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

color = [1, 0, 0]
geometryType = GL_LINE_LOOP

def draw():
	glClear(GL_COLOR_BUFFER_BIT)
	glLoadIdentity()
	glColor3fv(color)
	glBegin(geometryType)
	glVertex2f(-0.5, -0.5)
	glVertex2f(0.5, -0.5)
	glVertex2f(0.5, 0.5)
	glVertex2f(-0.5, 0.5)
	glEnd()
	glutSwapBuffers()

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

def colorMenuFn(val):
	global color
	if val == 1:
		color = [1,0,0]
	elif val == 2:
		color = [0,1,0]
	elif val == 3:
		color = [0,0,1]
	glutPostRedisplay()

def geometryMenuFn(val):
	global geometryType
	geometryType = val
	glutPostRedisplay()

def mainMenuFn(val):
	if val == 1:
		sys.exit(0)

def exitMenuFn(val):
	if val == 1:
		sys.exit(0)

glutInit([])
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB)
glutInitWindowSize(400, 400)
glutInitWindowPosition(0,0)
glutCreateWindow(sys.argv[0])
glutDisplayFunc(draw)
glutKeyboardFunc(keyboard)

colormenu = glutCreateMenu(colorMenuFn)
glutAddMenuEntry("Red", 1)
glutAddMenuEntry("Green", 2)
glutAddMenuEntry("Blue", 3)

geometrymenu = glutCreateMenu(geometryMenuFn)
glutAddMenuEntry("Points", GL_POINTS)
glutAddMenuEntry("Lines", GL_LINES)
glutAddMenuEntry("Line loop", GL_LINE_LOOP)
glutAddMenuEntry("Quads", GL_QUADS)

glutCreateMenu(mainMenuFn)
glutAddSubMenu("geometry", geometrymenu)
glutAddSubMenu("color", colormenu)
glutAddMenuEntry("quit", 1)
glutAttachMenu(GLUT_LEFT_BUTTON)

glutCreateMenu(exitMenuFn)
glutAddMenuEntry("exit", 1)
glutAttachMenu(GLUT_RIGHT_BUTTON)

glutMainLoop()