/*
 * Open Source Physics software is free software as described near the bottom of this code file.
 *
 * For additional information and documentation on Open Source Physics please see: 
 * <http://www.opensourcephysics.org/>
 */

package org.opensourcephysics.sip.ch05;
import org.opensourcephysics.controls.*;
import org.opensourcephysics.frames.*;

/**
 * ThreeBodyApp models the three body problem by extending
 * AbstractSimulation and implementing the doStep method.
 *
 * @author Wolfgang Christian, Jan Tobochnik, Harvey Gould
 * @version 1.0
 */
public class ThreeBodyApp extends AbstractSimulation {
  PlotFrame frame = new PlotFrame("x", "y", "Three-Body Orbits");
  ThreeBody trajectory = new ThreeBody();

  /**
   * Constructs ThreeBodyApp and initializes the drawing.
   */
  public ThreeBodyApp() {
    frame.addDrawable(trajectory);
    frame.setSquareAspect(true);
    frame.setSize(450, 450);
  }

  /**
   * Initializes the simulation;
   */
  public void initialize() {
    trajectory.odeSolver.setStepSize(control.getDouble("dt"));
    trajectory.initialize(ThreeBodyInitialConditions.MONTGOMERY);
    frame.setPreferredMinMax(-1.5, 1.5, -1.5, 1.5);
  }

  /**
   * Resets the animation into a predefined state.
   */
  public void reset() {
    control.setValue("dt", 0.1);
    enableStepsPerDisplay(true);
    initialize();
  }

  /**
   * Does an animation step.
   */
  protected void doStep() {
    trajectory.doStep();
    frame.setMessage("t="+decimalFormat.format(trajectory.state[4]));
  }

  /**
   * Starts the Java application.
   * @param args  command line parameters
   */
  public static void main(String[] args) {
    SimulationControl.createApp(new ThreeBodyApp());
  }
}

/* 
 * Open Source Physics software is free software; you can redistribute
 * it and/or modify it under the terms of the GNU General Public License (GPL) as
 * published by the Free Software Foundation; either version 2 of the License,
 * or(at your option) any later version.

 * Code that uses any portion of the code in the org.opensourcephysics package
 * or any subpackage (subdirectory) of this package must must also be be released
 * under the GNU GPL license.
 *
 * 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston MA 02111-1307 USA
 * or view the license online at http://www.gnu.org/copyleft/gpl.html
 *
 * Copyright (c) 2007  The Open Source Physics project
 *                     http://www.opensourcephysics.org
 */
