import sys, time, math
from OpenGL.GL import *
from OpenGL.GLU import *
from OpenGL.GLUT import *
from dmsgl import *
import os
startdir = os.getcwd() + os.sep

camera = PerspCamera()
camera.moveBackward(15)
fog = Fog(mode=GL_LINEAR,start=2,end=100,color=Color.X11['DeepSkyBlue'])
light = Light()
cow = WFObject(startdir+'cow.obj')
cowXform = SimpleTransform(rotateAngle=0, rotateAxis=[1,1,1])

overlayCamera = OrthoCamera()
overlayTex = Texture2D(startdir+'goldfrm.tiff', texenv=GL_REPLACE)
overlayBlend = Transparency(blendSource=GL_SRC_ALPHA, blendDest = GL_ONE_MINUS_SRC_ALPHA)


def draw():
    Color.X11['DeepSkyBlue'].clear()
    
    camera.apply()
    fog.apply()
    light.apply()

    cowXform.pushApply()
    cow.draw()
    cowXform.pop()

    fog.disable()

    overlayCamera.apply()
    overlayTex.apply()
    overlayBlend.apply()
    glBegin(GL_QUADS)
    glTexCoord2f(0, 0)
    glVertex2f(0, 0)
    glTexCoord2f(1, 0)
    glVertex2f(1, 0)
    glTexCoord2f(1, 1)
    glVertex2f(1, 1)
    glTexCoord2f(0, 1)
    glVertex2f(0, 1)
    glEnd()
    overlayBlend.disable()
    overlayTex.disable()

    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()

def update():
    global cameraVelPitch, cameraVelTurn, cameraVelDist
    global prevTime
    t = time.time()
    dt = t - prevTime
    prevTime = t
    camera.pitch(cameraVelPitch * dt)
    camera.turn(cameraVelTurn * dt)
    camera.moveForward(cameraVelDist * dt)
    cowXform.rotateAngle += dt * 50
    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)
glEnable(GL_DEPTH_TEST)
glutMainLoop()