Very basic line segment raster generater

line_rasterizer.py

def line_rasterizer(pt1, pt2):
    """ Normalize and rasterize a line based on two of its points.
    """
    xlen = abs(pt1[0]-pt2[0])
    ylen = abs(pt1[1]-pt2[1])

    xlower = min(pt1[0], pt2[0])
    xupper = max(pt1[0], pt2[0])
    ylower = min(pt1[1], pt2[1])
    yupper = max(pt1[1], pt2[1])


    if ylen > xlen:
        # make a stretched xlen
        xyratio = float(xlen)/ylen
        xarray = [int(round(xlower+x*xyratio)) for x in range(ylen+1)]
        yarray = range(ylower, yupper+1)
    if xlen > ylen:
        # make a stretched ylen
        yxratio = float(ylen)/xlen
        yarray = [int(round(ylower+y*yxratio)) for y in range(xlen+1)]
        xarray = range(xlower, xupper+1)
    if ylen == xlen:
        yarray = range(ylower, yupper+1)
        xarray = range(xlower, xupper+1)

    return zip(xarray, yarray)


if __name__ == "__main__":
    """ repack into tests
    """

    p1 = (20, 19)
    p2 = (10, 15)
    print line_rasterizer(p2, p1)