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, 41 insertions, 1 deletions

diff --git a/source/blender/gpu/GPU_viewport.h b/source/blender/gpu/GPU_viewport.h
index fce509377ab..e44657a4647 100644
--- a/source/blender/gpu/GPU_viewport.h
+++ b/source/blender/gpu/GPU_viewport.h
@@ -34,12 +34,52 @@
 
 #include <stdbool.h>
 
+#include "DNA_vec_types.h"
+
+#include "GPU_framebuffer.h"
+#include "GPU_texture.h"
+
 typedef struct GPUViewport GPUViewport;
 
-GPUViewport *GPU_viewport_create(void);
+#define MAX_BUFFERS 8
+#define MAX_TEXTURES 16
+#define MAX_PASSES 16
+
+/* All FramebufferLists are just the same pointers with different names */
+typedef struct FramebufferList {
+	struct GPUFrameBuffer *framebuffers[MAX_BUFFERS];
+} FramebufferList;
+
+typedef struct TextureList {
+	struct GPUTexture *textures[MAX_TEXTURES];
+} TextureList;
+
+typedef struct PassList {
+	struct DRWPass *passes[MAX_TEXTURES];
+} PassList;
 
+/* Buffer and textures used by the viewport by default */
+typedef struct DefaultFramebufferList {
+	struct GPUFrameBuffer *default_fb;
+} DefaultFramebufferList;
+
+typedef struct DefaultTextureList {
+	struct GPUTexture *color;
+	struct GPUTexture *depth;
+} DefaultTextureList;
+
+typedef struct DefaultPassList {
+	struct DRWPass *non_meshes_pass;
+	struct DRWPass *ob_center_pass;
+} DefaultPassList;
+
+GPUViewport *GPU_viewport_create(void);
+void GPU_viewport_bind(GPUViewport *viewport, const rcti *rect);
+void GPU_viewport_unbind(GPUViewport *viewport);
 void GPU_viewport_free(GPUViewport *viewport);
 
+void GPU_viewport_get_engine_data(GPUViewport *viewport, void **fbs, void **txs, void **pss);
+
 /* debug */
 bool GPU_viewport_debug_depth_create(GPUViewport *viewport, int width, int height, char err_out[256]);
 void GPU_viewport_debug_depth_free(GPUViewport *viewport);