Move shader initialization to a separate function

src/main.c

@@ -116,8 +116,6 @@ int main(int argc, char *argv[]) {
     state.inotify_fd = -1;
   }
 
-  initialize_shaders(&state, arguments.shader_file, arguments.buffer_file);
-
   state.window = initialize_window(WINDOW_WIDTH, WINDOW_HEIGHT);
   if (state.window == NULL) {
     glfwTerminate();
@@ -126,40 +124,14 @@ int main(int argc, char *argv[]) {
 
   unsigned int VAO = initialize_vertices();
 
-  state.screen_shader.program = glCreateProgram();
+  int err =
-  if (!state.screen_shader.program) {
+      initialize_shaders(&state, arguments.shader_file, arguments.buffer_file,
-    log_error("Could not create screen shader program");
+                         WINDOW_WIDTH, WINDOW_HEIGHT);
+  if (err) {
     glfwDestroyWindow(state.window);
     glfwTerminate();
     return EXIT_FAILURE;
   }
-  compile_shaders(&state.screen_shader.program, state.screen_shader.filename);
-  glUseProgram(state.screen_shader.program);
-  glUniform1i(glGetUniformLocation(state.screen_shader.program, "u_texture"),
-              0);
-
-  unsigned int framebuffer = 0;
-  unsigned int texture_color_buffer = 0;
-  if (state.buffer_shader.filename) {
-    state.buffer_shader.program = glCreateProgram();
-    if (!state.buffer_shader.program) {
-      log_error("Could not create buffer shader program");
-      glfwDestroyWindow(state.window);
-      glfwTerminate();
-      return EXIT_FAILURE;
-    }
-    compile_shaders(&state.buffer_shader.program, state.buffer_shader.filename);
-    glUseProgram(state.buffer_shader.program);
-    glUniform1i(glGetUniformLocation(state.buffer_shader.program, "u_texture"),
-                0);
-
-    if (initialize_framebuffer(&framebuffer, &texture_color_buffer,
-                               WINDOW_WIDTH, WINDOW_HEIGHT)) {
-      glfwDestroyWindow(state.window);
-      glfwTerminate();
-      return EXIT_FAILURE;
-    }
-  }
 
   /* Drawing loop */
   glfwSetTime(0.0);
@@ -184,7 +156,7 @@ int main(int argc, char *argv[]) {
 
     if (state.buffer_shader.filename) {
       /* bind the framebuffer and draw to it */
-      glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
+      glBindFramebuffer(GL_FRAMEBUFFER, state.framebuffer);
 
       /* Background */
       glClearColor(0, 0, 0, 1.0f);
@@ -204,7 +176,7 @@ int main(int argc, char *argv[]) {
 
       /* Draw the vertices */
       glBindVertexArray(VAO);
-      glBindTexture(GL_TEXTURE_2D, texture_color_buffer);
+      glBindTexture(GL_TEXTURE_2D, state.texture_color_buffer);
       glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
       glBindVertexArray(0);
     }
@@ -229,7 +201,7 @@ int main(int argc, char *argv[]) {
 
     /* Draw the vertices */
     glBindVertexArray(VAO);
-    glBindTexture(GL_TEXTURE_2D, texture_color_buffer);
+    glBindTexture(GL_TEXTURE_2D, state.texture_color_buffer);
     glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
     glBindVertexArray(0);
 

src/renderer.h

@@ -20,6 +20,9 @@ struct renderer_state {
   GLFWwindow *window; /**< GLFW window where the shaders are rendered. */
   struct shader_state screen_shader; /**< Shader for the main screen. */
   struct shader_state buffer_shader; /**< Shader for the framebuffer. */
+  unsigned int framebuffer;          /**< Framebuffer. */
+  unsigned int
+      texture_color_buffer; /**< Texture where the framebuffer renders. */
   int inotify_fd;           /**< inotify file descriptor. */
   size_t frame_count; /**< Frame count since the start of the render loop. */
   size_t prev_frame_count; /**< Frame count at the last log. */

src/shaders.c

@@ -8,16 +8,20 @@
 #include "shaders.h"
 
 /**
- * @brief Initialize shaders and setup inotify if required.
+ * @brief Initialize shaders, compile them, and create the required
+ * texture for the buffer shader.
  *
  * @param state The target renderer state.
  * @param shader_file The file name of the screen shader.
  * @param buffer_file The file name of the buffer shader, or NULL if no buffer
  * shader.
+ * @param texture_width The width of the texture for the buffer shader.
+ * @param texture_height The height of the texture for the buffer shader.
  * @return 0 on success, 1 on error.
  */
 int initialize_shaders(struct renderer_state *state, const char *shader_file,
-                       const char *buffer_file) {
+                       const char *buffer_file, int texture_width,
+                       int texture_height) {
   state->screen_shader.filename = shader_file;
   log_info("Screen shader file: %s", state->screen_shader.filename);
 
@@ -49,6 +53,35 @@ int initialize_shaders(struct renderer_state *state, const char *shader_file,
     }
   }
 
+  state->screen_shader.program = glCreateProgram();
+  if (!state->screen_shader.program) {
+    log_error("Could not create screen shader program");
+    return 1;
+  }
+  compile_shaders(&state->screen_shader.program, state->screen_shader.filename);
+  glUseProgram(state->screen_shader.program);
+  glUniform1i(glGetUniformLocation(state->screen_shader.program, "u_texture"),
+              0);
+
+  if (state->buffer_shader.filename) {
+    state->buffer_shader.program = glCreateProgram();
+    if (!state->buffer_shader.program) {
+      log_error("Could not create buffer shader program");
+      return 1;
+    }
+    compile_shaders(&state->buffer_shader.program,
+                    state->buffer_shader.filename);
+    glUseProgram(state->buffer_shader.program);
+    glUniform1i(glGetUniformLocation(state->buffer_shader.program, "u_texture"),
+                0);
+
+    if (initialize_framebuffer(&state->framebuffer,
+                               &state->texture_color_buffer, texture_width,
+                               texture_height)) {
+      return 1;
+    }
+  }
+
   return 0;
 }
 

src/shaders.h

@@ -4,7 +4,8 @@
 #include "renderer.h"
 
 int initialize_shaders(struct renderer_state *state, const char *shader_file,
-                       const char *buffer_file);
+                       const char *buffer_file, int window_width,
+                       int window_height);
 int compile_shaders(unsigned int *shader_program,
                     const char *const fragment_shader_file);
 char *read_file(const char *const filename);