In the process of trying to add MSAA to my rendering engine. I found out that it impossible to blit from an MSAA frame buffer to non-MSAA frame buffer at difference size.
I need to create refraction texture (non-MSAA) from previous render scene (MSAA) in half resolution texture but look like it impossible.
If this is the limitation of OpenGL spec , what should I do (can’t find it mention any where) ?
Should I do double blitting or using custom resolved blit shader ?
Any suggestion would be appreciate since I have this kind of situation in many place of my code (high-pass filter,tone-mapping,reflraction,reflection,edge detection).