GPUTexture: Add Cube view as 2D array

This is useful to read/write to the textures directly using compute
shaders and imageLoad/Store.

3 files changed, 14 insertions, 5 deletions

diff --git a/source/blender/gpu/GPU_texture.h b/source/blender/gpu/GPU_texture.h
index 4dbcd84672c..37edc2abeb2 100644
--- a/source/blender/gpu/GPU_texture.h
+++ b/source/blender/gpu/GPU_texture.h
@@ -230,6 +230,7 @@ GPUTexture *GPU_texture_create_error(int dimension, bool array);
  * Create an alias of the source texture data.
  * If \a src is freed, the texture view will continue to be valid.
  * If \a mip_start or \a mip_len is bigger than available mips they will be clamped.
+ * If \a cube_as_array is true, then the texture cube (array) becomes a 2D array texture.
  * TODO(@fclem): Target conversion is not implemented yet.
  */
 GPUTexture *GPU_texture_create_view(const char *name,
@@ -238,7 +239,8 @@ GPUTexture *GPU_texture_create_view(const char *name,
                                     int mip_start,
                                     int mip_len,
                                     int layer_start,
-                                    int layer_len);
+                                    int layer_len,
+                                    bool cube_as_array);
 
 void GPU_texture_update_mipmap(GPUTexture *tex,
                                int miplvl,
diff --git a/source/blender/gpu/intern/gpu_texture.cc b/source/blender/gpu/intern/gpu_texture.cc
index 0d2ec43533f..b41193f12fa 100644
--- a/source/blender/gpu/intern/gpu_texture.cc
+++ b/source/blender/gpu/intern/gpu_texture.cc
@@ -136,7 +136,8 @@ bool Texture::init_view(const GPUTexture *src_,
                         int mip_start,
                         int mip_len,
                         int layer_start,
-                        int layer_len)
+                        int layer_len,
+                        bool cube_as_array)
 {
   const Texture *src = unwrap(src_);
   w_ = src->w_;
@@ -165,6 +166,10 @@ bool Texture::init_view(const GPUTexture *src_,
   format_flag_ = to_format_flag(format);
   /* For now always copy the target. Target aliasing could be exposed later. */
   type_ = src->type_;
+  if (cube_as_array) {
+    BLI_assert(type_ & GPU_TEXTURE_CUBE);
+    type_ = (type_ & ~GPU_TEXTURE_CUBE) | GPU_TEXTURE_2D_ARRAY;
+  }
   sampler_state = src->sampler_state;
   return this->init_internal(src_, mip_start, layer_start);
 }
@@ -387,12 +392,13 @@ GPUTexture *GPU_texture_create_view(const char *name,
                                     int mip_start,
                                     int mip_len,
                                     int layer_start,
-                                    int layer_len)
+                                    int layer_len,
+                                    bool cube_as_array)
 {
   BLI_assert(mip_len > 0);
   BLI_assert(layer_len > 0);
   Texture *view = GPUBackend::get()->texture_alloc(name);
-  view->init_view(src, format, mip_start, mip_len, layer_start, layer_len);
+  view->init_view(src, format, mip_start, mip_len, layer_start, layer_len, cube_as_array);
   return wrap(view);
 }
 
diff --git a/source/blender/gpu/intern/gpu_texture_private.hh b/source/blender/gpu/intern/gpu_texture_private.hh
index 1e81980e95f..109e60e19a6 100644
--- a/source/blender/gpu/intern/gpu_texture_private.hh
+++ b/source/blender/gpu/intern/gpu_texture_private.hh
@@ -111,7 +111,8 @@ class Texture {
                  int mip_start,
                  int mip_len,
                  int layer_start,
-                 int layer_len);
+                 int layer_len,
+                 bool cube_as_array);
 
   virtual void generate_mipmap() = 0;
   virtual void copy_to(Texture *tex) = 0;