#include <iostream>
#include <GL/glew.h>
#include <GL/freeglut.h>

using namespace std;

#define WINDOW_TITLE "Modern OpenGL"

int WindowWidth = 800, WindowHeight = 600;

void UInitialize(int, char*[]);
void UInitWindow(int, char*[]);
void UResizeWindow(int, int);
void URenderGraphics(void);

int main(int argc, char* argv[]){
    UInitialize(argc, argv);
    glutMainLoop();
    exit(EXIT_SUCCESS);
}

void UInitialize(int argc, char* argv[]){

    GLenum GlewInitResult;

    UInitWindow(argc, argv);

    GlewInitResult = glewInit();

    if (GLEW_OK != GlewInitResult){
        fprintf(stderr, "ERROR: %s\n", glewGetErrorString(GlewInitResult));
        exit(EXIT_FAILURE);
    }
    fprintf(stdout, "INFO: OpenGL Version: %s\n", glGetString(GL_VERSION));
    glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
}

void UinitWindow(int argc, char* argv[]){
    glutInit(&argc, argv);
    glutInitWindowSize(WindowWidth, WindowHeight);
    glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA);
    glutCreateWindow(WINDOW_TITLE);
    glutReshapeFunc(UResizeWindow);
    glutDisplayFunc(URenderGraphics);
}

void UResizeWindow(int Width, int Height){
    glViewport(0, 0, Width, Height);
}

void URenderGraphics(void){
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glutSwapBuffers();
}