TriangulationProcess.java

/* Poly2Tri
 * Copyright (c) 2009-2010, Poly2Tri Contributors
 * http://code.google.com/p/poly2tri/
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * * Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 * * Neither the name of Poly2Tri nor the names of its contributors may be
 *   used to endorse or promote products derived from this software without specific
 *   prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.poly2tri.triangulation;

import java.util.ArrayList;
import java.util.List;

import org.poly2tri.Poly2Tri;
import org.poly2tri.geometry.polygon.Polygon;
import org.poly2tri.geometry.polygon.PolygonSet;
import org.poly2tri.triangulation.sets.ConstrainedPointSet;
import org.poly2tri.triangulation.sets.PointSet;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 
 * @author Thomas �hl�n, thahlen@gmail.com
 * 
 */
public class TriangulationProcess implements Runnable {
	private final static Logger logger = LoggerFactory
			.getLogger(TriangulationProcess.class);

	private TriangulationContext<?> _tcx;
	private TriangulationProcess _thread;
	private boolean _isTerminated = false;
	private int _pointCount = 0;
	private long _timestamp = 0;

	private boolean _awaitingTermination;
	private boolean _restart = false;

	private ArrayList<Triangulatable> _triangulations = new ArrayList<Triangulatable>();

	private ArrayList<TriangulationProcessListener> _listeners = new ArrayList<TriangulationProcessListener>();

	public void addListener(TriangulationProcessListener listener) {
		_listeners.add(listener);
	}

	public void removeListener(TriangulationProcessListener listener) {
		_listeners.remove(listener);
	}

	public void clearListeners() {
		_listeners.clear();
	}

	/**
	 * Notify all listeners of this new event
	 * @param event
	 */
	private void sendEvent(TriangulationProcessEvent event) {
		for (TriangulationProcessListener l : _listeners) {
			l.triangulationEvent(event, _tcx.getTriangulatable());
		}
	}

	public int getStepCount() {
		return _tcx.getStepCount();
	}

	public long getTimestamp() {
		return _timestamp;
	}

	public double getTriangulationTime() {
		return 0;
	}

	/**
	 * Uses SweepLine algorithm by default
	 * @param algorithm
	 */
	public TriangulationProcess() {
		this(TriangulationAlgorithm.DTSweep);
	}

	public TriangulationProcess(TriangulationAlgorithm algorithm) {
		//_algorithm = algorithm;
		_tcx = Poly2Tri.createContext(algorithm);
	}

	/**
	 * This retriangulates same set as previous triangulation
	 * useful if you want to do consecutive triangulations with 
	 * same data. Like when you when you want to do performance 
	 * tests.
	 */
	//    public void triangulate()
	//    {
	//        start();
	//    }

	/**
	 * Triangulate a PointSet with eventual constraints 
	 * 
	 * @param cps
	 */
	public void triangulate(PointSet ps) {
		_triangulations.clear();
		_triangulations.add(ps);
		start();
	}

	/**
	 * Triangulate a PointSet with eventual constraints 
	 * 
	 * @param cps
	 */
	public void triangulate(ConstrainedPointSet cps) {
		_triangulations.clear();
		_triangulations.add(cps);
		start();
	}

	/**
	 * Triangulate a PolygonSet
	 * 
	 * @param ps
	 */
	public void triangulate(PolygonSet ps) {
		_triangulations.clear();
		_triangulations.addAll(ps.getPolygons());
		start();
	}

	/**
	 * Triangulate a Polygon
	 * 
	 * @param ps
	 */
	public void triangulate(Polygon polygon) {
		_triangulations.clear();
		_triangulations.add(polygon);
		start();
	}

	/**
	 * Triangulate a List of Triangulatables
	 * 
	 * @param ps
	 */
	public void triangulate(List<Triangulatable> list) {
		_triangulations.clear();
		_triangulations.addAll(list);
		start();
	}

	private void start() {
		if (_thread == null /*|| _thread.getState() == State.TERMINATED*/) {
			_isTerminated = false;
			//			_thread = new Thread(this, _algorithm.name() + "."
			//					+ _tcx.getTriangulationMode());
			_thread = this;
			_thread.run();
			sendEvent(TriangulationProcessEvent.Started);
		} else {
			// Triangulation already running. Terminate it so we can start a new
			shutdown();
			_restart = true;
		}
	}

	public boolean isWaiting() {
		if (_thread != null) {
			return true;
		}
		return false;
	}

	public void run() {
		_pointCount = 0;
		try {
			for (Triangulatable t : _triangulations) {
				_tcx.clear();
				_tcx.prepareTriangulation(t);
				_pointCount += _tcx._points.size();
				Poly2Tri.triangulate(_tcx);
			}
			sendEvent(TriangulationProcessEvent.Done);
		} catch (RuntimeException e) {
			if (_awaitingTermination) {
				_awaitingTermination = false;
				logger.info("Thread[{}] : {}", _thread, e.getMessage());
				sendEvent(TriangulationProcessEvent.Aborted);
			} else {
				e.printStackTrace();
				sendEvent(TriangulationProcessEvent.Failed);
			}
		} catch (Exception e) {
			e.printStackTrace();
			logger.info("Triangulation exception {}", e.getMessage());
			sendEvent(TriangulationProcessEvent.Failed);
		} finally {
			_timestamp = System.currentTimeMillis();
			_isTerminated = true;
			_thread = null;
		}

		// Autostart a new triangulation?
		if (_restart) {
			_restart = false;
			start();
		}
	}

	public void resume() {
		if (_thread != null) {
			// Only force a resume when process is waiting for a notification
			/*if (_thread.getState() == State.WAITING) {
				synchronized (_tcx) {
					_tcx.notify();
				}
			} else if (_thread.getState() == State.TIMED_WAITING) {
				_tcx.waitUntilNotified(false);
			}*/
		}
	}

	public void shutdown() {
		_awaitingTermination = true;
		_tcx.terminateTriangulation();
		resume();
	}

	public TriangulationContext<?> getContext() {
		return _tcx;
	}

	public boolean isDone() {
		return _isTerminated;
	}

	public void requestRead() {
		//_tcx.waitUntilNotified(true);
	}

	public boolean isReadable() {
		if (_thread == null) {
			return true;
		} else {
			synchronized (_thread) {
				/*if (_thread.getState() == State.WAITING) {
					return true;
				} else if (_thread.getState() == State.TIMED_WAITING) {
					// Make sure that it stays readable
					//_tcx.waitUntilNotified(true);
					return true;
				}*/
				return false;
			}
		}
	}

	public int getPointCount() {
		return _pointCount;
	}
}