Bit Hacks
I found a short code from pyglet source code.
def _is_pow2(v):
# http://graphics.stanford.edu/~seander/bithacks.html#DetermineIfPowerOf2
return (v & (v - 1)) == 0
At a glance, I can understand how it works, but I have never devised it!
It is from “Bit Hacks” by Sean Eron Anderson. They are not only beautiful but very useful in graphics libraries.
