DYT/Tool/OpenSceneGraph-3.6.5/include/geos/geomgraph/index/MonotoneChainEdge.h
2024-12-25 07:49:36 +08:00

86 lines
2.6 KiB
C++

/**********************************************************************
*
* 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.
*
**********************************************************************/
#pragma once
#include <geos/export.h>
#include <geos/geom/Envelope.h> // for composition
#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable: 4251) // warning C4251: needs to have dll-interface to be used by clients of class
#endif
// Forward declarations
namespace geos {
namespace geom {
class CoordinateSequence;
}
namespace geomgraph {
class Edge;
namespace index {
class SegmentIntersector;
}
}
}
namespace geos {
namespace geomgraph { // geos::geomgraph
namespace index { // geos::geomgraph::index
/// \brief MonotoneChains are a way of partitioning the segments of an edge to
/// allow for fast searching of intersections.
class GEOS_DLL MonotoneChainEdge {
public:
//MonotoneChainEdge();
~MonotoneChainEdge() = default;
MonotoneChainEdge(Edge* newE);
const geom::CoordinateSequence* getCoordinates();
std::vector<size_t>& getStartIndexes();
double getMinX(std::size_t chainIndex);
double getMaxX(std::size_t chainIndex);
void computeIntersects(const MonotoneChainEdge& mce,
SegmentIntersector& si);
void computeIntersectsForChain(std::size_t chainIndex0,
const MonotoneChainEdge& mce, std::size_t chainIndex1,
SegmentIntersector& si);
protected:
Edge* e;
const geom::CoordinateSequence* pts; // cache a reference to the coord array, for efficiency
// the lists of start/end indexes of the monotone chains.
// Includes the end point of the edge as a sentinel
std::vector<size_t> startIndex;
// these envelopes are created once and reused
private:
void computeIntersectsForChain(std::size_t start0, std::size_t end0,
const MonotoneChainEdge& mce,
std::size_t start1, std::size_t end1,
SegmentIntersector& ei);
bool overlaps(std::size_t start0, std::size_t end0, const MonotoneChainEdge& mce, std::size_t start1, std::size_t end1);
};
} // namespace geos.geomgraph.index
} // namespace geos.geomgraph
} // namespace geos
#ifdef _MSC_VER
#pragma warning(pop)
#endif