Lots of comment updates

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

diff --git a/source/objectinstance.h b/source/objectinstance.h
index d665851fbb5d40fb0201d17c255ea8667572a04c..3dc5da6a399432bafa62197b01ae0e19d7475f5f 100644 (file)
--- a/source/objectinstance.h
+++ b/source/objectinstance.h
@@ -1,10 +1,3 @@
-/* $Id$
-
-This file is part of libmspgl
-Copyright © 2007-2008, 2010-2011  Mikko Rasa, Mikkosoft Productions
-Distributed under the LGPL
-*/
-
 #ifndef MSP_GL_OBJETCINSTANCE_H_
 #define MSP_GL_OBJETCINSTANCE_H_
 
@@ -18,9 +11,12 @@ class Object;
 class ProgramData;
 
 /**
-Represents a single instance of an Object.  An application can derive another
-class from this and overload the hook functions to specify location and other
-instance-specific parameters for the rendered objects.
+Represents a single instance of an Object.  A derived class can overload the
+hook functions to specify a model matrix and other instance-specific parameters
+for the rendered objects.
+
+ObjectInstances can benefit from being put in an InstanceScene, which will
+render all instances of the same object consecutively.
 */
 class ObjectInstance: public Renderable
 {
@@ -31,6 +27,7 @@ public:
        ObjectInstance(const Object &);
 
        const Object &get_object() const { return object; }
+       virtual long get_instance_key() const { return reinterpret_cast<long>(&object); }
 
        virtual void render(const Tag &tag = Tag()) const;
        virtual void render(Renderer &, const Tag & = Tag()) const;