Drop support for Renderables that don't accept a Renderer

[libs/gl.git] / source / renderable.h

diff --git a/source/renderable.h b/source/renderable.h
index 8e31d5a7ac79e0f4a379b581da4b68ef37823c05..78879a3d8030fb15fcd41136c16ec7c831541972 100644 (file)
--- a/source/renderable.h
+++ b/source/renderable.h
@@ -1,10 +1,3 @@
-/* $Id$
-
-This file is part of libmspgl
-Copyright © 2007, 2011  Mikko Rasa, Mikkosoft Productions
-Distributed under the LGPL
-*/
-
 #ifndef MSP_GL_RENDERABLE_H_
 #define MSP_GL_RENDERABLE_H_
 
@@ -16,6 +9,10 @@ namespace GL {
 
 class Renderer;
 
+/**
+Base class for renderable objects.  All Renderables must support rendering with
+a Renderer, and may optionally provide support for standalone rendering.
+*/
 class Renderable
 {
 protected:
@@ -23,8 +20,11 @@ protected:
 public:
        virtual ~Renderable() { }
 
+       /** Returns a key used for grouping Renderables in an InstanceScene. */
+       virtual long get_instance_key() const { return 0; }
+
        virtual void render(const Tag & = Tag()) const;
-       virtual void render(Renderer &, const Tag & = Tag()) const;
+       virtual void render(Renderer &, const Tag & = Tag()) const = 0;
 };
 
 } // namespace Msp