common code for shaders

src/file.c

@@ -5,6 +5,7 @@
 #include <sys/types.h>
 
 #include "logs.h"
+#include "strings.h"
 #include "types.h"
 
 time_t get_file_time(File file) {
@@ -64,4 +65,13 @@ File read_file(char *path) {
   return file;
 }
 
-void free_file(File *file) { free(file->content); }
+void prepend_file(File *src, File extra) {
+  char *old_src_content = src->content;
+  src->content = concat(extra.content, src->content);
+  free(old_src_content);
+}
+
+void free_file(File *file) {
+  free(file->content);
+  free(file->path);
+}

src/file.h

@@ -11,4 +11,6 @@ void update_file(File *file);
 
 void free_file(File *file);
 
+void prepend_file(File *src, File extra);
+
 #endif

src/forge.c

@@ -36,21 +36,33 @@ void compute_fps(Window *window, Timer *timer) {
   }
 }
 
-void loop(Window *window, ShaderProgram program, bool hot_reload,
-          File *fragment_shaders, Timer *timer) {
-  Context context;
+void hot_reload(ShaderProgram program, File *common_shader_code,
+                File *fragment_shaders) {
   int i;
+  bool force_update = false;
+
+  if (should_update_file(*common_shader_code)) {
+    update_file(common_shader_code);
+    force_update = true;
+  }
+
+  for (i = 0; i < FRAG_COUNT; i++) {
+    if (force_update || should_update_file(fragment_shaders[i])) {
+      update_file(&fragment_shaders[i]);
+      prepend_file(&fragment_shaders[i], *common_shader_code);
+      update_program(program, fragment_shaders, i);
+    }
+  }
+}
+
+void loop(Window *window, ShaderProgram program, bool hr,
+          File *common_shader_code, File *fragment_shaders, Timer *timer) {
+  Context context;
 
   compute_fps(window, timer);
 
-  if (hot_reload) {
-    // TODO extract to function
-    for (i = 0; i < FRAG_COUNT; i++) {
-      if (should_update_file(fragment_shaders[i])) {
-        update_file(&fragment_shaders[i]);
-        update_program(program, fragment_shaders, i);
-      }
-    }
+  if (hr) {
+    hot_reload(program, common_shader_code, fragment_shaders);
   }
 
   context = get_window_context(window);
@@ -60,23 +72,53 @@ void loop(Window *window, ShaderProgram program, bool hot_reload,
   refresh_window(window);
 }
 
+File read_fragment_shader_file(char *frag_path, int i) {
+  File fragment_shader;
+  char *file_path = malloc(sizeof(char) * 1024);
+
+  sprintf(file_path, "%s/frag%d.glsl", frag_path, i);
+  fragment_shader = read_file(file_path);
+  if (fragment_shader.error) {
+    exit(EXIT_FAILURE);
+  }
+
+  return fragment_shader;
+}
+
+void init_files(char *frag_path, File *common_shader_code,
+                File *fragment_shaders) {
+  int i;
+
+  for (i = 0; i < FRAG_COUNT + 1; i++) {
+    if (i == 0) {
+      (*common_shader_code) = read_fragment_shader_file(frag_path, i);
+    } else {
+      fragment_shaders[i - 1] = read_fragment_shader_file(frag_path, i);
+
+      prepend_file(&fragment_shaders[i - 1], *common_shader_code);
+    }
+  }
+}
+
+void free_files(File *common_shader_code, File *fragment_shaders) {
+  int i;
+
+  for (i = 0; i < FRAG_COUNT; i++) {
+    free_file(&fragment_shaders[i]);
+  }
+
+  free_file(common_shader_code);
+}
+
 void forge_run(Parameters params) {
   File fragment_shaders[FRAG_COUNT];
+  File common_shader_code;
   ShaderProgram program;
   Window *window;
   Timer timer;
   Context context;
-  int i;
-  char file_path[FRAG_COUNT][1024];
 
-  // TODO extract to function
-  for (i = 0; i < FRAG_COUNT; i++) {
-    sprintf(file_path[i], "%s/frag%d.glsl", params.frag_path, i + 1);
-    fragment_shaders[i] = read_file(file_path[i]);
-    if (fragment_shaders[i].error) {
-      exit(EXIT_FAILURE);
-    }
-  }
+  init_files(params.frag_path, &common_shader_code, fragment_shaders);
 
   window = init_window(PACKAGE " " VERSION, params.screen, error_callback,
                        key_callback);
@@ -93,13 +135,11 @@ void forge_run(Parameters params) {
   timer = create_timer(60);
 
   while (!window_should_close(window)) {
-    loop(window, program, params.hot_reload, fragment_shaders, &timer);
+    loop(window, program, params.hot_reload, &common_shader_code,
+         fragment_shaders, &timer);
   }
 
   close_window(window, true);
 
-  // TODO extract to function
-  for (i = 0; i < FRAG_COUNT; i++) {
-    free_file(&fragment_shaders[i]);
-  }
+  free_files(&common_shader_code, fragment_shaders);
 }

src/shaders.c

@@ -256,6 +256,4 @@ void apply_program(ShaderProgram program, Context context) {
     // draw output
     glDrawArrays(GL_TRIANGLES, 0, 6);
   }
-}
-
-// TODO clean buffers from opengl memories
+}

src/strings.c

@@ -0,0 +1,11 @@
+#include <stdlib.h>
+#include <string.h>
+
+char *concat(const char *s1, const char *s2) {
+  char *result =
+      malloc(strlen(s1) + strlen(s2) + 1); // +1 for the null-terminator
+  // in real code you would check for errors in malloc here
+  strcpy(result, s1);
+  strcat(result, s2);
+  return result;
+}

src/strings.h

@@ -0,0 +1,6 @@
+#ifndef STRINGS_H
+#define STRINGS_H
+
+char *concat(const char *s1, const char *s2);
+
+#endif