From 9f8670f50d623f3c4a1ca2a0bec4c4543807a639 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Fri, 2 Jul 2010 14:18:59 +0000
Subject: [PATCH] Implement basic cache in ShadeComposer

---
 include/osg/ShaderComposer |  14 ++++-
 src/osg/ShaderComposer.cpp | 106 +++++++++++++++++++++++++++++++++++++
 src/osg/State.cpp          |   7 +--
 3 files changed, 123 insertions(+), 4 deletions(-)

diff --git a/include/osg/ShaderComposer b/include/osg/ShaderComposer
index fbbd6d404..ff47209c6 100644
--- a/include/osg/ShaderComposer
+++ b/include/osg/ShaderComposer
@@ -23,6 +23,8 @@ namespace osg {
 // forward declare osg::State
 class State;
 
+typedef std::vector<osg::ShaderComponent*> ShaderComponents;
+
 class OSG_EXPORT ShaderComposer : public osg::Object
 {
     public:
@@ -31,12 +33,22 @@ class OSG_EXPORT ShaderComposer : public osg::Object
         ShaderComposer(const ShaderComposer& sa,const CopyOp& copyop=CopyOp::SHALLOW_COPY);
         META_Object(osg, ShaderComposer)
 
-        osg::Program* getOrCreateProgram() { return 0; }
+        virtual osg::Program* getOrCreateProgram(const ShaderComponents& shaderComponents);
+
+
+        typedef std::vector< const osg::Shader* >  Shaders;
+        virtual osg::Shader* composeMain(const Shaders& shaders);
 
     protected:
 
         virtual ~ShaderComposer();
 
+        typedef std::map< ShaderComponents, ref_ptr<Program> > ProgramMap;
+        ProgramMap _programMap;
+
+        typedef std::map< Shaders, ref_ptr<Shader> > ShaderMainMap;
+        ShaderMainMap _shaderMainMap;
+
 };
 
 }
diff --git a/src/osg/ShaderComposer.cpp b/src/osg/ShaderComposer.cpp
index 99038ba74..662d29bf2 100644
--- a/src/osg/ShaderComposer.cpp
+++ b/src/osg/ShaderComposer.cpp
@@ -32,3 +32,109 @@ ShaderComposer::~ShaderComposer()
     OSG_INFO<<"ShaderComposer::~ShaderComposer() "<<this<<std::endl;
 }
 
+osg::Program* ShaderComposer::getOrCreateProgram(const ShaderComponents& shaderComponents)
+{
+    ProgramMap::iterator itr = _programMap.find(shaderComponents);
+    if (itr != _programMap.end())
+    {
+        OSG_NOTICE<<"ShaderComposer::getOrCreateProgram(..) using cached Program"<<std::endl;
+        return itr->second.get();
+    }
+
+    // strip out vertex shaders
+    Shaders vertexShaders;
+    Shaders geometryShaders;
+    Shaders fragmentShaders;
+
+    for(ShaderComponents::const_iterator itr = shaderComponents.begin();
+        itr != shaderComponents.end();
+        ++itr)
+    {
+        const ShaderComponent* sc = *itr;
+
+        for(unsigned int i=0; i<sc->getNumShaders(); ++i)
+        {
+            const Shader* shader = sc->getShader(i);
+            switch(shader->getType())
+            {
+                case(Shader::VERTEX):
+                    vertexShaders.push_back(shader);
+                    break;
+                case(Shader::GEOMETRY):
+                    geometryShaders.push_back(shader);
+                    break;
+                case(Shader::FRAGMENT):
+                    fragmentShaders.push_back(shader);
+                    break;
+                case(Shader::UNDEFINED):
+                    OSG_WARN<<"Warning: ShaderCompose::getOrCreateProgam(ShaderComponts) encounterd invalid Shader::Type."<<std::endl;
+                    break;
+            }
+        }
+    }
+
+    osg::ref_ptr<osg::Program> program = new osg::Program;
+
+    if (!vertexShaders.empty())
+    {
+        ShaderMainMap::iterator itr = _shaderMainMap.find(vertexShaders);
+        if (itr == _shaderMainMap.end())
+        {
+            // no vertex shader in map yet, need to compose a new main shader
+            osg::Shader* mainShader = composeMain(vertexShaders);
+            _shaderMainMap[vertexShaders] = mainShader;
+            program->addShader(mainShader);
+        }
+        else
+        {
+            program->addShader(itr->second.get());
+        }
+    }
+
+    if (!geometryShaders.empty())
+    {
+        ShaderMainMap::iterator itr = _shaderMainMap.find(geometryShaders);
+        if (itr == _shaderMainMap.end())
+        {
+            // no vertex shader in map yet, need to compose a new main shader
+            osg::Shader* mainShader = composeMain(geometryShaders);
+            _shaderMainMap[geometryShaders] = mainShader;
+            program->addShader(mainShader);
+        }
+        else
+        {
+            program->addShader(itr->second.get());
+        }
+    }
+
+
+    if (!fragmentShaders.empty())
+    {
+        ShaderMainMap::iterator itr = _shaderMainMap.find(fragmentShaders);
+        if (itr == _shaderMainMap.end())
+        {
+            // no vertex shader in map yet, need to compose a new main shader
+            osg::Shader* mainShader = composeMain(fragmentShaders);
+            _shaderMainMap[fragmentShaders] = mainShader;
+            program->addShader(mainShader);
+        }
+        else
+        {
+            program->addShader(itr->second.get());
+        }
+    }
+
+
+    // assign newly created program to map.
+    _programMap[shaderComponents] = program;
+
+    OSG_NOTICE<<"ShaderComposer::getOrCreateProgram(..) created new Program"<<std::endl;
+
+    return program.get();
+}
+
+osg::Shader* ShaderComposer::composeMain(const Shaders& shaders)
+{
+    OSG_NOTICE<<"ShaderComposer::composeMain(Shaders) shaders.size()=="<<shaders.size()<<std::endl;
+    return 0;
+}
diff --git a/src/osg/State.cpp b/src/osg/State.cpp
index 02a2718b3..7122a4178 100644
--- a/src/osg/State.cpp
+++ b/src/osg/State.cpp
@@ -42,7 +42,7 @@ State::State():
     _graphicsContext = 0;
     _contextID = 0;
 
-    _shaderCompositionEnabled = true;
+    _shaderCompositionEnabled = false; // true;
     _shaderCompositionDirty = true;
     _shaderComposer = new ShaderComposer;
     _currentShaderCompositionProgram = 0L;
@@ -519,8 +519,9 @@ void State::apply(const StateSet* dstate)
         {
             if (_shaderCompositionDirty)
             {
-                // built lits of current ShaderComponents
-                _currentShaderCompositionProgram = _shaderComposer->getOrCreateProgram();
+                // build lits of current ShaderComponents
+                ShaderComponents shaderComponents;
+                _currentShaderCompositionProgram = _shaderComposer->getOrCreateProgram(shaderComponents);
             }
 
             if (_currentShaderCompositionProgram)