engine/shapes.c

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
 * This is GNU Go, a Go program. Contact gnugo@gnu.org, or see       *
 * http://www.gnu.org/software/gnugo/ for more information.          *
 *                                                                   *
 * Copyright 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,   *
 * 2008 and 2009 by the Free Software Foundation.                    *
 *                                                                   *
 * This program is free software; you can redistribute it and/or     *
 * modify it under the terms of the GNU General Public License as    *
 * published by the Free Software Foundation - version 3 or          *
 * (at your option) any later version.                               *
 *                                                                   *
 * This program is distributed in the hope that it will be useful,   *
 * but WITHOUT ANY WARRANTY; without even the implied warranty of    *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the     *
 * GNU General Public License in file COPYING for more details.      *
 *                                                                   *
 * You should have received a copy of the GNU General Public         *
 * License along with this program; if not, write to the Free        *
 * Software Foundation, Inc., 51 Franklin Street, Fifth Floor,       *
 * Boston, MA 02111, USA.                                            *
\* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

#include "gnugo.h"

#include <stdio.h>
#include <stdlib.h>

#include "liberty.h"
#include "patterns.h"

/* Maximum number of dragons considered by a, B, C, and d class patterns. */
#define MAX_DRAGONS_PER_PATTERN 5
#define MAX_STRINGS_PER_PATTERN 5

/* Values of joseki patterns. */
#define U_VALUE 40.0
#define J_VALUE 35.0
#define j_VALUE 24.0
#define t_VALUE 16.0


/* Take care of joseki patterns. */
static void
handle_joseki_patterns(struct pattern_attribute *attributes,
                       unsigned int class, int move,
                       int my_dragons[MAX_DRAGONS_PER_PATTERN],
                       int my_ndragons,
                       int your_dragons[MAX_DRAGONS_PER_PATTERN],
                       int your_ndragons)
{
  struct pattern_attribute *attribute;

  /* Pattern class J, joseki standard move. Add expand territory and
   * moyo, and require the value at least J_value.
   */
  if (class & CLASS_J) {
    TRACE("...joseki standard move\n");
    add_expand_territory_move(move);
    TRACE("...expands territory\n");
    add_expand_moyo_move(move);
    TRACE("...expands moyo\n");
    set_minimum_move_value(move, J_VALUE);
    TRACE("... minimum move value %f\n", J_VALUE);
  }

  /* Class `j' and `t' patterns are treated similarly. */
  if (class & (CLASS_j | CLASS_t)) {
    float min_value;
    float shape_value = 0.0;

    if (class & CLASS_j) {
      min_value = j_VALUE;
      TRACE("...less urgent joseki move\n");
      add_expand_territory_move(move);
      TRACE("...expands territory\n");
      add_expand_moyo_move(move);
      TRACE("...expands moyo\n");
    }
    else {
      min_value = t_VALUE;
      TRACE("...minor joseki move\n");
    }

    /* Board size modification. */
    min_value *= board_size / 19.0;

    for (attribute = attributes; attribute->type != LAST_ATTRIBUTE;
         attribute++) {
      if (attribute->type == SHAPE) {
        shape_value = attribute->value;
        min_value *= (1 + 0.01 * shape_value);
        break;
      }
    }

    if ((board_size >= 17) && (class & CLASS_F)) {
      /* Otherwise, `j' and `t' patterns not of CLASS_F would get
       * preferred in value_move_reasons().
       */
      min_value *= 1.005;

      set_maximum_move_value(move, min_value);
      scale_randomness(move, 5.0);
      TRACE("...move value %f (shape %f)\n", min_value, shape_value);
    }
    else
      TRACE("...minimum move value %f (shape %f)\n", min_value, shape_value);

    set_minimum_move_value(move, min_value);
  }

  /* Pattern class U, very urgent joseki move. Add strategical defense
   * and attack, plus a shape bonus of 15 and a minimum value of 40.
   */
  if (class & CLASS_U) {
    int k;

    TRACE("...joseki urgent move\n");
    for (k = 0; k < my_ndragons; k++) {
      add_strategical_defense_move(move, my_dragons[k]);
      TRACE("...strategical defense of %1m\n", my_dragons[k]);
    }
    for (k = 0; k < your_ndragons; k++) {
      add_strategical_attack_move(move, your_dragons[k]);
      TRACE("...strategical attack on %1m\n", your_dragons[k]);
    }
    add_shape_value(move, 15);
    TRACE("...shape value 15\n");
    set_minimum_move_value(move, U_VALUE);
    TRACE("...(min) move value %f\n", U_VALUE);
  }

  /* Pattern class T, joseki trick move. For the moment we never play
   * these.
   */
  if (class & CLASS_T) {
    TRACE("...joseki trick move\n");
    add_antisuji_move(move);
    TRACE("...antisuji\n");
  }

  for (attribute = attributes; attribute->type != LAST_ATTRIBUTE;
       attribute++) {
    switch (attribute->type) {
    case MIN_VALUE:
      set_minimum_move_value(move, attribute->value);
      TRACE("...(min) move value %f\n", attribute->value);
      break;

    case MAX_VALUE:
      set_maximum_move_value(move, attribute->value);
      TRACE("...max move value %f\n", attribute->value);
      break;

    case MIN_TERRITORY:
      set_minimum_territorial_value(move, attribute->value);
      TRACE("...(min) territorial value %f\n", attribute->value);
      break;

    case MAX_TERRITORY:
      set_maximum_territorial_value(move, attribute->value);
      TRACE("...max territorial value %f\n", attribute->value);
      break;

    case SHAPE:
      /* For class `j' and `t' patterns shape value has been counted
       * already.
       */
      if (!(class & (CLASS_j | CLASS_t))) {
        add_shape_value(move, attribute->value);
        TRACE("...shape value %f\n", attribute->value);
      }

      break;

    case FOLLOWUP:
      add_followup_value(move, attribute->value);
      TRACE("...followup value %f\n", attribute->value);
      break;

    case REVERSE_FOLLOWUP:
      add_reverse_followup_value(move, attribute->value);
      TRACE("...reverse followup value %f\n", attribute->value);
      break;

    default:
      /* Must not happen. */
      gg_assert(0);
    }
  }
}


/*
 * This callback is invoked for each matched pattern.
 */
static void
shapes_callback(int anchor, int color, struct pattern *pattern, int ll,
                void *data)
{
  int other = OTHER_COLOR(color);

  int k, l;
  int move;
  /* For restricted search, the pattern must intersect the search area */

  /* Dragons of our color. */
  int my_dragons[MAX_DRAGONS_PER_PATTERN];
  int my_ndragons = 0;

  /* Dragons of other color. */
  int your_dragons[MAX_DRAGONS_PER_PATTERN];
  int your_ndragons = 0;

  /* Strings of our color. */
  int my_strings[MAX_STRINGS_PER_PATTERN];
  int my_nstrings = 0;

  /* Strings of other color. */
  int your_strings[MAX_STRINGS_PER_PATTERN];
  int your_nstrings = 0;

  /* Make a local copy of the classification that we may modify. */
  unsigned int class = pattern->class;

  /* Don't accept fuseki marked patterns while scoring. */
  if (doing_scoring && (class & CLASS_F))
    return;

  /* Don't need auxiliary data in this callback. */
  UNUSED(data);

  /* Pick up the location of the move */
  move = AFFINE_TRANSFORM(pattern->move_offset, ll, anchor);

  /* For some classes of patterns we need to find all dragons present
   * in the pattern.
   */
  if ((class & (CLASS_B | CLASS_C | CLASS_c | CLASS_a | CLASS_d | CLASS_O
                | CLASS_J | CLASS_j | CLASS_U | CLASS_T | CLASS_t)) != 0) {
    /* Match each point. */
    for (k = 0; k < pattern->patlen; ++k) {
      int pos; /* absolute (board) co-ord of (transformed) pattern element */
      int origin; /* dragon origin */

      /* all the following stuff (currently) applies only at occupied cells */
      if (pattern->patn[k].att == ATT_dot)
        continue;

      /* transform pattern real coordinate */
      pos = AFFINE_TRANSFORM(pattern->patn[k].offset, ll, anchor);

      /* Already, matchpat rejects O patterns containing a friendly stone with
       * DEAD or CRITICAL matcher_status. If the stone is tactically
       * CRITICAL it still could have matcher_status ALIVE since it might
       * be amalgamated into a live dragon. In this case we want to reject the
       * pattern if (move) does not rescue it. This is most easily tested
       * here within shapes_callback(), since the value of (move) is not
       * known by matchpat().
       */
      if ((class & CLASS_O)
          && board[pos] == color
          && worm[pos].attack_points[0] != 0
          && !does_defend(move, pos))
        return;

      origin = dragon[pos].origin;
      if (board[pos] == color && my_ndragons < MAX_DRAGONS_PER_PATTERN) {
        for (l = 0; l < my_ndragons; l++) {
          if (my_dragons[l] == origin)
            break;
        }
        if (l == my_ndragons) {
          /* We found another dragon of our color. Check that it (or
           * rather the underlying worm) cannot be tactically
           * captured before adding it to the list of my_dragons.
           */
          if (worm[pos].attack_codes[0] == 0
              || does_defend(move, pos)) {
            /* Ok, add the dragon to the list. */
            my_dragons[l] = origin;
            my_ndragons++;
          }
        }
      }

      if (board[pos] == other && your_ndragons < MAX_DRAGONS_PER_PATTERN) {
        for (l = 0; l < your_ndragons; l++) {
          if (your_dragons[l] == origin)
            break;
        }
        if (l == your_ndragons) {
          /* We found another opponent dragon, add it to the list. */
          your_dragons[l] = origin;
          your_ndragons++;
        }
      }

      if (pattern->patn[k].att == ATT_O || pattern->patn[k].att == ATT_X) {
        origin = find_origin(pos);
        if (board[pos] == color && my_nstrings < MAX_STRINGS_PER_PATTERN) {
          for (l = 0; l < my_nstrings; l++) {
            if (my_strings[l] == origin)
              break;
          }
          if (l == my_nstrings) {
            /* We found another string of our color. Check that it
             * cannot be tactically captured before adding it to the
             * list of my_strings.
             */
            if (worm[pos].attack_codes[0] == 0
                || does_defend(move, pos)) {
              /* Ok, add the string to the list. */
              my_strings[l] = origin;
              my_nstrings++;
            }
          }
        }

        if (board[pos] == other && your_nstrings < MAX_STRINGS_PER_PATTERN) {
          for (l = 0; l < your_nstrings; l++) {
            if (your_strings[l] == origin)
              break;
          }
          if (l == your_nstrings) {
            /* We found another opponent string, add it to the list. */
            your_strings[l] = origin;
            your_nstrings++;
          }
        }
      }
    } /* loop over elements */
  } /* if we need to loop over the elements */

  /* Nothing to connect. Remove C class bit. */
  if (my_nstrings < 2)
    class &= ~CLASS_C;

  /* Nothing to cut. Remove B class bit. */
  if (your_nstrings < 2)
    class &= ~CLASS_B;

  /*
   * If this pattern can't produce any effect (e.g. if it was a B or C
   * pattern with only one dragon of the appropriate color), don't
   * do any expensive checking but return immediately.
   * If it only has some move_values, these will be ignored.
   */
  if (!pattern->helper
      && !allpats
      && !(pattern->autohelper_flag & HAVE_ACTION)
      && !(class & CLASS_MOVE_REASONS)
      && pattern->attributes->type == LAST_ATTRIBUTE)
    return;

  /* For sacrifice patterns, the survival of the stone to be played is
   * not checked (but it still needs to be legal). Otherwise we
   * discard moves which can be captured.
   */
  if (!(class & CLASS_s)) {
    /* Don't allow ko unsafety. */
    if (safe_move(move, color) != WIN) {
      if (0)
        TRACE("  move at %1m wasn't safe, discarded\n", move);
      return;
    }
  }
  else {
    /* Allow illegal ko captures at this stage. */
    if (!is_ko(move, color, NULL) && !is_legal(move, color)) {
      if (0)
        TRACE("  move at %1m wasn't legal, discarded\n", move);
      return;
    }
  }

  /* For class n patterns, the pattern is contingent on an opponent
   * move at * not being captured.
   */
  if (class & CLASS_n) {
    /* Allow ko unsafety. */
    if (safe_move(move, other) == 0) {
      if (0)
        TRACE("  opponent can't play safely at %1m, move discarded\n", move);
      return;
    }
  }

  /* If the pattern has a constraint, call the autohelper to see
   * if the pattern must be rejected.
   */
  if (pattern->autohelper_flag & HAVE_CONSTRAINT) {
    if (!pattern->autohelper(ll, move, color, 0))
      return;
  }

  /* Ask helper for acceptance of pattern. */
  if (pattern->helper) {
    /* ask helper function to consider the move */
    int accepted;
    DEBUG(DEBUG_HELPER, "  asking helper to consider '%s'+%d at %1m\n",
          pattern->name, ll, move);
    accepted = pattern->helper(pattern, ll, move, color);

    if (accepted) {
      DEBUG(DEBUG_HELPER, "helper likes pattern '%s' at %1m\n",
            pattern->name, move);
    }
    else {
      DEBUG(DEBUG_HELPER, "  helper does not like pattern '%s' at %1m\n",
            pattern->name, move);
      return;  /* pattern matcher does not like it */
    }
  }

  /* If using -a, want to see all matches even if not -v */
  if (allpats || verbose) {
    TRACE("pattern '%s'+%d matched at %1m\n", pattern->name, ll, move);
  }

  /* does the pattern have an action? */
  if (pattern->autohelper_flag & HAVE_ACTION)
    pattern->autohelper(ll, move, color, 1);

  /* Pattern class B, try to cut all combinations of opponent strings. */
  if (class & CLASS_B) {
    for (k = 0; k < your_nstrings; k++)
      for (l = k+1; l < your_nstrings; l++) {
        if (string_connect(your_strings[k], your_strings[l], NULL)
            && !play_connect_n(color, 1, 1, move,
                               your_strings[k], your_strings[l])) {
          add_cut_move(move, your_strings[k], your_strings[l]);
          TRACE("...cuts strings %1m, %1m\n",
                your_strings[k], your_strings[l]);
        }
      }
  }

  /* Pattern class C, try to connect all combinations of our strings. */
  if (class & CLASS_C) {
    for (k = 0; k < my_nstrings; k++)
      for (l = k+1; l < my_nstrings; l++) {
        if (disconnect(my_strings[k], my_strings[l], NULL)
            && !play_connect_n(color, 0, 1, move,
                               my_strings[k], my_strings[l])) {
          add_connection_move(move, my_strings[k], my_strings[l]);
          TRACE("...connects strings %1m, %1m\n",
                my_strings[k], my_strings[l]);
        }
      }
  }

  /* Pattern class c, add strategical defense move reason for all our
   * dragons and a small shape bonus.
   *
   * This is a preliminary effect of "weak connection" and may need to
   * be revised.
   */
  if (class & CLASS_c) {
    for (k = 0; k < my_ndragons; k++) {
      add_strategical_defense_move(move, my_dragons[k]);
      TRACE("...strategical defense (weak connection) of %1m\n",
            my_dragons[k]);
    }
    add_shape_value(move, 1);
    TRACE("...shape value 1\n");
  }

  /* Pattern class b is obsolete in the pattern databases handled here. */
  gg_assert(!(class & CLASS_b));

  /* Pattern class e, expand to make territory. */
  if (class & CLASS_e) {
    add_expand_territory_move(move);
    TRACE("...expands territory\n");
  }

  /* Pattern class E, expand to make moyo. */
  if (class & CLASS_E) {
    add_expand_moyo_move(move);
    TRACE("...expands moyo\n");
  }

  /* Pattern class i, an invasion. */
  if (class & CLASS_I) {
    add_invasion_move(move);
    TRACE("...is an invasion\n");
  }

  /* Pattern class a, strategical level attack on all opponent dragons. */
  if (class & CLASS_a) {
    for (k = 0; k < your_ndragons; k++) {
      add_strategical_attack_move(move, your_dragons[k]);
      TRACE("...strategical attack on %1m\n", your_dragons[k]);
    }
  }

  /* Pattern class d, strategical level defense of all own dragons. */
  if (class & CLASS_d) {
    for (k = 0; k < my_ndragons; k++) {
      add_strategical_defense_move(move, my_dragons[k]);
      TRACE("...strategical defense of %1m\n", my_dragons[k]);
    }
  }

  /* Pattern class W, worthwhile threat move. */
  if (class & CLASS_W) {
    TRACE("...worthwhile threat move\n");
    add_worthwhile_threat_move(move);
  }

  handle_joseki_patterns(pattern->attributes, class, move,
                         my_dragons, my_ndragons, your_dragons, your_ndragons);
}


/* This callback is invoked for each matched pattern from joseki
 * database.  This function is just a copy of relevant parts of
 * shapes_callback().  However, most of the common code resides in
 * handle_joseki_patterns().
 */
static void
joseki_callback(int move, int color, struct corner_pattern *pattern,
                int trans, int *stones, int num_stones)
{
  int k, l;
  int class = pattern->class;

  /* Dragons of our color. */
  int my_dragons[MAX_DRAGONS_PER_PATTERN];
  int my_ndragons = 0;

  /* Dragons of other color. */
  int your_dragons[MAX_DRAGONS_PER_PATTERN];
  int your_ndragons = 0;

  /* For urgent joseki patterns we need to find all dragons present in the
   * pattern since such patterns are assumed to have strategical effect on
   * them.
   */
  if (class & CLASS_U) {
    /* Loop over all stones in the pattern. */
    for (k = 0; k < num_stones; k++) {
      int pos = stones[k];
      int origin = dragon[pos].origin;

      if (board[pos] == color && my_ndragons < MAX_DRAGONS_PER_PATTERN) {
        for (l = 0; l < my_ndragons; l++) {
          if (my_dragons[l] == origin)
            break;
        }

        if (l == my_ndragons) {
          /* We found another dragon of our color. Check that it (or
           * rather the underlying worm) cannot be tactically
           * captured before adding it to the list of my_dragons.
           */
          if (worm[pos].attack_codes[0] == 0 || does_defend(move, pos)) {
            /* Ok, add the dragon to the list. */
            my_dragons[l] = origin;
            my_ndragons++;
          }
        }
      }

      if (board[pos] != color && your_ndragons < MAX_DRAGONS_PER_PATTERN) {
        for (l = 0; l < your_ndragons; l++) {
          if (your_dragons[l] == origin)
            break;
        }
        if (l == your_ndragons) {
          /* We found another opponent dragon, add it to the list. */
          your_dragons[l] = origin;
          your_ndragons++;
        }
      }
    }
  }

  /* For joseki patterns we don't check if the proposed move is safe or legal.
   */

  /* If the pattern has a constraint, call the autohelper to see
   * if the pattern must be rejected.
   */
  if (pattern->autohelper_flag & HAVE_CONSTRAINT) {
    if (!pattern->autohelper(trans, move, color, 0))
      return;
  }

  /* If using -a, want to see all matches even if not -v. */
  if (allpats || verbose)
    TRACE("pattern '%s'+%d matched at %1m\n", pattern->name, trans, move);

  /* Does the pattern have an action? */
  if (pattern->autohelper_flag & HAVE_ACTION)
    pattern->autohelper(trans, move, color, 1);

  /* Pattern class N, antisuji move. */
  if (class & CLASS_N) {
    TRACE("...antisuji move\n");
    add_antisuji_move(move);
  }

  handle_joseki_patterns(pattern->attributes, class, move,
                         my_dragons, my_ndragons, your_dragons, your_ndragons);
}


/*
 * Match all patterns in patterns.db and patterns2.db on all positions.
 *
 * This function is one of the basic generators of move reasons, called
 * by genmove().
 */
void
shapes(int color)
{
  TRACE("\nPattern matcher is looking for move reasons for %s!\n",
        color_to_string(color));

  matchpat(shapes_callback, color, &pat_db, NULL, NULL);

  /* Don't match joseki patterns while scoring. */
  if (josekidb && !doing_scoring)
#if 1
    corner_matchpat(joseki_callback, color, &joseki_db);
#else
    matchpat(shapes_callback, color, &joseki_db, NULL, NULL);
#endif

  if (!disable_fuseki && !doing_scoring)
    matchpat(shapes_callback, color, &fusekipat_db, NULL, NULL);
}


/*
 * Match all patterns in endgame.db on all positions.
 */
void
endgame_shapes(int color)
{
  TRACE("\nEndgame pattern matcher is looking for move reasons for %s!\n",
        color_to_string(color));

  matchpat(shapes_callback, color, &endpat_db, NULL, NULL);
}


/*
 * Local Variables:
 * tab-width: 8
 * c-basic-offset: 2
 * End:
 */