/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2008 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 OSGVOLUME_tile
#define OSGVOLUME_tile 1

#include <osg/Group>
#include <osg/Image>

#include <osgDB/ReaderWriter>

#include <osgVolume/VolumeTechnique>

namespace osgVolume {

class Volume;

class TileID
{
    public:
    
        TileID():
            level(-1),
            x(-1),
            y(-1),
            z(-1) {}

        TileID(int in_level, int in_x, int in_y, int in_z):
            level(in_level),
            x(in_x),
            y(in_y),
            z(in_z) {}
            
        bool operator == (const TileID& rhs) const        
        {
            return (level==rhs.level) && (x==rhs.x) && (y==rhs.y) && (z==rhs.z);
        }

        bool operator != (const TileID& rhs) const        
        {
            return (level!=rhs.level) || (x!=rhs.x) || (y!=rhs.y) || (z!=rhs.z);
        }

        bool operator < (const TileID& rhs) const
        {
            if (level<rhs.level) return true;
            if (level>rhs.level) return false;
            if (x<rhs.x) return true;
            if (x>rhs.x) return false;
            if (y<rhs.y) return true;
            if (y>rhs.y) return false;
            return z<rhs.z;
        }
        
        bool valid() const { return level>=0; }

        int level;
        int x;
        int y;
        int z;
};


/** VolumeTile provides a framework for loosely coupling 3d image data with rendering algorithms.
  * This allows TerrainTechnique's to be plugged in at runtime.*/
class OSGVOLUME_EXPORT VolumeTile : public osg::Group
{
    public:

        VolumeTile();
        
        /** Copy constructor using CopyOp to manage deep vs shallow copy.*/
        VolumeTile(const VolumeTile&,const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY);

        META_Node(osgVolume, VolumeTile);

        virtual void traverse(osg::NodeVisitor& nv);

        /** Call init on any attached TerrainTechnique.*/
        void init();


        /** Set the Volume that this Volume tile is a member of.*/
        void setVolume(Volume* ts);

        /** Get the Volume that this Volume tile is a member of.*/
        Volume* getVolume() { return _volume; }

        /** Get the const Volume that this Volume tile is a member of.*/
        const Volume* getVolume() const { return _volume; }

        
        /** Set the TileID (layer, x,y,z) of the VolumeTile.
          * The TileID is used so it can be located by its neighbours 
          * via the enclosing Volume node that manages a map of TileID to VolumeTiles.*/
        void setTileID(const TileID& tileID);
        
        /** Get the TileID (layer, x,y,z) of the VolumeTile.*/
        const TileID& getTileID() const { return _tileID; }
        
        
        void setLocator(osg::RefMatrix* locator) { _locator = locator; }
        osg::RefMatrix* getLocator() { return _locator.get(); }
        const osg::RefMatrix* getLocator() const { return _locator.get(); }


        void setImage(unsigned int i, osg::Image* image);
        osg::Image* getImage(unsigned int i) { return i<_images.size() ? _images[i].get() : 0; }
        const osg::Image* getImage(unsigned int i) const  { return i<_images.size() ? _images[i].get() : 0; }

        /** Set the VolumeTechnique*/
        void setVolumeTechnique(VolumeTechnique* VolumeTechnique);

        /** Get the VolumeTechnique*/
        VolumeTechnique* getVolumeTechnique() { return _volumeTechnique.get(); }
        
        /** Get the const VolumeTechnique*/
        const VolumeTechnique* getVolumeTechnique() const { return _volumeTechnique.get(); }


        /** Set the dirty flag on/off.*/
        void setDirty(bool dirty);

        /** return true if the tile is dirty and needs to be updated,*/
        bool getDirty() const { return _dirty; }


        virtual osg::BoundingSphere computeBound() const;

    protected:

        virtual ~VolumeTile();

        friend class Volume;

        Volume*                             _volume;
        
        bool                                _dirty;
        bool                                _hasBeenTraversal;
        
        TileID                              _tileID;

        osg::ref_ptr<VolumeTechnique>       _volumeTechnique;

        osg::ref_ptr<osg::RefMatrix>        _locator;        

        typedef std::vector< osg::ref_ptr<osg::Image> > Images;
        Images                              _images;
};

}

#endif