Membuat Persegi Warna-Warni dengan OpenGL dan Dev C++

#include <stdio.h>
#include <stdlib.h>
#include <gl/glut.h>

using namespace std;

void tampil(){
     glClearColor (1.0,1.0,1.0,1.0); //warna dasar putih
     glClear (GL_COLOR_BUFFER_BIT);
     
     glColor3f (1.0, 1.0, 0.0);//warna kuning
     
     glBegin(GL_POLYGON); //persegi kuning
     glVertex2f(0,0.5);
     glVertex2f(0.5,0);
     glVertex2f(0,-0.5);
     glVertex2f(-0.5,0);
     glEnd ();
     
     glColor3f (0.0, 0.0, 1.0); //warna biru
     
     glBegin(GL_POLYGON); // persegi biru
     glVertex2f(-0.5,1);
     glVertex2f(-1,0.5);
     glVertex2f(-0.5,0);
     glVertex2f(0,0.5);
     glEnd ();
     
     glColor3f (1.0, 0.0, 0.0); //warna merah
     
     glBegin(GL_POLYGON); //persegi merah
     glVertex2f(0.5,1);
     glVertex2f(0,0.5);
     glVertex2f(0.5,0);
     glVertex2f(1,0.5);
     glEnd ();
     
     glColor3f (0.0, 1.0, 0.0); //warna hijau
     
     glBegin(GL_POLYGON); //persegi hijau
     glVertex2f(-0.5,0);
     glVertex2f(-1,-0.5);
     glVertex2f(-0.5,-1);
     glVertex2f(0,-0.5);
     glEnd ();
     
     glColor3f (1.0, 0.0, 1.0); //warna ungu
     
     glBegin(GL_POLYGON); //persegi ungu
     glVertex2f(0.5,0);
     glVertex2f(0,-0.5);
     glVertex2f(0.5,-1);
     glVertex2f(1,-0.5);
     glEnd ();
     
     glFlush();
     }

int main(int argc, char *argv[])
{

    printf("Saat ini sedang ditampilkan Kotak Berwarna by Andi Sholihin (09.04.111.00011)");
    glutCreateWindow("Kotak Berwarna by Andi Sholihin");
    glutDisplayFunc(tampil);
    glutMainLoop();

    system("PAUSE");
    return EXIT_SUCCESS;
}