DYT/Tool/OpenSceneGraph-3.6.5/include/geos/operation/BoundaryOp.h

/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 2022 ISciences LLC
 *
 * 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/BoundaryOp.java fd5aebb
 *
 **********************************************************************/

#pragma once

#include <geos/algorithm/BoundaryNodeRule.h>
#include <geos/geom/Geometry.h>
#include <map>

namespace geos {
namespace geom {
class LineString;
class MultiLineString;
}
}

namespace geos {
namespace operation {

/**
 * Computes the boundary of a Geometry.
 * Allows specifying the BoundaryNodeRule to be used.
 * This operation will always return a Geometry of the appropriate
 * dimension for the boundary (even if the input geometry is empty).
 * The boundary of zero-dimensional geometries (Points) is
 * always the empty GeometryCollection.
 *
 * @author Martin Davis
 * @version 1.7
 */
class GEOS_DLL BoundaryOp {

public:
  /**
   * Creates a new instance for the given geometry.
   *
   * @param geom the input geometry
   */
  BoundaryOp(const geom::Geometry& geom);

  /**
   * Creates a new instance for the given geometry.
   *
   * @param geom the input geometry
   * @param bnRule the Boundary Node Rule to use
   */
  BoundaryOp(const geom::Geometry& geom, const algorithm::BoundaryNodeRule& bnRule);

 /**
   * Computes a geometry representing the boundary of a geometry.
   *
   * @param g the input geometry
   * @return the computed boundary
   */
  static std::unique_ptr<geom::Geometry> getBoundary(const geom::Geometry& g);

  /**
   * Computes a geometry representing the boundary of a geometry,
   * using an explicit BoundaryNodeRule.
   *
   * @param g the input geometry
   * @param bnRule the Boundary Node Rule to use
   * @return the computed boundary
   */
  static std::unique_ptr<geom::Geometry> getBoundary(const geom::Geometry& g, const algorithm::BoundaryNodeRule& bnRule);

  /**
   * Tests if a geometry has a boundary (it is non-empty).
   * The semantics are:
   * <ul>
   * <li>Empty geometries do not have boundaries.
   * <li>Points do not have boundaries.
   * <li>For linear geometries the existence of the boundary
   * is determined by the BoundaryNodeRule.
   * <li>Non-empty polygons always have a boundary.
   * </ul>
   *
   * @param geom the geometry providing the boundary
   * @param boundaryNodeRule  the Boundary Node Rule to use
   * @return true if the boundary exists
   */
  static bool hasBoundary(const geom::Geometry& geom, const algorithm::BoundaryNodeRule& boundaryNodeRule);

  /**
   * Gets the computed boundary.
   *
   * @return the boundary geometry
   */
  std::unique_ptr<geom::Geometry> getBoundary();

private:
  const geom::Geometry& m_geom;
  const geom::GeometryFactory& m_geomFact;
  const algorithm::BoundaryNodeRule& m_bnRule;

  std::unique_ptr<geom::Geometry> boundaryMultiLineString(const geom::MultiLineString& mLine);

  std::unique_ptr<geom::CoordinateSequence> computeBoundaryCoordinates(const geom::MultiLineString& mLine);

  std::unique_ptr<geom::Geometry> boundaryLineString(const geom::LineString& line);
};

}
}