ChessBoard Drawing Using Loop with OpenGL

OpenGL_ChessBoard.cpp

#include <stdio.h>
#include <GL/glut.h>

int x = 50, y = 50;
bool isBlack = true;

void whiteBox(int x, int y)
{
	glBegin(GL_LINE_LOOP);
	glVertex2i(x, y);
	glVertex2i(x, y + 50);
	glVertex2i(x + 50, y + 50);
	glVertex2i(x + 50, y);
	glEnd();
}

void blackBox(int x, int y)
{
	glBegin(GL_POLYGON);
	glVertex2i(x, y);
	glVertex2i(x, y + 50);
	glVertex2i(x + 50, y + 50);
	glVertex2i(x + 50, y);
	glEnd();
}

void myDisplay(void)
{
	glClear(GL_COLOR_BUFFER_BIT);
	glColor3f(0.0, 0.0, 0.0);
	glPointSize(1.0);

	for (int i = 0; i < 8; i++)
	{
		if (i % 2 == 0)
		{
			isBlack = true;
		}
		else
		{
			isBlack = false;
		}

		for (int j = 0; j < 8; j++)
		{
			if (isBlack)
			{
				blackBox(x, y);
				isBlack = false;
			}
			else
			{
				whiteBox(x, y);
				isBlack = true;
			}
			x += 50;
		}
		y += 50;
		x = 50;
	}

	blackBox(100, 100);
	whiteBox(150, 100);
	glFlush();
}


void myInit(void)
{
	glClearColor(1.0, 1.0, 1.0, 0.0);
	glColor3f(0.0f, 0.0f, 0.0f);
	glPointSize(4.0);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluOrtho2D(0.0, 640.0, 0.0, 480.0);
}

void main(int argc, char** argv)
{
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
	glutInitWindowSize(800, 600);
	glutInitWindowPosition(100, 150);
	glutCreateWindow("Draw an 8X8 chess board using loop");
	glutDisplayFunc(myDisplay);
	myInit();
	glutMainLoop();
}