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

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

  private static final String PARAM_XPOW = "xpow";
  private static final String PARAM_YPOW = "ypow";
  private static final String PARAM_ZPOW = "zpow";
  private static final String[] paramNames = { PARAM_XPOW, PARAM_YPOW, PARAM_ZPOW };

  private double xpow = 3.0;
  private double ypow = 3.0;
  private double zpow = 3.0;

  @Override
  public void transform(FlameTransformationContext pContext, XForm pXForm, XYZPoint pAffineTP, XYZPoint pVarTP, double pAmount) {
    // ho by Larry Berlin, http://aporev.deviantart.com/gallery/#/d2blmhg
    //    A Hyperbolic Octahedra
    //    As described in "CRC Concise Encyclopedia of Mathematics" by Weisstein 2nd ed.
    //
    //    f[u_, v_] = (Cos[u] * Cos[v])^3
    //    g[u_, v_] = (Sin[u] * Cos[v])^3
    //    h[u_, v_] = Sin[v]^3
    double u = pAffineTP.x;
    double v = pAffineTP.y;
    double w = pAffineTP.z;

    double at_omega_x = atan2(v * v, w * w);
    double at_omega_y = atan2(u * u, w * w);
    double sv = sin(v);
    double cv = cos(v);

    double su = sin(u);
    double cu = cos(u);

    double x = pow((cu * cv), xpow) + ((cu * cv) * xpow) + (0.25 * at_omega_x);
    double y = pow((su * cv), ypow) + ((su * cv) * ypow) + (0.25 * at_omega_y);
    double z = pow(sv, zpow) + sv * zpow;

    double rr = pAmount;

    pVarTP.x += rr * x;
    pVarTP.y += rr * y;
    pVarTP.z += rr * z;
  }

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

  @Override
  public Object[] getParameterValues() {
    return new Object[] { xpow, ypow, zpow };
  }

  @Override
  public void setParameter(String pName, double pValue) {
    if (PARAM_XPOW.equalsIgnoreCase(pName))
      xpow = pValue;
    else if (PARAM_YPOW.equalsIgnoreCase(pName))
      ypow = pValue;
    else if (PARAM_ZPOW.equalsIgnoreCase(pName))
      zpow = pValue;
    else
      throw new IllegalArgumentException(pName);
  }

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

}