/*
 *  Copyright (c) 2004 Cyrille Berger <cberger@cberger.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.
 *
 *  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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */
 
#include "kis_autobrush_resource.h"
#include <kdebug.h>

void KisAutobrushShape::createBrush( TQImage* img)
{
    img->create(m_w, m_h, 32);
    for(int j = 0; j < m_h; j++)
    {
        for(int i = 0; i < m_w; i++)
        {
            TQ_INT8 v = valueAt(i,j);
            img->setPixel( i, j, tqRgb(v,v,v));
        }
    }
}

KisAutobrushCircleShape::KisAutobrushCircleShape(TQ_INT32 w, TQ_INT32 h, double fh, double fv)
    : KisAutobrushShape( w, h, w / 2.0 - fh, h / 2.0 - fv),
        m_xcentre ( w / 2.0 ),
        m_ycentre ( h / 2.0 ),
        m_xcoef ( 2.0 / w ),
        m_ycoef ( 2.0 / h ),
        m_xfadecoef ( (m_fh == 0) ? 1 : ( 1.0 / m_fh)),
        m_yfadecoef ( (m_fv == 0) ? 1 : ( 1.0 / m_fv))
{
}
TQ_INT8 KisAutobrushCircleShape::valueAt(TQ_INT32 x, TQ_INT32 y)
{
    double xr = (x - m_xcentre) + 0.5;
    double yr = (y - m_ycentre) + 0.5;
    double n = norme( xr * m_xcoef, yr * m_ycoef);
    if( n > 1 )
    {
        return 255;
    }
    else
    {
        double normeFade = norme( xr * m_xfadecoef, yr * m_yfadecoef );
        if( normeFade > 1)
        {
            double xle, yle;
            // xle stands for x-coordinate limit exterior
            // yle stands for y-coordinate limit exterior
            // we are computing the coordinate on the external ellipse in order to compute
            // the fade value
            if( xr == 0 )
            {
                xle = 0;
                yle = yr > 0 ? 1/m_ycoef : -1/m_ycoef;
            } else {
                double c = yr / (double)xr;
                xle = sqrt(1 / norme( m_xcoef, c * m_ycoef ));
                xle = xr > 0 ? xle : -xle;
                yle = xle * c;
            }
            // On the internal limit of the fade area, normeFade is equal to 1
            double normeFadeLimitE = norme( xle * m_xfadecoef, yle * m_yfadecoef );
            return (uchar)(255 * ( normeFade - 1 ) / ( normeFadeLimitE - 1 ));
        } else {
            return 0;
        }
    }
}

KisAutobrushRectShape::KisAutobrushRectShape(TQ_INT32 w, TQ_INT32 h, double fh, double fv)
    : KisAutobrushShape( w, h, w / 2.0 - fh, h / 2.0 - fv),
        m_xcentre ( w / 2.0 ),
        m_ycentre ( h / 2.0 ),
        m_c( fv/fh)
{
}
TQ_INT8 KisAutobrushRectShape::valueAt(TQ_INT32 x, TQ_INT32 y)
{
    double xr = TQABS(x - m_xcentre);
    double yr = TQABS(y - m_ycentre);
    if( xr > m_fh || yr > m_fv )
    {
        if( yr <= ((xr - m_fh) * m_c + m_fv )  )
        {
            return (uchar)(255 * (xr - m_fh) / (m_w - m_fh));
        } else {
            return (uchar)(255 * (yr - m_fv) / (m_w - m_fv));
        }
    }
    else {
        return 0;
    }
}