OpenSceneGraph/include/osgUtil/TriStripVisitor

/* -*-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_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 upon Tanguy Fautre's triangulation code.
  */
class OSGUTIL_EXPORT TriStripVisitor : public BaseOptimizerVisitor
{
    public:

        /// default to traversing all children.
        TriStripVisitor(Optimizer* optimizer=0) :
                BaseOptimizerVisitor( optimizer, Optimizer::TRISTRIP_GEOMETRY),
                _cacheSize( 16 ),
                _minStripSize( 2 ),
                _generateFourPointPrimitivesQuads ( false ),
                _mergeTriangleStrips( 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);

        void mergeTriangleStrips(osg::Geometry::PrimitiveSetList& primitives);

        /** Stripify (make into strips of tria or quads) the accumulated list of Geometry drawables.*/
        void stripify();

        /// Accumulate the Geometry drawables to make into strips.
        virtual void apply(osg::Geode& geode);

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

        inline unsigned int getCacheSize() const
        {
            return _cacheSize;
        }

        inline void setMinStripSize( unsigned int size )
        {
            _minStripSize = size;
        }

        inline unsigned int getMinStripSize() const
        {
            return _minStripSize;
        }


        void setGenerateFourPointPrimitivesQuads(bool flag) { _generateFourPointPrimitivesQuads = flag; }
        bool getGenerateFourPointPrimitivesQuads() const { return _generateFourPointPrimitivesQuads; }

        void setMergeTriangleStrips(bool flag) { _mergeTriangleStrips = flag; }
        bool getMergeTriangleStrips() const { return _mergeTriangleStrips; }

    private:

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

        unsigned int _cacheSize;
        unsigned int _minStripSize;
        GeometryList _geometryList;
        bool         _generateFourPointPrimitivesQuads;
        bool         _mergeTriangleStrips;
};

}

#endif