HelloWindow.cpp

#include <chrono>
#include <glad/glad.h>
#include <GLFW/glfw3.h>

#include <iostream>
#include <thread>

void framebuffer_size_callback(GLFWwindow* window, int width, int height) {
    glViewport(0, 0, width, height);
}

void processInput(GLFWwindow* window) {
    if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS) {
        glfwSetWindowShouldClose(window, true);
    }
}

int main() {
    // initialize GLFW
    glfwInit();
    // configure GLFW
    // tell GLFW 3.3 is the OpenGL version
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    // explicitly use the core-profile,
    // Telling GLFW we want to use the core-profile means
    // we'll get access to a smaller subset of OpenGL features
    // without backwards-compatible features we no longer need
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
#ifdef MacOS
    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
#endif // MacOS
    // create a window object
    GLFWwindow *window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
    if (window == NULL) {
        std::cout << "Failed to create GLFW window" << std::endl;
        glfwTerminate();
        return -1;
    }
    glfwMakeContextCurrent(window);

    // [4.1 GLAD]: managers function pointers for OpenGL
    // initialize GLAD before we call any OpenGL function
    if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) {
        std::cout << "Failed to initialize GLAD" << std::endl;
        return -1;
    }

    // [4.2 Viewport]
    // tell OpenGL the size of the rendering window
    glViewport(0, 0, 800, 600);

    // resize window the viewport should be adjusted as well
    glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);

    // [4.3 Ready engines]
    // render loop
    while (!glfwWindowShouldClose(window)) {
        // [4.4 input]
        processInput(window);

        // rendering commands here
        glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT);

        // check and call events and swap the buffers
        glfwSwapBuffers(window);
        glfwPollEvents();
    }

    glfwTerminate();
    return 0;
}