diff --git a/src/main.c b/src/main.c
index 1f1115c..8553c0c 100644
--- a/src/main.c
+++ b/src/main.c
@@ -16,12 +16,12 @@ int main(int argc, char *argv[]) {
   }
 
   struct renderer_state state = {0};
-  
-  state.screen_shader_file = argv[1];
-  log_debug("Screen shader file: %s", state.screen_shader_file);
+
+  state.screen_shader.filename = argv[1];
+  log_debug("Screen shader file: %s", state.screen_shader.filename);
   if (argc >= 3) {
-    state.buffer_shader_file = argv[2];
-    log_debug("Buffer shader file: %s", state.buffer_shader_file);
+    state.buffer_shader.filename = argv[2];
+    log_debug("Buffer shader file: %s", state.buffer_shader.filename);
   }
 
   state.window = initialize_window(WINDOW_WIDTH, WINDOW_HEIGHT);
@@ -32,30 +32,32 @@ int main(int argc, char *argv[]) {
 
   unsigned int VAO = initialize_vertices();
 
-  state.screen_shader = glCreateProgram();
-  if (!state.screen_shader) {
+  state.screen_shader.program = glCreateProgram();
+  if (!state.screen_shader.program) {
     log_error("Could not create screen shader program");
     glfwDestroyWindow(state.window);
     glfwTerminate();
     return EXIT_FAILURE;
   }
-  compile_shaders(&state.screen_shader, state.screen_shader_file);
-  glUseProgram(state.screen_shader);
-  glUniform1i(glGetUniformLocation(state.screen_shader, "u_texture"), 0);
+  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_file) {
-    state.buffer_shader = glCreateProgram();
-    if (!state.buffer_shader) {
+  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, state.buffer_shader_file);
-    glUseProgram(state.buffer_shader);
-    glUniform1i(glGetUniformLocation(state.buffer_shader, "u_texture"), 0);
+    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)) {
@@ -78,14 +80,15 @@ int main(int argc, char *argv[]) {
     glfwGetCursorPos(state.window, &mouse_x, &mouse_y);
 
     if (state.time - state.prev_time >= 1.0) {
-      double fps = (state.frame_count - state.prev_frame_count) / (state.time - state.prev_time);
+      double fps = (state.frame_count - state.prev_frame_count) /
+                   (state.time - state.prev_time);
       log_debug("frame = %zu, time = %.2f, fps = %.2f, viewport = (%d, %d)",
                 state.frame_count, state.time, fps, viewport[2], viewport[3]);
       state.prev_frame_count = state.frame_count;
       state.prev_time = state.time;
     }
 
-    if (state.buffer_shader_file) {
+    if (state.buffer_shader.filename) {
       /* bind the framebuffer and draw to it */
       glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
 
@@ -94,13 +97,16 @@ int main(int argc, char *argv[]) {
       glClear(GL_COLOR_BUFFER_BIT);
 
       /* Setup uniforms */
-      glUseProgram(state.buffer_shader);
-      glUniform1ui(glGetUniformLocation(state.buffer_shader, "u_frame"), state.frame_count);
-      glUniform1f(glGetUniformLocation(state.buffer_shader, "u_time"), state.time);
-      glUniform2f(glGetUniformLocation(state.buffer_shader, "u_resolution"),
-                  viewport[2], viewport[3]);
-      glUniform2f(glGetUniformLocation(state.buffer_shader, "u_mouse"), mouse_x,
-                  mouse_y);
+      glUseProgram(state.buffer_shader.program);
+      glUniform1ui(glGetUniformLocation(state.buffer_shader.program, "u_frame"),
+                   state.frame_count);
+      glUniform1f(glGetUniformLocation(state.buffer_shader.program, "u_time"),
+                  state.time);
+      glUniform2f(
+          glGetUniformLocation(state.buffer_shader.program, "u_resolution"),
+          viewport[2], viewport[3]);
+      glUniform2f(glGetUniformLocation(state.buffer_shader.program, "u_mouse"),
+                  mouse_x, mouse_y);
 
       /* Draw the vertices */
       glBindVertexArray(VAO);
@@ -116,13 +122,16 @@ int main(int argc, char *argv[]) {
     glClear(GL_COLOR_BUFFER_BIT);
 
     /* Setup uniforms */
-    glUseProgram(state.screen_shader);
-    glUniform1ui(glGetUniformLocation(state.screen_shader, "u_frame"), state.frame_count);
-    glUniform1f(glGetUniformLocation(state.screen_shader, "u_time"), state.time);
-    glUniform2f(glGetUniformLocation(state.screen_shader, "u_resolution"),
-                viewport[2], viewport[3]);
-    glUniform2f(glGetUniformLocation(state.screen_shader, "u_mouse"), mouse_x,
-                mouse_y);
+    glUseProgram(state.screen_shader.program);
+    glUniform1ui(glGetUniformLocation(state.screen_shader.program, "u_frame"),
+                 state.frame_count);
+    glUniform1f(glGetUniformLocation(state.screen_shader.program, "u_time"),
+                state.time);
+    glUniform2f(
+        glGetUniformLocation(state.screen_shader.program, "u_resolution"),
+        viewport[2], viewport[3]);
+    glUniform2f(glGetUniformLocation(state.screen_shader.program, "u_mouse"),
+                mouse_x, mouse_y);
 
     /* Draw the vertices */
     glBindVertexArray(VAO);
diff --git a/src/renderer.c b/src/renderer.c
index 997ce22..fb7b7d9 100644
--- a/src/renderer.c
+++ b/src/renderer.c
@@ -200,9 +200,11 @@ void process_input(struct renderer_state *state) {
     state->time = 0.0;
     state->prev_time = 0.0;
     // recompile shaders
-    compile_shaders(&state->screen_shader, state->screen_shader_file);
-    if (state->buffer_shader_file) {
-      compile_shaders(&state->buffer_shader, state->buffer_shader_file);
+    compile_shaders(&state->screen_shader.program,
+                    state->screen_shader.filename);
+    if (state->buffer_shader.filename) {
+      compile_shaders(&state->buffer_shader.program,
+                      state->buffer_shader.filename);
     }
   } else if (glfwGetKey(state->window, GLFW_KEY_S) == GLFW_PRESS) {
     capture_screenshot();
diff --git a/src/renderer.h b/src/renderer.h
index 4d936ab..604d336 100644
--- a/src/renderer.h
+++ b/src/renderer.h
@@ -3,20 +3,26 @@
 
 #include <GLFW/glfw3.h>
 
+/**
+ * Structure representing the state of a shader.
+ */
+struct shader_state {
+  unsigned int program; /**< Shader program ID. */
+  const char *filename; /**< Shader file name. */
+};
+
 /**
  * Structure representing the state of the renderer and associated
  * shaders.
  */
 struct renderer_state {
-  GLFWwindow *window;             /**< GLFW window where the shaders are rendered. */
-  unsigned int screen_shader;     /**< Shader for the main screen. */
-  const char *screen_shader_file; /**< Screen shader file name. */
-  unsigned int buffer_shader;     /**< Shader for the background framebuffer. */
-  const char *buffer_shader_file; /**< Buffer shader file name. */
-  size_t frame_count;		  /**< Frame count since the beginning of the render loop. */
-  size_t prev_frame_count;	  /**< Frame count at the last log. */
-  double time;			  /**< Time in seconds since the beginning of the render loop. */
-  double prev_time;		  /**< Time in seconds at the last log. */
+  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. */
+  size_t frame_count; /**< Frame count since the start of the render loop. */
+  size_t prev_frame_count; /**< Frame count at the last log. */
+  double time; /**< Time in seconds since the beginning of the render loop. */
+  double prev_time; /**< Time in seconds at the last log. */
 };
 
 GLFWwindow *initialize_window(int width, int height);