OGR
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OGRPolygon Class Reference

#include <ogr_geometry.h>

Inheritance diagram for OGRPolygon:
OGRCurvePolygon OGRSurface OGRGeometry

Public Member Functions

 OGRPolygon ()
 Create an empty polygon.
 
virtual const char * getGeometryName () const
 Fetch WKT name for geometry type. More...
 
virtual OGRwkbGeometryType getGeometryType () const
 Fetch geometry type. More...
 
virtual OGRBoolean hasCurveGeometry (int bLookForNonLinear=FALSE) const
 Returns if this geometry is or has curve geometry. More...
 
virtual OGRGeometrygetCurveGeometry (const char *const *papszOptions=NULL) const
 Return curve version of this geometry. More...
 
virtual OGRGeometrygetLinearGeometry (double dfMaxAngleStepSizeDegrees=0, const char *const *papszOptions=NULL) const
 Return, possibly approximate, non-curve version of this geometry. More...
 
virtual int PointOnSurface (OGRPoint *poPoint) const
 This method relates to the SFCOM ISurface::get_PointOnSurface() method. More...
 
virtual int WkbSize () const
 Returns size of related binary representation. More...
 
virtual OGRErr importFromWkb (unsigned char *, int=-1, OGRwkbVariant=wkbVariantOldOgc)
 Assign geometry from well known binary data. More...
 
virtual OGRErr exportToWkb (OGRwkbByteOrder, unsigned char *, OGRwkbVariant=wkbVariantOldOgc) const
 Convert a geometry into well known binary format. More...
 
virtual OGRErr importFromWkt (char **)
 Assign geometry from well known text data. More...
 
virtual OGRErr exportToWkt (char **ppszDstText, OGRwkbVariant=wkbVariantOldOgc) const
 Convert a geometry into well known text format. More...
 
virtual OGRPolygonCurvePolyToPoly (double dfMaxAngleStepSizeDegrees=0, const char *const *papszOptions=NULL) const
 Return a polygon from a curve polygon. More...
 
OGRLinearRinggetExteriorRing ()
 Fetch reference to external polygon ring. More...
 
OGRLinearRinggetInteriorRing (int)
 Fetch reference to indicated internal ring. More...
 
OGRLinearRingstealExteriorRing ()
 "Steal" reference to external polygon ring. More...
 
OGRLinearRingstealInteriorRing (int)
 "Steal" reference to indicated interior ring. More...
 
virtual void closeRings ()
 Force rings to be closed. More...
 
- Public Member Functions inherited from OGRCurvePolygon
 OGRCurvePolygon ()
 Create an empty curve polygon.
 
virtual OGRGeometryclone () const
 Make a copy of this object. More...
 
virtual void empty ()
 Clear geometry information. This restores the geometry to it's initial state after construction, and before assignment of actual geometry. More...
 
virtual OGRErr transform (OGRCoordinateTransformation *poCT)
 Apply arbitrary coordinate transformation to geometry. More...
 
virtual void flattenTo2D ()
 Convert geometry to strictly 2D. In a sense this converts all Z coordinates to 0.0. More...
 
virtual OGRBoolean IsEmpty () const
 Returns TRUE (non-zero) if the object has no points. More...
 
virtual void segmentize (double dfMaxLength)
 Modify the geometry such it has no segment longer then the given distance. More...
 
virtual double get_Area () const
 Get the area of the surface object. More...
 
virtual int getDimension () const
 Get the dimension of this object. More...
 
virtual void getEnvelope (OGREnvelope *psEnvelope) const
 Computes and returns the bounding envelope for this geometry in the passed psEnvelope structure. More...
 
virtual void getEnvelope (OGREnvelope3D *psEnvelope) const
 Computes and returns the bounding envelope (3D) for this geometry in the passed psEnvelope structure. More...
 
virtual OGRBoolean Equals (OGRGeometry *) const
 Returns TRUE if two geometries are equivalent. More...
 
virtual OGRBoolean Intersects (const OGRGeometry *) const
 Do these features intersect? More...
 
virtual OGRBoolean Contains (const OGRGeometry *) const
 Test for containment. More...
 
virtual void setCoordinateDimension (int nDimension)
 Set the coordinate dimension. More...
 
OGRErr addRing (OGRCurve *)
 Add a ring to a polygon. More...
 
OGRErr addRingDirectly (OGRCurve *)
 Add a ring to a polygon. More...
 
OGRCurvegetExteriorRingCurve ()
 Fetch reference to external polygon ring. More...
 
int getNumInteriorRings () const
 Fetch the number of internal rings. More...
 
OGRCurvegetInteriorRingCurve (int)
 Fetch reference to indicated internal ring. More...
 
OGRCurvestealExteriorRingCurve ()
 "Steal" reference to external ring. More...
 
virtual void swapXY ()
 Swap x and y coordinates. More...
 
- Public Member Functions inherited from OGRGeometry
virtual int getCoordinateDimension () const
 Get the dimension of the coordinates in this object. More...
 
virtual OGRBoolean IsValid () const
 Test if the geometry is valid. More...
 
virtual OGRBoolean IsSimple () const
 Test if the geometry is simple. More...
 
virtual OGRBoolean IsRing () const
 Test if the geometry is a ring. More...
 
OGRwkbGeometryType getIsoGeometryType () const
 Get the geometry type that conforms with ISO SQL/MM Part3. More...
 
virtual void dumpReadable (FILE *, const char *=NULL, char **papszOptions=NULL) const
 Dump geometry in well known text format to indicated output file. More...
 
virtual char * exportToGML (const char *const *papszOptions=NULL) const
 Convert a geometry into GML format. More...
 
virtual char * exportToKML () const
 Convert a geometry into KML format. More...
 
virtual char * exportToJson () const
 Convert a geometry into GeoJSON format. More...
 
void assignSpatialReference (OGRSpatialReference *poSR)
 Assign spatial reference to this object. More...
 
OGRSpatialReferencegetSpatialReference (void) const
 Returns spatial reference system for object. More...
 
OGRErr transformTo (OGRSpatialReference *poSR)
 Transform geometry to new spatial reference system. More...
 
virtual OGRBoolean Disjoint (const OGRGeometry *) const
 Test for disjointness. More...
 
virtual OGRBoolean Touches (const OGRGeometry *) const
 Test for touching. More...
 
virtual OGRBoolean Crosses (const OGRGeometry *) const
 Test for crossing. More...
 
virtual OGRBoolean Within (const OGRGeometry *) const
 Test for containment. More...
 
virtual OGRBoolean Overlaps (const OGRGeometry *) const
 Test for overlap. More...
 
virtual OGRGeometryBoundary () const
 Compute boundary. More...
 
virtual double Distance (const OGRGeometry *) const
 Compute distance between two geometries. More...
 
virtual OGRGeometryConvexHull () const
 Compute convex hull. More...
 
virtual OGRGeometryBuffer (double dfDist, int nQuadSegs=30) const
 Compute buffer of geometry. More...
 
virtual OGRGeometryIntersection (const OGRGeometry *) const
 Compute intersection. More...
 
virtual OGRGeometryUnion (const OGRGeometry *) const
 Compute union. More...
 
virtual OGRGeometryUnionCascaded () const
 Compute union using cascading. More...
 
virtual OGRGeometryDifference (const OGRGeometry *) const
 Compute difference. More...
 
virtual OGRGeometrySymDifference (const OGRGeometry *) const
 Compute symmetric difference. More...
 
virtual OGRErr Centroid (OGRPoint *poPoint) const
 Compute the geometry centroid. More...
 
virtual OGRGeometrySimplify (double dTolerance) const
 Simplify the geometry. More...
 
OGRGeometrySimplifyPreserveTopology (double dTolerance) const
 Simplify the geometry while preserving topology. More...
 
virtual OGRGeometryPolygonize () const
 Polygonizes a set of sparse edges. More...
 
virtual OGRGeometrySymmetricDifference (const OGRGeometry *) const CPL_WARN_DEPRECATED("Non standard method. Use SymDifference() instead")
 Compute symmetric difference (deprecated) More...
 
virtual OGRGeometrygetBoundary () const CPL_WARN_DEPRECATED("Non standard method. Use Boundary() instead")
 Compute boundary (deprecated) More...
 

Static Protected Member Functions

static OGRCurvePolygonCastToCurvePolygon (OGRPolygon *poPoly)
 Cast to curve polygon. More...
 
- Static Protected Member Functions inherited from OGRCurvePolygon
static OGRPolygonCastToPolygon (OGRCurvePolygon *poCP)
 Convert to polygon. More...
 

Friends

class OGRMultiSurface
 

Additional Inherited Members

- Static Public Member Functions inherited from OGRSurface
static OGRPolygonCastToPolygon (OGRSurface *poSurface)
 Cast to polygon. More...
 
static OGRCurvePolygonCastToCurvePolygon (OGRSurface *poSurface)
 Cast to curve polygon. More...
 

Detailed Description

Concrete class representing polygons.

Note that the OpenGIS simple features polygons consist of one outer ring (linearring), and zero or more inner rings. A polygon cannot represent disconnected regions (such as multiple islands in a political body). The OGRMultiPolygon must be used for this.

Member Function Documentation

OGRCurvePolygon * OGRPolygon::CastToCurvePolygon ( OGRPolygon poPoly)
staticprotected

Cast to curve polygon.

The passed in geometry is consumed and a new one returned .

Parameters
poPolythe input geometry - ownership is passed to the method.
Returns
new geometry.

References OGRGeometry::assignSpatialReference(), OGRLinearRing::CastToLineString(), OGRGeometry::getCoordinateDimension(), OGRGeometry::getSpatialReference(), OGRCurvePolygon::OGRCurvePolygon(), and OGRCurvePolygon::setCoordinateDimension().

void OGRPolygon::closeRings ( )
virtual

Force rings to be closed.

If this geometry, or any contained geometries has polygon rings that are not closed, they will be closed by adding the starting point at the end.

Reimplemented from OGRGeometry.

References OGRGeometry::closeRings().

OGRPolygon * OGRPolygon::CurvePolyToPoly ( double  dfMaxAngleStepSizeDegrees = 0,
const char *const *  papszOptions = NULL 
) const
virtual

Return a polygon from a curve polygon.

This method is the same as C function OGR_G_CurvePolyToPoly().

The returned geometry is a new instance whose ownership belongs to the caller.

Parameters
dfMaxAngleStepSizeDegreesthe largest step in degrees along the arc, zero to use the default setting.
papszOptionsoptions as a null-terminated list of strings. Unused for now. Must be set to NULL.
Returns
a linestring
Since
OGR 2.0

Reimplemented from OGRCurvePolygon.

References OGRCurvePolygon::clone().

Referenced by OGRGeometryFactory::forceToMultiLineString(), OGRGeometryFactory::forceToMultiPolygon(), and OGRGeometryFactory::forceToPolygon().

OGRErr OGRPolygon::exportToWkb ( OGRwkbByteOrder  eByteOrder,
unsigned char *  pabyData,
OGRwkbVariant  eWkbVariant = wkbVariantOldOgc 
) const
virtual

Convert a geometry into well known binary format.

This method relates to the SFCOM IWks::ExportToWKB() method.

This method is the same as the C function OGR_G_ExportToWkb() or OGR_G_ExportToIsoWkb(), depending on the value of eWkbVariant.

Parameters
eByteOrderOne of wkbXDR or wkbNDR indicating MSB or LSB byte order respectively.
pabyDataa buffer into which the binary representation is written. This buffer must be at least OGRGeometry::WkbSize() byte in size.
eWkbVariantWhat standard to use when exporting geometries with three dimensions (or more). The default wkbVariantOldOgc is the historical OGR variant. wkbVariantIso is the variant defined in ISO SQL/MM and adopted by OGC for SFSQL 1.2.
Returns
Currently OGRERR_NONE is always returned.

Reimplemented from OGRCurvePolygon.

References OGRGeometry::getCoordinateDimension(), getGeometryType(), OGRGeometry::getIsoGeometryType(), and wkbVariantIso.

OGRErr OGRPolygon::exportToWkt ( char **  ppszDstText,
OGRwkbVariant  eWkbVariant = wkbVariantOldOgc 
) const
virtual

Convert a geometry into well known text format.

This method relates to the SFCOM IWks::ExportToWKT() method.

This method is the same as the C function OGR_G_ExportToWkt().

Parameters
ppszDstTexta text buffer is allocated by the program, and assigned to the passed pointer. After use, *ppszDstText should be freed with OGRFree().
eWkbVariantthe specification that must be conformed too :
  • wbkVariantOgc for old-style 99-402 extended dimension (Z) WKB types
  • wbkVariantIso for SFSQL 1.2 and ISO SQL/MM Part 3
Returns
Currently OGRERR_NONE is always returned.

Reimplemented from OGRCurvePolygon.

References CPLCalloc(), CPLDebug(), CPLStrdup(), OGRSimpleCurve::exportToWkt(), OGRGeometry::getCoordinateDimension(), getExteriorRing(), OGRSimpleCurve::getNumPoints(), OGRCurvePolygon::IsEmpty(), OGRSimpleCurve::setCoordinateDimension(), and wkbVariantIso.

Referenced by OGRGeometryFactory::organizePolygons().

OGRGeometry * OGRPolygon::getCurveGeometry ( const char *const *  papszOptions = NULL) const
virtual

Return curve version of this geometry.

Returns a geometry that has possibly CIRCULARSTRING, COMPOUNDCURVE, CURVEPOLYGON, MULTICURVE or MULTISURFACE in it, by de-approximating curve geometries.

If the geometry has no curve portion, the returned geometry will be a clone of it.

The ownership of the returned geometry belongs to the caller.

The reverse method is OGRGeometry::getLinearGeometry().

This function is the same as C function OGR_G_GetCurveGeometry().

Parameters
papszOptionsoptions as a null-terminated list of strings. Unused for now. Must be set to NULL.
Returns
a new geometry.
Since
GDAL 2.0

Reimplemented from OGRGeometry.

References OGRCurvePolygon::addRingDirectly(), OGRGeometry::assignSpatialReference(), OGRCurvePolygon::clone(), OGRGeometry::getCurveGeometry(), OGRGeometry::getGeometryType(), OGRGeometry::getSpatialReference(), OGRCurvePolygon::OGRCurvePolygon(), wkbFlatten, and wkbLineString.

OGRLinearRing * OGRPolygon::getExteriorRing ( )

Fetch reference to external polygon ring.

Note that the returned ring pointer is to an internal data object of the OGRPolygon. It should not be modified or deleted by the application, and the pointer is only valid till the polygon is next modified. Use the OGRGeometry::clone() method to make a separate copy within the application.

Relates to the SFCOM IPolygon::get_ExteriorRing() method.

Returns
pointer to external ring. May be NULL if the OGRPolygon is empty.

Referenced by OGRGeometryFactory::createFromFgf(), exportToWkt(), OGRGeometryFactory::forceToMultiLineString(), OGRGeometryFactory::forceToPolygon(), OGR_L_SetSpatialFilterRectEx(), and OGRGeometryFactory::organizePolygons().

const char * OGRPolygon::getGeometryName ( ) const
virtual

Fetch WKT name for geometry type.

There is no SFCOM analog to this method.

This method is the same as the C function OGR_G_GetGeometryName().

Returns
name used for this geometry type in well known text format. The returned pointer is to a static internal string and should not be modified or freed.

Reimplemented from OGRCurvePolygon.

OGRwkbGeometryType OGRPolygon::getGeometryType ( ) const
virtual

Fetch geometry type.

Note that the geometry type may include the 2.5D flag. To get a 2D flattened version of the geometry type apply the wkbFlatten() macro to the return result.

This method is the same as the C function OGR_G_GetGeometryType().

Returns
the geometry type code.

Reimplemented from OGRCurvePolygon.

References wkbPolygon, and wkbPolygon25D.

Referenced by exportToWkb().

OGRLinearRing * OGRPolygon::getInteriorRing ( int  iRing)

Fetch reference to indicated internal ring.

Note that the returned ring pointer is to an internal data object of the OGRPolygon. It should not be modified or deleted by the application, and the pointer is only valid till the polygon is next modified. Use the OGRGeometry::clone() method to make a separate copy within the application.

Relates to the SFCOM IPolygon::get_InternalRing() method.

Parameters
iRinginternal ring index from 0 to getNumInternalRings() - 1.
Returns
pointer to interior ring. May be NULL.

Referenced by OGRGeometryFactory::createFromFgf(), and OGRGeometryFactory::forceToMultiLineString().

OGRGeometry * OGRPolygon::getLinearGeometry ( double  dfMaxAngleStepSizeDegrees = 0,
const char *const *  papszOptions = NULL 
) const
virtual

Return, possibly approximate, non-curve version of this geometry.

Returns a geometry that has no CIRCULARSTRING, COMPOUNDCURVE, CURVEPOLYGON, MULTICURVE or MULTISURFACE in it, by approximating curve geometries.

The ownership of the returned geometry belongs to the caller.

The reverse method is OGRGeometry::getCurveGeometry().

This method is the same as the C function OGR_G_GetLinearGeometry().

Parameters
dfMaxAngleStepSizeDegreesthe largest step in degrees along the arc, zero to use the default setting.
papszOptionsoptions as a null-terminated list of strings. See OGRGeometryFactory::curveToLineString() for valid options.
Returns
a new geometry.
Since
GDAL 2.0

Reimplemented from OGRCurvePolygon.

References OGRGeometry::getLinearGeometry().

OGRBoolean OGRPolygon::hasCurveGeometry ( int  bLookForNonLinear = FALSE) const
virtual

Returns if this geometry is or has curve geometry.

Returns if a geometry is, contains or may contain a CIRCULARSTRING, COMPOUNDCURVE, CURVEPOLYGON, MULTICURVE or MULTISURFACE.

If bLookForNonLinear is set to TRUE, it will be actually looked if the geometry or its subgeometries are or contain a non-linear geometry in them. In which case, if the method returns TRUE, it means that getLinearGeometry() would return an approximate version of the geometry. Otherwise, getLinearGeometry() would do a conversion, but with just converting container type, like COMPOUNDCURVE -> LINESTRING, MULTICURVE -> MULTILINESTRING or MULTISURFACE -> MULTIPOLYGON, resulting in a "loss-less" conversion.

This method is the same as the C function OGR_G_HasCurveGeometry().

Parameters
bLookForNonLinearset it to TRUE to check if the geometry is or contains a CIRCULARSTRING.
Returns
TRUE if this geometry is or has curve geometry.
Since
GDAL 2.0

Reimplemented from OGRCurvePolygon.

OGRErr OGRPolygon::importFromWkb ( unsigned char *  pabyData,
int  nSize = -1,
OGRwkbVariant  eWkbVariant = wkbVariantOldOgc 
)
virtual

Assign geometry from well known binary data.

The object must have already been instantiated as the correct derived type of geometry object to match the binaries type. This method is used by the OGRGeometryFactory class, but not normally called by application code.

This method relates to the SFCOM IWks::ImportFromWKB() method.

This method is the same as the C function OGR_G_ImportFromWkb().

Parameters
pabyDatathe binary input data.
nSizethe size of pabyData in bytes, or zero if not known.
eWkbVariantif wkbVariantPostGIS1, special interpretation is done for curve geometries code
Returns
OGRERR_NONE if all goes well, otherwise any of OGRERR_NOT_ENOUGH_DATA, OGRERR_UNSUPPORTED_GEOMETRY_TYPE, or OGRERR_CORRUPT_DATA may be returned.

Reimplemented from OGRCurvePolygon.

OGRErr OGRPolygon::importFromWkt ( char **  ppszInput)
virtual

Assign geometry from well known text data.

The object must have already been instantiated as the correct derived type of geometry object to match the text type. This method is used by the OGRGeometryFactory class, but not normally called by application code.

This method relates to the SFCOM IWks::ImportFromWKT() method.

This method is the same as the C function OGR_G_ImportFromWkt().

Parameters
ppszInputpointer to a pointer to the source text. The pointer is updated to pointer after the consumed text.
Returns
OGRERR_NONE if all goes well, otherwise any of OGRERR_NOT_ENOUGH_DATA, OGRERR_UNSUPPORTED_GEOMETRY_TYPE, or OGRERR_CORRUPT_DATA may be returned.

Reimplemented from OGRCurvePolygon.

References CPLRealloc(), and OGRSimpleCurve::setPoints().

int OGRPolygon::PointOnSurface ( OGRPoint poPoint) const
virtual

This method relates to the SFCOM ISurface::get_PointOnSurface() method.

NOTE: Only implemented when GEOS included in build.

Parameters
poPointpoint to be set with an internal point.
Returns
OGRERR_NONE if it succeeds or OGRERR_FAILURE otherwise.

Reimplemented from OGRCurvePolygon.

References OGRPoint::empty(), OGRPoint::getX(), OGRPoint::getY(), OGRPoint::IsEmpty(), OGR_G_PointOnSurface(), OGRPoint::setX(), and OGRPoint::setY().

Referenced by OGRCurvePolygon::PointOnSurface().

OGRLinearRing * OGRPolygon::stealExteriorRing ( )

"Steal" reference to external polygon ring.

After the call to that function, only call to stealInteriorRing() or destruction of the OGRPolygon is valid. Other operations may crash.

Returns
pointer to external ring. May be NULL if the OGRPolygon is empty.

References OGRCurvePolygon::stealExteriorRingCurve().

Referenced by OGRGeometryFactory::forceToPolygon().

OGRLinearRing * OGRPolygon::stealInteriorRing ( int  iRing)

"Steal" reference to indicated interior ring.

After the call to that function, only call to stealInteriorRing() or destruction of the OGRPolygon is valid. Other operations may crash.

Parameters
iRinginternal ring index from 0 to getNumInternalRings() - 1.
Returns
pointer to interior ring. May be NULL.

Referenced by OGRGeometryFactory::forceToPolygon().

int OGRPolygon::WkbSize ( ) const
virtual

Returns size of related binary representation.

This method returns the exact number of bytes required to hold the well known binary representation of this geometry object. Its computation may be slightly expensive for complex geometries.

This method relates to the SFCOM IWks::WkbSize() method.

This method is the same as the C function OGR_G_WkbSize().

Returns
size of binary representation in bytes.

Reimplemented from OGRCurvePolygon.

References OGRGeometry::getCoordinateDimension().


The documentation for this class was generated from the following files:

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