DYT/Tool/OpenSceneGraph-3.6.5/include/geos/operation/buffer/BufferBuilder.h

/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 2009-2011 Sandro Santilli <strk@kbt.io>
 * Copyright (C) 2008-2010 Safe Software Inc.
 * Copyright (C) 2006-2007 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/buffer/BufferBuilder.java 149b38907 (JTS-1.12)
 *
 **********************************************************************/

#pragma once

#include <geos/export.h>

#include <vector>

#include <geos/operation/buffer/BufferOp.h> // for inlines (BufferOp enums)
#include <geos/operation/buffer/OffsetCurveBuilder.h> // for inline (OffsetCurveBuilder enums)
#include <geos/geomgraph/EdgeList.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 PrecisionModel;
class Geometry;
class GeometryFactory;
}
namespace algorithm {
class LineIntersector;
}
namespace noding {
class Noder;
class SegmentString;
class IntersectionAdder;
}
namespace geomgraph {
class Edge;
class Label;
class PlanarGraph;
}
namespace operation {
namespace buffer {
class BufferSubgraph;
}
namespace overlay {
class PolygonBuilder;
}
}
}

namespace geos {
namespace operation { // geos.operation
namespace buffer { // geos.operation.buffer

/**
 *
 * \brief
 * Builds the buffer geometry for a given input geometry and precision model.
 *
 * Allows setting the level of approximation for circular arcs,
 * and the precision model in which to carry out the computation.
 *
 * When computing buffers in floating point double-precision
 * it can happen that the process of iterated noding can fail to converge
 * (terminate).
 *
 * In this case a TopologyException will be thrown.
 * Retrying the computation in a fixed precision
 * can produce more robust results.
 *
 */
class GEOS_DLL BufferBuilder {

public:
    /**
     * Creates a new BufferBuilder
     *
     * @param nBufParams buffer parameters, this object will
     *                   keep a reference to the passed parameters
     *                   so caller must make sure the object is
     *                   kept alive for the whole lifetime of
     *                   the buffer builder.
     */
    BufferBuilder(const BufferParameters& nBufParams)
        :
        bufParams(nBufParams),
        workingPrecisionModel(nullptr),
        li(nullptr),
        intersectionAdder(nullptr),
        workingNoder(nullptr),
        geomFact(nullptr),
        edgeList(),
        isInvertOrientation(false)
    {}

    ~BufferBuilder();


    /**
     * Sets the precision model to use during the curve computation
     * and noding,
     * if it is different to the precision model of the Geometry.
     * If the precision model is less than the precision of the
     * Geometry precision model,
     * the Geometry must have previously been rounded to that precision.
     *
     * @param pm the precision model to use
     */
    void
    setWorkingPrecisionModel(const geom::PrecisionModel* pm)
    {
        workingPrecisionModel = pm;
    }

    /**
     * Sets the {@link noding::Noder} to use during noding.
     * This allows choosing fast but non-robust noding, or slower
     * but robust noding.
     *
     * @param newNoder the noder to use
     */
    void
    setNoder(noding::Noder* newNoder)
    {
        workingNoder = newNoder;
    }

    /**
    * Sets whether the offset curve is generated
    * using the inverted orientation of input rings.
    * This allows generating a buffer(0) polygon from the smaller lobes
    * of self-crossing rings.
    *
    * @param p_isInvertOrientation true if input ring orientation should be inverted
    */
    void
    setInvertOrientation(bool p_isInvertOrientation)
    {
        isInvertOrientation = p_isInvertOrientation;
    }


    std::unique_ptr<geom::Geometry> buffer(const geom::Geometry* g, double distance);

    /**
     * Generates offset curve for linear geometry.
     *
     * @param g non-areal geometry object
     * @param distance width of offset
     * @param leftSide controls on which side of the input geometry
     *        offset curve is generated.
     *
     * @note For left-side offset curve, the offset will be at the left side
     *       of the input line and retain the same direction.
     *       For right-side offset curve, it'll be at the right side
     *       and in the opposite direction.
     *
     * @note BufferParameters::setSingleSided parameter, which is specific to
     *       areal geometries only, is ignored by this routine.
     *
     * @note Not in JTS: this is a GEOS extension
     */
    std::unique_ptr<geom::Geometry> bufferLineSingleSided(
        const geom::Geometry* g,
        double distance, bool leftSide);

private:

    /**
     * Compute the change in depth as an edge is crossed from R to L
     */
    static int depthDelta(const geomgraph::Label& label);

    const BufferParameters& bufParams;

    const geom::PrecisionModel* workingPrecisionModel;

    algorithm::LineIntersector* li;

    noding::IntersectionAdder* intersectionAdder;

    noding::Noder* workingNoder;

    const geom::GeometryFactory* geomFact;

    geomgraph::EdgeList edgeList;

    std::vector<geomgraph::Label*> newLabels;

    bool isInvertOrientation;

    void computeNodedEdges(std::vector<noding::SegmentString*>& bufSegStr,
                           const geom::PrecisionModel* precisionModel);
    // throw(GEOSException);

    /**
     * Inserted edges are checked to see if an identical edge already
     * exists.
     * If so, the edge is not inserted, but its label is merged
     * with the existing edge.
     *
     * The function takes responsibility of releasing the Edge parameter
     * memory when appropriate.
     */
    void insertUniqueEdge(geomgraph::Edge* e);

    void createSubgraphs(geomgraph::PlanarGraph* graph,
                         std::vector<BufferSubgraph*>& list);

    /**
     * Completes the building of the input subgraphs by
     * depth-labelling them,
     * and adds them to the PolygonBuilder.
     * The subgraph list must be sorted in rightmost-coordinate order.
     *
     * @param subgraphList the subgraphs to build
     * @param polyBuilder the PolygonBuilder which will build
     *        the final polygons
     */
    void buildSubgraphs(const std::vector<BufferSubgraph*>& subgraphList,
                        overlay::PolygonBuilder& polyBuilder);

    /// \brief
    /// Return the externally-set noding::Noder OR a newly created
    /// one using the given precisionModel.
    ///
    /// NOTE: if an externally-set noding::Noder is available no
    /// check is performed to ensure it will use the
    /// given PrecisionModel
    ///
    noding::Noder* getNoder(const geom::PrecisionModel* precisionModel);


    /**
     * Gets the standard result for an empty buffer.
     * Since buffer always returns a polygonal result,
     * this is chosen to be an empty polygon.
     *
     * @return the empty result geometry, transferring ownership to caller.
     */
    std::unique_ptr<geom::Geometry> createEmptyResultGeometry() const;

    // Declare type as noncopyable
    BufferBuilder(const BufferBuilder& other) = delete;
    BufferBuilder& operator=(const BufferBuilder& rhs) = delete;
};

} // namespace geos::operation::buffer
} // namespace geos::operation
} // namespace geos

#ifdef _MSC_VER
#pragma warning(pop)
#endif