/* -*-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 OSGTERRAIN_COORDINATESYSTEM
#define OSGTERRAIN_COORDINATESYSTEM 1

#include <osg/Object>
#include <osg/Vec2>
#include <osg/Vec3>

#include <osgTerrain/Export>

namespace osgTerrain
{

/** CoordinateSystem encapsulate the coordinate system that associated with objects in a scene.*/
class CoordinateSystem : public osg::Object
{
    public:

        enum Type
        {
            GEOCENTRIC,
            GEOGRAPHIC,
            PROJECTED
        };
        
        CoordinateSystem();

        CoordinateSystem(const std::string& WTK, Type type=GEOCENTRIC);

        /** Copy constructor using CopyOp to manage deep vs shallow copy.*/
        CoordinateSystem(const CoordinateSystem&,const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY);
        
        META_Object(osgTerrain,CoordinateSystem);
        
        inline bool operator == (const CoordinateSystem& cs) const
        {
            if (this == &cs) return true;
            if (_type!=cs._type) return false;
            if (_WKT != cs._WKT) return false;
            return true;
        }
        
        inline bool operator != (const CoordinateSystem& cs) const
        {
            return !(*this==cs);
        }
                
        void setType(Type type) { _type = type; }
        Type getType() const { return _type; }
        

        /** Set the CoordinateSystem reference string, should be stored in OpenGIS Well Know Text form.*/
        void setWKT(const std::string& WKT) { _WKT = WKT; }
        
        /** Get the CoordinateSystem reference string.*/
        const std::string& getWKT() const { return _WKT; }
        
        
        /** CoordinateTransformation is a helper class for transforming between two different CoodinateSystems.
          * To use, simply constructor a CoordinateSystem::CoordinateTransformation convertor(sourceCS,destinateCS)
          * and then convert indiviual points via v_destination = convert(v_source), or the
          * CoordinateTransformation.convert(ptr,num) method when handling arrays of Vec2/Vec3's.*/
        class CoordinateTransformation : public osg::Referenced
        {
            public:
            
                static CoordinateTransformation* createCoordinateTransformation(const CoordinateSystem& source, const CoordinateSystem& destination);
                
                static void setCoordinateTransformationPrototpe(CoordinateTransformation* ct);
                
                virtual osg::Vec2 operator () (const osg::Vec2& source) const = 0;
                virtual osg::Vec3 operator () (const osg::Vec3& source) const = 0;
                
                virtual bool transform(unsigned int numPoints, osg::Vec2* vec2ptr) const = 0;
                virtual bool transform(unsigned int numPoints, osg::Vec3* vec3ptr) const = 0;
                
            protected:
            
                CoordinateTransformation() {}
                virtual ~CoordinateTransformation() {}
                
                virtual CoordinateTransformation* cloneCoordinateTransformation(const CoordinateSystem& source, const CoordinateSystem& destination) const = 0;
                
        };
        
    protected:

        virtual ~CoordinateSystem() {}
                
        Type        _type;
        std::string _WKT;

};

}
#endif