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#include "shader.h"
#include <glad/glad.h>
#include <GLFW/glfw3.h>
#include <stdio.h>
#include <stdlib.h>
extern unsigned char src_vertex_glsl[];
extern unsigned char src_fragment_glsl[];
static void framebuffer_size_callback(GLFWwindow *window, int w, int h);
int
main([[maybe_unused]] int argc, [[maybe_unused]] char **argv)
{
if (glfwInit() == GLFW_FALSE) {
fprintf(stderr, "glfwInit failed\n");
return 1;
}
if (atexit(glfwTerminate)) {
perror("main:atexit");
glfwTerminate();
return 1;
}
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
GLFWwindow *window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
if (window == NULL) {
fprintf(stderr, "glfwCreateWindow failed\n");
return 1;
}
glfwMakeContextCurrent(window);
if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) {
fprintf(stderr, "gladLoadGLLoader failed\n");
return 1;
}
glViewport(0, 0, 800, 600);
glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
static const float verts[] = {
0.5f, 0.5f, 0.0f, 1.0f, 0.0f, 1.0f, // top right
0.5f, -0.5f, 0.0f, 0.0f, 1.0f, 0.0f, // bottom right
-0.5f, -0.5f, 0.0f, 0.0f, 0.0f, 1.0f, // bottom left
-0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 0.0f // top left
};
static const GLuint indices[] = {
0, 1, 3, // first triangle
1, 2, 3 // second triangle
};
GLuint VBO;
glGenBuffers(1, &VBO);
GLuint EBO;
glGenBuffers(1, &EBO);
GLuint VAO;
glGenVertexArrays(1, &VAO);
glBindVertexArray(VAO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(verts), verts, GL_STATIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices) / 2, indices, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)0);
glEnableVertexAttribArray(0);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)(3 * sizeof(float)));
glEnableVertexAttribArray(1);
Shader shader;
if (shader_init(&shader,
(const char *)src_vertex_glsl,
(const char *)src_fragment_glsl))
{
fprintf(stderr, "shader_init failed\n");
return 1;
}
const GLint vertex_color_location =
shader_uniform_location(&shader, "ourColor");
//glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
while (!glfwWindowShouldClose(window)) {
shader_use(&shader);
const int r = 0;//rand();
glUniform4f(vertex_color_location,
!(r&1), !(r&2), !(r&4), !(r&8));
glBindVertexArray(VAO);
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
glfwSwapBuffers(window);
glfwPollEvents();
}
return 0;
}
static void
framebuffer_size_callback([[maybe_unused]] GLFWwindow *window, int w, int h)
{
glViewport(0, 0, w, h);
}
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