def draw_line()

in datasets/xiaolinwu.py [0:0]

• 28 lines of code
• 4 McCabe index (conditional complexity)

def draw_line(img, p1, p2, color):
    """Draws an anti-aliased line in img from p1 to p2 with the given color."""
    x1, y1 = p1
    x2, y2 = p2
    dx, dy = x2-x1, y2-y1
    steep = abs(dx) < abs(dy)
    p = lambda px, py: ((px,py), (py,px))[steep]
 
    if steep:
        x1, y1, x2, y2, dx, dy = y1, x1, y2, x2, dy, dx
    if x2 < x1:
        x1, x2, y1, y2 = x2, x1, y2, y1
 
    grad = dy/dx
    intery = y1 + _rfpart(x1) * grad
    def draw_endpoint(pt):
        x, y = pt
        xend = round(x)
        yend = y + grad * (xend - x)
        xgap = _rfpart(x + 0.5)
        px, py = int(xend), int(yend)
        putpixel(img, p(px, py), color, _rfpart(yend) * xgap)
        putpixel(img, p(px, py+1), color, _fpart(yend) * xgap)
        return px
 
    xstart = draw_endpoint(p(*p1)) + 1
    xend = draw_endpoint(p(*p2))
 
    for x in range(xstart, xend):
        y = int(intery)
        putpixel(img, p(x, y), color, _rfpart(intery))
        putpixel(img, p(x, y+1), color, _fpart(intery))
        intery += grad