This fixes a few issues and clear up some confusion
in the code.
Note that this changes the behavior of render region;
they now reduce the internal render size. This is
matching the new design documentation.
- Data passes have correct accumulation.
- Adhere to naming conventions for extents, film and render pixels.
- Jitter over final pixels first before doing random sampling
in order to speed up convergence.
- Ensure enough sample to cover at least all the film pixels once.
- Always include the four neighbor pixels in case one is nearer.
- Fix projection matrix computation to align overscan pixels.
Pull Request: https://projects.blender.org/blender/blender/pulls/124735
c72a1d698e