/*
  JWildfire - an image and animation processor written in Java 
  Copyright (C) 1995-2011 Andreas Maschke

  This 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 2.1 of the 
  License, or (at your option) any later version.
 
  This software 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 software; 
  if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jwildfire.create.tina.variation;

import static org.jwildfire.base.mathlib.MathLib.SMALL_EPSILON;
import static org.jwildfire.base.mathlib.MathLib.sqr;

import org.jwildfire.create.tina.base.Layer;
import org.jwildfire.create.tina.base.XForm;
import org.jwildfire.create.tina.base.XYZPoint;

public class PostCurlFunc extends VariationFunc {
  private static final long serialVersionUID = 1L;

  private static final String PARAM_C1 = "c1";
  private static final String PARAM_C2 = "c2";
  private static final String[] paramNames = { PARAM_C1, PARAM_C2 };

  private double c1 = 0;
  private double c2 = 0;

  @Override
  public void transform(FlameTransformationContext pContext, XForm pXForm, XYZPoint pAffineTP, XYZPoint pVarTP, double pAmount) {
    double x = pVarTP.x;
    double y = pVarTP.y;

    double re = 1 + _c1 * x + _c2 * (sqr(x) - sqr(y));
    double im = _c1 * y + _c22 * x * y;

    double r = sqr(re) + sqr(im) + SMALL_EPSILON;
    pVarTP.x = (x * re + y * im) / r;
    pVarTP.y = (y * re - x * im) / r;
  }

  @Override
  public String[] getParameterNames() {
    return paramNames;
  }

  @Override
  public Object[] getParameterValues() {
    return new Object[] { c1, c2 };
  }

  @Override
  public void setParameter(String pName, double pValue) {
    if (PARAM_C1.equalsIgnoreCase(pName))
      c1 = pValue;
    else if (PARAM_C2.equalsIgnoreCase(pName))
      c2 = pValue;
    else
      throw new IllegalArgumentException(pName);
  }

  @Override
  public String getName() {
    return "post_curl";
  }

  @Override
  public int getPriority() {
    return 1;
  }

  private double _c1, _c2, _c22;

  @Override
  public void init(FlameTransformationContext pContext, Layer pLayer, XForm pXForm, double pAmount) {
    _c1 = c1 * pAmount;
    _c2 = c2 * pAmount;
    _c22 = 2 * _c2;
  }

}