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Split into several files

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This commit is contained in:
Dimitri Lozeve 2021-02-23 19:42:11 +01:00
parent a3a19af3ec
commit 2480fa80ef
7 changed files with 275 additions and 226 deletions
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220
main.c
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@ -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"
#define UNUSED(a) (void)a
#include "shaders.h"
#include "renderer.h"
#define WINDOW_WIDTH 800
#define WINDOW_HEIGHT 600
@ -15,66 +12,9 @@
#define FRAGMENT_SHADER_FILE "main.frag"
int main() {
/* Initialize GLFW */
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);
GLFWwindow *window = initialize_window(WINDOW_WIDTH, WINDOW_HEIGHT);
/* Create window */
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 VAO = initialize_vertices();
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;
}

12
main.h
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@ -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 */

2
meson.build
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@ -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',
)

122
renderer.c Normal file
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@ -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);
}
}

12
renderer.h Normal file
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@ -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 */

125
shaders.c Normal file
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@ -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;
}

8
shaders.h Normal file
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@ -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 */