does not use any opengl for calculations (2.5 friendly!) and free from screen pixel artifacts. raytracing is used for occlusion.
Details
* Uses a 2D screenspace bucket grid that store intersecting faces and a list of UV pixels to optimize lookups between the brush rectangle UV pixels
* Buckets and faces are initialized when a brush first touches them.
* on initializing all the faces used have their UV pixels are converted into screenspace and copied into the buckets for painting (if the pixel is not occluded by a ray cast).
still a lot to do - blend modes, float buffer, image wrapping, image texture filtering.
Add feature requests here
http://wiki.blender.org/index.php/Wahooney_re/Paint_Branch_Proposals
d996f4e0b7