-/* (c) 2021 Aaron Taylor <ataylor at subgeniuskitty dot com> */
-/* See LICENSE.txt file for copyright and license details. */
+/* (c) 2021 Aaron Taylor <ataylor at subgeniuskitty dot com> */
+/* See LICENSE.txt file for copyright and license details. */
#include "screenhack.h"
+/* Keep this source code C89 compliant per XScreensaver's instructions. */
+
/* -------------------------------------------------------------------------- */
/* Data Structures */
/* -------------------------------------------------------------------------- */
/* the 'evolution_history' Pixmap and subsequently ignored. */
Bool * current_generation;
- /* When randomizing the seed generation, we can specify a population */
- /* density, or we can restrict to a single living cell. */
- int population_density;
- Bool population_single;
-
/* For more information on the encoding used for rule_number and on the */
/* method used to apply it: https://en.wikipedia.org/wiki/Wolfram_code */
uint8_t rule_number;
size_t admiration_delay; /* ...in seconds. */
/* The following values correspond directly to independent CLI options. */
- Bool rule_random;
- uint8_t rule_requested; /* Note: Repurposing Rule 0 as null value. */
+ Bool random_rule;
+ int requested_rule;
+ int seed_density;
int cell_size; /* If cell_size=N then draw NxN pixels per cell. */
int delay_microsec; /* ...between calls to WolframAutomata_draw(). */
int num_generations; /* Reset simulation after this many generations. */
enum seed_population seed;
};
+/* The following array contains rule numbers and starting seeds which were */
+/* preselected as being visually interesting. */
static const struct curated_ruleset curated_ruleset_list[] = {
{ 18, middle_cell},
{ 30, middle_cell},
unsigned short bg_red, bg_green, bg_blue;
};
+/* Since randomly selected colors would occasionally produce visually */
+/* indistinguishable foreground/background pairs, this array provides a */
+/* preselected list of complementary color pairs. */
static const struct color_pair color_list[] = {
/* For mapping X11 color names to RGB values: */
/* https://www.ehdp.com/methods/x11-color-names-rgb-values.htm */
/* Helper Functions */
/* -------------------------------------------------------------------------- */
+/* Some rules demonstrate behavior dominated by the starting seed. Thus, in */
+/* addition to a 50/50 random split of active/inactive cells, include other, */
+/* more biased random distributions in order to demonstrate such behavior. */
+static void
+randomize_seed_density(struct state * state)
+{
+ switch (random() % 3) {
+ case 0: state->seed_density = 30; break;
+ case 1: state->seed_density = 50; break;
+ case 2: state->seed_density = 70; break;
+ }
+}
+
static 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;
+ state->current_generation[i] = ((random() % 100) < state->seed_density) ? True : False;
}
}
static void *
WolframAutomata_init(Display * dpy, Window win)
{
- struct state * state = calloc(1, sizeof(*state));
+ struct state * state;
+ XGCValues gcv;
+ XWindowAttributes xgwa;
+ XColor fg, bg;
+ XColor blackx, blacks;
+ size_t color_index;
+ const struct curated_ruleset * curated_ruleset = NULL;
+
+ 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;
/* Set foreground and background colors for active/inactive cells. Either */
/* the user provided an index into the pre-defined color_list[] or a */
/* random entry from that same array should be selected. */
- size_t color_index = get_integer_resource(state->dpy, "color-index", "Integer");
+ color_index = get_integer_resource(state->dpy, "color-index", "Integer");
if (color_index == -1) {
color_index = random() % sizeof(color_list)/sizeof(color_list[0]);
} else if (color_index >= sizeof(color_list)/sizeof(color_list[0])) {
fprintf(stderr, "WARNING: Color index out of range.\n");
color_index = 0;
}
- XColor fg, bg;
fg.red = color_list[color_index].fg_red;
fg.green = color_list[color_index].fg_green;
fg.blue = color_list[color_index].fg_blue;
bg.red = color_list[color_index].bg_red;
bg.green = color_list[color_index].bg_green;
bg.blue = color_list[color_index].bg_blue;
- /* TODO: Since I 'alloc', presumably I must also 'free' these colors */
- /* at some point. Where/how? I don't want to eventually crash my */
- /* X server after months of use. */
XAllocColor(state->dpy, xgwa.colormap, &fg);
XAllocColor(state->dpy, xgwa.colormap, &bg);
state->fg = gcv.foreground = fg.pixel;
/* 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");
+ state->delay_microsec = get_integer_resource(state->dpy, "delay", "Integer");
}
if (state->delay_microsec < 0) state->delay_microsec = 0;
}
/* Time to figure out which rule to use for this simulation. */
- /* We ignore any weirdness resulting from the following cast since every */
+ /* We ignore any weirdness resulting from the following casts 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");
+ state->requested_rule = get_integer_resource(state->dpy, "rule", "Integer");
+ state->random_rule = get_boolean_resource(state->dpy, "random-rule", "Boolean");
/* Through the following set of branches, we enforce CLI flag precedence. */
- if (state->rule_random) {
+ if (state->random_rule) {
/* 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 if (state->requested_rule != -1) {
+ /* The user requested a specific rule. Use it. */
+ state->rule_number = (uint8_t) state->requested_rule;
} else {
/* No command-line options were specified, so select rules randomly */
/* from a curated list. */
}
/* 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");
/* 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 random_cell: randomize_seed_density(state); 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;
}
/* 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) {
+ if (get_boolean_resource(state->dpy, "seed-left", "Boolean")) {
state->current_generation[0] = True;
+ } else if (get_boolean_resource(state->dpy, "seed-center", "Boolean")) {
+ state->current_generation[state->number_of_cells/2] = True;
+ } else if (get_boolean_resource(state->dpy, "seed-right", "Boolean")) {
+ state->current_generation[state->number_of_cells-1] = True;
+ } else if (get_integer_resource(state->dpy, "seed-density", "Integer") != -1) {
+ state->seed_density = get_integer_resource(state->dpy, "seed-density", "Integer");
+ if (state->seed_density < 0 || state->seed_density > 100) state->seed_density = 50;
+ generate_random_seed(state);
} else {
+ randomize_seed_density(state);
generate_random_seed(state);
}
}
state->evolution_history = XCreatePixmap(state->dpy, state->win, state->dpy_width, state->num_generations*state->cell_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->dpy_width, state->num_generations*state->cell_size);
int window_y_offset;
/* Calculate and record new generation. */
- Bool new_generation[state->dpy_width];
+ Bool * new_generation = malloc(state->dpy_width * sizeof(Bool));
+ if (new_generation == NULL) {
+ fprintf(stderr, "ERROR: Failed to malloc() when calculating new generation.\n");
+ exit(EXIT_FAILURE);
+ }
for (xpos = 0; xpos < state->number_of_cells; xpos++) {
new_generation[xpos] = calculate_cell(state, xpos);
}
for (xpos = 0; xpos < state->number_of_cells; xpos++) {
state->current_generation[xpos] = new_generation[xpos];
}
+ free(new_generation);
render_current_generation(state);
/* Check for end of simulation. */
return state->delay_microsec;
}
+static void
+WolframAutomata_reshape(Display * dpy, Window win, void * closure, unsigned int w, unsigned int h)
+{
+ struct state * state = closure;
+ XWindowAttributes xgwa;
+ XGetWindowAttributes(state->dpy, state->win, &xgwa);
+
+ /* Only restart the simulation if the window changed size. */
+ if (state->dpy_width != xgwa.width || state->dpy_height != xgwa.height) {
+ WolframAutomata_free(dpy, win, closure);
+ closure = WolframAutomata_init(dpy, win);
+ }
+}
+
static const char * WolframAutomata_defaults[] = {
- "*delay-usec: 25000",
"*admiration-delay: 5",
- "*length: 5000",
- "*cell-size: 2",
+
"*color-index: -1",
- "*population-density: 50",
- "*population-single: False",
+
+ "*cell-size: 2",
"*random-cell-size: False",
+
+ "*delay: 25000",
"*random-delay: False",
+
+ "*length: 5000",
"*random-length: False",
+
+ "*rule: -1",
"*random-rule: False",
- "*rule-requested: 0",
+
+ "*seed-density: -1",
+ "*seed-left: False",
+ "*seed-center: False",
+ "*seed-right: False",
+
0
};
static XrmOptionDescRec WolframAutomata_options[] = {
- { "-delay-usec", ".delay-usec", XrmoptionSepArg, 0 },
{ "-admiration-delay", ".admiration-delay", XrmoptionSepArg, 0 },
- { "-length", ".length", XrmoptionSepArg, 0 },
- { "-cell-size", ".cell-size", XrmoptionSepArg, 0 },
+
{ "-color-index", ".color-index", XrmoptionSepArg, 0 },
- { "-population-density", ".population-density", XrmoptionSepArg, 0 },
- { "-population-single", ".population-single", XrmoptionNoArg, "True" },
+
+ { "-cell-size", ".cell-size", XrmoptionSepArg, 0 },
{ "-random-cell-size", ".random-cell-size", XrmoptionNoArg, "True" },
+
+ { "-delay", ".delay", XrmoptionSepArg, 0 },
{ "-random-delay", ".random-delay", XrmoptionNoArg, "True" },
+
+ { "-length", ".length", XrmoptionSepArg, 0 },
{ "-random-length", ".random-length", XrmoptionNoArg, "True" },
- { "-random-rule", ".rule-random", XrmoptionNoArg, "True" },
- { "-rule", ".rule-requested", XrmoptionSepArg, 0 },
- { 0, 0, 0, 0 }
-};
-static void
-WolframAutomata_reshape(Display * dpy, Window win, void * closure, unsigned int w, unsigned int h)
-{
- struct state * state = closure;
- XWindowAttributes xgwa;
- XGetWindowAttributes(state->dpy, state->win, &xgwa);
+ { "-rule", ".rule", XrmoptionSepArg, 0 },
+ { "-random-rule", ".random-rule", XrmoptionNoArg, "True" },
- /* Only restart the simulation if the window changed size. */
- if (state->dpy_width != xgwa.width || state->dpy_height != xgwa.height) {
- WolframAutomata_free(dpy, win, closure);
- closure = WolframAutomata_init(dpy, win);
- }
-}
+ { "-seed-density", ".seed-density", XrmoptionSepArg, 0 },
+ { "-seed-left", ".seed-left", XrmoptionNoArg, "True" },
+ { "-seed-center", ".seed-center", XrmoptionNoArg, "True" },
+ { "-seed-right", ".seed-right", XrmoptionNoArg, "True" },
+
+ { 0, 0, 0, 0 }
+};
XSCREENSAVER_MODULE ("1D Nearest-Neighbor Cellular Automata", WolframAutomata)