EVOLUTION-MANAGER

Edit File: LengthIndexOfPoint.h

/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 2005-2006 Refractions Research Inc.
 * Copyright (C) 2001-2002 Vivid Solutions 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.
 *
 **********************************************************************
 *
 * Last port: linearref/LengthIndexOfPoint.java rev. 1.10
 *
 **********************************************************************/

#ifndef GEOS_LINEARREF_LENGTHINDEXOFPOINT_H
#define GEOS_LINEARREF_LENGTHINDEXOFPOINT_H

#include <string>

#include <geos/geom/Coordinate.h>
#include <geos/geom/Geometry.h>
#include <geos/geom/LineSegment.h>
#include <geos/linearref/LinearLocation.h>

namespace geos {
namespace linearref { // geos::linearref

/**
 * \brief
 * Computes the length index of the point
 * on a linear Geometry nearest a given Coordinate.
 *
 * The nearest point is not necessarily unique; this class
 * always computes the nearest point closest to
 * the start of the geometry.
 */
class LengthIndexOfPoint {

private:
    const geom::Geometry* linearGeom;

double indexOfFromStart(const geom::Coordinate& inputPt, const double minIndex) const;

double segmentNearestMeasure(const geom::LineSegment* seg,
                                 const geom::Coordinate& inputPt,
                                 double segmentStartMeasure) const;
public:
    static double indexOf(const geom::Geometry* linearGeom, const geom::Coordinate& inputPt);

static double indexOfAfter(const geom::Geometry* linearGeom, const geom::Coordinate& inputPt, double minIndex);

LengthIndexOfPoint(const geom::Geometry* linearGeom);

/**
     * Find the nearest location along a linear Geometry to a given point.
     *
     * @param inputPt the coordinate to locate
     * @return the location of the nearest point
     */
    double indexOf(const geom::Coordinate& inputPt) const;

/** \brief
     * Finds the nearest index along the linear Geometry
     * to a given Coordinate after the specified minimum index.
     *
     * If possible the location returned will be strictly greater than the
     * <code>minLocation</code>.
     * If this is not possible, the
     * value returned will equal <code>minLocation</code>.
     * (An example where this is not possible is when
     * minLocation = [end of line] ).
     *
     * @param inputPt the coordinate to locate
     * @param minIndex the minimum location for the point location
     * @return the location of the nearest point
     */
    double indexOfAfter(const geom::Coordinate& inputPt, double minIndex) const;

};
}
}
#endif