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

camera = PerspCamera()
camera.moveBackward(20)
rotY = 0.0
rotX = 0.0
rotVelX = 0.0
rotVelY = 0.0
prevTime = time.time()

treeTex = Texture2D("tree.png")

def draw():
    glClearColor(0.5, 0.7, 1, 0)
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
    
    camera.apply()
    
    glRotatef(rotX, 1.0, 0.0, 0.0)
    glRotatef(rotY, 0.0, 1.0, 0.0)
    
    glColor4f(0.1, 1, 0.2, 1)
    glBegin(GL_QUADS)
    glVertex3f(-20, -3, -20)
    glVertex3f(20, -3, -20)
    glVertex3f(20, -3, 20)
    glVertex3f(-20, -3, 20)
    glEnd()

    glEnable(GL_BLEND)
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)
   
    for pos in [ [0,-8], [-2,-4], [3,0] ]:
        glPushMatrix()
        glTranslatef(pos[0], -3, pos[1])
        drawTree()
        glPopMatrix()
   
    glDisable(GL_BLEND)

    glutSwapBuffers()


def drawTree():
    treeTex.apply()
    glColor4f(1,1,1,1)
    glBegin(GL_QUADS)
    glTexCoord2f(0,0)
    glVertex3f(-3, 0, 0)
    glTexCoord2f(1,0)
    glVertex3f(3, 0, 0)
    glTexCoord2f(1,1)
    glVertex3f(3, 8, 0)
    glTexCoord2f(0,1)
    glVertex3f(-3, 8, 0)
    glEnd()
    treeTex.disable()


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

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

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

def update():
    global rotX, rotY, rotVelX, rotVelY, prevTime
    t = time.time()
    dt = t - prevTime
    prevTime = t
    rotX += rotVelX * dt
    rotY += rotVelY * dt
    glutPostRedisplay()

glutInit([])
glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH)
glutInitWindowSize(700,700)
glutCreateWindow(sys.argv[0])
glutDisplayFunc(draw)
glutKeyboardFunc(keyboard)
glutSpecialFunc(specialkey)
glutSpecialUpFunc(specialkeyUp)
glutIgnoreKeyRepeat(1)
glutIdleFunc(update)
glEnable(GL_DEPTH_TEST)
glutMainLoop()