# Example of GLUT text functions with a dynamically changing string
# This program also uses multiple projections - a perspective
# projection for the 3D teapot & text, and an ortho projection
# for the bitmapped text at the bottom of the window
#
# Dave Pape
# 27 September 2003

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

def drawStrokeString(text, font=GLUT_STROKE_ROMAN):
    for c in text:
        glutStrokeCharacter(font, ord(c))

def drawBitmapString(text, font=GLUT_BITMAP_TIMES_ROMAN_24):
    for c in text:
        glutBitmapCharacter(font, ord(c))



viewDistance = 30
viewRotY = 0
viewRotX = 0

def draw():
    global viewRotX, viewRotY, viewDistance
    glClearColor(0.5, 0.7, 1.0, 0.0)
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)

    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    gluPerspective(50.0, 1.0, 1.0, 100.0)
    glMatrixMode(GL_MODELVIEW)

    glLoadIdentity()
    glTranslatef(0.0, 0.0, -viewDistance)
    glRotatef(viewRotX, 1.0, 0.0, 0.0)
    glRotatef(viewRotY, 0.0, 1.0, 0.0)
    
    height = abs(math.sin(time.time()) * 10)
    glPushMatrix()
    glTranslatef(0, height - 5, 0)
    glColor3f(0.5, 0.5, 0)
    glutWireTeapot(1)
    glTranslatef(2, 0, 0)
    glScalef(0.005, 0.005, 0.005)
    glColor3f(0, 0, 0)
    drawStrokeString("teapot height = %.2f" % height)
    glPopMatrix()

    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    gluOrtho2D(0, 1, 0, 1)
    glMatrixMode(GL_MODELVIEW)
    glLoadIdentity()

    glColor3f(0.8, 0, 0)
    glRasterPos2f(0.3, 0.05)
    drawBitmapString("time = %f" % time.time())

    glutSwapBuffers()


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

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()

def update():
    glutPostRedisplay()

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

glEnable(GL_DEPTH_TEST)

glutMainLoop()