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

startdir = os.getcwd()

camera = PerspCamera()
camera.moveBackward(30)

light1 = Light()
light2 = Light()
light2.position = [-1, 1, -1, 0]
cow = WFObject('cow2.obj')

def RotationQuaternion(angle, axisX, axisY, axisZ):
    angle *= -math.pi / 180.0
    v = Vector((axisX, axisY, axisZ))
    v.normalize()
    v *= math.sin(angle/2)
    return quaternion(math.cos(angle/2), v[0], v[1], v[2])

q1 = RotationQuaternion(-60, 0, 1, 0)
q2 = RotationQuaternion(90, 1, 1, 1)
q3 = q1

def draw():
    Color.X11['DeepSkyBlue'].clear()
    camera.apply()
    light1.apply()
    light2.apply()
    glPushMatrix()
    glTranslatef(-10,0,0)
    glMultMatrixf(q1.matrix4)
    cow.draw()
    glPopMatrix()
    glPushMatrix()
    glTranslatef(10,0,0)
    glMultMatrixf(q2.matrix4)
    cow.draw()
    glPopMatrix()
    glPushMatrix()
    glMultMatrixf(q3.matrix4)
    cow.draw()
    glPopMatrix()
    glutSwapBuffers()


def keyboard(key, x, y):
    global cameraVelDist
    if key == chr(27):
        sys.exit(0)
    elif key == '.':
        cameraVelDist += 4
    elif key == ',':
        cameraVelDist += -4

def keyboardUp(key, x, y):
    global cameraVelDist
    if key == chr(27):
        sys.exit(0)
    elif key == '.':
        cameraVelDist -= 4
    elif key == ',':
        cameraVelDist -= -4

def specialkey(key,x,y):
    global cameraVelPitch, cameraVelTurn
    if key == GLUT_KEY_LEFT:
        cameraVelTurn += 90
    elif key == GLUT_KEY_RIGHT:
        cameraVelTurn -= 90
    elif key == GLUT_KEY_UP:
        cameraVelPitch += 90
    elif key == GLUT_KEY_DOWN:
        cameraVelPitch -= 90

def specialkeyUp(key,x,y):
    global cameraVelPitch, cameraVelTurn
    if key == GLUT_KEY_LEFT:
        cameraVelTurn -= 90
    elif key == GLUT_KEY_RIGHT:
        cameraVelTurn += 90
    elif key == GLUT_KEY_UP:
        cameraVelPitch -= 90
    elif key == GLUT_KEY_DOWN:
        cameraVelPitch += 90


cameraVelPitch = 0.0
cameraVelTurn = 0.0
cameraVelDist = 0.0
prevTime = time.time()
startTime = time.time()

def slerp(q, r, t):
    phi = math.acos(q.a*r.a + q.b*r.b + q.c*r.c + q.d*r.d)
    return (q * math.sin(phi*(1.0-t)) + r * math.sin(phi*t)) / math.sin(phi)

def update():
    global cameraVelPitch, cameraVelTurn, cameraVelDist, startTime, q3
    global prevTime
    t = time.time()
    dt = t - prevTime
    prevTime = t
    camera.pitch(cameraVelPitch * dt)
    camera.turn(cameraVelTurn * dt)
    camera.moveForward(cameraVelDist * dt)
    a = (t - startTime) / 5
    if a > 1:
        a = 1
        startTime = t
    q3 = slerp(q1, q2, a)
    glutPostRedisplay()

glutInit([])
glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH)
glutInitWindowSize(400,400)
glutCreateWindow(sys.argv[0])
glutDisplayFunc(draw)
glutKeyboardFunc(keyboard)
glutKeyboardUpFunc(keyboardUp)
glutSpecialFunc(specialkey)
glutSpecialUpFunc(specialkeyUp)
glutIgnoreKeyRepeat(1)
glutIdleFunc(update)
os.chdir(startdir)
glEnable(GL_DEPTH_TEST)
glEnable(GL_CULL_FACE)
glutMainLoop()