bezier.py

from PIL import Image, ImageDraw



def blend(p, q, t):
    """
    >>> blend((1.0, 1.0), (1.0, 2.0), 0)
    (1.0, 1.0)
    >>> blend((1.0, 1.0), (1.0, 2.0), 1)
    (1.0, 2.0)
    >>> blend((1.0, 1.0), (1.0, 2.0), 0.4)
    (1.0, 1.39999...)
    """

    return (p[0] * (1-t) + q[0] * t), (p[1] * ( 1- t) + q[1] * t)


im = Image.new("RGB", (512, 512), "white")
draw = ImageDraw.Draw(im)

p = (100, 100)
q = (400, 200)
r = (200, 400)

for t in range(0, 1000):
    draw.point(blend(blend(p, q, t/1000.0), blend(q, r, t/1000.0), t/1000.0),
            fill=128)

with open("bezier.png", "w") as f:
    im.save(f, "PNG")


#import doctest
#doctest.testmod()

Result

http://gyazo.com/3180ea55d085271dea136925165f341c.png