import math
import cv2
import numpy as np

def twiddle_tile(srcfile, destfile, twiddlefunc):
    for line in srcfile:
        gps = line.split()
        if len(gps) == 4 and gps[0] == "v":
            vert = [float(v) for v in gps[1:]]
            if vert[1] < 0.0: # don't twiddle bottom of tile
                dest.write(line + "\n")
            else:
                vert_prime = twiddlefunc(vert[0], vert[1], vert[2])
                dest.write("v {} {} {}\n".format(*vert_prime))
        else: # line is not a vertex, so write it back unchanged
            dest.write(line + "\n")

def make_image(image):
    stored_image = image
    width,height,channels = stored_image.shape
    def twiddle(x,y,z):
        u = int(((x/35.0) + 1.0) * (float(width)*.5))
        v = int(((z/35.0) + 1.0) * (float(height)*.5))
        if u < 0: 
            u = 0
        if v < 0: 
            v = 0 
        if u >= width: 
            u = width - 1
        if v >= height: 
            v = height - 1
        xp = x
        yp = y + (stored_image[u, v, 0] * .05)
        zp = z
        return (xp, yp, zp)
    return twiddle

if __name__ == '__main__':
    srcfn = "tile_blank_hires.obj"
    destfn = "computed_tile.obj"
    image = cv2.imread("newtexture.png")
    with open(srcfn, "rt") as src:
        with open(destfn, "wt") as dest:
            twiddle_tile(src, dest, make_image(image))