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


class OBJFile:
	def __init__(self, filename):
		self.vertices = []
		self.faces = []
		file = open(filename, "r")
		lines = file.readlines()
		for line in lines:
			values = string.split(line)
			if len(values) < 1:
				continue
			if values[0] == 'v':
				x = string.atof(values[1])
				y = string.atof(values[2])
				z = string.atof(values[3])
				self.vertices.append([x,y,z])
			elif values[0] == 'f':
				face = []
				for v in values[1:]:
					w = string.split(v,'/')
					face.append(string.atoi(w[0]))
				self.faces.append(face)

	def draw(self):
		for f in self.faces:
			glBegin(GL_POLYGON)
			for v in f:
				glVertex3fv(self.vertices[v-1])
			glEnd()


viewRotY = 0
viewRotX = 0

cow = OBJFile("cow.obj")

def draw():
    glClear(GL_COLOR_BUFFER_BIT)
    
    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    glOrtho(-15, 15, -15, 15, -10, 10)
    glMatrixMode(GL_MODELVIEW)

    glLoadIdentity()
    glRotatef(viewRotX, 1.0, 0.0, 0.0)
    glRotatef(viewRotY, 0.0, 1.0, 0.0)
    
    cow.draw()
    glutSwapBuffers()


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

def specialkey(key,x,y):
    global viewRotX, viewRotY
    if key == GLUT_KEY_LEFT:
        viewRotY = viewRotY + 3
    elif key == GLUT_KEY_RIGHT:
        viewRotY = viewRotY - 3
    elif key == GLUT_KEY_UP:
        viewRotX = viewRotX + 3
    elif key == GLUT_KEY_DOWN:
        viewRotX = viewRotX - 3
    glutPostRedisplay()

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