From 541bf02f18ad27e8c8101e4255586ddbfef40916 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Tue, 10 May 2011 07:37:55 +0000
Subject: [PATCH] Store uniform information inside Program to reduce
 glGetUniformLocation calls

---
 source/program.cpp | 23 ++++++++++++++++++++++-
 source/program.h   |  9 +++++++++
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/source/program.cpp b/source/program.cpp
index 77fe7e75..1343c00f 100644
--- a/source/program.cpp
+++ b/source/program.cpp
@@ -215,11 +215,28 @@ void Program::link()
 		if(!(*i)->is_compiled())
 			(*i)->compile();
 
+	uniforms.clear();
+
 	glLinkProgramARB(id);
 	int value;
 	glGetObjectParameterivARB(id, GL_OBJECT_LINK_STATUS_ARB, &value);
 	if(!(linked = value))
 		throw CompileError(get_info_log());
+
+	glGetObjectParameterivARB(id, GL_OBJECT_ACTIVE_UNIFORMS_ARB, &value);
+	for(int i=0; i<value; ++i)
+	{
+		UniformInfo info;
+		char name[128];
+		int len = 0;
+		glGetActiveUniformARB(id, i, 128, &len, &info.size, &info.type, name);
+		if(len)
+		{
+			info.name = name;
+			info.location = glGetUniformLocationARB(id, name);
+			uniforms[name] = info;
+		}
+	}
 }
 
 string Program::get_info_log() const
@@ -244,7 +261,11 @@ void Program::bind() const
 
 int Program::get_uniform_location(const string &n) const
 {
-	return glGetUniformLocationARB(id, n.c_str());
+	map<string, UniformInfo>::const_iterator i = uniforms.find(n);
+	if(i==uniforms.end())
+		return -1;
+
+	return i->second.location;
 }
 
 void Program::unbind()
diff --git a/source/program.h b/source/program.h
index 4ff3f53a..80ddf15c 100644
--- a/source/program.h
+++ b/source/program.h
@@ -56,11 +56,20 @@ public:
 		std::string create_flags() const;
 	};
 
+	struct UniformInfo
+	{
+		std::string name;
+		int location;
+		int size;
+		GLenum type;
+	};
+
 private:
 	unsigned id;
 	std::list<Shader *> shaders;
 	bool del_shaders;
 	bool linked;
+	std::map<std::string, UniformInfo> uniforms;
 
 public:
 	Program();
-- 
2.45.2