#ifdef _WIN32
/*This is windows specific*/
#include <windows.h> 
#endif

#ifdef __APPLE__
/*OpenGL includes for Mac OS X*/
#include <OpenGL/gl.h>
#include <OpenGL/glu.h>
#include <GLUT/glut.h>
#else
/*OpenGL includes for other OS's*/
#include <GL/gl.h>
#include <GL/glu.h>
#include <GL/glut.h>
#endif

void myInit(void)
{
	glClearColor(0,0,0,0);
	glColor3f(1,1,1);
	glPointSize(1);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluOrtho2D(0,640,0,480);
}

void myDisplay(void)
{
	int x,y;

	glDrawBuffer(GL_BACK);
	glClear(GL_COLOR_BUFFER_BIT);
	 
	glBegin(GL_POINTS);
		for(y=0;y<480;y++) for(x=0;x<640;x++) if((x+y)%2) glVertex2i(x,y);

	glEnd();
	glFlush();
	glFinish();
	glutSwapBuffers();
}

int main(int argc,char **argv)
{
	glutInit(&argc,argv);
	glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB);
	glutInitWindowSize(640,480);
	glutInitWindowPosition(100,150);
	glutCreateWindow("Hello World");
	glutDisplayFunc(myDisplay);

	myInit();
	glutMainLoop();
	return(0);
}