/* 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: 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?
// (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
/* -------------------------------------------------------------------------- */
{240, random_cell}
};
+// TODO: Decorations
+struct color_pair {
+ char * fg;
+ char * bg;
+};
+
+// 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"}
+};
+
/* -------------------------------------------------------------------------- */
/* Helper Functions */
/* -------------------------------------------------------------------------- */
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);
}
}
}
static void *
WolframAutomata_init(Display * dpy, Window win)
{
- struct state * state = calloc(1, sizeof(*state)); // TODO: Check calloc() call
+ 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->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);
- state->delay_microsec = get_integer_resource(state->dpy, "delay-usec", "Integer");
- if (state->delay_microsec < 0) state->delay_microsec = 0;
-
- state->pixel_size = get_integer_resource(state->dpy, "pixel-size", "Integer");
+ /* 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. */
- state->num_generations = get_integer_resource(state->dpy, "num-generations", "Integer");
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 */
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() in WolframAutomata_init().\n");
+ fprintf(stderr, "ERROR: Failed to calloc() for cell generation in WolframAutomata_init().\n");
exit(EXIT_FAILURE);
}
if (curated_ruleset) {
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);
+ 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);
static const char * WolframAutomata_defaults[] = {
".background: black",
".foreground: white",
+ "*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",
"*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-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 }
};
closure = WolframAutomata_init(dpy, win);
}
-XSCREENSAVER_MODULE ("1D Nearest-Neighbor Cellular Automata", WolframAutomata)
+XSCREENSAVER_MODULE ("1D Nearest-Neighbor Cellular Automata", HACKNAME)