Main: Texture::getBuffer - const correctness

OgreMain/include/OgreTexture.h

@@ -400,7 +400,7 @@ namespace Ogre {
             @remarks The buffer is invalidated when the resource is unloaded or destroyed.
             Do not use it after the lifetime of the containing texture.
         */
-        virtual const HardwarePixelBufferSharedPtr& getBuffer(size_t face=0, size_t mipmap=0);
+        virtual const HardwarePixelBufferSharedPtr& getBuffer(size_t face=0, size_t mipmap=0) const;
 
 
         /** Populate an Image with the contents of this texture. 

OgreMain/include/OgreTextureManager.h

@@ -435,7 +435,7 @@ namespace Ogre {
                 : Texture(creator, name, handle, group)
             {
             }
-            const HardwarePixelBufferSharedPtr& getBuffer(size_t, size_t) override
+            const HardwarePixelBufferSharedPtr& getBuffer(size_t, size_t) const override
             {
                 static HardwarePixelBufferSharedPtr nullBuffer;
                 return nullBuffer;

OgreMain/src/OgreTexture.cpp

@@ -376,7 +376,7 @@ namespace Ogre {
             }
         }
     }
-    const HardwarePixelBufferSharedPtr& Texture::getBuffer(size_t face, size_t mipmap)
+    const HardwarePixelBufferSharedPtr& Texture::getBuffer(size_t face, size_t mipmap) const
     {
         OgreAssert(face < getNumFaces(), "out of range");
         OgreAssert(mipmap <= mNumMipmaps, "out of range");