#include <cstdio>
#include <cstdlib>
#ifdef OSX
#include <GLUT/glut.h>
#include <OpenGL/gl.h>
#include <OpenGL/glu.h>
#else
#include <GL/glut.h>
#include <GL/gl.h>
#include <GL/glu.h>
#endif
#include <cmath>

int width;
int height;

void init(){
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
}

void myReshape(int w, int h) {
	glViewport(0, 0, w, h);
	width = w;
	height = h;
}

void DrawBox(){
	glBegin(GL_QUADS);
		glVertex2f(0.0, 0.0);
		glVertex2f(0.10, 0.0);
		glVertex2f(0.10, .10);
		glVertex2f(0.0, .10);
	glEnd();

}

void myDisplay() {
	glClear(GL_COLOR_BUFFER_BIT);

	glColor3f(0,0,0);
	glPushMatrix();
	for (int i=0; i<10; i++) {
	
		glPushMatrix();	
		for (int j=0; j<10; j++) {
			if ((i+j)%2 == 0) {
				glColor3f(0,0,0);
			} else {
				glColor3f(1,1,1);
			}
			DrawBox();
			glTranslatef(.1,0,0);	
		}
		glPopMatrix();
		glTranslatef(0,.1,0);
	}
	glPopMatrix();
	glutSwapBuffers();		

}

void myMouse(int b, int s, int x, int y) {
	if (b==GLUT_LEFT_BUTTON) {
		printf("Mouse click at %f %f\n", (float)x/(float)width, (float)y/(float)height); 
	}
}

int main(int argc, char** argv)
{
	glutInit(&argc, argv);

	glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
	glutInitWindowSize(400,400);
	glutInitWindowPosition(0,0);
	glutCreateWindow(argv[0]);
	
	glMatrixMode(GL_PROJECTION);
	gluOrtho2D(0.0, 1.0, 0.0, 1.0);

	//Callbacks	
	glutDisplayFunc(myDisplay);
	glutReshapeFunc(myReshape);
	glutMouseFunc(myMouse);

	init();
	glutMainLoop();
	return 0;
}