# This program demonstrates how multiple transformations accumulate
# An un-transformed triangle is drawn, followed by one with a
# translation, followed by another with one more translation,
# which is added to the first
import sys
from OpenGL.GLUT import *
from OpenGL.GL import *
from OpenGL.GLU import *


def draw():
	glLoadIdentity()
	glClear(GL_COLOR_BUFFER_BIT)

	glColor3f(0, 0, 1)
	glBegin(GL_TRIANGLES)
	glVertex2f(0.0, 0.0)
	glVertex2f(0.5, 0.0)
	glVertex2f(0.25, 0.5)
	glEnd()

	glTranslatef(0.25, 0.25, 0.0)
	glColor3f(0, 1, 0)
	glBegin(GL_TRIANGLES)
	glVertex2f(0.0, 0.0)
	glVertex2f(0.5, 0.0)
	glVertex2f(0.25, 0.5)
	glEnd()

	glTranslatef(-0.25, -1.0, 0.0)
	glColor3f(1, 0, 0)
	glBegin(GL_TRIANGLES)
	glVertex2f(0.0, 0.0)
	glVertex2f(0.5, 0.0)
	glVertex2f(0.25, 0.5)
	glEnd()

	glFlush()

def keyboard(key, x, y):
	if key == chr(27):
		sys.exit(0)

glutInit([])
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB)
glutInitWindowSize(300, 300)
glutInitWindowPosition(0,0)
glutCreateWindow(sys.argv[0])
glutDisplayFunc(draw)
glutKeyboardFunc(keyboard)
glutMainLoop()