a25856f2a8
This is a usefull feature that can be used to do a lot of precomputation on the GPU instead of the CPU. Implementation is simple and only covers the most usefull case. How to use: - Create shader with transform feedback. - Create a pass with DRW_STATE_TRANS_FEEDBACK. - Create a target Gwn_VertBuf (make sure it's big enough). - Create a shading group with DRW_shgroup_transform_feedback_create(). - Add your draw calls to the shading group. - Render your pass normaly. Current limitation: - Only one output buffer. - Cannot pause/resume tfb rendering to interleave with normal drawcalls. - Cannot get the number of verts drawn.