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filterswirl.cpp

/**********************************************************************************
* Copyright (c) 2003, Christoph Rueegg <opendev@cdrnet.ch> and Matthias Bader     *
* All rights reserved.                                                            *
*                                                                                 *
* Project Website: http://www.cdrnet.net/projects/painter/                        *
*                                                                                 *
* Redistribution and use in source and binary forms, with or without modification,*
* are permitted provided that the following conditions are met:                   *
*                                                                                 *
* 1. Redistributions of source code must retain the above copyright notice,       *
* this list of conditions and the following disclaimer.                           *
*                                                                                 *
* 2. Redistributions in binary form must reproduce the above copyright notice,    *
* this list of conditions and the following disclaimer in the documentation       *
* and/or other materials provided with the distribution.                          *
*                                                                                 *
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"     *
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE       *
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE      *
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE        *
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR             *
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF            *
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS        *
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN         *
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* THE POSSIBILITY OF SUCH DAMAGE.                                                 *
**********************************************************************************/

#include "filterswirl.h"
#include <cmath>

SwirlFilter::SwirlFilter() : StatefullTransformationFilter()
{
  shift = 0;
}

SwirlFilter::~SwirlFilter()
{
}

ChannelFilter<unsigned char>* SwirlFilter::EmptyClone()
{
  SwirlFilter *copy = new SwirlFilter();
  copy->SetSubChannel(StatefullTransformationFilter::GetSubChannel());
  return(copy);
}

void SwirlFilter::OnStart(Channel<unsigned char>* source, Channel<unsigned char>* target, int x, int y)
{
  height = target->GetHeight();
  width = target->GetWidth();
}

void SwirlFilter::OnEnd(Channel<unsigned char>* source, Channel<unsigned char>* target, int x0, int y0, int x1, int y1)
{
  int height = target->GetHeight();
  int width = target->GetWidth();
  for(int x=0;x<width;x++)
    for(int y=0;y<height;y++)
      source->Set(x,y,target->Get(x,y));  
}

bool SwirlFilter::OnRender(Channel<unsigned char>* source, Channel<unsigned char>* target, int x0, int y0, int x1, int y1)
{
  shift = shift+1%256;
  int kx,ky;
  for(int x=0;x<width;x++)
    for(int y=0;y<height;y++)
    {
      ky = (int)(y+sin((y-y1+shift)*16.0/height)*height/32.0);
      kx = (int)(x+sin((x-x1+shift)*16.0/width)*width/32.0);
      source->Normalize(&kx,&ky);
      target->Set(x,y,source->Get(kx,ky));
    }
  return(true);
}

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