def bresenham_supercover_line()

in habitat/utils/visualizations/fog_of_war.py [0:0]

• 50 lines of code
• 12 McCabe index (conditional complexity)

def bresenham_supercover_line(pt1, pt2):
    r"""Line drawing algo based
    on http://eugen.dedu.free.fr/projects/bresenham/
    """

    ystep, xstep = 1, 1

    x, y = pt1
    dx, dy = pt2 - pt1

    if dy < 0:
        ystep *= -1
        dy *= -1

    if dx < 0:
        xstep *= -1
        dx *= -1

    line_pts = [[x, y]]

    ddx, ddy = 2 * dx, 2 * dy
    if ddx > ddy:
        errorprev = dx
        error = dx
        for _ in range(int(dx)):
            x += xstep
            error += ddy

            if error > ddx:
                y += ystep
                error -= ddx
                if error + errorprev < ddx:
                    line_pts.append([x, y - ystep])
                elif error + errorprev > ddx:
                    line_pts.append([x - xstep, y])
                else:
                    line_pts.append([x - xstep, y])
                    line_pts.append([x, y - ystep])

            line_pts.append([x, y])

            errorprev = error
    else:
        errorprev = dx
        error = dx
        for _ in range(int(dy)):
            y += ystep
            error += ddx

            if error > ddy:
                x += xstep
                error -= ddy
                if error + errorprev < ddy:
                    line_pts.append([x - xstep, y])
                elif error + errorprev > ddy:
                    line_pts.append([x, y - ystep])
                else:
                    line_pts.append([x - xstep, y])
                    line_pts.append([x, y - ystep])

            line_pts.append([x, y])

            errorprev = error

    return line_pts