Clay-Engine (merge clay-engine)

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)

1 files changed, 2 insertions, 0 deletions

diff --git a/source/blender/gpu/gawain/batch.h b/source/blender/gpu/gawain/batch.h
index 932ee182703..8b5c48cca79 100644
--- a/source/blender/gpu/gawain/batch.h
+++ b/source/blender/gpu/gawain/batch.h
@@ -57,6 +57,8 @@ void Batch_Uniform3fv(Batch*, const char* name, const float data[3]);
 void Batch_Uniform4fv(Batch*, const char* name, const float data[4]);
 
 void Batch_draw(Batch*);
+void Batch_draw_stupid(Batch* batch);
+void Batch_draw_stupid_instanced(Batch* batch, unsigned int instance_vbo, int instance_count);