/*
 * Copyright (c) 2016 Vivid Solutions.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * and Eclipse Distribution License v. 1.0 which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 *
 * http://www.eclipse.org/org/documents/edl-v10.php.
 */
package org.locationtech.jts.geom.prep;

import org.locationtech.jts.geom.Geometry;

/**
 * Computes the <tt>covers</tt> spatial relationship predicate
 * for a {@link PreparedPolygon} relative to all other {@link Geometry} classes.
 * Uses short-circuit tests and indexing to improve performance. 
 * <p>
 * It is not possible to short-circuit in all cases, in particular
 * in the case where the test geometry touches the polygon linework.
 * In this case full topology must be computed.
 * 
 * @author Martin Davis
 *
 */
class PreparedPolygonCovers 
	extends AbstractPreparedPolygonContains
{
	/**
	 * Computes the </tt>covers</tt> predicate between a {@link PreparedPolygon}
	 * and a {@link Geometry}.
	 * 
	 * @param prep the prepared polygon
	 * @param geom a test geometry
	 * @return true if the polygon covers the geometry
	 */
	public static boolean covers(PreparedPolygon prep, Geometry geom)
	{
    PreparedPolygonCovers polyInt = new PreparedPolygonCovers(prep);
    return polyInt.covers(geom);
	}

  /**
   * Creates an instance of this operation.
   * 
   * @param prepPoly the PreparedPolygon to evaluate
   */
	public PreparedPolygonCovers(PreparedPolygon prepPoly)
	{
		super(prepPoly);
		requireSomePointInInterior = false;
	}
		
	/**
	 * Tests whether this PreparedPolygon <tt>covers</tt> a given geometry.
	 * 
	 * @param geom the test geometry
	 * @return true if the test geometry is covered
	 */
	public boolean covers(Geometry geom)
	{
		return eval(geom);
	}
	
	/**
	 * Computes the full topological <tt>covers</tt> predicate.
	 * Used when short-circuit tests are not conclusive.
	 * 
	 * @param geom the test geometry
	 * @return true if this prepared polygon covers the test geometry
	 */
	protected boolean fullTopologicalPredicate(Geometry geom)
	{
		boolean result = prepPoly.getGeometry().covers(geom);
		return result;
	}
	
}