wip demo mode

src/args.c

@@ -30,7 +30,7 @@ static void print_help(int status_code) {
        "  -s, --screen        output screen number (default: primary)\n"
        "  -f, --frag          fragment shaders directory (default: TODO)\n"
        "  -fc, --frag-config  fragment shaders config file (default: TODO)\n"
-       "  -t, --tempo         base tempo (default: 120)\n"
+       "  -t, --tempo         base tempo (default: 60)\n"
        "  --demo              demonstration mode\n");
   exit(status_code);
 }
@@ -84,7 +84,7 @@ Parameters args_parse(int argc, char **argv) {
   params.frag_path = 0;
   params.frag_config_path = 0;
   params.hot_reload = false;
-  params.base_tempo = 120.0f;
+  params.base_tempo = 60.0f;
   params.demo = false;
 
   for (i = 1; i < argc; i++) {

src/forge.c

@@ -8,6 +8,7 @@
 #include "file.h"
 #include "forge.h"
 #include "logs.h"
+#include "rand.h"
 #include "shaders.h"
 #include "timer.h"
 #include "types.h"
@@ -44,19 +45,20 @@ static unsigned int compute_fps(Window *window, Timer *timer) {
 static void init_context(ShaderProgram program, Context *context,
                          Parameters params) {
   int size;
+  int i;
+
   context->tempo = params.base_tempo;
   context->demo = params.demo;
 
-  // TODO temporary state
-  size = program.frag_count * program.sub_type_count * sizeof(unsigned int);
-  context->sub_state = malloc(size);
-  memset(context->sub_state, 0, size);
-  context->sub_state[program.sub_type_count * 0 + 0] = 1;
-  context->sub_state[program.sub_type_count * 1 + 0] = 1;
-  context->sub_state[program.sub_type_count * 2 + 1] = 1;
-  context->sub_state[program.sub_type_count * 3 + 1] = 3;
-  context->sub_state[program.sub_type_count * 5 + 1] = 6;
-  // TODO fix here ??
+  size = program.frag_count * program.sub_type_count;
+  context->sub_state = malloc(size * sizeof(unsigned int));
+  memset(context->sub_state, 0, sizeof(&context->sub_state));
+
+  if (params.demo) {
+    for (i = 0; i < size; i++) {
+      context->sub_state[i] = rand_uint(program.sub_variant_count);
+    }
+  }
 }
 
 static void hot_reload(ShaderProgram program, File *common_shader_code,
@@ -162,10 +164,10 @@ void forge_run(Parameters params) {
 
   window_get_context(window, &context);
 
-  init_context(program, &context, params);
-
   program = shaders_init(fragment_shaders, shader_config, context);
 
+  init_context(program, &context, params);
+
   if (program.error) {
     window_close(window, true);
     exit(EXIT_FAILURE);

src/main.c

@@ -1,11 +1,13 @@
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <time.h>
 
 #include "args.h"
 #include "config.h"
 #include "forge.h"
 #include "main.h"
+#include "rand.h"
 
 int main(int argc, char **argv) {
   Parameters params;
@@ -14,6 +16,8 @@ int main(int argc, char **argv) {
 
   puts(PACKAGE " " VERSION);
 
+  set_seed((unsigned long)time(NULL));
+
   forge_run(params);
 
   return EXIT_SUCCESS;

src/rand.c

@@ -0,0 +1,31 @@
+#include "rand.h"
+
+static unsigned long long mcg_state = 0xcafef00dd15ea5e5u; // Must be odd
+static unsigned long long const multiplier = 6364136223846793005u;
+
+// https://en.wikipedia.org/wiki/Permuted_congruential_generator
+static unsigned long rand(void) {
+  unsigned long long x = mcg_state;
+  unsigned count = (unsigned)(x >> 61);
+
+  mcg_state = x * multiplier;
+  x ^= x >> 22;
+  return (unsigned long)(x >> (22 + count));
+}
+
+void set_seed(unsigned long long seed) {
+  mcg_state = 2 * seed + 1;
+  (void)rand();
+}
+
+unsigned char rand_uchar(const unsigned int max) {
+  return max == 0 ? 0 : (unsigned char)(rand() % max);
+}
+
+unsigned short rand_ushort(const unsigned int max) {
+  return max == 0 ? 0 : (unsigned short)(rand() % max);
+}
+
+unsigned int rand_uint(const unsigned int max) {
+  return max == 0 ? 0 : (unsigned int)(rand() % max);
+}

src/rand.h

@@ -0,0 +1,9 @@
+#ifndef RAND_H
+#define RAND_H
+
+void set_seed(unsigned long long seed);
+unsigned char rand_uchar(unsigned int max);
+unsigned short rand_ushort(unsigned int max);
+unsigned int rand_uint(unsigned int max);
+
+#endif

src/shaders.c

@@ -345,5 +345,5 @@ void shaders_apply(ShaderProgram program, Context context) {
     }
   }
 
-  use_program(program, program.frag_monitor_index, true, context);
+  use_program(program, program.frag_output_index, true, context);
 }