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/**********************************************************************
*
* 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.
*
**********************************************************************
*
* Last port: geomgraph/Label.java r428 (JTS-1.12+)
*
**********************************************************************/
#ifndef GEOS_GEOMGRAPH_LABEL_H
#define GEOS_GEOMGRAPH_LABEL_H
#include <geos/export.h>
#include <geos/geom/Location.h>
#include <geos/geomgraph/TopologyLocation.h>
#include <geos/inline.h>
#include <iosfwd> // for operator<<
namespace geos {
namespace geomgraph { // geos.geomgraph
/** \brief
* A <code>Label</code> indicates the topological relationship of a component
* of a topology graph to a given <code>Geometry</code>.
*
* This class supports labels for relationships to two <code>Geometry</code>s,
* which is sufficient for algorithms for binary operations.
*
* Topology graphs support the concept of labeling nodes and edges in the graph.
* The label of a node or edge specifies its topological relationship to one or
* more geometries. (In fact, since JTS operations have only two arguments labels
* are required for only two geometries). A label for a node or edge has one or
* two elements, depending on whether the node or edge occurs in one or both of the
* input <code>Geometry</code>s. Elements contain attributes which categorize the
* topological location of the node or edge relative to the parent
* <code>Geometry</code>; that is, whether the node or edge is in the interior,
* boundary or exterior of the <code>Geometry</code>. Attributes have a value
* from the set <code>{Interior, Boundary, Exterior}</code>. In a node each
* element has a single attribute <code>&lt;On&gt;</code>. For an edge each element has a
* triplet of attributes <code>&lt;Left, On, Right&gt;</code>.
*
* It is up to the client code to associate the 0 and 1 <code>TopologyLocation</code>s
* with specific geometries.
*
*/
class GEOS_DLL Label {
public:
friend std::ostream& operator<< (std::ostream&, const Label&);
/** \brief
* Converts a Label to a Line label
* (that is, one with no side Locations)
*
*/
static Label toLineLabel(const Label& label);
/** \brief
* Construct a Label with a single location for both Geometries.
*/
Label(geom::Location onLoc);
/** \brief
* Construct a Label with the location specified
* for the given Geometry.
*
* Other geometry location will be set to
* Location::NONE.
*/
Label(uint32_t geomIndex, geom::Location onLoc);
/** \brief
* Construct a Label with On, Left and Right locations for both Geometries.
*
* Initialize the locations for both Geometries to the given values.
*/
Label(geom::Location onLoc, geom::Location leftLoc, geom::Location rightLoc);
/// Copy ctor
Label(const Label& l);
Label& operator= (const Label& l);
/** \brief
* Initialize both locations to Location::NONE
*
* isNull() should return true after this kind of construction
*/
Label();
/** \brief
* Construct a Label with On, Left and Right locations for the
* given Geometries.
* Initialize the locations for the other Geometry to
* Location::NONE
*/
Label(uint32_t geomIndex, geom::Location onLoc, geom::Location leftLoc, geom::Location rightLoc);
void flip();
geom::Location getLocation(uint32_t geomIndex, uint32_t posIndex) const;
geom::Location getLocation(uint32_t geomIndex) const;
void setLocation(uint32_t geomIndex, uint32_t posIndex, geom::Location location);
void setLocation(uint32_t geomIndex, geom::Location location);
void setAllLocations(uint32_t geomIndex, geom::Location location);
void setAllLocationsIfNull(uint32_t geomIndex, geom::Location location);
void setAllLocationsIfNull(geom::Location location);
/** \brief
* Merge this label with another one.
*
* Merging updates any null attributes of this label with the attributes
* from lbl
*/
void merge(const Label& lbl);
int getGeometryCount() const;
bool isNull() const;
bool isNull(uint32_t geomIndex) const;
bool isAnyNull(uint32_t geomIndex) const;
bool isArea() const;
bool isArea(uint32_t geomIndex) const;
bool isLine(uint32_t geomIndex) const;
bool isEqualOnSide(const Label& lbl, uint32_t side) const;
bool allPositionsEqual(uint32_t geomIndex, geom::Location loc) const;
/** \brief
* Converts one GeometryLocation to a Line location
*/
void toLine(uint32_t geomIndex);
std::string toString() const;
private:
TopologyLocation elt[2];
};
std::ostream& operator<< (std::ostream&, const Label&);
} // namespace geos.geomgraph
} // namespace geos
#ifdef GEOS_INLINE
# include "geos/geomgraph/Label.inl"
#endif
#endif // ifndef GEOS_GEOMGRAPH_LABEL_H