GPU: Compute Pipeline.

With the compute pipeline calculation can be offloaded to the GPU.
This patch only adds the framework for compute. So no changes for users at
this moment.

NOTE: As this is an OpenGL4.3 feature it must always have a fallback.

Use `GPU_compute_shader_support` to check if compute pipeline can be used.
Check `gpu_shader_compute*` test cases for usage.

This patch also adds support for shader storage buffer objects and device only
vertex/index buffers.

An alternative that had been discussed was adding this to the `GPUBatch`, this
was eventually not chosen as it would lead to more code when used as part of a
shading group. The idea is that we add an `eDRWCommandType` in the near
future.

Reviewed By: fclem

Differential Revision: https://developer.blender.org/D10913

1 files changed, 3 insertions, 0 deletions

diff --git a/source/blender/gpu/intern/gpu_vertex_buffer_private.hh b/source/blender/gpu/intern/gpu_vertex_buffer_private.hh
index 67a09f6f83c..9531c2c1a5f 100644
--- a/source/blender/gpu/intern/gpu_vertex_buffer_private.hh
+++ b/source/blender/gpu/intern/gpu_vertex_buffer_private.hh
@@ -66,6 +66,7 @@ class VertBuf {
   void allocate(uint vert_len);
   void resize(uint vert_len);
   void upload(void);
+  virtual void bind_as_ssbo(uint binding) = 0;
 
   VertBuf *duplicate(void);
 
@@ -96,6 +97,8 @@ class VertBuf {
   }
 
   virtual void update_sub(uint start, uint len, void *data) = 0;
+  virtual const void *read() const = 0;
+  virtual void *unmap(const void *mapped_data) const = 0;
 
  protected:
   virtual void acquire_data(void) = 0;