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

void display(void)
{
	glClear (GL_COLOR_BUFFER_BIT);

	glColor3f (1.0, 1.0, 1.0);
	glBegin(GL_POLYGON);
		glVertex3f (0.25, 0.25, 0.0);
		glVertex3f (0.75, 0.25, 0.0);
		glVertex3f (0.75, 0.75, 0.0);
		glVertex3f (0.25, 0.75, 0.0);
	glEnd();

	glColor3f (0.0, 0.0, 1.0);
	glBegin(GL_POLYGON);
		glVertex3f (1.25, 0.25, 0.0);
		glVertex3f (1.75, 0.25, 0.0);
		glVertex3f (1.75, 0.75, 0.0);
		glVertex3f (1.25, 0.75, 0.0);
	glEnd();

	glFlush ();
}

void reshape(int w, int h)
{
//	glViewport(0, 0, w, h);
	printf("windows size: %dx%d\n", w, h);
}

int main(int argc, char** argv)
{
	glutInit(&argc, argv);
	glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
	glutInitWindowSize (250, 250); 
	glutInitWindowPosition (100, 100);
	glutCreateWindow ("hello");
	glClearColor (1.0, 0.0, 0.0, 0.0);

	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glOrtho(0.0, 1.0, 0.0, 1.0, -1.0, 1.0);

	glViewport(0, 0, 250, 250);

	glutDisplayFunc(display); 
	glutReshapeFunc(reshape);
	glutMainLoop();
	return 0;
}