FilterSource.h

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/*
-----------------------------------------------------------------------------
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 FILTERSOURCE_H
#define FILTERSOURCE_H

#include "Common.h"

#include "FilterBase.h"


class FilterRGB24 : public FilterBase
{
public:
    FilterRGB24 (void) {}
    virtual ~FilterRGB24 (void) {}

    virtual unsigned int getPixelSize (void) { return 3; }

protected:
    virtual unsigned int filter (unsigned char * src, short x, short y,
        short * size, unsigned int pixSize, unsigned int val)
    { VT_RGBA(val,src[0],src[1],src[2],0xFF); return val; }
};

class FilterRGBA32 : public FilterBase
{
public:
    FilterRGBA32 (void) {}
    virtual ~FilterRGBA32 (void) {}

    virtual unsigned int getPixelSize (void) { return 4; }

protected:
    virtual unsigned int filter (unsigned char * src, short x, short y,
        short * size, unsigned int pixSize, unsigned int val)
    { 
        if ((intptr_t(src)&0x3) == 0) 
            return *(unsigned int*)src;
        else 
        {
            VT_RGBA(val,src[0],src[1],src[2],src[3]); 
            return val; 
        }
    }
};

class FilterBGR24 : public FilterBase
{
public:
    FilterBGR24 (void) {}
    virtual ~FilterBGR24 (void) {}

    virtual unsigned int getPixelSize (void) { return 3; }

protected:
    virtual unsigned int filter (unsigned char * src, short x, short y,
        short * size, unsigned int pixSize, unsigned int val)
    { VT_RGBA(val,src[2],src[1],src[0],0xFF); return val; }
};

class FilterYV12 : public FilterBase
{
public:
    FilterYV12 (void) {}
    virtual ~FilterYV12 (void) {}

    virtual unsigned int getPixelSize (void) { return 1; }

    void setBuffs (unsigned char * buff, short * size)
    {
        unsigned int buffSize = size[0] * size[1];
        m_buffV = buff + buffSize;
        m_buffU = m_buffV + (buffSize >> 2);
        m_pitchUV = size[0] >> 1;
    }

protected:
    unsigned char * m_buffV;
    unsigned char * m_buffU;
    short m_pitchUV;

    int interpol (int a, int b, int c, int d)
    { return (9 * (b + c) - a - d + 8) >> 4; }

    int interpolH (unsigned char * src)
    { return interpol(*(src-1), *src, *(src+1), *(src+2)); }

    int interpolV (unsigned char * src)
    { return interpol(*(src-m_pitchUV), *src, *(src+m_pitchUV), *(src+2*m_pitchUV)); }

    int interpolVH (unsigned char * src)
    {
        return interpol(interpolV(src-1), interpolV(src), interpolV(src+1),
            interpolV(src+2));
    }

    bool isEdge (short x, short y, short * size)
    { return x <= 1 || x >= size[0] - 4 || y <= 1 || y >= size[1] - 4; }

    unsigned char * interParA (unsigned char * src, short x, short size, short shift)
    { return x > 1 ? src - shift : src; }
    unsigned char * interParC (unsigned char * src, short x, short size, short shift)
    { return x < size - 2 ? src + shift : src; }
    unsigned char * interParD (unsigned char * src, short x, short size, short shift)
    { return x < size - 4 ? src + 2 * shift : x < size - 2 ? src + shift : src; }

    int interpolEH (unsigned char * src, short x, short size)
    { 
        return interpol(*interParA(src, x, size, 1), *src,
            *interParC(src, x, size, 1), *interParD(src, x, size, 1));
    }

    int interpolEV (unsigned char * src, short y, short size)
    { 
        return interpol(*interParA(src, y, size, m_pitchUV), *src,
            *interParC(src, y, size, m_pitchUV), *interParD(src, y, size, m_pitchUV));
    }

    int interpolEVH (unsigned char * src, short x, short y, short * size)
    {
        return interpol(interpolEV(interParA(src, x, size[0], 1), y, size[1]),
            interpolEV(src, y, size[1]), interpolEV(interParC(src, x, size[0], 1), y, size[1]),
            interpolEV(interParD(src, x, size[0], 1), y, size[1]));
    }


    virtual unsigned int filter (unsigned char * src, short x, short y,
        short * size, unsigned int pixSize, unsigned int val)
    {
        // V & U offset
        long offset = (x >> 1) + m_pitchUV * (y >> 1);
        // get modified YUV -> CDE: C = Y - 16; D = U - 128; E = V - 128
        int c = *src - 16;
        int d = m_buffU[offset] - 128;
        int e = m_buffV[offset] - 128;
        // if horizontal interpolation is needed
        if ((x & 1) == 1) {
            // if vertical interpolation is needed too
            if ((y & 1) == 1)
            {
                // if this pixel is on the edge
                if (isEdge(x, y, size))
                {
                    // get U & V from edge
                    d = interpolEVH(m_buffU + offset, x, y, size) - 128;
                    e = interpolEVH(m_buffV + offset, x, y, size) - 128;
                }
                // otherwise get U & V from inner range
                else
                {
                    d = interpolVH(m_buffU + offset) - 128;
                    e = interpolVH(m_buffV + offset) - 128;
                }
                // otherwise use horizontal interpolation only
            }
            else {
                // if this pixel is on the edge
                if (isEdge(x, y, size))
                {
                    // get U & V from edge
                    d = interpolEH(m_buffU + offset, x, size[0]) - 128;
                    e = interpolEH(m_buffV + offset, x, size[0]) - 128;
                }
                // otherwise get U & V from inner range
                else
                {
                    d = interpolH(m_buffU + offset) - 128;
                    e = interpolH(m_buffV + offset) - 128;
                }
                // otherwise if only vertical interpolation is needed
            }
        }
        else if ((y & 1) == 1) {
            // if this pixel is on the edge
            if (isEdge(x, y, size))
            {
                // get U & V from edge
                d = interpolEV(m_buffU + offset, y, size[1]) - 128;
                e = interpolEV(m_buffV + offset, y, size[1]) - 128;
            }
            // otherwise get U & V from inner range
            else
            {
                d = interpolV(m_buffU + offset) - 128;
                e = interpolV(m_buffV + offset) - 128;
            }
        }
        // convert to RGB
        // R = clip(( 298 * C           + 409 * E + 128) >> 8)
        // G = clip(( 298 * C - 100 * D - 208 * E + 128) >> 8)
        // B = clip(( 298 * C + 516 * D           + 128) >> 8)
        int red = (298 * c + 409 * e + 128) >> 8;
        if (red >= 0x100) red = 0xFF;
        else if (red < 0) red = 0;
        int green = (298 * c - 100 * d - 208 * e) >> 8;
        if (green >= 0x100) green = 0xFF;
        else if (green < 0) green = 0;
        int blue = (298 * c + 516 * d + 128) >> 8;
        if (blue >= 0x100) blue = 0xFF;
        else if (blue < 0) blue = 0;
        // return result
        VT_RGBA(val, red, green, blue, 0xFF);
        return val;
    }
};


#endif