How to detect sprite collision，sprites are non-rectangular

[freezyh]

[Lockless00]

those are some interesting shapes, but if you're using sprites I guess you are making a game and performance matters. simplify the shapes and save some compute power for different things.
in any other case complex shapes can be identified as a composition of lines

[davidfig]

Also, start with a simple box-box intersection check. Only do the more expensive polygon-polygon check if the box-box check succeeds.