FilterNormal.h

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/* $Id: FilterNormal.h 35082 2011-02-22 19:30:37Z jesterking $
-----------------------------------------------------------------------------
This source file is part of blendTex library

Copyright (c) 2007 The Zdeno Ash Miklas

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.

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 Lesser General Public License for more details.

You should have received a copy of the GNU Lesser 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, or go to
http://www.gnu.org/copyleft/lesser.txt.
-----------------------------------------------------------------------------
*/

#if !defined FILTERNORMAL_H
#define FILTERNORMAL_H

#include "Common.h"

#include "FilterBase.h"


// scale constants for normals
const float depthScaleKoef = 255.0;
const float normScaleKoef = float(depthScaleKoef / 2.0);


class FilterNormal : public FilterBase
{
public:
        FilterNormal (void);
        virtual ~FilterNormal (void) {}

        unsigned short getColor (void) { return m_colIdx; }
        void setColor (unsigned short colIdx);

        float getDepth (void) { return m_depth; }
        void setDepth (float depth);

protected:
        float m_depth;
        float m_depthScale;

        unsigned short m_colIdx;

        template <class SRC> unsigned int tFilter (SRC * src, short x, short y,
                short * size, unsigned int pixSize, unsigned int val = 0)
        {
                // get value of required color
                int actPix = int(VT_C(val,m_colIdx));
                int upPix = actPix;
                int leftPix = actPix;
                // get upper and left pixel from actual pixel
                if (y > 0)
                {
                        val = convertPrevious(src - pixSize * size[0], x, y - 1, size, pixSize);
                        upPix = VT_C(val,m_colIdx);
                }
                if (x > 0)
                {
                        val = convertPrevious(src - pixSize, x - 1, y, size, pixSize);
                        leftPix = VT_C(val,m_colIdx);
                }
                // height differences (from blue color)
                float dx = (actPix - leftPix) * m_depthScale;
                float dy = (actPix - upPix) * m_depthScale;
                // normalize vector
                float dz = float(normScaleKoef / sqrt(dx * dx + dy * dy + 1.0));
                dx = dx * dz + normScaleKoef;
                dy = dy * dz + normScaleKoef;
                dz += normScaleKoef;
                // return normal vector converted to color
                VT_RGBA(val, dx, dy, dz, 0xFF);
                return val;
        }

        virtual unsigned int filter (unsigned char * src, short x, short y,
                short * size, unsigned int pixSize, unsigned int val = 0)
        { return tFilter(src, x, y, size, pixSize, val); }
        virtual unsigned int filter (unsigned int * src, short x, short y,
                short * size, unsigned int pixSize, unsigned int val = 0)
        { return tFilter(src, x, y, size, pixSize, val); }
};


#endif