//C++ header - Open Scene Graph - Copyright (C) 1998-2001 Robert Osfield
//Distributed under the terms of the GNU Library General Public License (LGPL)
//as published by the Free Software Foundation.

#ifndef OSGUTIL_Tesselator
#define OSGUTIL_Tesselator

#include <osg/Geometry>

#include <osgUtil/Export>

#include <osg/GLU>

#include <vector>

/* Win32 calling conventions. (or a least thats what the GLUT example tess.c uses.)*/
#ifndef CALLBACK
#define CALLBACK
#endif


namespace osgUtil {

/** A simple class for tessellating a single polygon boundary.
  * Currently uses old style glu tessellation functions for portability.
  * It be nice to use the modern glu tessellation functions or to find
  * a small set of code for doing this job better.*/
class OSGUTIL_EXPORT Tesselator
{
    public:
   
        Tesselator();
        ~Tesselator();

        enum InputBoundaryDirection
        {
            CLOCK_WISE,
            COUNTER_CLOCK_WISE
        };
        
        typedef std::vector<osg::Vec3*> VertexPointList;
        
        struct Prim : public osg::Referenced
        {
            Prim(GLenum mode):_mode(mode) {}
        
            typedef std::vector<osg::Vec3*> VecList;

            GLenum  _mode;
            VecList _vertices;
        };
        
        void beginTesselation();
        
        void beginContour();
        void addVertex(osg::Vec3* vertex);
        void endContour();
        
        void endTesselation();

        typedef std::vector< osg::ref_ptr<Prim> > PrimList;
        
        PrimList& getPrimList() { return _primList; }        
        
        void retesselatePolygons(osg::Geometry& geom);
        
        void reset();
        
    protected:
        
        void begin(GLenum mode);
        void vertex(osg::Vec3* vertex);
        void combine(osg::Vec3* vertex);
        void end();
        void error(GLenum errorCode);

    
        static void beginCallback(GLenum which, void* userData);
        static void vertexCallback(GLvoid *data, void* userData);
        static void combineCallback(GLdouble coords[3], void* vertex_data[4],
                              GLfloat weight[4], void** outData,
                              void* useData);
        static void endCallback(void* userData);
        static void errorCallback(GLenum errorCode, void* userData);
        
        
        struct Vec3d
        {
            double _v[3];
        };


        typedef std::vector<Vec3d*> Vec3dList;

        GLUtesselator*  _tobj;
        PrimList        _primList;
        Vec3dList       _coordData;
        GLenum          _errorCode;

};

}

#endif