I have problems with the render of a textured full screen quad when it´s enabled the MSAA 16x.
The scenario is:
- create FBO with MSAA 16x (A)
- create FBO without MSAA to resolve the antialiased FBO (B)
- bind FBO-A with MSAA
- render fullscreen textured quad:
- Minification filtering GL_LINEAR
- same size as FBO (A & B)
- 1:1 pixel / texel mapping
- resolve the FBO-A to FBO-B with glBlitFramebuffer(0,0,w,h,0,0,w,h,color, GL_NEAREST)
The result in the FBO-B (without msaa) is blurred.The mapping is done 1:1 pixel/texel, so filtering should not affect.
Some tests:
- If the MSAA is configured in 8x the result is clear, no blured image is present. I think this is right and what does not happen with MSAA 16x.
- if configure the filtering to GL_NEAREST the result is correct.
- The test are performed with nvidia 480, 580, 680, 780 and 980
Questions:
- is the result (blurred) correct if the filtering is GL_LINEAR?
- can be a fail in the driver? some kind of optimization?