import sys
from OpenGL.GLUT import *
from OpenGL.GL import *
from OpenGL.GLU import *

flatShade = 0

def draw():
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
	glMatrixMode(GL_PROJECTION)
	glLoadIdentity()
	gluPerspective(60, 1, 0.1, 1000)
	glMatrixMode(GL_MODELVIEW)
	glLoadIdentity()
	glTranslatef(0, 0, -10)

	global flatShade
	if flatShade:
		glShadeModel(GL_FLAT)
	else:
		glShadeModel(GL_SMOOTH)

	drawTriangle()
#	drawTriangleStrip()

	glutSwapBuffers()


def drawTriangle():
	glBegin(GL_TRIANGLES)
	glColor3f(1, 0, 0)
	glVertex3f(-1, -1, 4)
	glColor3f(0, 1, 0)
	glVertex3f(1, -1, 4)
	glColor3f(0, 0, 1)
	glVertex3f(0, 1, 4)
	glEnd()

def drawTriangleStrip():
	glBegin(GL_TRIANGLE_STRIP)
	glColor3f(1, 0, 0)
	glVertex3f(-3, -1, 4)
	glColor3f(0, 1, 0)
	glVertex3f(-2, 1, 4)
	glColor3f(0, 0, 1)
	glVertex3f(-1, -1, 4)
	glColor3f(1, 1, 0)
	glVertex3f(0, 1, 4)
	glColor3f(1, 0, 1)
	glVertex3f(1, -1, 4)
	glColor3f(0, 1, 1)
	glVertex3f(2, 1, 4)
	glEnd()


def keyboard(key, x, y):
	global flatShade
	if key == chr(27):
		sys.exit(0)
	elif key == ' ':
		flatShade = not flatShade
	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)
glEnable(GL_DEPTH_TEST)
glutMainLoop()