Initial work by Clément Foucault with contributions from Dalai Felinto
(mainly per-collection engine settings logic, and depsgraph iterator placeholder).
This makes Blender require OpenGL 3.3. Which means Intel graphic card
and OSX will break. Disable CLAY_ENGINE in CMake in those cases.
This is a prototype render engine intended to help the design of real
render engines. This is mainly an engine with enphasis in matcap and
ambient occlusion.
Implemented Features
--------------------
* Clay Render Engine, following the new API, to be used as reference for
future engines
* A more complete Matcap customization with more options
* Per-Collection render engine settings
* New Ground Truth AO - not enabled
Missing Features
----------------
* Finish object edit mode
- Fix shaders to use new matrix
- Fix artifacts when edge does off screen
- Fix depth issue
- Selection sillhouette
- Mesh wires
- Use mesh normals (for higher quality matcap)
- Non-Mesh objects drawing
- Widget drawing
- Performance issues
* Finish mesh edit mode
- Derived-Mesh-less edit mode API (mesh_rende.c)
* General edit mode
- Per-collection edit mode settings
* General engines
- Per-collection engine settings
(they are their, but they still need to be flushed by depsgraph, and
used by the drawing code)
Errors are caught & reported by our GL debug callback. This gives us way more useful information than sporadic calls to glGetError.
I removed almost all use of glGetError, including our own GPU_ASSERT_NO_GL_ERRORS and GPU_CHECK_ERRORS_AROUND macros.
Still used in rna_Image_gl_load because it passes unvalidated input to OpenGL functions.
Still used in gpu_state_print_fl_ex as an exception handling hack -- will rewrite this soon.
The optimism embodied by this commit will not prevent OpenGL errors. We need to analyze what would cause GL to fail at certain points and proactively intercept these failures. Or guarantee they can't happen.
