# Example of creating a new custom geometry function - a tree
#
# Dave Pape
# 27 September 2004

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

viewRotY = 0
viewRotX = 0

def drawTree():
	glColor3f(0.5, 0.3, 0)
	glRotatef(-90, 1, 0, 0)
	gluCylinder(treeQuadric, 1, 1, 2, 8, 1)
	glTranslatef(0, 0, 2)
	glColor3f(0, 1, 0)
	gluCylinder(treeQuadric, 4, 0, 6, 8, 1)

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)
    
    drawTree()

    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)

treeQuadric = gluNewQuadric()

glutMainLoop()