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

viewDistance = 2.5
viewRotY = 0.0
viewRotX = 0.0
cameraVelX = 0.0
cameraVelY = 0.0
prevTime = time.time()
startTime = time.time()

textureID = 0

videoWidth, videoHeight = 320, 240
texWidth, texHeight = 512, 256

def initTexture():
    global textureID
    textureID = glGenTextures(1)
    glBindTexture(GL_TEXTURE_2D, textureID)
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, texWidth, texHeight,
                 0, GL_RGB, GL_UNSIGNED_BYTE, '\xff\x00\x00'*texWidth*texHeight)
    glBindTexture(GL_TEXTURE_2D, 0)


def grabTexture():
    glBindTexture(GL_TEXTURE_2D, textureID)
    glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, videoWidth, videoHeight,
                GL_RGB, GL_UNSIGNED_BYTE, videoInput.grabVideo())
    glBindTexture(GL_TEXTURE_2D, 0)


def draw():
    grabTexture()
    glClearColor(0, 0.3, 0.5, 0)
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
    
    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    gluPerspective(50.0, 1.0, 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)

    glEnable(GL_TEXTURE_2D)
    glBindTexture(GL_TEXTURE_2D, textureID)
    glMatrixMode(GL_TEXTURE)
    glLoadIdentity()
    glTranslatef(0.0, -1.0+videoHeight/float(texHeight), 0.0)
    glScalef(videoWidth/float(texWidth), -videoHeight/float(texHeight), 1.0)
    glMatrixMode(GL_MODELVIEW)

    offset = time.time() - startTime
    for row in range(0,20):
        glBegin(GL_TRIANGLE_STRIP)
        for col in range(0,20):
            glTexCoord2f(col/20.0+math.sin(row+offset)*0.04, row/20.0)
            glVertex2f(col/10.0 - 1.0, row/10.0 - 1.0)
            glTexCoord2f(col/20.0+math.sin(row+1+offset)*0.04, (row+1)/20.0)
            glVertex2f(col/10.0 - 1.0, (row+1)/10.0 - 1.0)
        glEnd()

    glDisable(GL_TEXTURE_2D)
    
    glutSwapBuffers()


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

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

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

def update():
    global viewRotX, viewRotY, cameraVelX, cameraVelY
    global prevTime
    t = time.time()
    dt = t - prevTime
    prevTime = t
    viewRotX += cameraVelX * dt
    viewRotY += cameraVelY * dt
    glutPostRedisplay()

glutInit([])
glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH)
glutInitWindowSize(400,400)
glutCreateWindow(sys.argv[0])
glutDisplayFunc(draw)
glutKeyboardFunc(keyboard)
glutSpecialFunc(specialkey)
glutSpecialUpFunc(specialkeyUp)
glutIgnoreKeyRepeat(1)
glutIdleFunc(update)
glEnable(GL_DEPTH_TEST)
videoInput.openVideo("/dev/video", videoWidth, videoHeight)
initTexture()
quadric = gluNewQuadric()
gluQuadricTexture(quadric, GL_TRUE)
glutMainLoop()