random seed

src/forge.c

@@ -44,6 +44,7 @@ static unsigned int compute_fps(Window *window, Timer *timer) {
 
 static void init_context(ShaderProgram program, Context *context,
                          Parameters params) {
+
   int size;
   int i;
 
@@ -59,6 +60,16 @@ static void init_context(ShaderProgram program, Context *context,
       context->sub_state[i] = rand_uint(program.sub_variant_count);
     }
   }
+
+  context->seeds = malloc(program.frag_count * sizeof(unsigned int));
+  for (i = 0; i < (int)program.frag_count; i++) {
+    context->seeds[i] = rand_uint(1000);
+  }
+}
+
+static void free_context(Context context) {
+  free(context.sub_state);
+  free(context.seeds);
 }
 
 static void hot_reload(ShaderProgram program, File *common_shader_code,
@@ -188,5 +199,5 @@ void forge_run(Parameters params) {
 
   window_close(window, true);
 
-  free(context.sub_state);
+  free_context(context);
 }

src/shaders.c

@@ -138,6 +138,7 @@ static void init_single_program(ShaderProgram *program, unsigned int i,
   char name[32];
   char *tex_prefix;
   char *sub_prefix;
+  char *seed_prefix;
 
   program->programs[i] = glCreateProgram();
 
@@ -162,6 +163,14 @@ static void init_single_program(ShaderProgram *program, unsigned int i,
       program->programs[i],
       config_file_get_str(shader_config, "UNIFORM_DEMO", "iDemo"));
 
+  seed_prefix =
+      config_file_get_str(shader_config, "UNIFORM_SEED_PREFIX", "seed");
+  for (j = 0; j < program->frag_count; j++) {
+    sprintf(name, "%s%d", seed_prefix, j + 1);
+    program->iseed_locations[i * program->frag_count + j] =
+        glGetUniformLocation(program->programs[i], name);
+  }
+
   for (j = 0; j < program->sub_type_count; j++) {
     sprintf(name, "SUB_%d_PREFIX", j + 1);
     sub_prefix = config_file_get_str(shader_config, name, 0);
@@ -204,6 +213,8 @@ static void init_programs(ShaderProgram *program, ConfigFile shader_config) {
   program->ifps_locations = malloc(program->frag_count * sizeof(GLuint));
   program->ires_locations = malloc(program->frag_count * sizeof(GLuint));
   program->idemo_locations = malloc(program->frag_count * sizeof(GLuint));
+  program->iseed_locations =
+      malloc(program->frag_count * program->frag_count * sizeof(GLuint));
   program->vpos_locations = malloc(program->frag_count * sizeof(GLuint));
   program->textures_locations =
       malloc(program->frag_count * program->tex_count * sizeof(GLuint));
@@ -314,6 +325,12 @@ static void use_program(ShaderProgram program, int i, bool output,
   glUniform1i(program.idemo_locations[i], (const GLint)(context.demo ? 1 : 0));
   glUniform2fv(program.ires_locations[i], 1, (const GLfloat *)&resolution);
 
+  // set seeds uniforms
+  for (j = 0; j < program.frag_count; j++) {
+    glUniform1i(program.iseed_locations[i * program.frag_count + j],
+                (const GLint)context.seeds[j]);
+  }
+
   // set subroutines for fragment
   for (j = 0; j < program.sub_type_count; j++) {
     k = context.sub_state[i * program.sub_type_count + j];

src/types.h

@@ -57,6 +57,7 @@ typedef struct ShaderProgram {
   GLuint *ifps_locations;
   GLuint *ires_locations;
   GLuint *idemo_locations;
+  GLuint *iseed_locations;
 
   GLuint *vpos_locations;
 
@@ -77,6 +78,7 @@ typedef struct Context {
   float tempo;
   unsigned int *sub_state;
   bool demo;
+  unsigned int *seeds;
 } Context;
 
 typedef struct Timer {