meshnode.h

/*--License:
        Lilith 3D Engine
        Copyright Lee Thomason (Grinning Lizard Software) 2002-2004
        www.grinninglizard.com/lilith

        This program is free software; you can redistribute it and/or
        modify it under the terms of the GNU General Public License
        as published by the Free Software Foundation; either version 2
        of the License, or (at your option) any later version.

        This program 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
        GNU General Public License for more details.

        You should have received a copy of the GNU General Public License
        along with this program; if not, write to the Free Software
        Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

        The full text of the license can be found in license.txt
*/

#ifndef MESHNODE_INCLUDED
#define MESHNODE_INCLUDED

#include "../grinliz/gldebug.h"

namespace lilith3d
{

// The parent of an Mesh - and never anything else! Backcasting
// is used extensively.
class MeshNode
{
  public:
                
        MeshNode() : next(0), prev(0)   {} 
        virtual ~MeshNode()
        {
                // Make sure to take ourselves out of the container.
                if ( InList() ) ListRemove();
        }
        
        // The mesh is in a doubly linked list of things that might be drawn:
        MeshNode* next;                 
        MeshNode* prev;

        bool InList()           {       GLASSERT( !prev || (prev&&next) );
                                                        GLASSERT( !next || (prev&&next) );
                                                        return next != 0;
                                                }

        void ListRemove()       {       GLASSERT( prev );
                                                        GLASSERT( next );
                                                        prev->next = next;
                                                        next->prev = prev;
                                                        prev = next = 0;
                                                }
        void ListAddAfter( MeshNode* add )
                                                {
                                                        GLASSERT( add->next == 0 );
                                                        GLASSERT( add->prev == 0 );
                                                        if ( next )
                                                        {
                                                                next->prev = add;
                                                                add->next = next;
                                                        }
                                                        next = add;
                                                        add->prev = this;
                                                }
};

};

#endif

---