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

SPOT_DIRECTION = 1
SPOT_CUTOFF    = 2
SPOT_EXPONENT  = 3

viewRotX = 0
viewRotY = 0

lightPos = [ 0, 4, 10, 1 ]
spotDirection = [ 0, 0, -1 ]
spotCutoff = 30
spotExponent = 0.0

mouseMode = SPOT_DIRECTION



def draw():
    glClearColor(0.5, 0.8, 1.0, 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, -25.0)
    glRotatef(viewRotX, 1.0, 0.0, 0.0)
    glRotatef(viewRotY, 0.0, 1.0, 0.0)
    
    defineLight()
    glEnable(GL_LIGHTING)
    drawFloorMesh(32,32)
    drawTeapot()
    drawPedestal()
    drawBall()
    glDisable(GL_LIGHTING)
	
    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    gluOrtho2D(0.0, 1.0, 0.0, 1.0)
    glMatrixMode(GL_MODELVIEW)
    glLoadIdentity()
    glColor3f(1.0, 0.0, 0.5)
    glRasterPos2f(0.01, 0.01)
    drawBitmapString("direction = %.2f  %.2f  %.2f\t cutoff = %.1f\t exponent = %.2f" % (spotDirection[0], spotDirection[1], spotDirection[2], spotCutoff, spotExponent))

    glutSwapBuffers()


def defineLight():
    white = [ 1, 1, 1, 1 ]
    glEnable(GL_LIGHT0)
    glLightfv(GL_LIGHT0, GL_DIFFUSE, white)
    glLightfv(GL_LIGHT0, GL_POSITION, lightPos)
    glLightfv(GL_LIGHT0, GL_SPOT_DIRECTION, spotDirection)
    glLightf(GL_LIGHT0, GL_SPOT_CUTOFF, spotCutoff)
    glLightf(GL_LIGHT0, GL_SPOT_EXPONENT, spotExponent)
    drawSpotlight()


def drawSpotlight():
    glColor3f(1.0, 1.0, 0.0)
    glPointSize(12.0)
    glBegin(GL_POINTS)
    glVertex3fv(lightPos)
    glEnd()
    glBegin(GL_LINES)
    glVertex3fv(lightPos)
    glVertex3f(spotDirection[0]*100, spotDirection[1]*100, spotDirection[2]*100)
    glEnd()


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)
    glutSolidTeapot(2.0)
    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()


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()
    glTranslatef(-10.0, fabs(sin(currentTime())) * 3.0, -15.0)
    glutSolidSphere(2.0, 16, 8)
    glPopMatrix()


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


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


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


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


def mousebutton(button, state, x, y):
    global mouseMode
    if (button == GLUT_LEFT_BUTTON) and (state == GLUT_DOWN):
        mouseMode = SPOT_DIRECTION
    elif (button == GLUT_MIDDLE_BUTTON) and (state == GLUT_DOWN):
        mouseMode = SPOT_CUTOFF
    elif (button == GLUT_RIGHT_BUTTON) and (state == GLUT_DOWN):
        mouseMode = SPOT_EXPONENT


def mousemotion(x, y):
    global spotDirection, spotCutoff, spotExponent
    if mouseMode == SPOT_DIRECTION:
        spotDirection[0] = float(x) / glutGet(GLUT_WINDOW_WIDTH) * 2.0 - 1.0
        spotDirection[1] = 1.0 - float(y) / glutGet(GLUT_WINDOW_HEIGHT) * 2.0
    elif mouseMode == SPOT_CUTOFF:
        spotCutoff = float(x) / glutGet(GLUT_WINDOW_WIDTH) * 90.0
        if spotCutoff < 0:
            spotCutoff = 0
        elif spotCutoff > 90:
            spotCutoff = 90
    elif mouseMode == SPOT_EXPONENT:
        spotExponent = float(x) / glutGet(GLUT_WINDOW_WIDTH) * 10.0
        if spotExponent < 0:
            spotExponent = 0

glutInit([])
glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH)
glutInitWindowSize(700,400)
glutCreateWindow(sys.argv[0])
glutDisplayFunc(draw)
glutKeyboardFunc(keyboard)
glutSpecialFunc(specialkey)
glutMouseFunc(mousebutton)
glutMotionFunc(mousemotion)
glutIdleFunc(glutPostRedisplay)
glEnable(GL_DEPTH_TEST)
glEnable(GL_LIGHTING)
glEnable(GL_LIGHT0)
glutMainLoop()
SPOT_DIRECTION = 1
SPOT_CUTOFF    = 2
SPOT_EXPONENT  = 3