| 6088 | section all the substance and tone of each of the contributor |
| 6089 | acknowledgements and/or dedications given therein. |
| 6090 | |
| 6091 | L. Preserve all the Invariant Sections of the Document, |
| 6092 | unaltered in their text and in their titles. Section numbers |
| 6093 | or the equivalent are not considered part of the section |
| 6094 | titles. |
| 6095 | |
| 6096 | M. Delete any section Entitled "Endorsements". Such a section |
| 6097 | may not be included in the Modified Version. |
| 6098 | |
| 6099 | N. Do not retitle any existing section to be Entitled |
| 6100 | "Endorsements" or to conflict in title with any Invariant |
| 6101 | Section. |
| 6102 | |
| 6103 | O. Preserve any Warranty Disclaimers. |
| 6104 | |
| 6105 | If the Modified Version includes new front-matter sections or |
| 6106 | appendices that qualify as Secondary Sections and contain no |
| 6107 | material copied from the Document, you may at your option |
| 6108 | designate some or all of these sections as invariant. To do this, |
| 6109 | add their titles to the list of Invariant Sections in the Modified |
| 6110 | Version's license notice. These titles must be distinct from any |
| 6111 | other section titles. |
| 6112 | |
| 6113 | You may add a section Entitled "Endorsements", provided it contains |
| 6114 | nothing but endorsements of your Modified Version by various |
| 6115 | parties--for example, statements of peer review or that the text |
| 6116 | has been approved by an organization as the authoritative |
| 6117 | definition of a standard. |
| 6118 | |
| 6119 | You may add a passage of up to five words as a Front-Cover Text, |
| 6120 | and a passage of up to 25 words as a Back-Cover Text, to the end |
| 6121 | of the list of Cover Texts in the Modified Version. Only one |
| 6122 | passage of Front-Cover Text and one of Back-Cover Text may be |
| 6123 | added by (or through arrangements made by) any one entity. If the |
| 6124 | Document already includes a cover text for the same cover, |
| 6125 | previously added by you or by arrangement made by the same entity |
| 6126 | you are acting on behalf of, you may not add another; but you may |
| 6127 | replace the old one, on explicit permission from the previous |
| 6128 | publisher that added the old one. |
| 6129 | |
| 6130 | The author(s) and publisher(s) of the Document do not by this |
| 6131 | License give permission to use their names for publicity for or to |
| 6132 | assert or imply endorsement of any Modified Version. |
| 6133 | |
| 6134 | 5. COMBINING DOCUMENTS |
| 6135 | |
| 6136 | You may combine the Document with other documents released under |
| 6137 | this License, under the terms defined in section 4 above for |
| 6138 | modified versions, provided that you include in the combination |
| 6139 | all of the Invariant Sections of all of the original documents, |
| 6140 | unmodified, and list them all as Invariant Sections of your |
| 6141 | combined work in its license notice, and that you preserve all |
| 6142 | their Warranty Disclaimers. |
| 6143 | |
| 6144 | The combined work need only contain one copy of this License, and |
| 6145 | multiple identical Invariant Sections may be replaced with a single |
| 6146 | copy. If there are multiple Invariant Sections with the same name |
| 6147 | but different contents, make the title of each such section unique |
| 6148 | by adding at the end of it, in parentheses, the name of the |
| 6149 | original author or publisher of that section if known, or else a |
| 6150 | unique number. Make the same adjustment to the section titles in |
| 6151 | the list of Invariant Sections in the license notice of the |
| 6152 | combined work. |
| 6153 | |
| 6154 | In the combination, you must combine any sections Entitled |
| 6155 | "History" in the various original documents, forming one section |
| 6156 | Entitled "History"; likewise combine any sections Entitled |
| 6157 | "Acknowledgements", and any sections Entitled "Dedications". You |
| 6158 | must delete all sections Entitled "Endorsements." |
| 6159 | |
| 6160 | 6. COLLECTIONS OF DOCUMENTS |
| 6161 | |
| 6162 | You may make a collection consisting of the Document and other |
| 6163 | documents released under this License, and replace the individual |
| 6164 | copies of this License in the various documents with a single copy |
| 6165 | that is included in the collection, provided that you follow the |
| 6166 | rules of this License for verbatim copying of each of the |
| 6167 | documents in all other respects. |
| 6168 | |
| 6169 | You may extract a single document from such a collection, and |
| 6170 | distribute it individually under this License, provided you insert |
| 6171 | a copy of this License into the extracted document, and follow |
| 6172 | this License in all other respects regarding verbatim copying of |
| 6173 | that document. |
| 6174 | |
| 6175 | 7. AGGREGATION WITH INDEPENDENT WORKS |
| 6176 | |
| 6177 | A compilation of the Document or its derivatives with other |
| 6178 | separate and independent documents or works, in or on a volume of |
| 6179 | a storage or distribution medium, is called an "aggregate" if the |
| 6180 | copyright resulting from the compilation is not used to limit the |
| 6181 | legal rights of the compilation's users beyond what the individual |
| 6182 | works permit. When the Document is included in an aggregate, this |
| 6183 | License does not apply to the other works in the aggregate which |
| 6184 | are not themselves derivative works of the Document. |
| 6185 | |
| 6186 | If the Cover Text requirement of section 3 is applicable to these |
| 6187 | copies of the Document, then if the Document is less than one half |
| 6188 | of the entire aggregate, the Document's Cover Texts may be placed |
| 6189 | on covers that bracket the Document within the aggregate, or the |
| 6190 | electronic equivalent of covers if the Document is in electronic |
| 6191 | form. Otherwise they must appear on printed covers that bracket |
| 6192 | the whole aggregate. |
| 6193 | |
| 6194 | 8. TRANSLATION |
| 6195 | |
| 6196 | Translation is considered a kind of modification, so you may |
| 6197 | distribute translations of the Document under the terms of section |
| 6198 | 4. Replacing Invariant Sections with translations requires special |
| 6199 | permission from their copyright holders, but you may include |
| 6200 | translations of some or all Invariant Sections in addition to the |
| 6201 | original versions of these Invariant Sections. You may include a |
| 6202 | translation of this License, and all the license notices in the |
| 6203 | Document, and any Warranty Disclaimers, provided that you also |
| 6204 | include the original English version of this License and the |
| 6205 | original versions of those notices and disclaimers. In case of a |
| 6206 | disagreement between the translation and the original version of |
| 6207 | this License or a notice or disclaimer, the original version will |
| 6208 | prevail. |
| 6209 | |
| 6210 | If a section in the Document is Entitled "Acknowledgements", |
| 6211 | "Dedications", or "History", the requirement (section 4) to |
| 6212 | Preserve its Title (section 1) will typically require changing the |
| 6213 | actual title. |
| 6214 | |
| 6215 | 9. TERMINATION |
| 6216 | |
| 6217 | You may not copy, modify, sublicense, or distribute the Document |
| 6218 | except as expressly provided under this License. Any attempt |
| 6219 | otherwise to copy, modify, sublicense, or distribute it is void, |
| 6220 | and will automatically terminate your rights under this License. |
| 6221 | |
| 6222 | However, if you cease all violation of this License, then your |
| 6223 | license from a particular copyright holder is reinstated (a) |
| 6224 | provisionally, unless and until the copyright holder explicitly |
| 6225 | and finally terminates your license, and (b) permanently, if the |
| 6226 | copyright holder fails to notify you of the violation by some |
| 6227 | reasonable means prior to 60 days after the cessation. |
| 6228 | |
| 6229 | Moreover, your license from a particular copyright holder is |
| 6230 | reinstated permanently if the copyright holder notifies you of the |
| 6231 | violation by some reasonable means, this is the first time you have |
| 6232 | received notice of violation of this License (for any work) from |
| 6233 | that copyright holder, and you cure the violation prior to 30 days |
| 6234 | after your receipt of the notice. |
| 6235 | |
| 6236 | Termination of your rights under this section does not terminate |
| 6237 | the licenses of parties who have received copies or rights from |
| 6238 | you under this License. If your rights have been terminated and |
| 6239 | not permanently reinstated, receipt of a copy of some or all of |
| 6240 | the same material does not give you any rights to use it. |
| 6241 | |
| 6242 | 10. FUTURE REVISIONS OF THIS LICENSE |
| 6243 | |
| 6244 | The Free Software Foundation may publish new, revised versions of |
| 6245 | the GNU Free Documentation License from time to time. Such new |
| 6246 | versions will be similar in spirit to the present version, but may |
| 6247 | differ in detail to address new problems or concerns. See |
| 6248 | `http://www.gnu.org/copyleft/'. |
| 6249 | |
| 6250 | Each version of the License is given a distinguishing version |
| 6251 | number. If the Document specifies that a particular numbered |
| 6252 | version of this License "or any later version" applies to it, you |
| 6253 | have the option of following the terms and conditions either of |
| 6254 | that specified version or of any later version that has been |
| 6255 | published (not as a draft) by the Free Software Foundation. If |
| 6256 | the Document does not specify a version number of this License, |
| 6257 | you may choose any version ever published (not as a draft) by the |
| 6258 | Free Software Foundation. If the Document specifies that a proxy |
| 6259 | can decide which future versions of this License can be used, that |
| 6260 | proxy's public statement of acceptance of a version permanently |
| 6261 | authorizes you to choose that version for the Document. |
| 6262 | |
| 6263 | 11. RELICENSING |
| 6264 | |
| 6265 | "Massive Multiauthor Collaboration Site" (or "MMC Site") means any |
| 6266 | World Wide Web server that publishes copyrightable works and also |
| 6267 | provides prominent facilities for anybody to edit those works. A |
| 6268 | public wiki that anybody can edit is an example of such a server. |
| 6269 | A "Massive Multiauthor Collaboration" (or "MMC") contained in the |
| 6270 | site means any set of copyrightable works thus published on the MMC |
| 6271 | site. |
| 6272 | |
| 6273 | "CC-BY-SA" means the Creative Commons Attribution-Share Alike 3.0 |
| 6274 | license published by Creative Commons Corporation, a not-for-profit |
| 6275 | corporation with a principal place of business in San Francisco, |
| 6276 | California, as well as future copyleft versions of that license |
| 6277 | published by that same organization. |
| 6278 | |
| 6279 | "Incorporate" means to publish or republish a Document, in whole or |
| 6280 | in part, as part of another Document. |
| 6281 | |
| 6282 | An MMC is "eligible for relicensing" if it is licensed under this |
| 6283 | License, and if all works that were first published under this |
| 6284 | License somewhere other than this MMC, and subsequently |
| 6285 | incorporated in whole or in part into the MMC, (1) had no cover |
| 6286 | texts or invariant sections, and (2) were thus incorporated prior |
| 6287 | to November 1, 2008. |
| 6288 | |
| 6289 | The operator of an MMC Site may republish an MMC contained in the |
| 6290 | site under CC-BY-SA on the same site at any time before August 1, |
| 6291 | 2009, provided the MMC is eligible for relicensing. |
| 6292 | |
| 6293 | |
| 6294 | ADDENDUM: How to use this License for your documents |
| 6295 | ==================================================== |
| 6296 | |
| 6297 | To use this License in a document you have written, include a copy of |
| 6298 | the License in the document and put the following copyright and license |
| 6299 | notices just after the title page: |
| 6300 | |
| 6301 | Copyright (C) YEAR YOUR NAME. |
| 6302 | Permission is granted to copy, distribute and/or modify this document |
| 6303 | under the terms of the GNU Free Documentation License, Version 1.3 |
| 6304 | or any later version published by the Free Software Foundation; |
| 6305 | with no Invariant Sections, no Front-Cover Texts, and no Back-Cover |
| 6306 | Texts. A copy of the license is included in the section entitled ``GNU |
| 6307 | Free Documentation License''. |
| 6308 | |
| 6309 | If you have Invariant Sections, Front-Cover Texts and Back-Cover |
| 6310 | Texts, replace the "with...Texts." line with this: |
| 6311 | |
| 6312 | with the Invariant Sections being LIST THEIR TITLES, with |
| 6313 | the Front-Cover Texts being LIST, and with the Back-Cover Texts |
| 6314 | being LIST. |
| 6315 | |
| 6316 | If you have Invariant Sections without Cover Texts, or some other |
| 6317 | combination of the three, merge those two alternatives to suit the |
| 6318 | situation. |
| 6319 | |
| 6320 | If your document contains nontrivial examples of program code, we |
| 6321 | recommend releasing these examples in parallel under your choice of |
| 6322 | free software license, such as the GNU General Public License, to |
| 6323 | permit their use in free software. |
| 6324 | |
| 6325 | \1f |
| 6326 | File: gnugo.info, Node: GTP License, Prev: GFDL, Up: Copying |
| 6327 | |
| 6328 | A.3 The Go Text Protocol License |
| 6329 | ================================ |
| 6330 | |
| 6331 | In order to facilitate the use of the Go Text Protocol, the two files |
| 6332 | `gtp.c' and `gtp.h' are licensed under the following terms. |
| 6333 | |
| 6334 | Copyright 2001 by the Free Software Foundation. |
| 6335 | |
| 6336 | Permission is hereby granted, free of charge, to any person |
| 6337 | obtaining a copy of this file `gtp.x', to deal in the Software without |
| 6338 | restriction, including without limitation the rights to use, copy, |
| 6339 | modify, merge, publish, distribute, and/or sell copies of the Software, |
| 6340 | and to permit persons to whom the Software is furnished to do so, |
| 6341 | provided that the above copyright notice(s) and this permission notice |
| 6342 | appear in all copies of the Software and that both the above copyright |
| 6343 | notice(s) and this permission notice appear in supporting documentation. |
| 6344 | |
| 6345 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| 6346 | EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| 6347 | MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT |
| 6348 | OF THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR |
| 6349 | HOLDERS INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL |
| 6350 | INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING |
| 6351 | FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, |
| 6352 | NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION |
| 6353 | WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| 6354 | |
| 6355 | Except as contained in this notice, the name of a copyright holder |
| 6356 | shall not be used in advertising or otherwise to promote the sale, use |
| 6357 | or other dealings in this Software without prior written authorization |
| 6358 | of the copyright holder. |
| 6359 | |
| 6360 | \1f |
| 6361 | File: gnugo.info, Node: Concept Index, Next: Functions Index, Prev: Copying, Up: Top |
| 6362 | |
| 6363 | Concept Index |
| 6364 | ************* |
| 6365 | |
| 6366 | \0\b[index\0\b] |
| 6367 | * Menu: |
| 6368 | |
| 6369 | * aa_confirm_safety: GTP command reference. |
| 6370 | (line 492) |
| 6371 | * accurate_approxlib: GTP command reference. |
| 6372 | (line 207) |
| 6373 | * accuratelib: GTP command reference. |
| 6374 | (line 200) |
| 6375 | * adjacent dragons: Dragons. (line 145) |
| 6376 | * advance_random_seed: GTP command reference. |
| 6377 | (line 960) |
| 6378 | * all_legal: GTP command reference. |
| 6379 | (line 223) |
| 6380 | * amalgamation of worms into dragons: Amalgamation. (line 6) |
| 6381 | * analyze_eyegraph: GTP command reference. |
| 6382 | (line 710) |
| 6383 | * analyze_semeai: GTP command reference. |
| 6384 | (line 400) |
| 6385 | * analyze_semeai_after_move: GTP command reference. |
| 6386 | (line 406) |
| 6387 | * API: API. (line 26) |
| 6388 | * area: Territory and Moyo. (line 6) |
| 6389 | * ascii description of shapes: Patterns Overview. (line 27) |
| 6390 | * ascii interface: Ascii. (line 6) |
| 6391 | * ascii mode: Invoking GNU Go. (line 336) |
| 6392 | * attack: GTP command reference. |
| 6393 | (line 288) |
| 6394 | * attack shapes database: Patterns Overview. (line 6) |
| 6395 | * attack_either: GTP command reference. |
| 6396 | (line 294) |
| 6397 | * autohelper actions: Autohelper Actions. (line 6) |
| 6398 | * Autohelpers: Autohelpers and Constraints. |
| 6399 | (line 6) |
| 6400 | * automaton: DFA. (line 29) |
| 6401 | * black: GTP command reference. |
| 6402 | (line 111) |
| 6403 | * block_off: GTP command reference. |
| 6404 | (line 437) |
| 6405 | * board_state: The Board State. (line 6) |
| 6406 | * boardsize: GTP command reference. |
| 6407 | (line 63) |
| 6408 | * break_in: GTP command reference. |
| 6409 | (line 431) |
| 6410 | * cache: Invoking GNU Go. (line 119) |
| 6411 | * cache-size: Invoking GNU Go. (line 119) |
| 6412 | * captures: GTP command reference. |
| 6413 | (line 229) |
| 6414 | * CGoban: CGoban. (line 6) |
| 6415 | * clear_board: GTP command reference. |
| 6416 | (line 77) |
| 6417 | * clear_cache: GTP command reference. |
| 6418 | (line 284) |
| 6419 | * color: GTP command reference. |
| 6420 | (line 175) |
| 6421 | * color (dragon): Dragons. (line 98) |
| 6422 | * colored display <1>: Dragons in Color. (line 6) |
| 6423 | * colored display: Colored Display. (line 6) |
| 6424 | * combination_attack: GTP command reference. |
| 6425 | (line 479) |
| 6426 | * combination_defend: GTP command reference. |
| 6427 | (line 485) |
| 6428 | * command line options: Invoking GNU Go. (line 6) |
| 6429 | * connect: GTP command reference. |
| 6430 | (line 419) |
| 6431 | * connection shapes database <1>: Connections Database. |
| 6432 | (line 6) |
| 6433 | * connection shapes database: Patterns Overview. (line 6) |
| 6434 | * connections: Connection. (line 6) |
| 6435 | * connections database: Connections Database. |
| 6436 | (line 6) |
| 6437 | * corner matcher: Corner Matcher. (line 6) |
| 6438 | * countlib: GTP command reference. |
| 6439 | (line 187) |
| 6440 | * cputime: GTP command reference. |
| 6441 | (line 717) |
| 6442 | * cutting stone: Worms. (line 124) |
| 6443 | * cutting stone, potential: Worms. (line 133) |
| 6444 | * data structures: Basic Data Structures. |
| 6445 | (line 6) |
| 6446 | * debugging on a graphical board: view.pike. (line 6) |
| 6447 | * debugging options: Invoking GNU Go. (line 415) |
| 6448 | * Debugging the reading code: Debugging. (line 6) |
| 6449 | * decide-dragon: Decide dragon. (line 6) |
| 6450 | * decide-string: Decide string. (line 6) |
| 6451 | * decrease_depths: GTP command reference. |
| 6452 | (line 334) |
| 6453 | * defence shapes database: Patterns Overview. (line 6) |
| 6454 | * defend: GTP command reference. |
| 6455 | (line 302) |
| 6456 | * defend_both: GTP command reference. |
| 6457 | (line 385) |
| 6458 | * depth: Invoking GNU Go. (line 242) |
| 6459 | * Depth of reading: Tactical Reading. (line 6) |
| 6460 | * description of shapes: Patterns Overview. (line 27) |
| 6461 | * dfa: DFA. (line 29) |
| 6462 | * dfa.c: DFA. (line 29) |
| 6463 | * dfa.h: DFA. (line 29) |
| 6464 | * disconnect: GTP command reference. |
| 6465 | (line 425) |
| 6466 | * distance from liberty to dragon: Worms. (line 109) |
| 6467 | * does_attack: GTP command reference. |
| 6468 | (line 308) |
| 6469 | * does_defend: GTP command reference. |
| 6470 | (line 315) |
| 6471 | * does_surround: GTP command reference. |
| 6472 | (line 972) |
| 6473 | * dragon: Worms and Dragons. (line 27) |
| 6474 | * dragon escape_route: Dragons. (line 207) |
| 6475 | * dragon genus: Dragons. (line 213) |
| 6476 | * dragon lunch: Dragons. (line 230) |
| 6477 | * dragon number: Dragons. (line 100) |
| 6478 | * dragon origin: Dragons. (line 104) |
| 6479 | * dragon safety: Dragons. (line 176) |
| 6480 | * dragon size: Dragons. (line 112) |
| 6481 | * dragon status: Dragons. (line 131) |
| 6482 | * dragon weakness: Dragons. (line 199) |
| 6483 | * dragon_data: GTP command reference. |
| 6484 | (line 854) |
| 6485 | * dragon_status: GTP command reference. |
| 6486 | (line 452) |
| 6487 | * dragon_stones: GTP command reference. |
| 6488 | (line 860) |
| 6489 | * dragons: Dragons. (line 6) |
| 6490 | * draw_search_area: GTP command reference. |
| 6491 | (line 1008) |
| 6492 | * dump_stack: GTP command reference. |
| 6493 | (line 731) |
| 6494 | * echo: GTP command reference. |
| 6495 | (line 913) |
| 6496 | * echo_err: GTP command reference. |
| 6497 | (line 919) |
| 6498 | * editing pattern database: Editing Patterns. (line 6) |
| 6499 | * editing patterns: Editing Patterns. (line 6) |
| 6500 | * effective size: Dragons. (line 116) |
| 6501 | * effective size (worm): Worms. (line 48) |
| 6502 | * eliminate the randomness: Tuning. (line 155) |
| 6503 | * emacs mode: Emacs. (line 6) |
| 6504 | * escape_route: Dragons. (line 207) |
| 6505 | * estimate_score: GTP command reference. |
| 6506 | (line 621) |
| 6507 | * eval_eye: GTP command reference. |
| 6508 | (line 444) |
| 6509 | * experimental_score: GTP command reference. |
| 6510 | (line 626) |
| 6511 | * eye shapes database: Patterns Overview. (line 6) |
| 6512 | * eye space display: Colored Display. (line 48) |
| 6513 | * eye_data: GTP command reference. |
| 6514 | (line 866) |
| 6515 | * false eye: Half Eyes. (line 6) |
| 6516 | * fast pattern matching: DFA. (line 29) |
| 6517 | * final_score: GTP command reference. |
| 6518 | (line 589) |
| 6519 | * final_status: GTP command reference. |
| 6520 | (line 597) |
| 6521 | * final_status_list: GTP command reference. |
| 6522 | (line 605) |
| 6523 | * findlib: GTP command reference. |
| 6524 | (line 193) |
| 6525 | * finish_sgftrace: GTP command reference. |
| 6526 | (line 889) |
| 6527 | * finite state automaton: DFA. (line 29) |
| 6528 | * fixed_handicap: GTP command reference. |
| 6529 | (line 135) |
| 6530 | * FIXME: Coding Styles. (line 83) |
| 6531 | * followup_influence: GTP command reference. |
| 6532 | (line 799) |
| 6533 | * format of the pattern database: Patterns Overview. (line 27) |
| 6534 | * formatted printing: Print Utilities. (line 6) |
| 6535 | * GDB <1>: Debugging. (line 30) |
| 6536 | * GDB: GTP and GDB techniques. |
| 6537 | (line 6) |
| 6538 | * generation of helper functions: Autohelpers and Constraints. |
| 6539 | (line 6) |
| 6540 | * genmove: GTP command reference. |
| 6541 | (line 512) |
| 6542 | * genmove_black: GTP command reference. |
| 6543 | (line 496) |
| 6544 | * genmove_white: GTP command reference. |
| 6545 | (line 504) |
| 6546 | * genus: Dragons. (line 213) |
| 6547 | * genus (worm): Worms. (line 155) |
| 6548 | * get_connection_node_counter: GTP command reference. |
| 6549 | (line 697) |
| 6550 | * get_handicap: GTP command reference. |
| 6551 | (line 160) |
| 6552 | * get_komi: GTP command reference. |
| 6553 | (line 105) |
| 6554 | * get_life_node_counter: GTP command reference. |
| 6555 | (line 646) |
| 6556 | * get_owl_node_counter: GTP command reference. |
| 6557 | (line 661) |
| 6558 | * get_random_seed: GTP command reference. |
| 6559 | (line 948) |
| 6560 | * get_reading_node_counter: GTP command reference. |
| 6561 | (line 673) |
| 6562 | * get_trymove_counter: GTP command reference. |
| 6563 | (line 685) |
| 6564 | * gg-undo: GTP command reference. |
| 6565 | (line 571) |
| 6566 | * gg_genmove: GTP command reference. |
| 6567 | (line 529) |
| 6568 | * GMP: GMP and GTP. (line 6) |
| 6569 | * GNU Go's GDB commands: Debugging. (line 82) |
| 6570 | * go position: Hash Calculation. (line 10) |
| 6571 | * grid optimization: Details. (line 6) |
| 6572 | * GTP <1>: GTP and GDB techniques. |
| 6573 | (line 6) |
| 6574 | * GTP: GMP and GTP. (line 6) |
| 6575 | * GTP command reference: GTP command reference. |
| 6576 | (line 6) |
| 6577 | * half eye: Half Eyes. (line 6) |
| 6578 | * half_eye_data: GTP command reference. |
| 6579 | (line 872) |
| 6580 | * Hash node: Hash Organization. (line 8) |
| 6581 | * Hashing of positions: Hashing. (line 6) |
| 6582 | * help: GTP command reference. |
| 6583 | (line 925) |
| 6584 | * helper functions in pattern matching: Helper Functions. (line 6) |
| 6585 | * how GNU Go learns new joseki: Joseki Compiler. (line 6) |
| 6586 | * How to debug the reading code: Debugging. (line 6) |
| 6587 | * implementation of pattern matching <1>: Corner Matcher. (line 6) |
| 6588 | * implementation of pattern matching: PM Implementation. (line 6) |
| 6589 | * increase_depths: GTP command reference. |
| 6590 | (line 328) |
| 6591 | * inessential string: Worms. (line 165) |
| 6592 | * initial_influence: GTP command reference. |
| 6593 | (line 737) |
| 6594 | * installation: GNU/Linux and Unix. (line 6) |
| 6595 | * invariant_hash: GTP command reference. |
| 6596 | (line 248) |
| 6597 | * invariant_hash_for_moves: GTP command reference. |
| 6598 | (line 255) |
| 6599 | * invincible worm: Worms. (line 178) |
| 6600 | * invoking GNU Go: Invoking GNU Go. (line 6) |
| 6601 | * is_legal: GTP command reference. |
| 6602 | (line 217) |
| 6603 | * is_surrounded: GTP command reference. |
| 6604 | (line 966) |
| 6605 | * jago: Other Clients. (line 6) |
| 6606 | * joseki <1>: Corner Matcher. (line 6) |
| 6607 | * joseki: Joseki Compiler. (line 6) |
| 6608 | * kgs-genmove_cleanup: GTP command reference. |
| 6609 | (line 544) |
| 6610 | * known_command: GTP command reference. |
| 6611 | (line 933) |
| 6612 | * komi: GTP command reference. |
| 6613 | (line 97) |
| 6614 | * ladder_attack: GTP command reference. |
| 6615 | (line 322) |
| 6616 | * last_move: GTP command reference. |
| 6617 | (line 235) |
| 6618 | * level <1>: GTP command reference. |
| 6619 | (line 557) |
| 6620 | * level: Invoking GNU Go. (line 225) |
| 6621 | * level of play: Invoking GNU Go. (line 25) |
| 6622 | * liberties (worm): Worms. (line 74) |
| 6623 | * liberties, higher order (worm): Worms. (line 74) |
| 6624 | * licence, documentation (GFDL): GFDL. (line 3) |
| 6625 | * licence, program (GPL): GPL. (line 3) |
| 6626 | * limit_search: GTP command reference. |
| 6627 | (line 996) |
| 6628 | * list_stones: GTP command reference. |
| 6629 | (line 181) |
| 6630 | * loadsgf: GTP command reference. |
| 6631 | (line 166) |
| 6632 | * lunch: Dragons. (line 230) |
| 6633 | * lunch (worm): Worms. (line 114) |
| 6634 | * matchpat.c: DFA. (line 29) |
| 6635 | * Monte Carlo Go: Monte Carlo Go. (line 6) |
| 6636 | * move generation: Move Generators. (line 6) |
| 6637 | * move generators: Move Generators. (line 6) |
| 6638 | * move reasons <1>: Move Reasons. (line 6) |
| 6639 | * move reasons: Move Generators. (line 6) |
| 6640 | * move_history: GTP command reference. |
| 6641 | (line 241) |
| 6642 | * move_influence: GTP command reference. |
| 6643 | (line 776) |
| 6644 | * move_probabilities: GTP command reference. |
| 6645 | (line 783) |
| 6646 | * move_uncertainty: GTP command reference. |
| 6647 | (line 791) |
| 6648 | * moyo: Territory and Moyo. (line 6) |
| 6649 | * name: GTP command reference. |
| 6650 | (line 47) |
| 6651 | * neighbor dragons: Dragons. (line 145) |
| 6652 | * orientation: GTP command reference. |
| 6653 | (line 85) |
| 6654 | * origin (worm): Worms. (line 58) |
| 6655 | * output file: Output File. (line 6) |
| 6656 | * owl_attack: GTP command reference. |
| 6657 | (line 340) |
| 6658 | * owl_attack_certain: Dragons. (line 296) |
| 6659 | * owl_attack_code: Dragons. (line 291) |
| 6660 | * owl_attack_point: Dragons. (line 286) |
| 6661 | * owl_connection_defends: GTP command reference. |
| 6662 | (line 378) |
| 6663 | * owl_defend: GTP command reference. |
| 6664 | (line 346) |
| 6665 | * owl_defense_certain: Dragons. (line 314) |
| 6666 | * owl_defense_code: Dragons. (line 309) |
| 6667 | * owl_defense_point: Dragons. (line 305) |
| 6668 | * owl_does_attack: GTP command reference. |
| 6669 | (line 366) |
| 6670 | * owl_does_defend: GTP command reference. |
| 6671 | (line 372) |
| 6672 | * owl_second_attack_point: Dragons. (line 301) |
| 6673 | * owl_second_defense_point: Dragons. (line 319) |
| 6674 | * owl_substantial: GTP command reference. |
| 6675 | (line 393) |
| 6676 | * owl_threaten_attack: GTP command reference. |
| 6677 | (line 352) |
| 6678 | * owl_threaten_defense: GTP command reference. |
| 6679 | (line 359) |
| 6680 | * pattern attributes: Pattern Classification. |
| 6681 | (line 6) |
| 6682 | * pattern database <1>: DFA. (line 29) |
| 6683 | * pattern database: Patterns Overview. (line 6) |
| 6684 | * pattern matching <1>: DFA. (line 29) |
| 6685 | * pattern matching: Patterns Overview. (line 6) |
| 6686 | * pattern matching optimization: Details. (line 6) |
| 6687 | * pattern overview: Patterns Overview. (line 6) |
| 6688 | * pattern.c: Patterns Overview. (line 6) |
| 6689 | * pattern.h: Patterns Overview. (line 6) |
| 6690 | * persistent cache: Persistent Cache. (line 6) |
| 6691 | * place_free_handicap: GTP command reference. |
| 6692 | (line 143) |
| 6693 | * play: GTP command reference. |
| 6694 | (line 127) |
| 6695 | * playwhite: GTP command reference. |
| 6696 | (line 119) |
| 6697 | * popgo: GTP command reference. |
| 6698 | (line 277) |
| 6699 | * position: Hash Calculation. (line 10) |
| 6700 | * position struct: Basic Data Structures. |
| 6701 | (line 6) |
| 6702 | * potential cutting stone: Worms. (line 133) |
| 6703 | * printsgf: GTP command reference. |
| 6704 | (line 899) |
| 6705 | * product: DFA. (line 29) |
| 6706 | * protocol_version: GTP command reference. |
| 6707 | (line 39) |
| 6708 | * qGo: Other Clients. (line 6) |
| 6709 | * quarry: Other Clients. (line 6) |
| 6710 | * query_boardsize: GTP command reference. |
| 6711 | (line 71) |
| 6712 | * query_orientation: GTP command reference. |
| 6713 | (line 91) |
| 6714 | * quit: GTP command reference. |
| 6715 | (line 33) |
| 6716 | * Read result: Hash Organization. (line 8) |
| 6717 | * Reading code: Tactical Reading. (line 6) |
| 6718 | * Reading code debugging tools: Debugging. (line 6) |
| 6719 | * reading DEPTH: Tactical Reading. (line 6) |
| 6720 | * Reading optimisation: Hashing. (line 6) |
| 6721 | * Reading process: Tactical Reading. (line 6) |
| 6722 | * reading return codes: Reading Basics. (line 51) |
| 6723 | * reading shadow: Persistent Cache. (line 50) |
| 6724 | * reading.c <1>: Reading Basics. (line 122) |
| 6725 | * reading.c: Tactical Reading. (line 6) |
| 6726 | * reading.h: Tactical Reading. (line 6) |
| 6727 | * reg_genmove: GTP command reference. |
| 6728 | (line 521) |
| 6729 | * report_uncertainty: GTP command reference. |
| 6730 | (line 941) |
| 6731 | * reset_connection_node_counter: GTP command reference. |
| 6732 | (line 691) |
| 6733 | * reset_life_node_counter: GTP command reference. |
| 6734 | (line 637) |
| 6735 | * reset_owl_node_counter: GTP command reference. |
| 6736 | (line 655) |
| 6737 | * reset_reading_node_counter: GTP command reference. |
| 6738 | (line 667) |
| 6739 | * reset_search_mask: GTP command reference. |
| 6740 | (line 990) |
| 6741 | * reset_trymove_counter: GTP command reference. |
| 6742 | (line 679) |
| 6743 | * restricted_genmove: GTP command reference. |
| 6744 | (line 537) |
| 6745 | * return codes: Reading Basics. (line 51) |
| 6746 | * same_dragon: GTP command reference. |
| 6747 | (line 464) |
| 6748 | * scoring: Scoring. (line 6) |
| 6749 | * semeai: Dragons. (line 254) |
| 6750 | * semeai_attack_certain: Dragons. (line 254) |
| 6751 | * semeai_attack_point: Dragons. (line 254) |
| 6752 | * semeai_defense_certain: Dragons. (line 254) |
| 6753 | * semeai_defense_point: Dragons. (line 254) |
| 6754 | * set_free_handicap: GTP command reference. |
| 6755 | (line 152) |
| 6756 | * set_random_seed: GTP command reference. |
| 6757 | (line 954) |
| 6758 | * set_search_diamond: GTP command reference. |
| 6759 | (line 984) |
| 6760 | * set_search_limit: GTP command reference. |
| 6761 | (line 1002) |
| 6762 | * SGF (Smart Game Format): SGF Support. (line 6) |
| 6763 | * SGF files in memory: SGF. (line 6) |
| 6764 | * shape attributes: Pattern Classification. |
| 6765 | (line 6) |
| 6766 | * showboard: GTP command reference. |
| 6767 | (line 723) |
| 6768 | * Smart Game Format: SGF Support. (line 6) |
| 6769 | * Speedup of reading process: Hashing. (line 6) |
| 6770 | * start_sgftrace: GTP command reference. |
| 6771 | (line 879) |
| 6772 | * string: Worms and Dragons. (line 27) |
| 6773 | * superstring: General Utilities. (line 249) |
| 6774 | * surround: Dragons. (line 238) |
| 6775 | * surround_map: GTP command reference. |
| 6776 | (line 979) |
| 6777 | * surround_size: Dragons. (line 238) |
| 6778 | * surround_status: Dragons. (line 238) |
| 6779 | * symmetry and transformations: Symmetry & transformations. |
| 6780 | (line 6) |
| 6781 | * symmetry and transformations of shapes: Symmetry & transformations. |
| 6782 | (line 6) |
| 6783 | * tactical_analyze_semeai: GTP command reference. |
| 6784 | (line 413) |
| 6785 | * teaching josekis to GNU Go: Joseki Compiler. (line 6) |
| 6786 | * territory: Territory and Moyo. (line 6) |
| 6787 | * test_eyeshape: GTP command reference. |
| 6788 | (line 704) |
| 6789 | * The Go Modem Protocol and Go Text Protocol: GMP and GTP. (line 6) |
| 6790 | * the joseki compiler: Joseki Compiler. (line 6) |
| 6791 | * time_left: GTP command reference. |
| 6792 | (line 583) |
| 6793 | * time_settings: GTP command reference. |
| 6794 | (line 576) |
| 6795 | * timers: General Utilities. (line 328) |
| 6796 | * traces: Traces. (line 6) |
| 6797 | * Transposition table: Hashing. (line 6) |
| 6798 | * Trying hypothetical moves: Tactical Reading. (line 6) |
| 6799 | * tryko: GTP command reference. |
| 6800 | (line 270) |
| 6801 | * trymove: GTP command reference. |
| 6802 | (line 264) |
| 6803 | * tune_move_ordering: GTP command reference. |
| 6804 | (line 906) |
| 6805 | * tuning GNU Go: Traces. (line 6) |
| 6806 | * tuning the pattern database: Tuning. (line 6) |
| 6807 | * tuning the shapes database: Tuning. (line 6) |
| 6808 | * UCT algorithm: Monte Carlo Go. (line 6) |
| 6809 | * unconditional_status: GTP command reference. |
| 6810 | (line 470) |
| 6811 | * undo: GTP command reference. |
| 6812 | (line 564) |
| 6813 | * Usage of the stack in reading: Tactical Reading. (line 6) |
| 6814 | * version: GTP command reference. |
| 6815 | (line 55) |
| 6816 | * weakness: Dragons. (line 199) |
| 6817 | * worm <1>: Worms. (line 6) |
| 6818 | * worm: Worms and Dragons. (line 27) |
| 6819 | * worm_cutstone: GTP command reference. |
| 6820 | (line 847) |
| 6821 | * worm_data: GTP command reference. |
| 6822 | (line 806) |
| 6823 | * worm_stones: GTP command reference. |
| 6824 | (line 841) |
| 6825 | * Zobrist hashing algorithm: Hashing. (line 6) |
| 6826 | |