Loonie3Func.java

/*
  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.EPSILON;
import static org.jwildfire.base.mathlib.MathLib.sqr;
import static org.jwildfire.base.mathlib.MathLib.sqrt;

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

public class Loonie3Func extends SimpleVariationFunc {
  private static final long serialVersionUID = 1L;

  @Override
  public void transform(FlameTransformationContext pContext, XForm pXForm, XYZPoint pAffineTP, XYZPoint pVarTP, double pAmount) {
    /* loonie2 by dark-beam, http://dark-beam.deviantart.com/art/Loonie2-update-2-Loonie3-457414891 */
    double r2 = 2 * _sqrvvar;
    if (pAffineTP.x > EPSILON) {
      r2 = sqr((sqr(pAffineTP.x) + sqr(pAffineTP.y)) / pAffineTP.x);
    }
    if (r2 < _sqrvvar) {
      double r = pAmount * sqrt(_sqrvvar / r2 - 1.0);
      pVarTP.x += r * pAffineTP.x;
      pVarTP.y += r * pAffineTP.y;
    }
    else {
      pVarTP.x += pAmount * pAffineTP.x;
      pVarTP.y += pAmount * pAffineTP.y;
    }

    if (pContext.isPreserveZCoordinate()) {
  pVarTP.z += pAmount * pAffineTP.z;
}

  }

  @Override
  public String getName() {
    return "loonie3";
  }

  private double _sqrvvar;

  @Override
  public void init(FlameTransformationContext pContext, Layer pLayer, XForm pXForm, double pAmount) {
    _sqrvvar = pAmount * pAmount;
  }

}