X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=source%2Frenderable.h;h=b53fa9ac839307347bb614db7052dcfbe5a7a8cb;hb=db498c7e634fa999cf4b4a8b67c49813009b1790;hp=3432a87ee77ed4db3c72600061127bef767c768d;hpb=f2592f0e67d92043952eb7a2e39df182720cd990;p=libs%2Fgl.git

diff --git a/source/renderable.h b/source/renderable.h
index 3432a87e..b53fa9ac 100644
--- a/source/renderable.h
+++ b/source/renderable.h
@@ -16,6 +16,12 @@ a Renderer, and may optionally provide support for standalone rendering.
 
 The render methods take a Tag to identify a render pass.  It is most commonly
 used together with Techniques and Pipelines to implement multipass rendering.
+
+The setup_frame and finish_frame methods provide a mechanism for performing
+once-per-frame operations.  This is most useful for effects, which may need to
+do auxiliary rendering.  With complex rendering hierarchies, these methods may
+be called multiple times for one frame, but it's guaranteed that no rendering
+will occur before a setup_frame call or after a finish_frame call.
 */
 class Renderable
 {
@@ -32,6 +38,12 @@ public:
 	matrix exists. */
 	virtual const Matrix *get_matrix() const { return 0; }
 
+	/** Called when starting to render a new frame. */
+	virtual void setup_frame() const { }
+
+	/** Called when a complete frame has been rendered. */
+	virtual void finish_frame() const { }
+
 	/** Renders the renderable without a renderer.  This can be convenient in
 	some simple cases, but most renderables don't need to implement this
 	method. */