From 6a135773515b020ea3f163a11d06150ae5c0e69f Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Wed, 27 Feb 2008 14:09:02 +0000
Subject: [PATCH] Allow Renderables in a Scene to specify ordering

---
 source/renderable.h |  1 +
 source/scene.cpp    | 10 +++++++++-
 source/scene.h      |  7 ++++++-
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/source/renderable.h b/source/renderable.h
index 00b8b901..aeee1666 100644
--- a/source/renderable.h
+++ b/source/renderable.h
@@ -17,6 +17,7 @@ namespace GL {
 class Renderable
 {
 public:
+	virtual int get_order() const { return 0; }
 	virtual bool has_pass(const Tag &tag) const =0;
 
 	virtual void render(const Tag &tag=Tag()) const =0;
diff --git a/source/scene.cpp b/source/scene.cpp
index 20399daf..607166d5 100644
--- a/source/scene.cpp
+++ b/source/scene.cpp
@@ -24,10 +24,18 @@ void Scene::remove(const Renderable &r)
 
 void Scene::render(const Tag &tag) const
 {
-	for(set<const Renderable *>::const_iterator i=renderables.begin(); i!=renderables.end(); ++i)
+	for(set<const Renderable *, Compare>::const_iterator i=renderables.begin(); i!=renderables.end(); ++i)
 		if((*i)->has_pass(tag))
 			(*i)->render(tag);
 }
 
+
+bool Scene::Compare::operator()(const Renderable *a, const Renderable *b) const
+{
+	if(a->get_order()!=b->get_order())
+		return a->get_order()<b->get_order();
+	return a<b;
+}
+
 } // namespace GL
 } // namespace Msp
diff --git a/source/scene.h b/source/scene.h
index 6bfad812..9766ab21 100644
--- a/source/scene.h
+++ b/source/scene.h
@@ -17,7 +17,12 @@ namespace GL {
 class Scene: public Renderable
 {
 private:
-	std::set<const Renderable *> renderables;
+	struct Compare
+	{
+		bool operator()(const Renderable *, const Renderable *) const;
+	};
+
+	std::set<const Renderable *, Compare> renderables;
 
 public:
 	void add(const Renderable &);
-- 
2.45.2