Rasterizing a 2D polygon

static_rtti picture static_rtti · Aug 27, 2009 · Viewed 10.8k times · Source

I need to create a binary bitmap from a closed 2D polygon represented as a list of points. Could you please point me to efficient and sufficiently simple algorithms to do that, or, even better, some C++ code?

Thanks a lot!

PS: I would like to avoid adding a dependency to my project. However if you suggest an open-source library, I can always look at the code, so it can be useful too.

Answer

plinth picture plinth · Aug 27, 2009

The magic google phrase you want is either "non-zero winding rule" or "even odd polygon fill".

See the wikipedia entries for:

Both are very easy to implement and sufficiently fast for most purposes. With some cleverness, they can be made antialiased as well.