Reorganize files and add Mandelbrot shader

src/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, or `NULL` on error.
+ */
+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);
+  }
+}