GPUFrameBuffer: GL backend isolation

This is related to the Vulkan port T68990.

This is a full cleanup of the Framebuffer module and a separation
of OpenGL related functions.

There is some changes with how the default framebuffers are handled.
Now the default framebuffers are individually wrapped inside special
GLFrameBuffers. This make it easier to keep track of the currently bound
framebuffer state and have some specificity for operations on these
framebuffers.

Another change is dropping the optimisation of only configuring the
changed attachements during framebuffers update. This does not give
any benefits and add some complexity to the code. This might be brought
back if it has a performance impact on some systems.

This also adds support for naming framebuffers but it is currently not
used.

1 files changed, 2 insertions, 1 deletions

diff --git a/source/blender/gpu/intern/gpu_backend.hh b/source/blender/gpu/intern/gpu_backend.hh
index f63f3cead2b..ec60e6b5704 100644
--- a/source/blender/gpu/intern/gpu_backend.hh
+++ b/source/blender/gpu/intern/gpu_backend.hh
@@ -32,6 +32,7 @@ namespace gpu {
 
 class Batch;
 class DrawList;
+class FrameBuffer;
 class Shader;
 class UniformBuf;
 
@@ -45,7 +46,7 @@ class GPUBackend {
 
   virtual Batch *batch_alloc(void) = 0;
   virtual DrawList *drawlist_alloc(int list_length) = 0;
-  // virtual FrameBuffer *framebuffer_alloc(void) = 0;
+  virtual FrameBuffer *framebuffer_alloc(const char *name) = 0;
   virtual Shader *shader_alloc(const char *name) = 0;
   // virtual Texture *texture_alloc(void) = 0;
   virtual UniformBuf *uniformbuf_alloc(int size, const char *name) = 0;