#include <iostream>
#include<windows.h>       
#include<gl\glut.h>       
using namespace std; 
//sourcea.ir
int color = 0;
GLint width = 800;
GLint hight = 600;
 
void init()
{
    
    glClearColor(0, 1, 1, 0);
    
    glMatrixMode(GL_PROJECTION);
    
    gluOrtho2D(0, width, 0, hight);
}
 
void drawSquare(GLint x1, GLint y1, GLint x2, GLint y2, GLint x3, GLint y3, GLint x4, GLint y4)
{
    
    if (color == 0)
    {
        glColor3f(1, 1, 1); 
        color = 1;
    }
    
    else
    {
        glColor3f(0, 0, 0); 
        color = 0;
    }
 
    
    glBegin(GL_POLYGON);
    glVertex2i(x1, y1);
    glVertex2i(x2, y2);
    glVertex2i(x3, y3);
    glVertex2i(x4, y4);
    glEnd();
}
void chessboard()
{
    glClear(GL_COLOR_BUFFER_BIT); 
    GLint x, y;
    GLint squareWidthInPixel = 100;
    GLint squareHightInPixel = 75;
    for (x = 0; x <= width; x += squareWidthInPixel)
    {
        for (y = 0; y <= hight; y += squareHightInPixel)
        {
            drawSquare(x, y + squareHightInPixel, x + squareWidthInPixel, y + squareHightInPixel, x + squareWidthInPixel, y, x, y);
        }
    }
    
    glFlush();
}
 
int main(int agrc, char ** argv)
{
    
    glutInit(&agrc, argv);
    
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
    
    glutInitWindowPosition(100, 100);
    
    glutInitWindowSize(800, 600);
    
    glutCreateWindow("Chess Board using 'OpenGL' in C++");
    
    init();
    
    glutDisplayFunc(chessboard);
    
    glutMainLoop();
}