Curl3DFunc.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 org.jwildfire.create.tina.base.Layer;
import org.jwildfire.create.tina.base.XForm;
import org.jwildfire.create.tina.base.XYZPoint;

public class Curl3DFunc extends VariationFunc {
  private static final long serialVersionUID = 1L;

  private static final String PARAM_CX = "cx";
  private static final String PARAM_CY = "cy";
  private static final String PARAM_CZ = "cz";
  private static final String[] paramNames = { PARAM_CX, PARAM_CY, PARAM_CZ };

  private double cx = 0;
  private double cy = 0.05;
  private double cz = 0.05;

  private double sqr(double pVal) {
    return pVal * pVal;
  }

  @Override
  public void transform(FlameTransformationContext pContext, XForm pXForm, XYZPoint pAffineTP, XYZPoint pVarTP, double pAmount) {
    double r2 = sqr(pAffineTP.x) + sqr(pAffineTP.y) + sqr(pAffineTP.z);
    double r = pAmount / (r2 * c2 + c2x * pAffineTP.x - c2y * pAffineTP.y + c2z * pAffineTP.z + 1);

    pVarTP.x += r * (pAffineTP.x + cx * r2);
    pVarTP.y += r * (pAffineTP.y - cy * r2);
    pVarTP.z += r * (pAffineTP.z + cz * r2);
  }

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

  @Override
  public Object[] getParameterValues() {
    return new Object[] { cx, cy, cz };
  }

  @Override
  public void setParameter(String pName, double pValue) {
    if (PARAM_CX.equalsIgnoreCase(pName))
      cx = pValue;
    else if (PARAM_CY.equalsIgnoreCase(pName))
      cy = pValue;
    else if (PARAM_CZ.equalsIgnoreCase(pName))
      cz = pValue;
    else
      throw new IllegalArgumentException(pName);
  }

  @Override
  public String getName() {
    return "curl3D";
  }

  private double c2x, c2y, c2z, c2;

  @Override
  public void init(FlameTransformationContext pContext, Layer pLayer, XForm pXForm, double pAmount) {
    c2x = 2 * cx;
    c2y = 2 * cy;
    c2z = 2 * cz;

    double cx2 = sqr(cx);
    double cy2 = sqr(cy);
    double cz2 = sqr(cz);

    c2 = cx2 + cy2 + cz2;
  }

}