Add a method to render targets and cameras to retrieve a Metal texture

include/ignition/rendering/Camera.hh

@@ -317,6 +317,14 @@ namespace ignition
       /// \return Texture Id of type GLuint.
       public: virtual unsigned int RenderTextureGLId() const = 0;
 
+      /// \brief Get the Metal texture id associated with the render texture
+      /// used by this camera. A valid Id is obtained only if the underlying
+      /// render engine is Metal based.
+      /// The pointer set by this function must be released to an
+      /// id<MTLTexture> using CFBridgingRelease.
+      /// \param[out] _textureIdPtr the address of a void* pointer.
+      public: virtual void RenderTextureMetalId(void *_textureIdPtr) const = 0;
+
       /// \brief Add a render pass to the camera
       /// \param[in] _pass New render pass to add
       public: virtual void AddRenderPass(const RenderPassPtr &_pass) = 0;

include/ignition/rendering/RenderTarget.hh

@@ -109,6 +109,13 @@ namespace ignition
       /// \brief Returns the OpenGL texture Id. A valid Id is returned only
       // if this is an OpenGL render texture
       public: virtual unsigned int GLId() const = 0;
+
+      /// \brief Gets the Metal texture id. A valid Id is obtained only
+      /// if this is an Metal render texture.
+      /// The pointer set by this function must be released to an
+      /// id<MTLTexture> using CFBridgingRelease.
+      /// \param[out] _textureIdPtr the address of a void* pointer.
+      public: virtual void MetalId(void *_textureIdPtr) const = 0;
     };
 
     /* \class RenderWindow RenderWindow.hh \

include/ignition/rendering/base/BaseCamera.hh

@@ -179,6 +179,10 @@ namespace ignition
       // Documentation inherited.
       public: virtual unsigned int RenderTextureGLId() const override;
 
+      // Documentation inherited.
+      public: virtual void RenderTextureMetalId(void *_textureIdPtr)
+          const override;
+
       // Documentation inherited.
       public: virtual void AddRenderPass(const RenderPassPtr &_pass) override;
 
@@ -804,6 +808,14 @@ namespace ignition
       return 0u;
     }
 
+    //////////////////////////////////////////////////
+    template <class T>
+    void BaseCamera<T>::RenderTextureMetalId(void */*_textureIdPtr*/) const
+    {
+      ignerr << "RenderTextureMetalId is not supported by current render"
+          << " engine" << std::endl;
+    }
+
     //////////////////////////////////////////////////
     template <class T>
     void BaseCamera<T>::AddRenderPass(const RenderPassPtr &_pass)

include/ignition/rendering/base/BaseRenderTarget.hh

@@ -105,6 +105,9 @@ namespace ignition
 
       // Documentation inherited.
       public: virtual unsigned int GLId() const override;
+
+      // Documentation inherited.
+      public: virtual void MetalId(void *_textureIdPtr) const override;
     };
 
     template <class T>
@@ -291,6 +294,12 @@ namespace ignition
       return 0u;
     }
 
+    //////////////////////////////////////////////////
+    template <class T>
+    void BaseRenderTexture<T>::MetalId(void */*_textureIdPtr*/) const
+    {
+    }
+
     //////////////////////////////////////////////////
     // BaseRenderWindow
     //////////////////////////////////////////////////

ogre2/include/ignition/rendering/ogre2/Ogre2Camera.hh

@@ -114,6 +114,10 @@ namespace ignition
       // Documentation inherited.
       public: virtual unsigned int RenderTextureGLId() const override;
 
+      // Documentation inherited.
+      public: virtual void RenderTextureMetalId(void *_textureIdPtr)
+          const override;
+
       // Documentation inherited.
       public: void SetShadowsDirty() override;
 

ogre2/include/ignition/rendering/ogre2/Ogre2RenderTarget.hh

@@ -136,6 +136,9 @@ namespace ignition
       // Documentation inherited
       public: unsigned int GLIdImpl() const;
 
+      // Documentation inherited
+      public: void MetalIdImpl(void *_textureIdPtr) const;
+
       /// \brief Destroy the render texture
       protected: void DestroyTargetImpl();
 
@@ -253,6 +256,9 @@ namespace ignition
       // Documentation inherited
       public: virtual unsigned int GLId() const override;
 
+      // Documentation inherited
+      public: virtual void MetalId(void *_textureIdPtr) const override;
+
       // Documentation inherited
       // TODO(anyone): this function should be removed.
       // We didn't do it to preserve ABI.

ogre2/src/Ogre2Camera.cc

@@ -207,6 +207,21 @@ unsigned int Ogre2Camera::RenderTextureGLId() const
   return rt->GLId();
 }
 
+//////////////////////////////////////////////////
+void Ogre2Camera::RenderTextureMetalId(void *_textureIdPtr) const
+{
+  if (!this->renderTexture)
+    return;
+
+  Ogre2RenderTexturePtr rt =
+      std::dynamic_pointer_cast<Ogre2RenderTexture>(this->renderTexture);
+
+  if (!rt)
+    return;
+
+  rt->MetalId(_textureIdPtr);
+}
+
 //////////////////////////////////////////////////
 void Ogre2Camera::SetShadowsDirty()
 {

ogre2/src/Ogre2RenderTarget.cc

@@ -547,6 +547,16 @@ unsigned int Ogre2RenderTarget::GLIdImpl() const
   return static_cast<unsigned int>(texId);
 }
 
+//////////////////////////////////////////////////
+void Ogre2RenderTarget::MetalIdImpl(void *_textureIdPtr) const
+{
+  if (!this->dataPtr->ogreTexture[0])
+    return;
+
+  this->dataPtr->ogreTexture[1]->
+      getCustomAttribute("msFinalTextureBuffer", _textureIdPtr);
+}
+
 //////////////////////////////////////////////////
 uint8_t Ogre2RenderTarget::TargetFSAA() const
 {
@@ -883,6 +893,12 @@ unsigned int Ogre2RenderTexture::GLId() const
   return Ogre2RenderTarget::GLIdImpl();
 }
 
+//////////////////////////////////////////////////
+void Ogre2RenderTexture::MetalId(void *_textureIdPtr) const
+{
+  Ogre2RenderTarget::MetalIdImpl(_textureIdPtr);
+}
+
 //////////////////////////////////////////////////
 void Ogre2RenderTexture::PreRender()
 {