LineSequencer.h

/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 2011 Sandro Santilli <strk@kbt.io>
 * 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.
 *
 **********************************************************************
 *
 * Last port: operation/linemerge/LineSequencer.java r378 (JTS-1.12)
 *
 **********************************************************************/

#ifndef GEOS_OP_LINEMERGE_LINESEQUENCER_H
#define GEOS_OP_LINEMERGE_LINESEQUENCER_H

#include <geos/export.h>

#include <geos/operation/linemerge/LineMergeGraph.h> // for composition
#include <geos/geom/Geometry.h> // for inlines
#include <geos/geom/LineString.h> // for inlines

#include <vector>
#include <list>
#include <memory> // for unique_ptr

#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 GeometryFactory;
class Geometry;
class LineString;
}
namespace planargraph {
class DirectedEdge;
class Subgraph;
class Node;
}
}


namespace geos {
namespace operation { // geos::operation
namespace linemerge { // geos::operation::linemerge

class GEOS_DLL LineSequencer {

private:
    typedef std::list<planargraph::DirectedEdge*> DirEdgeList;
    typedef std::vector< DirEdgeList* > Sequences;

    LineMergeGraph graph;
    const geom::GeometryFactory* factory;
    unsigned int lineCount;
    bool isRun;
    std::unique_ptr<geom::Geometry> sequencedGeometry;
    bool isSequenceableVar;

    void addLine(const geom::LineString* lineString);
    void computeSequence();
    Sequences* findSequences();
    DirEdgeList* findSequence(planargraph::Subgraph& graph);

    void delAll(Sequences&);

    static geom::LineString* reverse(const geom::LineString* line);

    geom::Geometry* buildSequencedGeometry(const Sequences& sequences);

    static const planargraph::Node* findLowestDegreeNode(
        const planargraph::Subgraph& graph);

    void addReverseSubpath(const planargraph::DirectedEdge* de,
                           DirEdgeList& deList,
                           DirEdgeList::iterator lit,
                           bool expectedClosed);

    static const planargraph::DirectedEdge* findUnvisitedBestOrientedDE(
        const planargraph::Node* node);

    DirEdgeList* orient(DirEdgeList* seq);

    DirEdgeList* reverse(DirEdgeList& seq);

    bool hasSequence(planargraph::Subgraph& graph);

public:

    static geom::Geometry*
    sequence(const geom::Geometry& geom)
    {
        LineSequencer sequencer;
        sequencer.add(geom);
        return sequencer.getSequencedLineStrings();
    }

    LineSequencer()
        :
        factory(nullptr),
        lineCount(0),
        isRun(false),
        sequencedGeometry(nullptr),
        isSequenceableVar(false)
    {}

    static bool isSequenced(const geom::Geometry* geom);

    bool
    isSequenceable()
    {
        computeSequence();
        return isSequenceableVar;
    }

    void
    add(const geom::Geometry& geometry)
    {
        geometry.applyComponentFilter(*this);
    }

    template <class TargetContainer>
    void
    add(TargetContainer& geoms)
    {
        for(typename TargetContainer::const_iterator i = geoms.begin(),
                e = geoms.end(); i != e; ++i) {
            const geom::Geometry* g = *i;
            add(*g);
        }
    }

    void
    filter(const geom::Geometry* g)
    {
        if(const geom::LineString* ls = dynamic_cast<const geom::LineString*>(g)) {
            addLine(ls);
        }
    }

    geom::Geometry*
    getSequencedLineStrings(bool release = 1)
    {
        computeSequence();
        if(release) {
            return sequencedGeometry.release();
        }
        else {
            return sequencedGeometry.get();
        }
    }
};

} // namespace geos::operation::linemerge
} // namespace geos::operation
} // namespace geos

#ifdef _MSC_VER
#pragma warning(pop)
#endif

#endif // GEOS_OP_LINEMERGE_LINESEQUENCER_H