I just discovered that there is a bug in how Zwoptex is rendering rotated untrimmed sprites in Zwoptex. The result is an inaccurate texture for the coordinates.
This only affects rotated sprites that are untrimmed. Rotated sprites that are trimmed work fine.
You can see the error in an example below. The red represents where the images should be rendered.
I’ll be fixing this in the next day or two and publishing an update along with a few other new little things ( nothing major! ).
Update: I’ve fixed the bug. I’ll be pushing update 1.0.2 out in the next couple of hours and posting some release notes!
-Robert

