Removes various image filtering/mipmapping leftovers from
pre-2.80 days.
Code: removes all mipmap handling from ImBuf (which is about half of
ImBuf struct size), removes now unused "sample procedural texture
with mipmaps" code, now-unused FELINE filter, etc. The osatex
parameter to various CPU texture sampling functions is never
actually used, which means none of the mipmap code was ever executing.
User visible part: there were settings on the legacy Texture data
block (as used by Brushes etc.), under Sampling section: "MIP Map",
"Gaussian Filter", "Filter Type", "Eccentricity", "Minimum Size" --
they had no effect anywhere, so they are gone, and what remains is
only "Interpolation" and "Size".
RNA / Python API part: removes the ImageTexture RNA properties
corresponding to the above: filter_type, use_mipmap, use_mipmap_gauss,
filter_lightprobes, filter_eccentricity, use_filter_size_min.
Pull Request: https://projects.blender.org/blender/blender/pulls/139978
f685f23434