OpenSceneGraph/include/osgUtil/IncrementalCompileOperation

/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield 
 *
 * This library is open source and may be redistributed and/or modified under  
 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or 
 * (at your option) any later version.  The full license is in LICENSE file
 * included with this distribution, and on the openscenegraph.org website.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
 * OpenSceneGraph Public License for more details.
*/

#ifndef OSGUTIL_INCREMENTALCOMPILEOPERATOR
#define OSGUTIL_INCREMENTALCOMPILEOPERATOR

#include <osgUtil/GLObjectsVisitor>

namespace osgUtil {

class OSGUTIL_EXPORT IncrementalCompileOperation : public osg::GraphicsOperation
{
    public:

        IncrementalCompileOperation();
        
        /** Set the target frame rate that the IncrementalCompileOperation should assume.
          * Typically one would set this to the value refresh rate of your display system i.e. 60Hz.
          * Default value is 100.
          * Usage notes.  The TargetFrameRate and the MinimumTimeAvailableForGLCompileAndDeletePerFrame
          * parameters are not directly used by IncrementalCompileOperation, but are should be used as a guide for how
          * long to set aside per frame for compiling and deleting OpenGL objects. The longer amount of
          * time to set aside  the faster databases will be paged in but with increased chance of frame drops,
          * the lower the amount of time the set aside the slower databases will paged it but with better
          * chance of avoid any frame drops.  The default values are chosen to achieve the later when running
          * on a modern mid to high end  PC. 
          * The way to compute the amount of available time use a scheme such as :
          *    availableTime = maximum(1.0/targetFrameRate - timeTakenDuringUpdateCullAndDraw, minimumTimeAvailableForGLCompileAndDeletePerFrame). 
          */
        void setTargetFrameRate(double tfr) { _targetFrameRate = tfr; }

        /** Get the target frame rate that the IncrementalCompileOperation should assume.*/
        double getTargetFrameRate() const { return _targetFrameRate; }
        
        /** Set the minimum amount of time (in seconds) that should be made available for compiling and delete OpenGL objects per frame.
          * Default value is 0.001 (1 millisecond). 
          * For usage see notes in setTargetFrameRate.*/
        void setMinimumTimeAvailableForGLCompileAndDeletePerFrame(double ta) { _minimumTimeAvailableForGLCompileAndDeletePerFrame = ta; }

        /** Get the minimum amount of time that should be made available for compiling and delete OpenGL objects per frame.
          * For usage see notes in setTargetFrameRate.*/
        double getMinimumTimeAvailableForGLCompileAndDeletePerFrame() const { return _minimumTimeAvailableForGLCompileAndDeletePerFrame; }

        /** Set the maximum number of OpenGL objects that the page should attempt to compile per frame.
          * Note, Lower values reduces chances of a frame drop but lower the rate that database will be paged in at.
          * Default value is 8. */
        void setMaximumNumOfObjectsToCompilePerFrame(unsigned int num) { _maximumNumOfObjectsToCompilePerFrame = num; }

        /** Get the maximum number of OpenGL objects that the page should attempt to compile per frame.*/
        unsigned int getMaximumNumOfObjectsToCompilePerFrame() const { return _maximumNumOfObjectsToCompilePerFrame; }


        /** FlushTimeRatio governs how much of the spare time in each frame is used for flushing deleted OpenGL objects.
          * Default value is 0.5, valid range is 0.1 to 0.9.*/
        void setFlushTimeRatio(double ratio) { _flushTimeRatio = ratio; }
        double getFlushTimeRatio() const { return _flushTimeRatio; }

        /** ConservativeTimeRatio governs how much of the measured spare time in each frame is used for flushing deleted and compile new OpenGL objects.
          * Default value is 0.5, valid range is 0.1 to 1.0.
          * A ratio near 1.0 will lead to paged databases being compiled and merged quicker but increase the chances of frame drop.
          * A ratio near 0.1 will lead to paged databases being compiled and merged closer but reduse the chances of frame drop.*/
        void setConservativeTimeRatio(double ratio) { _conservativeTimeRatio = ratio; }
        double getConservativeTimeRatio() const { return _conservativeTimeRatio; }



        typedef std::vector<osg::GraphicsContext*> Contexts;
        void assignContexts(Contexts& contexts);
        void removeContexts(Contexts& contexts);

        void addGraphicsContext(osg::GraphicsContext* gc);
        void removeGraphicsContext(osg::GraphicsContext* gc);


        /** Merge subgraphs that have been compiled.*/
        void mergeCompiledSubgraphs();

        virtual void operator () (osg::GraphicsContext* context);
        


        struct CompileData : public osg::Referenced
        {
            typedef std::list< osg::ref_ptr<osg::Drawable> > Drawables;
            typedef std::list< osg::ref_ptr<osg::Texture> >  Textures;
            typedef std::list< osg::ref_ptr<osg::Program> >  Programs;
            
            bool empty() const { return _drawables.empty() && _textures.empty() &&  _programs.empty(); }
            
            Drawables   _drawables;
            Textures    _textures;
            Programs    _programs;
        };

        class CompileSet;
        typedef std::set<osg::GraphicsContext*> ContextSet;
        typedef std::map<osg::GraphicsContext*, CompileData >  CompileMap;
        
        struct CompileCompletedCallback : public osg::Referenced
        {
            virtual bool compileCompleted(CompileSet* compileSet) = 0;
        };

        class CompileSet : public osg::Referenced
        {
        public:
        
            
            CompileSet() {}
            
            CompileSet(osg::Node*subgraphToCompile):
                _subgraphToCompile(subgraphToCompile) {}

            CompileSet(osg::Group* attachmentPoint, osg::Node*subgraphToCompile):
                _attachmentPoint(attachmentPoint),
                _subgraphToCompile(subgraphToCompile) {}
        
            void buildCompileMap(ContextSet& context, GLObjectsVisitor::Mode mode=GLObjectsVisitor::COMPILE_DISPLAY_LISTS|GLObjectsVisitor::COMPILE_STATE_ATTRIBUTES);

            bool compileCompleted() const
            {
                for(CompileMap::const_iterator itr = _compileMap.begin();
                    itr != _compileMap.end();
                    ++itr)
                {
                    if (!(itr->second.empty())) return false;
                }
                return true;
            }

            osg::ref_ptr<osg::Group>                _attachmentPoint;
            osg::ref_ptr<osg::Node>                 _subgraphToCompile;
            osg::ref_ptr<CompileCompletedCallback>  _compileCompletedCallback;
            CompileMap                              _compileMap;
            
        // protected:
        
            virtual ~CompileSet() {}
        };
        
        typedef std::list< osg::ref_ptr<CompileSet> >  CompileSets;


        /** Add a subgraph to be compiled.*/
        void add(osg::Node* subgraphToCompile);

        /** Add a subgraph to be compiled and add automatically to attachPoint on call to mergeCompiledSubgraphs.*/
        void add(osg::Group* attachmentPoint, osg::Node* subgraphToCompile);

        /** Add a CompileSet to be compiled.*/
        void add(CompileSet* compileSet, bool callBuildCompileMap=true);


        OpenThreads::Mutex* getToCompiledMutex() { return &_toCompileMutex; }
        CompileSets& getToCompile() { return _compiled; }
        
        OpenThreads::Mutex* getCompiledMutex() { return &_compiledMutex; }
        CompileSets& getCompiled() { return _compiled; }

    protected:

        virtual ~IncrementalCompileOperation();
        
        // forward declare to keep within class namespace
        class CollectStateToCompile;
    
        double              _targetFrameRate;
        double              _minimumTimeAvailableForGLCompileAndDeletePerFrame;
        unsigned int        _maximumNumOfObjectsToCompilePerFrame;
        double              _flushTimeRatio;
        double              _conservativeTimeRatio;

        OpenThreads::Mutex  _toCompileMutex;
        CompileSets         _toCompile;
        
        OpenThreads::Mutex  _compiledMutex;
        CompileSets         _compiled;
        
        ContextSet          _contexts;

};


}

#endif