88 lines
2.7 KiB
C++
88 lines
2.7 KiB
C++
/**********************************************************************
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*
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* GEOS - Geometry Engine Open Source
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* http://geos.osgeo.org
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*
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* Copyright (C) 2005-2006 Refractions Research Inc.
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* Copyright (C) 2001-2002 Vivid Solutions Inc.
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*
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* This is free software; you can redistribute and/or modify it under
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* the terms of the GNU Lesser General Public Licence as published
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* by the Free Software Foundation.
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* See the COPYING file for more information.
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*
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**********************************************************************
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*
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* Last port: linearref/LengthIndexOfPoint.java rev. 1.10
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*
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**********************************************************************/
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#pragma once
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#include <string>
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#include <geos/geom/Coordinate.h>
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#include <geos/geom/Geometry.h>
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#include <geos/geom/LineSegment.h>
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#include <geos/linearref/LinearLocation.h>
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namespace geos {
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namespace linearref { // geos::linearref
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/**
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* \brief
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* Computes the length index of the point
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* on a linear Geometry nearest a given Coordinate.
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*
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* The nearest point is not necessarily unique; this class
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* always computes the nearest point closest to
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* the start of the geometry.
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*/
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class LengthIndexOfPoint {
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private:
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const geom::Geometry* linearGeom;
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double indexOfFromStart(const geom::Coordinate& inputPt, const double minIndex) const;
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double segmentNearestMeasure(const geom::LineSegment* seg,
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const geom::Coordinate& inputPt,
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double segmentStartMeasure) const;
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public:
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static double indexOf(const geom::Geometry* linearGeom, const geom::Coordinate& inputPt);
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static double indexOfAfter(const geom::Geometry* linearGeom, const geom::Coordinate& inputPt, double minIndex);
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LengthIndexOfPoint(const geom::Geometry* linearGeom);
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/**
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* Find the nearest location along a linear Geometry to a given point.
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*
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* @param inputPt the coordinate to locate
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* @return the location of the nearest point
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*/
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double indexOf(const geom::Coordinate& inputPt) const;
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/** \brief
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* Finds the nearest index along the linear Geometry
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* to a given Coordinate after the specified minimum index.
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*
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* If possible the location returned will be strictly greater than the
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* <code>minLocation</code>.
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* If this is not possible, the
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* value returned will equal <code>minLocation</code>.
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* (An example where this is not possible is when
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* minLocation = [end of line] ).
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*
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* @param inputPt the coordinate to locate
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* @param minIndex the minimum location for the point location
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* @return the location of the nearest point
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*/
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double indexOfAfter(const geom::Coordinate& inputPt, double minIndex) const;
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};
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}
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}
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