# Demonstration of "depth fighting"
#
import sys
import time
from OpenGL.GLUT import *
from OpenGL.GL import *
from OpenGL.GLU import *

angle = 0
prevTime = time.time()

def draw():
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
	glLoadIdentity()
	glTranslatef(0, 0, -3)
	global angle
	glRotatef(angle, 0, 1, 0)

	glColor3f(0, 0, 1)
	glBegin(GL_QUADS)
	glVertex2f(-2, -1.5)
	glVertex2f(1, -1.5)
	glVertex2f(1, 1.5)
	glVertex2f(-2, 1.5)
	glEnd()

#	glTranslatef(1, 0, 0.0008)
	glColor3f(1, 0, 0)
	glBegin(GL_QUADS)
	glVertex2f(-1, -1)
	glVertex2f(2, -1)
	glVertex2f(2, 1)
	glVertex2f(-1, 1)
	glEnd()

	glutSwapBuffers()


def keyboard(key, x, y):
	if key == chr(27):
		sys.exit(0)
	elif key == ' ':
		global angle
		angle = angle + 1
		glutPostRedisplay()

glutInit(sys.argv)
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH)
glutInitWindowSize(400, 400)
glutInitWindowPosition(0,0)
glutCreateWindow(sys.argv[0])
glutDisplayFunc(draw)
glutKeyboardFunc(keyboard)
glMatrixMode(GL_PROJECTION)
gluPerspective(60, 1, 1, 100)
glMatrixMode(GL_MODELVIEW)
glEnable(GL_DEPTH_TEST)
glutMainLoop()