GPUTexture: Add support for texture view

This is an OpenGL 4.3 feature that enables creating a texture using a range
of the same data as another texture.

2 files changed, 24 insertions, 0 deletions

diff --git a/source/blender/gpu/opengl/gl_texture.cc b/source/blender/gpu/opengl/gl_texture.cc
index 37bf2f6b8b3..0a5c7f8e79e 100644
--- a/source/blender/gpu/opengl/gl_texture.cc
+++ b/source/blender/gpu/opengl/gl_texture.cc
@@ -175,6 +175,28 @@ bool GLTexture::init_internal(GPUVertBuf *vbo)
   return true;
 }
 
+bool GLTexture::init_internal(const GPUTexture *src, int mip_offset, int layer_offset)
+{
+  BLI_assert(GLContext::texture_storage_support);
+
+  const GLTexture *gl_src = static_cast<const GLTexture *>(unwrap(src));
+  GLenum internal_format = to_gl_internal_format(format_);
+  target_ = to_gl_target(type_);
+
+  glTextureView(tex_id_,
+                target_,
+                gl_src->tex_id_,
+                internal_format,
+                mip_offset,
+                mipmaps_,
+                layer_offset,
+                this->layer_count());
+
+  debug::object_label(GL_TEXTURE, tex_id_, name_);
+
+  return true;
+}
+
 /** \} */
 
 /* -------------------------------------------------------------------- */
diff --git a/source/blender/gpu/opengl/gl_texture.hh b/source/blender/gpu/opengl/gl_texture.hh
index 9e128da90e8..d4d024f5e3e 100644
--- a/source/blender/gpu/opengl/gl_texture.hh
+++ b/source/blender/gpu/opengl/gl_texture.hh
@@ -74,6 +74,8 @@ class GLTexture : public Texture {
   bool init_internal() override;
   /** Return true on success. */
   bool init_internal(GPUVertBuf *vbo) override;
+  /** Return true on success. */
+  bool init_internal(const GPUTexture *src, int mip_offset, int layer_offset) override;
 
  private:
   bool proxy_check(int mip);