Split into several files

main.c

@@ -1,13 +1,10 @@
 #include <GL/glew.h>
 #include <GLFW/glfw3.h>
-#include <stdbool.h>
-#include <stdio.h>
 #include <stdlib.h>
 
 #include "log.h"
-#include "main.h"
+#include "shaders.h"
-
+#include "renderer.h"
-#define UNUSED(a) (void)a
 
 #define WINDOW_WIDTH 800
 #define WINDOW_HEIGHT 600
@@ -15,66 +12,9 @@
 #define FRAGMENT_SHADER_FILE "main.frag"
 
 int main() {
-  /* Initialize GLFW */
+  GLFWwindow *window = initialize_window(WINDOW_WIDTH, WINDOW_HEIGHT);
-  if (!glfwInit()) {
-    log_error("[GLFW] Failed to init");
-    return EXIT_FAILURE;
-  }
-  glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
-  glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
-  glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
 
-  /* Create window */
+  unsigned int VAO = initialize_vertices();
-  GLFWwindow *window =
-      glfwCreateWindow(WINDOW_WIDTH, WINDOW_HEIGHT, "OpenGL Test", NULL, NULL);
-  if (window == NULL) {
-    log_error("[GLFW] Failed to create window");
-    glfwTerminate();
-    return EXIT_FAILURE;
-  }
-  glfwMakeContextCurrent(window);
-  log_debug("[GLFW] Created window of size %d, %d", WINDOW_WIDTH,
-            WINDOW_HEIGHT);
-
-  glViewport(0, 0, WINDOW_WIDTH, WINDOW_HEIGHT);
-  glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
-
-  /* Initialize OpenGL */
-  if (glewInit() != GLEW_OK) {
-    log_error("[GLEW] Failed to initialize");
-    return EXIT_FAILURE;
-  }
-  log_debug("[GLEW] Initialized successfully");
-
-  /* Define vertices */
-  float vertices[] = {
-      -1.0, -1.0, 0.0, // bottom left
-      -1.0, 1.0,  0.0, // top left
-      1.0,  -1.0, 0.0, // top right
-      1.0,  1.0,  0.0  // bottom right
-  };
-  unsigned int indices[] = {
-      0, 1, 2, // first triangle
-      1, 2, 3  // second triangle
-  };
-
-  unsigned int VBO = 0;
-  glGenBuffers(1, &VBO);
-  unsigned int EBO = 0;
-  glGenBuffers(1, &EBO);
-  unsigned int VAO = 0;
-  glGenVertexArrays(1, &VAO);
-
-  glBindVertexArray(VAO);
-  glBindBuffer(GL_ARRAY_BUFFER, VBO);
-  glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
-  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
-  glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices,
-               GL_STATIC_DRAW);
-
-  glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void *)0);
-  glEnableVertexAttribArray(0);
-  log_debug("Vertex data initialized successfully");
 
   unsigned int shader_program = glCreateProgram();
   int result = compile_shaders(&shader_program, FRAGMENT_SHADER_FILE);
@@ -86,7 +26,7 @@ int main() {
   /* Drawing loop */
   size_t frame = 0;
   while (!glfwWindowShouldClose(window)) {
-    process_input(window, &shader_program);
+    process_input(window, &shader_program, FRAGMENT_SHADER_FILE);
 
     /* Background */
     glClearColor(0, 0, 0, 1.0f);
@@ -94,6 +34,7 @@ int main() {
 
     glUseProgram(shader_program);
 
+    /* Setup uniforms */
     float time = glfwGetTime();
     int frag_time_location = glGetUniformLocation(shader_program, "u_time");
     glUniform1f(frag_time_location, time);
@@ -113,6 +54,7 @@ int main() {
         glGetUniformLocation(shader_program, "u_mouse");
     glUniform2f(frag_mouse_resolution_location, mouse_x, mouse_y);
 
+    /* Draw the vertices */
     // glPolygonMode(GL_FRONT_AND_BACK, GL_LINE); /* For wireframe mode */
     glBindVertexArray(VAO);
     glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
@@ -127,151 +69,3 @@ int main() {
   return EXIT_SUCCESS;
 }
 
-/**
- * @brief Compile shaders from source files.
- *
- * This function reads the source files of the vertex and fragment
- * shaders, compiles them, and links them together in a shader
- * program.
- *
- * @param shader_program Pointer to the ID of the shader program
- * where the shaders will be stored.
- * @param fragment_shader_file File name of the fragment shader.
- * @return 0 on success, 1 on error.
- */
-int compile_shaders(unsigned int *shader_program,
-                    const char *const fragment_shader_file) {
-  /* Compile vertex shader */
-  const char *const vertex_shader_source =
-      "#version 330 core\n"
-      "layout (location = 0) in vec3 aPos;\n"
-      "void main()\n"
-      "{\n"
-      "  gl_Position = vec4(aPos, 1.0);\n"
-      "}\n";
-
-  unsigned int vertex_shader = glCreateShader(GL_VERTEX_SHADER);
-  glShaderSource(vertex_shader, 1, &vertex_shader_source, NULL);
-  glCompileShader(vertex_shader);
-  int success = 0;
-  char info_log[512];
-  glGetShaderiv(vertex_shader, GL_COMPILE_STATUS, &success);
-  if (!success) {
-    glGetShaderInfoLog(vertex_shader, 512, NULL, info_log);
-    log_error("Vertex shader compilation failed: %s", info_log);
-  }
-
-  /* Compile fragment shader */
-  const char *const fragment_shader_source = read_file(fragment_shader_file);
-  if (fragment_shader_source == NULL) {
-    log_error("Could not load fragment shader from file %s",
-              fragment_shader_file);
-    return 1;
-  }
-  unsigned int fragment_shader = glCreateShader(GL_FRAGMENT_SHADER);
-  glShaderSource(fragment_shader, 1, &fragment_shader_source, NULL);
-  glCompileShader(fragment_shader);
-  glGetShaderiv(fragment_shader, GL_COMPILE_STATUS, &success);
-  if (!success) {
-    glGetShaderInfoLog(fragment_shader, 512, NULL, info_log);
-    log_error("Fragment shader compilation failed: %s", info_log);
-    return 1;
-  }
-
-  /* Link shaders */
-  unsigned int new_shader_program = glCreateProgram();
-  glAttachShader(new_shader_program, vertex_shader);
-  glAttachShader(new_shader_program, fragment_shader);
-  glLinkProgram(new_shader_program);
-  glGetShaderiv(new_shader_program, GL_LINK_STATUS, &success);
-  if (!success) {
-    glGetShaderInfoLog(new_shader_program, 512, NULL, info_log);
-    log_error("Shader program linking failed: %s", info_log);
-    return 1;
-  }
-
-  glDeleteProgram(*shader_program);
-  *shader_program = new_shader_program;
-
-  free((void *)fragment_shader_source);
-  glDeleteShader(vertex_shader);
-  glDeleteShader(fragment_shader);
-
-  log_debug("Shaders compiled successfully");
-
-  return 0;
-}
-
-/**
- * @brief Callback to adjust the size of the viewport when the window
- * is resized.
- *
- * @param window The current window.
- * @param width The new width.
- * @param height The new height.
- */
-void framebuffer_size_callback(GLFWwindow *window, int width, int height) {
-  UNUSED(window);
-  glViewport(0, 0, width, height);
-}
-
-/**
- * @brief Ensure the window is closed when the user presses the escape
- * key.
- *
- * @param window The current window.
- * @param shader_program Pointer to the shader program to update if needed.
- */
-void process_input(GLFWwindow *window, unsigned int *shader_program) {
-  if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS) {
-    log_debug("Quitting");
-    glfwSetWindowShouldClose(window, true);
-  } else if (glfwGetKey(window, GLFW_KEY_R) == GLFW_PRESS) {
-    compile_shaders(shader_program, FRAGMENT_SHADER_FILE);
-  }
-}
-
-/**
- * @brief Reads a file in a heap-allocated buffer.
- *
- * This function computes the length of the file, allocate a buffer of
- * the correct size, and reads the file in the buffer. Returns `NULL`
- * on error.
- *
- * @param filename The file to read.
- * @return A buffer containing the contents of the file, or `NULL` if
- * there was an error.
- */
-char *read_file(const char *const filename) {
-  FILE *fd = fopen(filename, "r");
-  if (fd == NULL) {
-    log_error("Could not open file %s", filename);
-    return NULL;
-  }
-
-  if (fseek(fd, 0, SEEK_END) == -1) {
-    perror("fseek");
-    return NULL;
-  }
-  long size = ftell(fd);
-  if (size == -1) {
-    perror("ftell");
-    return NULL;
-  }
-  rewind(fd);
-  char *buf = calloc(size + 1, 1);
-  if (buf == NULL) {
-    log_error("Failed to allocate memory to read file %s", filename);
-    return NULL;
-  }
-
-  long bytes_read = fread(buf, 1, size, fd);
-  if (bytes_read != size) {
-    log_error("Failed to read file %s (%ld bytes read out of %ld total)",
-              filename, bytes_read, size);
-    return NULL;
-  }
-
-  fclose(fd);
-  return buf;
-}

main.h

@@ -1,12 +0,0 @@
-#ifndef MAIN_H
-#define MAIN_H
-
-#include <GLFW/glfw3.h>
-
-char *read_file(const char *const filename);
-int compile_shaders(unsigned int *shader_program,
-                    const char *const fragment_shader_file);
-void process_input(GLFWwindow *window, unsigned int *shader_program);
-void framebuffer_size_callback(GLFWwindow *window, int width, int height);
-
-#endif /* MAIN_H */

meson.build

@@ -14,7 +14,7 @@ glew_dep = dependency('glew')
 
 executable(
   'shadertool',
-  sources: ['main.c', 'log.c'],
+  sources: ['main.c', 'renderer.c', 'shaders.c', 'log.c'],
   dependencies: [glfw_dep, glew_dep],
   c_args: '-DLOG_USE_COLOR',
 )

renderer.c

@@ -0,0 +1,122 @@
+#include <GL/glew.h>
+#include <GLFW/glfw3.h>
+
+#include "log.h"
+#include "renderer.h"
+#include "shaders.h"
+
+#define UNUSED(a) (void)a
+
+/**
+ * @brief Initialize GLFW and OpenGL, and create a window.
+ *
+ * @param width The width of the window to create.
+ * @param height The height of the window to create.
+ * @return A pointer to the newly created GLFW window.
+ */
+GLFWwindow *initialize_window(int width, int height) {
+  /* Initialize GLFW */
+  if (!glfwInit()) {
+    log_error("[GLFW] Failed to init");
+    return NULL;
+  }
+  glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+  glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+  glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+
+  /* Create window */
+  GLFWwindow *window =
+      glfwCreateWindow(width, height, "ShaderTool", NULL, NULL);
+  if (window == NULL) {
+    log_error("[GLFW] Failed to create window");
+    glfwTerminate();
+    return NULL;
+  }
+  glfwMakeContextCurrent(window);
+  log_debug("[GLFW] Created window of size %d, %d", width, height);
+
+  glViewport(0, 0, width, height);
+  glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
+
+  /* Initialize OpenGL */
+  if (glewInit() != GLEW_OK) {
+    log_error("[GLEW] Failed to initialize");
+    return NULL;
+  }
+  log_debug("[GLEW] Initialized successfully");
+
+  return window;
+}
+
+/**
+ * @brief Initialize the vertex array.
+ *
+ * This functions defines a simple rectangle containing the whole
+ * viewport.
+ *
+ * @return The vertex array object ID.
+ */
+unsigned int initialize_vertices() {
+  /* Define vertices */
+  float vertices[] = {
+      -1.0, -1.0, 0.0, // bottom left
+      -1.0, 1.0,  0.0, // top left
+      1.0,  -1.0, 0.0, // top right
+      1.0,  1.0,  0.0  // bottom right
+  };
+  unsigned int indices[] = {
+      0, 1, 2, // first triangle
+      1, 2, 3  // second triangle
+  };
+
+  unsigned int VBO = 0;
+  glGenBuffers(1, &VBO);
+  unsigned int EBO = 0;
+  glGenBuffers(1, &EBO);
+  unsigned int VAO = 0;
+  glGenVertexArrays(1, &VAO);
+
+  glBindVertexArray(VAO);
+  glBindBuffer(GL_ARRAY_BUFFER, VBO);
+  glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
+  glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices,
+               GL_STATIC_DRAW);
+
+  glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void *)0);
+  glEnableVertexAttribArray(0);
+  log_debug("Vertex data initialized successfully");
+
+  return VAO;
+}
+
+/**
+ * @brief Callback to adjust the size of the viewport when the window
+ * is resized.
+ *
+ * @param window The current window.
+ * @param width The new width.
+ * @param height The new height.
+ */
+void framebuffer_size_callback(GLFWwindow *window, int width, int height) {
+  UNUSED(window);
+  glViewport(0, 0, width, height);
+}
+
+/**
+ * @brief Ensure the window is closed when the user presses the escape
+ * key.
+ *
+ * @param window The current window.
+ * @param shader_program Pointer to the shader program to update if needed.
+ * @param fragment_shader_file The shader file to reload if needed.
+ */
+void process_input(GLFWwindow *window, unsigned int *shader_program,
+                   const char *const fragment_shader_file) {
+  if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS) {
+    log_debug("Quitting");
+    glfwSetWindowShouldClose(window, true);
+  } else if (glfwGetKey(window, GLFW_KEY_R) == GLFW_PRESS) {
+    compile_shaders(shader_program, fragment_shader_file);
+  }
+}

renderer.h

@@ -0,0 +1,12 @@
+#ifndef RENDERER_H
+#define RENDERER_H
+
+#include <GLFW/glfw3.h>
+
+GLFWwindow *initialize_window(int width, int height);
+unsigned int initialize_vertices();
+void process_input(GLFWwindow *window, unsigned int *shader_program,
+                   const char *const fragment_shader_file);
+void framebuffer_size_callback(GLFWwindow *window, int width, int height);
+
+#endif /* RENDERER_H */

shaders.c

@@ -0,0 +1,125 @@
+#include <GL/glew.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "log.h"
+
+/**
+ * @brief Reads a file in a heap-allocated buffer.
+ *
+ * This function computes the length of the file, allocate a buffer of
+ * the correct size, and reads the file in the buffer. Returns `NULL`
+ * on error.
+ *
+ * @param filename The file to read.
+ * @return A buffer containing the contents of the file, or `NULL` if
+ * there was an error.
+ */
+char *read_file(const char *const filename) {
+  FILE *fd = fopen(filename, "r");
+  if (fd == NULL) {
+    log_error("Could not open file %s", filename);
+    return NULL;
+  }
+
+  if (fseek(fd, 0, SEEK_END) == -1) {
+    perror("fseek");
+    return NULL;
+  }
+  long size = ftell(fd);
+  if (size == -1) {
+    perror("ftell");
+    return NULL;
+  }
+  rewind(fd);
+  char *buf = calloc(size + 1, 1);
+  if (buf == NULL) {
+    log_error("Failed to allocate memory to read file %s", filename);
+    return NULL;
+  }
+
+  long bytes_read = fread(buf, 1, size, fd);
+  if (bytes_read != size) {
+    log_error("Failed to read file %s (%ld bytes read out of %ld total)",
+              filename, bytes_read, size);
+    return NULL;
+  }
+
+  fclose(fd);
+  return buf;
+}
+
+/**
+ * @brief Compile shaders from source files.
+ *
+ * This function reads the source files of the vertex and fragment
+ * shaders, compiles them, and links them together in a shader
+ * program.
+ *
+ * @param shader_program Pointer to the ID of the shader program
+ * where the shaders will be stored.
+ * @param fragment_shader_file File name of the fragment shader.
+ * @return 0 on success, 1 on error.
+ */
+int compile_shaders(unsigned int *shader_program,
+                    const char *const fragment_shader_file) {
+  /* Compile vertex shader */
+  const char *const vertex_shader_source =
+      "#version 330 core\n"
+      "layout (location = 0) in vec3 aPos;\n"
+      "void main()\n"
+      "{\n"
+      "  gl_Position = vec4(aPos, 1.0);\n"
+      "}\n";
+
+  unsigned int vertex_shader = glCreateShader(GL_VERTEX_SHADER);
+  glShaderSource(vertex_shader, 1, &vertex_shader_source, NULL);
+  glCompileShader(vertex_shader);
+  int success = 0;
+  char info_log[512];
+  glGetShaderiv(vertex_shader, GL_COMPILE_STATUS, &success);
+  if (!success) {
+    glGetShaderInfoLog(vertex_shader, 512, NULL, info_log);
+    log_error("Vertex shader compilation failed: %s", info_log);
+  }
+
+  /* Compile fragment shader */
+  const char *const fragment_shader_source = read_file(fragment_shader_file);
+  if (fragment_shader_source == NULL) {
+    log_error("Could not load fragment shader from file %s",
+              fragment_shader_file);
+    return 1;
+  }
+  unsigned int fragment_shader = glCreateShader(GL_FRAGMENT_SHADER);
+  glShaderSource(fragment_shader, 1, &fragment_shader_source, NULL);
+  glCompileShader(fragment_shader);
+  glGetShaderiv(fragment_shader, GL_COMPILE_STATUS, &success);
+  if (!success) {
+    glGetShaderInfoLog(fragment_shader, 512, NULL, info_log);
+    log_error("Fragment shader compilation failed: %s", info_log);
+    return 1;
+  }
+
+  /* Link shaders */
+  unsigned int new_shader_program = glCreateProgram();
+  glAttachShader(new_shader_program, vertex_shader);
+  glAttachShader(new_shader_program, fragment_shader);
+  glLinkProgram(new_shader_program);
+  glGetShaderiv(new_shader_program, GL_LINK_STATUS, &success);
+  if (!success) {
+    glGetShaderInfoLog(new_shader_program, 512, NULL, info_log);
+    log_error("Shader program linking failed: %s", info_log);
+    return 1;
+  }
+
+  glDeleteProgram(*shader_program);
+  *shader_program = new_shader_program;
+
+  free((void *)fragment_shader_source);
+  glDeleteShader(vertex_shader);
+  glDeleteShader(fragment_shader);
+
+  log_debug("Shaders compiled successfully");
+
+  return 0;
+}

shaders.h

@@ -0,0 +1,8 @@
+#ifndef SHADERS_H
+#define SHADERS_H
+
+char *read_file(const char *const filename);
+int compile_shaders(unsigned int *shader_program,
+                    const char *const fragment_shader_file);
+
+#endif /* SHADERS_H */