Add new method Layer::reads_context() which returns true iff the layer needs to be...

[synfig.git] / synfig-core / trunk / src / synfig / layer.h

diff --git a/synfig-core/trunk/src/synfig/layer.h b/synfig-core/trunk/src/synfig/layer.h
index fa7b3b7..a995299 100644 (file)
--- a/synfig-core/trunk/src/synfig/layer.h
+++ b/synfig-core/trunk/src/synfig/layer.h
@@ -428,6 +428,14 @@ public:
        //! Duplicates the Layer
        virtual Handle clone(const GUID& deriv_guid=GUID())const;
 
+       //! Returns true if the layer needs to be able to examine its context.
+       /*! context to render itself, other than for simple blending.  For
+       **  example, the blur layer will return true - it can't do its job
+       **  if it can't see its context, and the circle layer will return
+       **  false - rendering a circle doesn't depend on the underlying
+       **  context until the final blend operation. */
+       virtual bool reads_context()const;
+
 #ifdef THIS_CODE_IS_NOT_USED
        //! Duplicates the Layer without duplicating the value nodes
        virtual Layer *simple_clone()const;