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

cameraDist = 10
cameraXrot = 0
cameraYrot = 0

def draw():
	global cameraDist, cameraXrot, cameraYrot
	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, -cameraDist)
	glRotatef(-cameraXrot, 1, 0, 0)
	glRotatef(-cameraYrot, 0, 1, 0)

	drawShape()

	glutSwapBuffers()


def drawShape():
	glBegin(GL_TRIANGLES)
	glColor3f(1, 1, 0)
	glVertex3f(0, 0, 0)
	glColor3f(0, 1, 0)
	glVertex3f(3, 0, 0)
	glColor3f(0.2, 0, 0.4)
	glVertex3f(2, 4, -1)
	glEnd()

triangleVertices = [ [ 0, 0, 0],   [3, 0, 0],   [2, 4, -1] ]
triangleColors = [ [1, 1, 0],   [0, 1, 0],   [0.2, 0, 0.4] ]

def drawData():
	glBegin(GL_TRIANGLES)
	for i in range(0,3):
		glColor3fv(triangleVertices[i])
		glVertex3fv(triangleColors[i])
	glEnd()

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

def specialkey(key,x,y):
    global cameraXrot, cameraYrot
    if key == GLUT_KEY_LEFT:
        cameraYrot = cameraYrot - 3
    elif key == GLUT_KEY_RIGHT:
        cameraYrot = cameraYrot + 3
    elif key == GLUT_KEY_UP:
        cameraXrot = cameraXrot - 3
    elif key == GLUT_KEY_DOWN:
        cameraXrot = cameraXrot + 3
    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)
glutSpecialFunc(specialkey)
glEnable(GL_DEPTH_TEST)
glutMainLoop()