From 56c9bfa0b47583fb9067705a69c3639a17d4a097 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Thu, 4 Feb 2010 14:12:45 +0000
Subject: [PATCH] Make Tag directly comparable and use it as a key in relevant
 maps

---
 source/pipeline.cpp  |  8 ++++----
 source/pipeline.h    |  4 +++-
 source/tag.cpp       | 29 ++++++++++++++++++-----------
 source/tag.h         |  5 ++++-
 source/technique.cpp | 14 +++++++-------
 source/technique.h   |  4 +++-
 6 files changed, 39 insertions(+), 25 deletions(-)

diff --git a/source/pipeline.cpp b/source/pipeline.cpp
index 5969246b..9d5870cd 100644
--- a/source/pipeline.cpp
+++ b/source/pipeline.cpp
@@ -37,17 +37,17 @@ Pipeline::~Pipeline()
 
 PipelinePass &Pipeline::add_pass(const Tag &tag)
 {
-	if(passes.count(tag.id))
+	if(passes.count(tag))
 		throw KeyError("Pass already exists");
 
-	PipelinePass &pass=passes[tag.id];
+	PipelinePass &pass=passes[tag];
 	pass_order.push_back(tag);
 	return pass;
 }
 
 PipelinePass &Pipeline::get_pass(const Tag &tag)
 {
-	map<unsigned, PipelinePass>::iterator i=passes.find(tag.id);
+	PassMap::iterator i=passes.find(tag);
 	if(i==passes.end())
 		throw KeyError("Unknown pass");
 	return i->second;
@@ -55,7 +55,7 @@ PipelinePass &Pipeline::get_pass(const Tag &tag)
 
 const PipelinePass &Pipeline::get_pass(const Tag &tag) const
 {
-	map<unsigned, PipelinePass>::const_iterator i=passes.find(tag.id);
+	PassMap::const_iterator i=passes.find(tag);
 	if(i==passes.end())
 		throw KeyError("Unknown pass");
 	return i->second;
diff --git a/source/pipeline.h b/source/pipeline.h
index afa9ed5e..8edd6795 100644
--- a/source/pipeline.h
+++ b/source/pipeline.h
@@ -24,7 +24,9 @@ class Texture2D;
 class Pipeline: public Renderable
 {
 private:
-	std::map<unsigned, PipelinePass> passes;
+	typedef std::map<Tag, PipelinePass> PassMap;
+
+	PassMap passes;
 	std::vector<Tag> pass_order;
 	std::vector<const Renderable *> renderables;
 	std::vector<Effect *> effects;
diff --git a/source/tag.cpp b/source/tag.cpp
index 8e29bee1..76adf7d1 100644
--- a/source/tag.cpp
+++ b/source/tag.cpp
@@ -1,28 +1,35 @@
 /* $Id$
 
 This file is part of libmspgl
-Copyright © 2007  Mikko Rasa, Mikkosoft Productions
+Copyright © 2007, 2010  Mikko Rasa, Mikkosoft Productions
 Distributed under the LGPL
 */
 
 #include "tag.h"
 
+namespace {
+
+template<typename T>
+inline unsigned hash(T begin, T end)
+{
+	unsigned result=0;
+	for(T i=begin; (i!=end && *i); ++i)
+		result=((result>>29)|(result<<5))^static_cast<unsigned char>(*i);
+	return result;
+}
+
+}
+
 namespace Msp {
 namespace GL {
 
 Tag::Tag(const char *s):
-	id(0)
-{
-	for(const char *i=s; *i; ++i)
-		id=id*id+*i;
-}
+	id(s ? hash<const char *>(s, 0) : 0)
+{ }
 
 Tag::Tag(const std::string &s):
-	id(0)
-{
-	for(std::string::const_iterator i=s.begin(); i!=s.end(); ++i)
-		id=id*id+*i;
-}
+	id(hash(s.begin(), s.end()))
+{ }
 
 } // namespace GL
 } // namespace Msp
diff --git a/source/tag.h b/source/tag.h
index b2d4fd51..47c4643e 100644
--- a/source/tag.h
+++ b/source/tag.h
@@ -1,7 +1,7 @@
 /* $Id$
 
 This file is part of libmspgl
-Copyright © 2007  Mikko Rasa, Mikkosoft Productions
+Copyright © 2007, 2010  Mikko Rasa, Mikkosoft Productions
 Distributed under the LGPL
 */
 
@@ -20,6 +20,9 @@ struct Tag
 	Tag(): id(0) { }
 	Tag(const char *);
 	Tag(const std::string &s);
+
+	bool operator<(const Tag &t) const { return id<t.id; }
+	bool operator==(const Tag &t) const { return id==t.id; }
 };
 
 } // namespace GL
diff --git a/source/technique.cpp b/source/technique.cpp
index 53c7a9ae..c7bd25ed 100644
--- a/source/technique.cpp
+++ b/source/technique.cpp
@@ -26,18 +26,18 @@ Technique::Technique():
 
 Technique::~Technique()
 {
-	for(map<unsigned, ObjectPass>::iterator i=passes.begin(); i!=passes.end(); ++i)
+	for(PassMap::iterator i=passes.begin(); i!=passes.end(); ++i)
 		delete i->second.shdata;
 }
 
 bool Technique::has_pass(const GL::Tag &tag) const
 {
-	return passes.count(tag.id);
+	return passes.count(tag);
 }
 
 const ObjectPass &Technique::get_pass(const GL::Tag &tag) const
 {
-	map<unsigned, ObjectPass>::const_iterator i=passes.find(tag.id);
+	PassMap::const_iterator i=passes.find(tag);
 	if(i==passes.end())
 		throw KeyError("Unknown pass");
 	return i->second;
@@ -76,7 +76,7 @@ Technique::Loader::Loader(Technique &t, Collection &c):
 
 void Technique::Loader::finish()
 {
-	for(map<unsigned, ObjectPass>::iterator i=tech.passes.begin(); i!=tech.passes.end(); ++i)
+	for(PassMap::iterator i=tech.passes.begin(); i!=tech.passes.end(); ++i)
 		if(i->second.shdata)
 		{
 			for(unsigned j=0; j<tech.textures.size(); ++j)
@@ -97,12 +97,12 @@ void Technique::Loader::material_inline()
 
 void Technique::Loader::pass(const string &n)
 {
-	unsigned id=Tag(n).id;
-	if(tech.passes.count(id))
+	Tag tag(n);
+	if(tech.passes.count(tag))
 		throw KeyError("Duplicate pass name", n);
 	ObjectPass p;
 	load_sub(p, coll);
-	tech.passes[id]=p;
+	tech.passes[tag]=p;
 }
 
 void Technique::Loader::shader(const string &n)
diff --git a/source/technique.h b/source/technique.h
index ef7e9e12..468131f7 100644
--- a/source/technique.h
+++ b/source/technique.h
@@ -58,9 +58,11 @@ private:
 		TextureSlot(): texture(0) { }
 	};
 
+	typedef std::map<Tag, ObjectPass> PassMap;
+
 	std::vector<TextureSlot> textures;
 	const Texture *main_texture;
-	std::map<unsigned, ObjectPass> passes;
+	PassMap passes;
 	ObjectPass *normal_pass;
 	const Material *material;
 
-- 
2.43.0