simplegeometryprecisionreducer.h

在Linux下做的QuadTree的程序

/**********************************************************************
 * $Id: SimpleGeometryPrecisionReducer.h 1820 2006-09-06 16:54:23Z mloskot $
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.refractions.net
 *
 * Copyright (C) 2005-2006 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_PRECISION_SIMPLEGEOMETRYPRECISIONREDUCER_H
#define GEOS_PRECISION_SIMPLEGEOMETRYPRECISIONREDUCER_H


// Forward declarations
namespace geos {
	namespace geom { 
		class PrecisionModel;
		class Geometry;
	}
}

namespace geos {
namespace precision { // geos.precision

/** \brief
 * Reduces the precision of a {@link Geometry}
 * according to the supplied {@link PrecisionModel}, without
 * attempting to preserve valid topology.
 * 
 * The topology of the resulting geometry may be invalid if
 * topological collapse occurs due to coordinates being shifted.
 * It is up to the client to check this and handle it if necessary.
 * Collapses may not matter for some uses.  An example
 * is simplifying the input to the buffer algorithm.
 * The buffer algorithm does not depend on the validity of the input geometry.
 *
 */
class SimpleGeometryPrecisionReducer {

private:

	const geom::PrecisionModel *newPrecisionModel;

	bool removeCollapsed;

	//bool changePrecisionModel;

public:

	SimpleGeometryPrecisionReducer(const geom::PrecisionModel *pm);

	/**
	 * Sets whether the reduction will result in collapsed components
	 * being removed completely, or simply being collapsed to an (invalid)
	 * Geometry of the same type.
	 *
	 * @param removeCollapsed if <code>true</code> collapsed
	 * components will be removed
	 */
	void setRemoveCollapsedComponents(bool nRemoveCollapsed);

	/*
	 * Sets whether the {@link PrecisionModel} of the new reduced Geometry
	 * will be changed to be the {@link PrecisionModel} supplied to
	 * specify the reduction.  The default is to not change the
	 * precision model
	 *
	 * @param changePrecisionModel if <code>true</code> the precision
	 * model of the created Geometry will be the
	 * the precisionModel supplied in the constructor.
	 */
	//void setChangePrecisionModel(bool nChangePrecisionModel);

	const geom::PrecisionModel* getPrecisionModel();

	bool getRemoveCollapsed();
	geom::Geometry* reduce(const geom::Geometry *geom);
};

} // namespace geos.precision
} // namespace geos

#endif // GEOS_PRECISION_SIMPLEGEOMETRYPRECISIONREDUCER_H

/**********************************************************************
 * $Log$
 * Revision 1.2  2006/04/03 13:56:55  strk
 * Made externally-owned PrecisionModel  const
 *
 * Revision 1.1  2006/03/23 09:17:19  strk
 * precision.h header split, minor optimizations
 *
 **********************************************************************/