/*
  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.atan2;
import static org.jwildfire.base.mathlib.MathLib.cos;
import static org.jwildfire.base.mathlib.MathLib.pow;
import static org.jwildfire.base.mathlib.MathLib.sin;
import static org.jwildfire.base.mathlib.MathLib.sqr;

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

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

  private static final String PARAM_POWER = "power";
  private static final String PARAM_DIVISOR = "divisor";
  private static final String[] paramNames = { PARAM_POWER, PARAM_DIVISOR };

  private int power = genRandomPower();
  private int divisor = 2;

  @Override
  public void transform(FlameTransformationContext pContext, XForm pXForm, XYZPoint pAffineTP, XYZPoint pVarTP, double pAmount) {
    // post_juliaq by Zueuk, http://zueuk.deviantart.com/art/juliaq-Apophysis-plugins-340813357
    double a = atan2(pVarTP.y, pVarTP.x) * inv_power + pContext.random(Integer.MAX_VALUE) * inv_power_2pi;
    double sina = sin(a);
    double cosa = cos(a);
    double r = pAmount * pow(sqr(pVarTP.x) + sqr(pVarTP.y), half_inv_power);
    pVarTP.x += r * cosa;
    pVarTP.y += r * sina;
  }

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

  @Override
  public Object[] getParameterValues() {
    return new Object[] { power, divisor };
  }

  @Override
  public void setParameter(String pName, double pValue) {
    if (PARAM_POWER.equalsIgnoreCase(pName)) {
      power = Tools.FTOI(pValue);
    }
    else if (PARAM_DIVISOR.equalsIgnoreCase(pName))
      divisor = Tools.FTOI(pValue);
    else
      throw new IllegalArgumentException(pName);
  }

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

  private int genRandomPower() {
    int res = (int) (Math.random() * 5.0 + 2.5);
    return Math.random() < 0.5 ? res : -res;
  }

  private double half_inv_power, inv_power, inv_power_2pi;

  @Override
  public void init(FlameTransformationContext pContext, Layer pLayer, XForm pXForm, double pAmount) {
    half_inv_power = 0.5 * divisor / (double) power;
    inv_power = divisor / (double) power;
    inv_power_2pi = M_2PI / (double) power;
  }

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

}