/**********************************************************************
 * $Id: NodingValidator.h 1931 2006-12-05 09:59:04Z strk $
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.refractions.net
 *
 * Copyright (C) 2006      Refractions Research Inc.
 *
 * This is free software; you can redistribute and/or modify it under
 * the terms of the GNU Lesser General Public Licence as published
 * by the Free Software Foundation. 
 * See the COPYING file for more information.
 *
 **********************************************************************/

#ifndef GEOS_NODING_NODINGVALIDATOR_H
#define GEOS_NODING_NODINGVALIDATOR_H

#include <vector>
#include <iostream>

#include <geos/inline.h>

#include <geos/algorithm/LineIntersector.h>
//#include <geos/geom/Coordinate.h>

// Forward declarations
namespace geos {
	namespace geom {
		class Coordinate;
	}
	namespace noding {
		class SegmentString;
	}
}

namespace geos {
namespace noding { // geos.noding

/**
 * Validates that a collection of {@link SegmentString}s is correctly noded.
 * Throws a TopologyException if a noding error is found.
 *
 * Last port: noding/NodingValidator.java rev. 1.6 (JTS-1.7)
 *
 */
class NodingValidator {
private:
	algorithm::LineIntersector li;
	const std::vector<SegmentString*>& segStrings;

	/**
	 * Checks if a segment string contains a segment
	 * pattern a-b-a (which implies a self-intersection)
	 */
	void checkCollapses() const;

	void checkCollapses(const SegmentString& ss) const;

	void checkCollapse(const geom::Coordinate& p0, const geom::Coordinate& p1,
			const geom::Coordinate& p2) const;

	/**
	 * Checks all pairs of segments for intersections at an
	 * interior point of a segment
	 */
	void checkInteriorIntersections();

	void checkInteriorIntersections(const SegmentString& ss0,
			const SegmentString& ss1);

	void checkInteriorIntersections(
			const SegmentString& e0, unsigned int segIndex0,
			const SegmentString& e1, unsigned int segIndex1);

	/**
	 * Checks for intersections between an endpoint of a segment string
	 * and an interior vertex of another segment string
	 */
	void checkEndPtVertexIntersections() const;

	void checkEndPtVertexIntersections(const geom::Coordinate& testPt,
			const std::vector<SegmentString*>& segStrings) const;

	/**
	 * @return true if there is an intersection point which is not an
	 *         endpoint of the segment p0-p1
	 */
	bool hasInteriorIntersection(const algorithm::LineIntersector& aLi,
			const geom::Coordinate& p0, const geom::Coordinate& p1) const;

public:

	NodingValidator(const std::vector<SegmentString*>& newSegStrings):
		segStrings(newSegStrings)
	{}

	~NodingValidator() {}

	void checkValid();

};


} // namespace geos.noding
} // namespace geos

//#ifdef GEOS_INLINE
//# include "geos/noding/NodingValidator.inl"
//#endif

#endif // GEOS_NODING_NODINGVALIDATOR_H

/**********************************************************************
 * $Log$
 * Revision 1.2  2006/03/24 09:52:41  strk
 * USE_INLINE => GEOS_INLINE
 *
 * Revision 1.1  2006/03/09 16:46:49  strk
 * geos::geom namespace definition, first pass at headers split
 *
 **********************************************************************/

