A simple example of the line_rasterizer used with the flaschen.py library.

ft_line_raster.py

import flaschen

UDP_IP = 'localhost'
UDP_PORT = 1337

ft = flaschen.Flaschen(UDP_IP, UDP_PORT, 45, 35)

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

    # two points describe a line
    # we will use the bounding pixels for our line
    print "Please input two points. (x1, y1) and (x2, y2)."
    x1 = int(raw_input("x1="))
    y1 = int(raw_input("y1="))
    x2 = int(raw_input("x2="))
    y2 = int(raw_input("y2="))
    p1 = (x1, y1)
    p2 = (x2, y2)

    color = (255, 255, 255)

    # get all the points in the line segment
    points = line_rasterizer(p2, p1)
    
    for x,y in points:
        ft.set(x, y, color)

    ft.send()