content: /**
   * This file is part of Aion-Lightning <aion-lightning.org>.
   *
   *  Aion-Lightning is free software: you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License as published by
   *  the Free Software Foundation, either version 3 of the License, or
   *  (at your option) any later version.
   *
   *  Aion-Lightning 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 Aion-Lightning.
   *  If not, see <http://www.gnu.org/licenses/>.
   */
  package com.aionemu.gameserver.model.geometry;
  
  import java.util.Collection;
  
  import com.aionemu.gameserver.configs.main.WorldConfig;
  import com.aionemu.gameserver.model.templates.zone.Point2D;
  import com.aionemu.gameserver.utils.MathUtil;
  import com.aionemu.gameserver.world.zone.ZoneName;
  
  /**
   * Area of free form
   *
   * @author SoulKeeper
   */
  public class PolyArea extends AbstractArea {
  
  	/**
  	 * Polygon used to calculate isInside()
  	 */
  	private final Polygon2D poly;
  
  	/**
  	 * Creates new area from given points
  	 *
  	 * @param points
  	 *            list of points
  	 * @param zMin
  	 *            minimal z
  	 * @param zMax
  	 *            maximal z
  	 */
  	public PolyArea(ZoneName zoneName, int worldId, Collection<Point2D> points, float zMin, float zMax) {
  		this(zoneName, worldId, points.toArray(new Point2D[points.size()]), zMin, zMax);
  	}
  
  	/**
  	 * Creates new area from given points
  	 *
  	 * @param points
  	 *            list of points
  	 * @param zMin
  	 *            minimal z
  	 * @param zMax
  	 *            maximal z
  	 */
  	public PolyArea(ZoneName zoneName, int worldId, Point2D[] points, float zMin, float zMax) {
  		super(zoneName, worldId, zMin, zMax);
  
  		if (points.length < 3) {
  			throw new IllegalArgumentException("Not enough points, needed at least 3 but got " + points.length);
  		}
  
  		float[] xPoints = new float[points.length];
  		float[] yPoints = new float[points.length];
  
  		for (int i = 0, n = points.length; i < n; i++) {
  			Point2D p = points[i];
  			xPoints[i] = p.getX();
  			yPoints[i] = p.getY();
  		}
  		this.poly = new Polygon2D(xPoints, yPoints, points.length);
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	@Override
  	public boolean isInside2D(float x, float y) {
  		return poly.contains(x, y);
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	@Override
  	public double getDistance2D(float x, float y) {
  		if (isInside2D(x, y)) {
  			return 0;
  		}
  		else {
  			Point2D cp = getClosestPoint(x, y);
  			return MathUtil.getDistance(cp.getX(), cp.getY(), x, y);
  		}
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	@Override
  	public double getDistance3D(float x, float y, float z) {
  		if (isInside3D(x, y, z)) {
  			return 0;
  		}
  		else if (isInsideZ(z)) {
  			return getDistance2D(x, y);
  		}
  		else {
  			Point3D cp = getClosestPoint(x, y, z);
  			return MathUtil.getDistance(cp.getX(), cp.getY(), cp.getZ(), x, y, z);
  		}
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	@Override
  	public Point2D getClosestPoint(float x, float y) {
  
  		Point2D closestPoint = null;
  		double closestDistance = 0;
  		for (int i = 0; i < poly.xpoints.length; i++) {
  			int nextIndex = i + 1;
  			if (nextIndex == poly.xpoints.length) {
  				nextIndex = 0;
  			}
  
  			float p1x = poly.xpoints[i];
  			float p1y = poly.ypoints[i];
  			float p2x = poly.xpoints[nextIndex];
  			float p2y = poly.ypoints[nextIndex];
  
  			Point2D point = MathUtil.getClosestPointOnSegment(p1x, p1y, p2x, p2y, x, y);
  
  			if (closestPoint == null) {
  				closestPoint = point;
  				closestDistance = MathUtil.getDistance(closestPoint.getX(), closestPoint.getY(), x, y);
  			}
  			else {
  				double newDistance = MathUtil.getDistance(point.getX(), point.getY(), x, y);
  				if (newDistance < closestDistance) {
  					closestPoint = point;
  					closestDistance = newDistance;
  				}
  			}
  		}
  
  		return closestPoint;
  	}
  
  	@Override
  	public boolean intersectsRectangle(RectangleArea area) {
  		if (area.getMinZ() > getMaxZ() || area.getMaxZ() < getMinZ()) {
  			return false;
  		}
  		return poly.intersects(area.getMinX(), area.getMinY(), WorldConfig.WORLD_REGION_SIZE, WorldConfig.WORLD_REGION_SIZE);
  	}
  }
  