libprocter/cparentmap.h

/***************************************************************************
                          CParentMap.h  -  Utility class to get map data from parent surfaces
                             -------------------
    begin                : zo apr 26 2009
    copyright            : (C) 2009 by CJP
    email                : cornware-cjp@users.sourceforge.net
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/
#ifndef LIBPROCTERCPARENTMAP_H
#define LIBPROCTERCPARENTMAP_H

#include <libprocter/cmap.h>
#include <libprocter/ctilesurface.h>

namespace libProcTer {

template<typename T>
class CParentMap
{
public:
        CParentMap(const CGridPosition &pos, const CTileSurface * const *parents, CTileSurface::eTextureType type);

        T *getLandel(int x, int y);

protected:
        CMap<T> *m_Maps[4];


        unsigned int m_dx, m_dy;
};


template<typename T>
CParentMap<T>::CParentMap(const CGridPosition &pos, const CTileSurface * const *parents, CTileSurface::eTextureType type)
{
        for(unsigned int i=0; i < 4; i++)
        {
                if(parents[i] == NULL)
                        {m_Maps[i] = NULL; continue;}

                m_Maps[i] = (CMap<T> *)(parents[i]->getInternalMap(type));
        }

        m_dx = 2*PROCTER_TEX_RES;
        m_dy = 2*PROCTER_TEX_RES;
        if(pos.u & 0x1) m_dx = PROCTER_TEX_RES;
        if(pos.v & 0x1) m_dy = PROCTER_TEX_RES;
}

template<typename T>
T *CParentMap<T>::getLandel(int x, int y)
{
        //Make relative to parent 0
        x += m_dx;
        y += m_dy;

        //Convert to parent scale
        x >>= 1;
        y >>= 1;

        //Select parent
        unsigned int parent_index = 0;
        if(x >= PROCTER_TEX_RES)
        {
                parent_index++;
                x -= PROCTER_TEX_RES;
        }
        if(y >= PROCTER_TEX_RES)
        {
                parent_index += 2;
                y -= PROCTER_TEX_RES;
        }

        CMap<T> *map = m_Maps[parent_index];
        if(map == NULL) return NULL;

        T *base = map->getData();
        if(base == NULL) return NULL;

        return base + (x + PROCTER_TEX_RES*y);
}

}

#endif

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