OpenSceneGraph/include/osgUtil/TriStripVisitor

/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2003 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_TRISTRIPVISITOR
#define OSGUTIL_TRISTRIPVISITOR 1

#include <osg/NodeVisitor>
#include <osg/Geode>
#include <osg/Geometry>

#include <osgUtil/Optimizer>

#include <set>

namespace osgUtil {

/** A tri stripping visitor for converting Geometry surface primitives into tri strips.
  * The current implemention is based up Tanguy Fautre's triangulation code.
  */
class OSGUTIL_EXPORT TriStripVisitor : public osg::NodeVisitor
{
    public:

        /// default to traversing all children.
        TriStripVisitor(Optimizer* =0) : 
                osg::NodeVisitor( osg::NodeVisitor::TRAVERSE_ALL_CHILDREN ), 
                _cacheSize( 16 ),
                _minStripSize( 2 ),
                _generateFourPointPrimitivesQuads ( false)
        {}

        /** Convert mesh primitives in Geometry into Tri Strips.
          * Converts all primitive types except points
          * and lines, linestrips which it leaves unchanged.
          */
        void stripify(osg::Geometry& drawable);

        /** Stripfy the accumulated list of Geometry drawables.*/
        void stripify();

        /// accumulate the Geometry drawables to stripify
        virtual void apply(osg::Geode& geode);

        inline void setCacheSize( unsigned int size )
        {
            _cacheSize = size;
        }
        
        inline unsigned int getCacheSize()
        {
            return _cacheSize;
        }

        inline const unsigned int getCacheSize() const
        {
            return _cacheSize;
        }
        
        inline void setMinStripSize( unsigned int size )
        {
            _minStripSize = size;
        }
        
        inline unsigned int getMinStripSize()
        {
            return _minStripSize;
        }

        inline const unsigned int getMinStripSize() const
        {
            return _minStripSize;
        }
        
        inline bool isOperationPermissableForObject(const osg::Object* object) const
        {
            return _optimizer ? _optimizer->isOperationPermissableForObject(object,osgUtil::Optimizer::TRISTRIP_GEOMETRY) : true; 
        }
        
        void setGenerateFourPointPrimitivesQuads(bool flag) { _generateFourPointPrimitivesQuads = flag; }
        bool getGenerateFourPointPrimitivesQuads() const { return _generateFourPointPrimitivesQuads; }
        

    private:
    
        typedef std::set<osg::Geometry*> GeometryList;

        Optimizer*   _optimizer;
        unsigned int _cacheSize;
        unsigned int _minStripSize;
        GeometryList _geometryList;
        bool         _generateFourPointPrimitivesQuads;
};

}

#endif