OpenGL tutorial01

備忘。

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// Include standard headers
#include <stdio.h>
#include <stdlib.h>

// Include GLEW
#include <GL/glew.h>

// Include GLFW
#include <glfw3.h>
GLFWwindow* window;

// Include GLM
#include <glm/glm.hpp>
using namespace glm;

int main(void)
{
    // Initialise GLFW
    if (!glfwInit())
    {
        fprintf(stderr, "Failed to initialize GLFW\n");
        getchar();
        return -1;
    }

    glfwWindowHint(GLFW_SAMPLES, 4);// 4x antialiasing，4倍反鋸齒
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);// We want OpenGL 3.3
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); // To make MacOS happy; should not be needed
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

    // Open a window and create its OpenGL context
    window = glfwCreateWindow(1024, 768, "Tutorial 01", NULL, NULL);
    if (window == NULL) {
        fprintf(stderr, "Failed to open GLFW window. If you have an Intel GPU, they are not 3.3 compatible. Try the 2.1 version of the tutorials.\n");
        getchar();
        glfwTerminate();
        return -1;
    }
    glfwMakeContextCurrent(window);

    // Initialize GLEW
    if (glewInit() != GLEW_OK) {
        fprintf(stderr, "Failed to initialize GLEW\n");
        getchar();
        glfwTerminate();
        return -1;
    }

    // Ensure we can capture the escape key being pressed below
    glfwSetInputMode(window, GLFW_STICKY_KEYS, GL_TRUE);

    // Grey background，RGBA表示
    glClearColor(0.5f, 0.5f, 0.5f, 0.0f);

    do {
        // Clear the screen. It's not mentioned before Tutorial 02, but it can cause flickering, so it's there nonetheless.
        glClear(GL_COLOR_BUFFER_BIT);

        // Draw nothing, see you in tutorial 2 !


        // Swap buffers
        glfwSwapBuffers(window);
        glfwPollEvents();

    } 

    // Check if the ESC key was pressed or the window was closed
    while (glfwGetKey(window, GLFW_KEY_ESCAPE) != GLFW_PRESS && glfwWindowShouldClose(window) == 0);

    // Close OpenGL window and terminate GLFW
    glfwTerminate();

    return 0;
}