The selection engine renders `uint` texture where each element of the
geometry is represented as an index.
When the geometry have modifiers, the original index was used for the
texture.
However this is not necessary for the select engine to work. The real
mesh indexes can be used in the texture and, only at the end, the
original index can be retrieved on the CPU itself.
Advantages of this approach:
- Optimizes the code to generate selection buffers.
- Makes the select id texture more informative as it identifies the
real elements instead of the original ones.
Pull Request: https://projects.blender.org/blender/blender/pulls/119977
157c4cfbc1