[d3d11] Introduce GetCommonBuffer helper

Also update GetCommonTexture documentation.

src/d3d11/d3d11_buffer.cpp

@@ -150,4 +150,14 @@ namespace dxvk {
     return m_device->GetDXVKDevice()->createBuffer(info, memoryFlags);
   }
   
+
+  D3D11Buffer* GetCommonBuffer(ID3D11Resource* pResource) {
+    D3D11_RESOURCE_DIMENSION dimension = D3D11_RESOURCE_DIMENSION_UNKNOWN;
+    pResource->GetType(&dimension);
+
+    return dimension == D3D11_RESOURCE_DIMENSION_BUFFER
+      ? static_cast<D3D11Buffer*>(pResource)
+      : nullptr;
+  }
+
 }

src/d3d11/d3d11_buffer.h

@@ -77,5 +77,15 @@ namespace dxvk {
       const D3D11_BUFFER_DESC* pDesc) const;
     
   };
+
+
+  /**
+   * \brief Retrieves buffer from resource pointer
+   * 
+   * \param [in] pResource The resource to query
+   * \returns Pointer to buffer, or \c nullptr
+   */
+  D3D11Buffer* GetCommonBuffer(
+          ID3D11Resource*       pResource);
   
 }

src/d3d11/d3d11_texture.h

@@ -365,11 +365,10 @@ namespace dxvk {
   
   
   /**
-   * \brief Retrieves common info about a texture
+   * \brief Retrieves texture from resource pointer
    * 
-   * \param [in] pResource The resource. Must be a texture.
+   * \param [in] pResource The resource to query
-   * \param [out] pTextureInfo Pointer to the texture info struct.
+   * \returns Pointer to texture info, or \c nullptr
-   * \returns E_INVALIDARG if the resource is not a texture
    */
   D3D11CommonTexture* GetCommonTexture(
           ID3D11Resource*       pResource);