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0c731d4a AT |
1 | /* (c) 2021 Aaron Taylor <ataylor at subgeniuskitty dot com> */ |
2 | /* See LICENSE.txt file for copyright and license details. */ | |
3 | ||
4 | ||
5 | /* TODO: Write description explaining that this simulates all 1D NN CAs, and explain briefly what all those terms imply. */ | |
6 | /* TODO: Explain things like the topology of the space. */ | |
7 | /* TODO: Explain how the numbering for a CA expands to the actual rules. */ | |
8 | /* TODO: Briefly explain the four different classes of behavior and their implications. */ | |
9 | /* TODO: Include a link to Wikipedia. */ | |
10 | /* TODO: I suppose a lot of this stuff goes in the README instead. */ | |
11 | /* TODO: Explain the data structures in detail. */ | |
12 | /* TODO: Explain all the options, like the various starting conditions. */ | |
13 | ||
14 | ||
15 | /* TODO: Check manpage for all functions I use and ensure my includes are correct. I don't want to depend on picking up includes via screenhack.h. */ | |
16 | /* TODO: Verify everything in this file is C89. Get rid of things like '//' comments, pack all my declarations upfront, no stdint, etc. */ | |
0c731d4a AT |
17 | |
18 | #include "screenhack.h" | |
19 | ||
20 | // Command line options | |
7ce88c8e | 21 | // directory to output XBM files of each run (and call an external command to convert to PNGs?) |
2b742550 | 22 | // -save-dir STRING |
7ce88c8e | 23 | // number of generations to simulate |
2b742550 | 24 | // -num-generations N |
7ce88c8e | 25 | // delay time (speed of simulation) |
2b742550 | 26 | // -delay-usec N |
7ce88c8e | 27 | // foreground and background color |
2b742550 | 28 | // ??? (strings of some sort, but I need to look up what X resources to interact with) |
7ce88c8e | 29 | // display info overlay with CA number and start conditions? |
2b742550 | 30 | // -overlay |
7ce88c8e | 31 | // which ruleset number to use? Or random? Or random from small set of hand-selected interesting examples? |
2b742550 AT |
32 | // Options (with precedence): -rule N |
33 | // -rule-curated | |
34 | // -rule-random | |
7ce88c8e | 35 | // which starting population to use? Or random? Or one bit in middle? Or one bit on edge? (For random: Can I allow specifying a density like 25%, 50%, 75%?) |
2b742550 AT |
36 | // Options (with precedence): -population STRING (string is a comma separated list of cell IDs to populate, starting from 0) |
37 | // -population-curated | |
38 | // -population-random | |
39 | // size of pixel square (e.g. 1x1, 2x2, 3x3, etc) | |
40 | // -pixel-size N | |
0c731d4a AT |
41 | |
42 | struct state { | |
7ce88c8e AT |
43 | /* Various X resources */ |
44 | Display * dpy; | |
45 | Window win; | |
46 | GC gc; | |
47 | ||
48 | // TODO: Explain that this holds the whole evolution of the CA and the actual displayed visualization is simply a snapshot into this pixmap. | |
49 | Pixmap evolution_history; | |
7ce88c8e AT |
50 | |
51 | // TODO: Explain all of these. | |
7ce88c8e AT |
52 | unsigned long fg, bg; |
53 | int xlim, ylim, ypos; // explain roughly how and where we use these. Note: I'm not thrilled xlim/ylim since they are actually the width of the display, not the limit of the index (off by one). Change those names. | |
54 | Bool display_info; | |
7ce88c8e AT |
55 | |
56 | Bool * current_generation; | |
57 | uint8_t ruleset; | |
c428f3d5 AT |
58 | |
59 | /* Misc Commandline Options */ | |
60 | int pixel_size; /* Size of CA cell in pixels (e.g. pixel_size=3 means 3x3 pixels per cell). */ | |
61 | int delay_microsec; /* Requested delay to screenhack framework before next call to WolframAutomata_draw(). */ | |
7969381e | 62 | int num_generations; /* Number of generations of the CA to simulate before restarting. */ |
c428f3d5 AT |
63 | |
64 | /* Expository Variables - Not strictly necessary, but makes some code easier to read. */ | |
65 | size_t number_of_cells; | |
0c731d4a AT |
66 | }; |
67 | ||
68 | static void * | |
69 | WolframAutomata_init(Display * dpy, Window win) | |
70 | { | |
7ce88c8e AT |
71 | struct state * state = calloc(1, sizeof(*state)); // TODO: Check calloc() call |
72 | XGCValues gcv; | |
73 | XWindowAttributes xgwa; | |
74 | ||
75 | state->dpy = dpy; | |
76 | state->win = win; | |
77 | ||
78 | XGetWindowAttributes(state->dpy, state->win, &xgwa); | |
79 | state->xlim = xgwa.width; | |
80 | state->ylim = xgwa.height; | |
81 | state->ypos = 0; // TODO: Explain why. | |
82 | ||
83 | state->fg = gcv.foreground = get_pixel_resource(state->dpy, xgwa.colormap, "foreground", "Foreground"); | |
84 | state->bg = gcv.background = get_pixel_resource(state->dpy, xgwa.colormap, "background", "Background"); | |
85 | state->gc = XCreateGC(state->dpy, state->win, GCForeground, &gcv); | |
86 | ||
c428f3d5 | 87 | state->delay_microsec = get_integer_resource(state->dpy, "delay-usec", "Integer"); |
7ce88c8e AT |
88 | if (state->delay_microsec < 0) state->delay_microsec = 0; |
89 | ||
c428f3d5 AT |
90 | state->pixel_size = get_integer_resource(state->dpy, "pixel-size", "Integer"); |
91 | if (state->pixel_size < 1) state->pixel_size = 1; | |
92 | if (state->pixel_size > state->xlim) state->pixel_size = state->xlim; | |
93 | ||
94 | state->number_of_cells = state->xlim / state->pixel_size; | |
95 | ||
7969381e AT |
96 | /* |
97 | * The minimum number of generations is 2 since we must allocate enough | |
98 | * space to hold the seed generation and at least one pass through | |
99 | * WolframAutomata_draw(), which is where we check whether or not we've | |
100 | * reached the end of the pixmap. | |
101 | */ | |
102 | state->num_generations = get_integer_resource(state->dpy, "num-generations", "Integer"); | |
103 | if (state->num_generations < 0) state->num_generations = 2; | |
104 | ||
7ce88c8e AT |
105 | // TODO: These should be command-line options, but I need to learn how the get_integer_resource() and similar functions work first. |
106 | state->display_info = True; | |
107 | state->ruleset = 30; | |
7ce88c8e | 108 | |
c428f3d5 | 109 | state->current_generation = calloc(1, (sizeof(*(state->current_generation))*state->number_of_cells)); // TODO: Check calloc() call TODO: Can't recall precedence; can I eliminate any parenthesis? |
7ce88c8e AT |
110 | // TODO: Make the starting state a user-configurable option. At least give the user some options like 'random', 'one-middle', 'one edge', etc. |
111 | // Ideally accept something like a list of integers representing starting pixels to be "on". | |
c428f3d5 | 112 | state->current_generation[0] = True; |
7ce88c8e | 113 | |
c428f3d5 | 114 | state->evolution_history = XCreatePixmap(state->dpy, state->win, state->xlim, state->num_generations*state->pixel_size, xgwa.depth); |
7ce88c8e AT |
115 | // Pixmap contents are undefined after creation. Explicitly set a black |
116 | // background by drawing a black rectangle over the entire pixmap. | |
117 | XSetForeground(state->dpy, state->gc, state->bg); | |
c428f3d5 | 118 | XFillRectangle(state->dpy, state->evolution_history, state->gc, 0, 0, state->xlim, state->num_generations*state->pixel_size); |
7ce88c8e AT |
119 | XSetForeground(state->dpy, state->gc, state->fg); |
120 | // TODO: Need to draw starting generation on pixmap and increment state->ypos. | |
121 | ||
122 | return state; | |
0c731d4a AT |
123 | } |
124 | ||
125 | // TODO: function decorations? | |
126 | // TODO: Explain why this santizes the index for accessing current_generation (i.e. it creates a circular topology). | |
127 | size_t | |
128 | sindex(struct state * state, int index) | |
129 | { | |
7ce88c8e | 130 | while (index < 0) { |
c428f3d5 | 131 | index += state->number_of_cells; |
7ce88c8e | 132 | } |
c428f3d5 AT |
133 | while (index >= state->number_of_cells) { |
134 | index -= state->number_of_cells; | |
7ce88c8e AT |
135 | } |
136 | return (size_t) index; | |
0c731d4a AT |
137 | } |
138 | ||
139 | // TODO: function decorations? | |
140 | // TODO: At least give a one-sentence explanation of the algorithm since this function is the core of the simulation. | |
141 | Bool | |
142 | calculate_cell(struct state * state, int cell_id) | |
143 | { | |
7ce88c8e AT |
144 | uint8_t cell_pattern = 0; |
145 | int i; | |
146 | for (i = -1; i < 2; i++) { | |
147 | cell_pattern = cell_pattern << 1; | |
148 | if (state->current_generation[sindex(state, cell_id+i)] == True) { | |
149 | cell_pattern |= 1; | |
150 | } | |
151 | } | |
152 | if ((state->ruleset >> cell_pattern) & 1) { | |
153 | return True; | |
154 | } else { | |
155 | return False; | |
156 | } | |
0c731d4a AT |
157 | } |
158 | ||
159 | // TODO: function decorations? | |
160 | void | |
161 | render_current_generation(struct state * state) | |
162 | { | |
7ce88c8e | 163 | size_t xpos; |
c428f3d5 | 164 | for (xpos = 0; xpos < state->number_of_cells; xpos++) { |
7ce88c8e | 165 | if (state->current_generation[xpos] == True) { |
c428f3d5 | 166 | XFillRectangle(state->dpy, state->evolution_history, state->gc, xpos*state->pixel_size, state->ypos, state->pixel_size, state->pixel_size); |
7ce88c8e AT |
167 | } |
168 | } | |
0c731d4a AT |
169 | } |
170 | ||
171 | static unsigned long | |
172 | WolframAutomata_draw(Display * dpy, Window win, void * closure) | |
173 | { | |
174 | // TODO: Mark these basic sections of the function | |
175 | //draw() | |
7ce88c8e AT |
176 | // calculate (and store) new generation |
177 | // draw new generation as line of pixels on pixmap | |
178 | // calculate current 'viewport' into pixmap | |
179 | // display on screen | |
0c731d4a AT |
180 | // check for termination condition |
181 | ||
182 | struct state * state = closure; | |
183 | int xpos; | |
7ce88c8e | 184 | int window_y_offset; |
0c731d4a | 185 | |
7ce88c8e | 186 | Bool new_generation[state->xlim]; |
c428f3d5 | 187 | for (xpos = 0; xpos < state->number_of_cells; xpos++) { |
7ce88c8e AT |
188 | new_generation[xpos] = calculate_cell(state, xpos); |
189 | } | |
c428f3d5 | 190 | for (xpos = 0; xpos < state->number_of_cells; xpos++) { |
7ce88c8e AT |
191 | state->current_generation[xpos] = new_generation[xpos]; |
192 | } | |
193 | render_current_generation(state); | |
194 | ||
195 | // Was this the final generation of this particular simulation? If so, give | |
196 | // the user a moment to bask in the glory of our output and then start a | |
197 | // new simulation. | |
c428f3d5 AT |
198 | if (state->ypos/state->pixel_size < state->num_generations-1) { |
199 | state->ypos += state->pixel_size; | |
7ce88c8e AT |
200 | } else { |
201 | // TODO: Wait for a second or two, clear the screen and do a new iteration with suitably changed settings. | |
202 | // Note: Since we can't actually loop or sleep here, we need to add a flag to the state struct to indicate that we're in an 'admiration timewindow' (and indicate when it should end) | |
c428f3d5 | 203 | printf("infinite hamster wheel\n"); |
7ce88c8e AT |
204 | while (1) continue; |
205 | } | |
206 | ||
207 | // Calculate the vertical offset of the current 'window' into the history | |
208 | // of the CA. After the CA's evolution extends past what we can display, have | |
209 | // the window track the current generation and most recent history. | |
210 | if (state->ypos < state->ylim) { | |
211 | window_y_offset = 0; | |
212 | } else { | |
213 | window_y_offset = state->ypos - (state->ylim - 1); | |
214 | } | |
215 | ||
216 | // Render everything to the display. | |
217 | XCopyArea(state->dpy, state->evolution_history, state->win, state->gc, 0, window_y_offset, state->xlim, state->ylim, 0, 0); | |
218 | // TODO: Print info on screen if display_info is true. Will need fonts/etc. Do I want to create a separate pixmap for this during the init() function and then just copy the pixmap each time we draw the screen in draw()? | |
0c731d4a AT |
219 | |
220 | return state->delay_microsec; | |
221 | } | |
222 | ||
c428f3d5 | 223 | // TODO: Fix formatting |
0c731d4a AT |
224 | static const char * WolframAutomata_defaults[] = { |
225 | ".background: black", | |
226 | ".foreground: white", | |
c428f3d5 | 227 | "*delay-usec: 2500", |
7969381e AT |
228 | // TODO: Difference between dot and asterisk? Presumably the asterisk matches all resouces of attribute "pixelsize"? Apply answer to all new options. |
229 | "*pixel-size: 2", | |
230 | "*num-generations: 5000", | |
0c731d4a AT |
231 | 0 |
232 | }; | |
233 | ||
c428f3d5 | 234 | // TODO: Fix formatting |
0c731d4a | 235 | static XrmOptionDescRec WolframAutomata_options[] = { |
c428f3d5 AT |
236 | { "-delay-usec", ".delay-usec", XrmoptionSepArg, 0 }, |
237 | { "-pixel-size", ".pixel-size", XrmoptionSepArg, 0 }, | |
7969381e | 238 | { "-num-generations", ".num-generations", XrmoptionSepArg, 0 }, |
0c731d4a AT |
239 | { 0, 0, 0, 0 } |
240 | }; | |
241 | ||
242 | static Bool | |
243 | WolframAutomata_event(Display * dpy, Window win, void * closure, XEvent * event) | |
244 | { | |
245 | return False; | |
246 | } | |
247 | ||
248 | static void | |
249 | WolframAutomata_free(Display * dpy, Window win, void * closure) | |
250 | { | |
251 | struct state * state = closure; | |
252 | XFreeGC(state->dpy, state->gc); | |
7ce88c8e AT |
253 | XFreePixmap(state->dpy, state->evolution_history); |
254 | free(state->current_generation); | |
0c731d4a AT |
255 | free(state); |
256 | } | |
257 | ||
258 | static void | |
259 | WolframAutomata_reshape(Display * dpy, Window win, void * closure, unsigned int w, unsigned int h) | |
260 | { | |
7ce88c8e | 261 | WolframAutomata_free(dpy, win, closure); |
b0ea929b | 262 | closure = WolframAutomata_init(dpy, win); |
0c731d4a AT |
263 | } |
264 | ||
265 | XSCREENSAVER_MODULE ("1D Nearest-Neighbor Cellular Automata", WolframAutomata) | |
266 |