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

viewRotX = 0
viewRotY = 0
viewDistance = 25

def draw():
    glClearColor(0.5, 0.8, 1, 0.0)
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
    glEnable(GL_DEPTH_TEST)
    
    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    gluPerspective(50.0, 1.75, 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)
    
    defineLight()
    glEnable(GL_LIGHTING)
    global floorMeshDList
    glCallList(floorMeshDList)
    drawTeapot()
    drawPedestal()
    drawBall()
    glDisable(GL_LIGHTING)

    glutSwapBuffers()


def defineLight():
    glEnable(GL_LIGHT0)
    glLightfv(GL_LIGHT0, GL_DIFFUSE, [1, 1, 1, 1])
    glLightfv(GL_LIGHT0, GL_POSITION, [-1, 2, 1])


def drawFloorMesh(columns,rows):
    green = [ 0, 0.8, 0.1, 1 ]
    black = [ 0, 0, 0, 1 ]
    glMaterialfv(GL_FRONT, GL_AMBIENT, green)
    glMaterialfv(GL_FRONT, GL_DIFFUSE, green)
    glMaterialfv(GL_FRONT, GL_SPECULAR, black)
    glNormal3f(0.0, 1.0, 0.0)
    for j in range(0,rows):
        glBegin(GL_TRIANGLE_STRIP)
        for i in range(0,columns):
            x = ((float(i)) / columns) * 40.0 - 20.0
            z = ((float(j)) / rows) * 40.0 - 20.0
            glVertex3f(x, -2.0, z)
            z = ((float(j)+1) / rows) * 40.0 - 20.0
            glVertex3f(x, -2.0, z)
        glEnd()


def drawTeapot():
    red = [ 0.8, 0, 0, 1 ]
    white = [ 1, 1, 1, 1 ]
    glMaterialfv(GL_FRONT, GL_AMBIENT, red)
    glMaterialfv(GL_FRONT, GL_DIFFUSE, red)
    glMaterialfv(GL_FRONT, GL_SPECULAR, white)
    glMaterialf(GL_FRONT, GL_SHININESS, 90.0)
    glPushMatrix()
    glTranslatef(2.0, 4.0, -1.0)
    glRotatef(currentTime() * 30.0, 0.0, 1.0, 0.0)
    global teapotDList
    glCallList(teapotDList)
    glPopMatrix()


quadric = None
def drawPedestal():
    global quadric
    grey = [ 0.6, 0.6, 0.6, 1 ]
    white = [ 1, 1, 1, 1 ]
    if not quadric:
        quadric = gluNewQuadric()
    glMaterialfv(GL_FRONT, GL_AMBIENT, grey)
    glMaterialfv(GL_FRONT, GL_DIFFUSE, grey)
    glMaterialfv(GL_FRONT, GL_SPECULAR, white)
    glMaterialf(GL_FRONT, GL_SHININESS, 30.0)
    glPushMatrix()
    glTranslatef(2.0, -2.0, -1.0)
    glRotatef(-90.0, 1.0, 0.0, 0.0)
    gluCylinder(quadric, 4.0, 4.0, 4.0, 16, 1)
    glTranslatef(0.0, 0.0, 4.0)
    gluDisk(quadric, 0.0, 4.0, 16, 1)
    glPopMatrix()


ballkeys = [ [0, -10, 0, -15],  [2,  0, 0, -15],  [4,  10, 0, 0],  [9,  0, 0, 15] ]

def lerp(a,b,frac):
    return a + (b-a)*frac

def interpolateKeys(keys, t):
    first = 0
    while (first+1 < len(keys)) and (keys[first+1][0] <= t):
            first += 1
    if first+1 == len(keys):
        return keys[len(keys)-1][1:]
    frac = float(t - keys[first][0]) / (keys[first+1][0] - keys[first][0])
    x = lerp(keys[first][1], keys[first+1][1], frac)
    y = lerp(keys[first][2], keys[first+1][2], frac)
    z = lerp(keys[first][3], keys[first+1][3], frac)
    return (x, y, z)


def drawBall():
    cyan = [ 0, 1, 1, 1 ]
    black = [ 0, 0, 0, 1 ]
    glMaterialfv(GL_FRONT, GL_AMBIENT, cyan)
    glMaterialfv(GL_FRONT, GL_DIFFUSE, cyan)
    glMaterialfv(GL_FRONT, GL_SPECULAR, black)
    glPushMatrix()
    pos = interpolateKeys(ballkeys, currentTime())
    glTranslatef(pos[0], pos[1], pos[2])
    glutSolidSphere(2.0, 16, 8)
    glPopMatrix()



startTime = time.time()
def currentTime():
    return time.time() - startTime


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


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


glutInit([])
glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH)
glutInitWindowSize(700,400)
glutCreateWindow(sys.argv[0])
glutDisplayFunc(draw)
glutKeyboardFunc(keyboard)
glutSpecialFunc(specialkey)
glutIdleFunc(glutPostRedisplay)
glEnable(GL_DEPTH_TEST)
glEnable(GL_LIGHTING)
glEnable(GL_LIGHT0)


floorMeshDList = glGenLists(1)
glNewList(floorMeshDList, GL_COMPILE)
drawFloorMesh(32,32)
glEndList()

teapotDList = glGenLists(1)
glNewList(teapotDList, GL_COMPILE)
glutSolidTeapot(2)
glEndList()

glutMainLoop()