TargetFunc.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.M_2PI;
import static org.jwildfire.base.mathlib.MathLib.M_PI;
import static org.jwildfire.base.mathlib.MathLib.atan2;
import static org.jwildfire.base.mathlib.MathLib.cos;
import static org.jwildfire.base.mathlib.MathLib.fabs;
import static org.jwildfire.base.mathlib.MathLib.fmod;
import static org.jwildfire.base.mathlib.MathLib.log;
import static org.jwildfire.base.mathlib.MathLib.sin;
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 TargetFunc extends VariationFunc {
  private static final long serialVersionUID = 1L;

  private static final String PARAM_EVEN = "even";
  private static final String PARAM_ODD = "odd";
  private static final String PARAM_SIZE = "size";
  private static final String[] paramNames = { PARAM_EVEN, PARAM_ODD, PARAM_SIZE };

  private double even = -M_PI + Math.random() + M_2PI;
  private double odd = -M_PI + Math.random() + M_2PI;
  private double size = 0.5 + Math.random() * 0.75;

  @Override
  public void transform(FlameTransformationContext pContext, XForm pXForm, XYZPoint pAffineTP, XYZPoint pVarTP, double pAmount) {
    /* target by Michael Faber, http://michaelfaber.deviantart.com/art/Target-362520023?q=gallery%3Afractal-resources%2F24660058&qo=0 */
    double a = atan2(pAffineTP.y, pAffineTP.x);
    double r = sqrt(sqr(pAffineTP.x) + sqr(pAffineTP.y));
    double t = log(r);
    if (t < 0.0)
      t -= t_size_2;

    t = fmod(fabs(t), size);

    if (t < t_size_2)
      a += even;
    else
      a += odd;

    double s = sin(a);
    double c = cos(a);

    pVarTP.x += r * c;
    pVarTP.y += r * s;

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

  }

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

  @Override
  public Object[] getParameterValues() {
    return new Object[] { even, odd, size };
  }

  @Override
  public void setParameter(String pName, double pValue) {
    if (PARAM_EVEN.equalsIgnoreCase(pName))
      even = pValue;
    else if (PARAM_ODD.equalsIgnoreCase(pName))
      odd = pValue;
    else if (PARAM_SIZE.equalsIgnoreCase(pName))
      size = pValue;
    else
      throw new IllegalArgumentException(pName);
  }

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

  private double t_size_2;

  @Override
  public void init(FlameTransformationContext pContext, Layer pLayer, XForm pXForm, double pAmount) {
    t_size_2 = 0.5 * size;
  }

}