GPUTexture: GL Backend Isolation

This is a massive cleanup needed for vulkan support T68990. It provides:

- More meaningful enums with conversion functions.
- Less hacky supports of arrays and cubemaps (all considered layered).
- More inline with the stateless design of vulkan and modern GL.
- Methods Fallbacks are using framebuffer functions that are wrapped
  instead of implementing inside the texture module.

What is not in there:
- API change.
- Samplers support (breaks a few effects).

# Conflicts:
#	source/blender/gpu/GPU_texture.h

1 files changed, 6 insertions, 0 deletions

diff --git a/source/blender/gpu/intern/gpu_state_private.hh b/source/blender/gpu/intern/gpu_state_private.hh
index 61234c4612c..6ce240df108 100644
--- a/source/blender/gpu/intern/gpu_state_private.hh
+++ b/source/blender/gpu/intern/gpu_state_private.hh
@@ -26,6 +26,8 @@
 
 #include "GPU_state.h"
 
+#include "gpu_texture_private.hh"
+
 #include <cstring>
 
 namespace blender {
@@ -160,6 +162,10 @@ class GPUStateManager {
   virtual ~GPUStateManager(){};
 
   virtual void apply_state(void) = 0;
+
+  virtual void texture_bind(Texture *tex, eGPUSamplerState sampler, int unit) = 0;
+  virtual void texture_unbind(Texture *tex) = 0;
+  virtual void texture_unbind_all(void) = 0;
 };
 
 }  // namespace gpu