/* TODO: I suppose a lot of this stuff goes in the README instead. */
/* TODO: Explain the data structures in detail. */
/* TODO: Explain all the options, like the various starting conditions. */
+/* TODO: Explain all the dependencies like libXpm. */
+/* TODO: Explain that the program is inherently double-buffered but if you don't have VSync turned on, all those alternating lines are going to look terrible when they scroll upward. */
-
+/* TODO: Add a #define for the hack version. */
/* 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. */
/* TODO: Verify everything in this file is C89. Get rid of things like '//' comments, pack all my declarations upfront, no stdint, etc. */
+#include <X11/Intrinsic.h>
#include "screenhack.h"
+/*
+ * We do a few manual manipulations of X resources in this hack, like picking
+ * random colors. In order to ensure our manual manipulations always use the
+ * same X resource specification as Xscreensaver, we pass HACKNAME to
+ * Xscreensaver via the XSCREENSAVER_MODULE() line at the bottom of this file,
+ * and then always use HACKNAME or MAKE_STRING(HACKNAME) as the base of the
+ * resource specification when making manual manipulations.
+ */
+#define HACKNAME WolframAutomata
+#define MAKE_STRING_X(s) #s
+#define MAKE_STRING(s) MAKE_STRING_X(s)
+
// Command line options
// directory to output XBM files of each run (and call an external command to convert to PNGs?)
// -save-dir STRING
+// (could use libXpm to save an XPM and then convert to PNG with ImageMagick) (this is a single function call to go from pixmap -> file)
+// (since it depends on an external library, make this whole feature optional at build-time?)
// number of generations to simulate
+// -random-generations
// -num-generations N
// delay time (speed of simulation)
+// -random-delay
// -delay-usec N
// foreground and background color
-// ??? (strings of some sort, but I need to look up what X resources to interact with)
+// -random-colors (highest precedence)
+// -foreground "COLORNAME"
+// -background "COLORNAME"
+// (default is black and white)
+// (mention sample color combinations in manpage, and link to: https://en.wikipedia.org/wiki/X11_color_names)
+// (note to the user that most color names they can naturally think of (e.g. red, purple, gray, pink, etc) are valid X11 color names for these CLI options.)
// display info overlay with CA number and start conditions?
// -overlay
// which ruleset number to use? Or random? Or random from small set of hand-selected interesting examples?
-// Options (with precedence): -rule N
-// -rule-curated
-// -rule-random
-// 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%?)
-// Options (with precedence): -population STRING (string is a comma separated list of cell IDs to populate, starting from 0)
-// -population-curated
-// -population-random
+// In order of precedence:
+// -rule-random (select a random rule on each run)
+// -rule N (always simulate Rule N on each run)
+// (if neither of the above two are specified, then a random CURATED rule is selected on each run)
+// which starting population to use, random or one bit? (for random: allow specifying a density)
+// In order of precedence:
+// -population-single
+// -population-random DENSITY
+// (the two options above only apply to the simulation under the -rule-random or -rule N options. in curated mode, starting population is defined in the curation array)
+// TODO: In the future, add the option for user to pass list of cell IDs to turn ON.
// size of pixel square (e.g. 1x1, 2x2, 3x3, etc)
+// -random-pixel-size
// -pixel-size N
+/* -------------------------------------------------------------------------- */
+/* Data Structures */
+/* -------------------------------------------------------------------------- */
+
struct state {
/* Various X resources */
Display * dpy;
Bool display_info;
Bool * current_generation;
- uint8_t ruleset;
+
+ // TODO: Describe these.
+ uint8_t rule_number; // Note: This is not a CLI option. You're thinking of rule_requested.
+ uint8_t rule_requested; // Note: Repurposing Rule 0 as a null value.
+ Bool rule_random;
+
+ // TODO: Describe these.
+ int population_density;
+ Bool population_single;
/* Misc Commandline Options */
int pixel_size; /* Size of CA cell in pixels (e.g. pixel_size=3 means 3x3 pixels per cell). */
size_t number_of_cells;
};
-static void *
-WolframAutomata_init(Display * dpy, Window win)
-{
- struct state * state = calloc(1, sizeof(*state)); // TODO: Check calloc() call
- XGCValues gcv;
- XWindowAttributes xgwa;
-
- state->dpy = dpy;
- state->win = win;
-
- XGetWindowAttributes(state->dpy, state->win, &xgwa);
- state->xlim = xgwa.width;
- state->ylim = xgwa.height;
- state->ypos = 0; // TODO: Explain why.
-
- state->fg = gcv.foreground = get_pixel_resource(state->dpy, xgwa.colormap, "foreground", "Foreground");
- state->bg = gcv.background = get_pixel_resource(state->dpy, xgwa.colormap, "background", "Background");
- state->gc = XCreateGC(state->dpy, state->win, GCForeground, &gcv);
-
- state->delay_microsec = get_integer_resource(state->dpy, "delay-usec", "Integer");
- if (state->delay_microsec < 0) state->delay_microsec = 0;
+// TODO: Decorations
+enum seed_population {
+ random_cell,
+ middle_cell,
+ edge_cell
+};
- state->pixel_size = get_integer_resource(state->dpy, "pixel-size", "Integer");
- if (state->pixel_size < 1) state->pixel_size = 1;
- if (state->pixel_size > state->xlim) state->pixel_size = state->xlim;
+// TODO: Decorations
+struct curated_ruleset {
+ uint8_t rule;
+ enum seed_population seed;
+};
- state->number_of_cells = state->xlim / state->pixel_size;
+// TODO: Decorations
+static const struct curated_ruleset curated_ruleset_list[] = {
+ {18, middle_cell},
+ {30, middle_cell},
+ {45, middle_cell},
+ {54, middle_cell},
+ {57, middle_cell},
+ {73, middle_cell},
+ {105, middle_cell},
+ {109, middle_cell},
+ {129, middle_cell},
+ {133, middle_cell},
+ {135, middle_cell},
+ {150, middle_cell},
+ {30, edge_cell},
+ {45, edge_cell},
+ {57, edge_cell},
+ {60, edge_cell},
+ {75, edge_cell},
+ {107, edge_cell},
+ {110, edge_cell},
+ {133, edge_cell},
+ {137, edge_cell},
+ {169, edge_cell},
+ {225, edge_cell},
+ {22, random_cell},
+ {30, random_cell},
+ {54, random_cell},
+ {62, random_cell},
+ {90, random_cell},
+ {105, random_cell},
+ {108, random_cell},
+ {110, random_cell},
+ {126, random_cell},
+ {146, random_cell},
+ {150, random_cell},
+ {182, random_cell},
+ {184, random_cell},
+ {225, random_cell},
+ {240, random_cell}
+};
- /*
- * The minimum number of generations is 2 since we must allocate enough
- * space to hold the seed generation and at least one pass through
- * WolframAutomata_draw(), which is where we check whether or not we've
- * reached the end of the pixmap.
- */
- state->num_generations = get_integer_resource(state->dpy, "num-generations", "Integer");
- if (state->num_generations < 0) state->num_generations = 2;
+// TODO: Decorations
+struct color_pair {
+ char * fg;
+ char * bg;
+};
- // TODO: These should be command-line options, but I need to learn how the get_integer_resource() and similar functions work first.
- state->display_info = True;
- state->ruleset = 30;
+// TODO: Decorations
+static const struct color_pair color_list[] = {
+ {"red", "black"},
+ {"olive", "black"},
+ {"teal", "black"},
+ {"slateblue", "black"},
+ {"violet", "black"},
+ {"purple", "black"},
+ {"white", "black"},
+ {"white", "darkgreen"},
+ {"white", "darkmagenta"},
+ {"white", "darkred"},
+ {"white", "darkblue"},
+ {"darkslategray", "darkslategray1"},
+ {"lightsteelblue", "darkslategray"},
+ {"royalblue4", "royalblue"},
+ {"antiquewhite2", "antiquewhite4"},
+ {"darkolivegreen1", "darkolivegreen"},
+ {"darkseagreen1", "darkseagreen4"},
+ {"pink", "darkred"},
+ {"lightblue", "darkgreen"},
+ {"red", "blue"},
+ {"red", "darkgreen"},
+ {"aqua", "teal"},
+ {"darkblue", "teal"},
+ {"khaki", "seagreen"},
+ {"khaki", "darkolivegreen"},
+ {"lightslategray", "darkslategray"},
+ {"tomato", "darkslategray"},
+ {"tomato", "darkcyan"}
+};
- 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?
- // TODO: Make the starting state a user-configurable option. At least give the user some options like 'random', 'one-middle', 'one edge', etc.
- // Ideally accept something like a list of integers representing starting pixels to be "on".
- state->current_generation[0] = True;
+/* -------------------------------------------------------------------------- */
+/* Helper Functions */
+/* -------------------------------------------------------------------------- */
- state->evolution_history = XCreatePixmap(state->dpy, state->win, state->xlim, state->num_generations*state->pixel_size, xgwa.depth);
- // Pixmap contents are undefined after creation. Explicitly set a black
- // background by drawing a black rectangle over the entire pixmap.
- XSetForeground(state->dpy, state->gc, state->bg);
- XFillRectangle(state->dpy, state->evolution_history, state->gc, 0, 0, state->xlim, state->num_generations*state->pixel_size);
- XSetForeground(state->dpy, state->gc, state->fg);
- // TODO: Need to draw starting generation on pixmap and increment state->ypos.
-
- return state;
+// TODO: decorations? inline?
+void
+generate_random_seed(struct state * state)
+{
+ int i;
+ for (i = 0; i < state->number_of_cells; i++) {
+ state->current_generation[i] = ((random() % 100) < state->population_density) ? True : False;
+ }
}
// TODO: function decorations?
cell_pattern |= 1;
}
}
- if ((state->ruleset >> cell_pattern) & 1) {
+ if ((state->rule_number >> cell_pattern) & 1) {
return True;
} else {
return False;
for (xpos = 0; xpos < state->number_of_cells; xpos++) {
if (state->current_generation[xpos] == True) {
XFillRectangle(state->dpy, state->evolution_history, state->gc, xpos*state->pixel_size, state->ypos, state->pixel_size, state->pixel_size);
+ } else {
+ XSetForeground(state->dpy, state->gc, state->bg);
+ XFillRectangle(state->dpy, state->evolution_history, state->gc, xpos*state->pixel_size, state->ypos, state->pixel_size, state->pixel_size);
+ XSetForeground(state->dpy, state->gc, state->fg);
+ }
+ }
+}
+
+/* -------------------------------------------------------------------------- */
+/* Screenhack API Functions */
+/* -------------------------------------------------------------------------- */
+
+static Bool
+WolframAutomata_event(Display * dpy, Window win, void * closure, XEvent * event)
+{
+ return False;
+}
+
+static void
+WolframAutomata_free(Display * dpy, Window win, void * closure)
+{
+ struct state * state = closure;
+ XFreeGC(state->dpy, state->gc);
+ XFreePixmap(state->dpy, state->evolution_history);
+ free(state->current_generation);
+ free(state);
+}
+
+static void *
+WolframAutomata_init(Display * dpy, Window win)
+{
+ struct state * state = calloc(1, sizeof(*state));
+ if (!state) {
+ fprintf(stderr, "ERROR: Failed to calloc() for state struct in WolframAutomata_init().\n");
+ exit(EXIT_FAILURE);
+ }
+
+ XGCValues gcv;
+ XWindowAttributes xgwa;
+ const struct curated_ruleset * curated_ruleset = NULL;
+
+ state->dpy = dpy;
+ state->win = win;
+
+ XGetWindowAttributes(state->dpy, state->win, &xgwa);
+ state->xlim = xgwa.width;
+ state->ylim = xgwa.height;
+ state->ypos = 0; // TODO: Explain why.
+
+ if (get_boolean_resource(state->dpy, "random-colors", "Boolean")) {
+ XrmDatabase db = XtDatabase(state->dpy);
+ size_t rand_i = random() % sizeof(color_list)/sizeof(color_list[0]);
+ XrmPutStringResource(&db, MAKE_STRING(HACKNAME) ".background", color_list[rand_i].bg);
+ XrmPutStringResource(&db, MAKE_STRING(HACKNAME) ".foreground", color_list[rand_i].fg);
+ }
+
+ state->fg = gcv.foreground = get_pixel_resource(state->dpy, xgwa.colormap, "foreground", "Foreground");
+ state->bg = gcv.background = get_pixel_resource(state->dpy, xgwa.colormap, "background", "Background");
+ state->gc = XCreateGC(state->dpy, state->win, GCForeground, &gcv);
+
+ /* Set the size of each simulated cell as NxN pixels for pixel_size=N. */
+ if (get_boolean_resource(state->dpy, "random-pixel-size", "Boolean")) {
+ /* Although we are choosing the pixel size 'randomly', a truly random */
+ /* selection would bias toward large numbers since there are more of */
+ /* them. To avoid this, we select a random number for a bit shift, */
+ /* resulting in a pixel size of 1, 2, 4, 8, 16 or 32, equally likely. */
+ state->pixel_size = 1 << (random() % 6);
+ } else {
+ state->pixel_size = get_integer_resource(state->dpy, "pixel-size", "Integer");
+ }
+ if (state->pixel_size < 1) state->pixel_size = 1;
+ if (state->pixel_size > state->xlim) state->pixel_size = state->xlim;
+
+ state->number_of_cells = state->xlim / state->pixel_size;
+ // TODO: Do we want to enforce that number_of_cells > 0?
+
+ /* Set the delay (in microseconds) between simulation of each generation */
+ /* of the simulation, also known as the delay between calls to */
+ /* WolframAutomata_draw(), which simulates one generation per call. */
+ if (get_boolean_resource(state->dpy, "random-delay", "Boolean")) {
+ /* When randomly setting the delay, the problem is to avoid being too */
+ /* fast or too slow, as well as ensuring slower speeds are chosen */
+ /* with the same likelihood as faster speeds, as perceived by a */
+ /* human. By empirical observation, we note that for 1x1 up to 4x4 */
+ /* pixel cell sizes, values for state->delay_microsec between */
+ /* 2048 (2^11) and 16556 (2^14) produce pleasant scroll rates. To */
+ /* maintain this appearance, we bitshift state->pixel_size down until */
+ /* it is a maximum of 4x4 pixels in size, record how many bitshifts */
+ /* took place, and then shift our valid window for */
+ /* state->delay_microsec up by an equal number of bitshifts. For */
+ /* example, if state->pixel_size=9, then it takes one right shift to */
+ /* reach state->pixel_size=4. Thus, the valid window for */
+ /* state->delay_microsec becomes 4096 (2^12) up to 32768 (2^15). */
+ size_t pixel_shift_range = 1;
+ size_t pixel_size_temp = state->pixel_size;
+ while (pixel_size_temp > 4) {
+ pixel_size_temp >>= 1;
+ pixel_shift_range++;
+ }
+ /* In the below line, '3' represents the total range, namely '14-11' */
+ /* from '2^14' and '2^11' as the endpoints. Similarly, the '11' in */
+ /* the below line represents the starting point of this range, from */
+ /* the exponent in '2^11'. */
+ state->delay_microsec = 1 << ((random() % 3) + 11 + pixel_shift_range);
+ } else {
+ state->delay_microsec = get_integer_resource(state->dpy, "delay-usec", "Integer");
+ }
+ if (state->delay_microsec < 0) state->delay_microsec = 0;
+
+ /* Set the number of generations to simulate before wiping the simulation */
+ /* and re-running with new settings. */
+ if (get_boolean_resource(state->dpy, "random-num-generations", "Boolean")) {
+ /* By empirical observation, keep the product */
+ /* state->num_generations * state->pixel_size */
+ /* below 10,000 to avoid BadAlloc errors from the X server due to */
+ /* requesting an enormous pixmap. This value works on both a 12 core */
+ /* Xeon with 108 GiB of RAM and a Sun Ultra 2 with 2 GiB of RAM. */
+ state->num_generations = random() % (10000 / state->pixel_size);
+ /* Ensure selected value is large enough to at least fill the screen. */
+ /* Cast to avoid overflow. */
+ if ((long)state->num_generations * (long)state->pixel_size < state->ylim) {
+ state->num_generations = (state->ylim / state->pixel_size) + 1;
}
+ } else {
+ state->num_generations = get_integer_resource(state->dpy, "num-generations", "Integer");
+ }
+ /* The minimum number of generations is 2 since we must allocate enough */
+ /* space to hold the seed generation and at least one pass through */
+ /* WolframAutomata_draw(), which is where we check whether or not we've */
+ /* reached the end of the pixmap. */
+ if (state->num_generations < 0) state->num_generations = 2;
+ /* The maximum number of generations is pixel_size dependent. This is a */
+ /* soft limit and may be increased if you have plenty of RAM (and a */
+ /* cooperative X server). The value 10,000 was determined empirically. */
+ if ((long)state->num_generations * (long)state->pixel_size > 10000) {
+ state->num_generations = 10000 / state->pixel_size;
+ }
+
+ /* Time to figure out which rule to use for this simulation. */
+ /* We ignore any weirdness resulting from the following cast since every */
+ /* bit pattern is also a valid rule; if the user provides weird input, */
+ /* then we'll return weird (but well-defined!) output. */
+ state->rule_requested = (uint8_t) get_integer_resource(state->dpy, "rule-requested", "Integer");
+ state->rule_random = get_boolean_resource(state->dpy, "rule-random", "Boolean");
+ /* Through the following set of branches, we enforce CLI flag precedence. */
+ if (state->rule_random) {
+ /* If this flag is set, the user wants truly random rules rather than */
+ /* random rules from a curated list. */
+ state->rule_number = (uint8_t) random();
+ } else if (state->rule_requested != 0) {
+ /* Rule 0 is terribly uninteresting, so we are reusing it as a 'null' */
+ /* value and hoping nobody notices. Finding a non-zero value means */
+ /* the user requested a specific rule. Use it. */
+ state->rule_number = state->rule_requested;
+ } else {
+ /* No command-line options were specified, so select rules randomly */
+ /* from a curated list. */
+ size_t number_of_array_elements = sizeof(curated_ruleset_list)/sizeof(curated_ruleset_list[0]);
+ curated_ruleset = &curated_ruleset_list[random() % number_of_array_elements];
+ state->rule_number = curated_ruleset->rule;
}
+
+ /* Time to construct the seed generation for this simulation. */
+ state->population_single = get_boolean_resource(state->dpy, "population-single", "Boolean");
+ state->population_density = get_integer_resource(state->dpy, "population-density", "Integer");
+ if (state->population_density < 0 || state->population_density > 100) state->population_density = 50;
+ state->current_generation = calloc(1, sizeof(*state->current_generation)*state->number_of_cells);
+ if (!state->current_generation) {
+ fprintf(stderr, "ERROR: Failed to calloc() for cell generation in WolframAutomata_init().\n");
+ exit(EXIT_FAILURE);
+ }
+ if (curated_ruleset) {
+ /* If we're using a curated ruleset, ignore any CLI flags related to */
+ /* setting the seed generation, instead drawing that information from */
+ /* the curated ruleset. */
+ switch (curated_ruleset->seed) {
+ case random_cell: generate_random_seed(state); break;
+ case middle_cell: state->current_generation[state->number_of_cells/2] = True; break;
+ case edge_cell : state->current_generation[0] = True; break;
+ }
+ } else {
+ /* If we're not using a curated ruleset, process any relevant flags */
+ /* from the user, falling back to a random seed generation if nothing */
+ /* else is specified. */
+ if (state->population_single) {
+ state->current_generation[0] = True;
+ } else {
+ generate_random_seed(state);
+ }
+ }
+
+ // TODO: These should be command-line options, but I need to learn how the get_integer_resource() and similar functions work first.
+ state->display_info = True;
+
+ state->evolution_history = XCreatePixmap(state->dpy, state->win, state->xlim, state->num_generations*state->pixel_size, xgwa.depth);
+ // Pixmap contents are undefined after creation. Explicitly set a black
+ // background by drawing a black rectangle over the entire pixmap.
+ XColor blackx, blacks;
+ XAllocNamedColor(state->dpy, DefaultColormapOfScreen(DefaultScreenOfDisplay(state->dpy)), "black", &blacks, &blackx);
+ XSetForeground(state->dpy, state->gc, blacks.pixel);
+ XFillRectangle(state->dpy, state->evolution_history, state->gc, 0, 0, state->xlim, state->num_generations*state->pixel_size);
+ XSetForeground(state->dpy, state->gc, state->fg);
+ render_current_generation(state);
+ state->ypos += state->pixel_size;
+
+ return state;
}
static unsigned long
} else {
// TODO: Wait for a second or two, clear the screen and do a new iteration with suitably changed settings.
// 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)
- printf("infinite hamster wheel\n");
- while (1) continue;
+ WolframAutomata_free(dpy, win, state);
+ closure = WolframAutomata_init(dpy, win);
}
// Calculate the vertical offset of the current 'window' into the history
static const char * WolframAutomata_defaults[] = {
".background: black",
".foreground: white",
- "*delay-usec: 2500",
+ "*random-colors: False",
+ "*delay-usec: 25000",
// TODO: Difference between dot and asterisk? Presumably the asterisk matches all resouces of attribute "pixelsize"? Apply answer to all new options.
"*pixel-size: 2",
"*num-generations: 5000",
+ "*rule-requested: 0",
+ "*rule-random: False",
+ "*population-density: 50",
+ "*population-single: False",
+ "*random-delay: False",
+ "*random-pixel-size: False",
+ "*random-num-generations: False",
0
};
// TODO: Fix formatting
static XrmOptionDescRec WolframAutomata_options[] = {
+ { "-background", ".background", XrmoptionSepArg, 0},
+ { "-foreground", ".foreground", XrmoptionSepArg, 0},
+ { "-random-colors", ".random-colors", XrmoptionNoArg, "True"},
{ "-delay-usec", ".delay-usec", XrmoptionSepArg, 0 },
{ "-pixel-size", ".pixel-size", XrmoptionSepArg, 0 },
{ "-num-generations", ".num-generations", XrmoptionSepArg, 0 },
+ { "-rule", ".rule-requested", XrmoptionSepArg, 0 },
+ { "-rule-random", ".rule-random", XrmoptionNoArg, "True" },
+ { "-population-density", ".population-density", XrmoptionSepArg, 0 },
+ { "-population-single", ".population-single", XrmoptionNoArg, "True" },
+ { "-random-delay", ".random-delay", XrmoptionNoArg, "True" },
+ { "-random-pixel-size", ".random-pixel-size", XrmoptionNoArg, "True" },
+ { "-random-num-generations", ".random-num-generations", XrmoptionNoArg, "True" },
+
{ 0, 0, 0, 0 }
};
-static Bool
-WolframAutomata_event(Display * dpy, Window win, void * closure, XEvent * event)
-{
- return False;
-}
-
-static void
-WolframAutomata_free(Display * dpy, Window win, void * closure)
-{
- struct state * state = closure;
- XFreeGC(state->dpy, state->gc);
- XFreePixmap(state->dpy, state->evolution_history);
- free(state->current_generation);
- free(state);
-}
-
static void
WolframAutomata_reshape(Display * dpy, Window win, void * closure, unsigned int w, unsigned int h)
{
closure = WolframAutomata_init(dpy, win);
}
-XSCREENSAVER_MODULE ("1D Nearest-Neighbor Cellular Automata", WolframAutomata)
+XSCREENSAVER_MODULE ("1D Nearest-Neighbor Cellular Automata", HACKNAME)