maphorizon3.cpp

使用stl技术,(还没看,是听说的)

/***************************************************************************
*                                                                         *
*   This program is free software; you can redistribute it and/or modify  *
*   it under the terms of the GNU Lesser General Public License as        *
*   published by the Free Software Foundation; either version 2 of the    *
*   License, or (at your option) any later version.                       *
*                                                                         *
***************************************************************************/
/**
@file 
MapHorizon3.cpp
@brief
Utility that pre-calculate horizon mapping for real-time
light mapping of terrain
*/
#include "MapUtil.h"
#include "MapHorizon3.h"
#include "OgrePagingLandScapeOptions.h"

#include <iostream>

namespace Ogre
{

MapHorizon3::MapHorizon3()
{   
    hMap = 0;
}
MapHorizon3::~MapHorizon3()
{
    if (hMap)
        delete[] hMap;   
}




void MapHorizon3::calcHorizonMap()
{
    uint W = MapUtil::getSingleton().getMapWidth ();
    uint H  = MapUtil::getSingleton().getMapHeight ();
    uint size = W*H;
    Real *LandZHorizonPos = new Real [size];
    Real *LandZHorizonNeg = new Real [size];

    memset (LandZHorizonPos, -1.0f, sizeof(Real) * size);

    Vector3 scale = PagingLandScapeOptions::getSingleton().scale;
    uchar *mHeightMapData = MapUtil::getSingleton().getHeightMapData ();

    uint curr_row = 0;
    for(uint nX = 0; nX < W; nX++)
    {
        for(uint nZ = 0; nZ < H; nZ++) 
        {
            uint nVert = curr_row + nZ;

            for(uint nZset = 0; nZset < H; nZset++) 
            {
                if(nZset != nZ)
                {
                    uint nVertSet = curr_row + nZset;

                    Real fDistY = (mHeightMapData[nVert] - mHeightMapData[nVertSet]) * scale.y;
                    Real fDistZ = (nZ - nZset) * scale.z;

                    assert(fDistZ != 0);

                    if(fDistZ > 0) 
                    {
                        Real fCosAngle = fDistY / Math::Sqrt(fDistY * fDistY + fDistZ * fDistZ);

                        if(LandZHorizonPos[nVertSet] < fCosAngle)
                            LandZHorizonPos[nVertSet] = fCosAngle;
                    } 
                    else 
                    {
                        Real fCosAngle = fDistY / Math::Sqrt(fDistY * fDistY + fDistZ * fDistZ);

                        if (LandZHorizonNeg[nVertSet] < fCosAngle)
                             LandZHorizonNeg[nVertSet] = fCosAngle;
                    }
                }
              }

        }
        curr_row += W;
    }
}


}//ogre namespace