#include <stdio.h>

#include <GL/glew.h>
#include <GLFW/glfw3.h>

int main()
{
    // Initialise GLFW
    glewExperimental = true; // Needed for core profile
    if (!glfwInit()) {
        fprintf( stderr, "Failed to initialize GLFW\n" );
        return -1;
    }

    glfwWindowHint(GLFW_SAMPLES, 4); // 4x antialiasing
    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); // We don't want the old OpenGL 

    // Open a window and create its OpenGL context
    GLFWwindow* window; // (In the accompanying source code, this variable is global for simplicity)
    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" );
        glfwTerminate();
        return -1;
    }
    glfwMakeContextCurrent(window); // Initialize GLEW
    glewExperimental=true; // Needed in core profile
    if (glewInit() != GLEW_OK) {
        fprintf(stderr, "Failed to initialize GLEW\n");
        return -1;
    }

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

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