A collection of 1 or more geometry objects. More...
#include <ogr_geometry.h>
Public Member Functions  
OGRGeometryCollection ()  
Create an empty geometry collection.  
OGRGeometryCollection (const OGRGeometryCollection &other)  
Copy constructor.  
OGRGeometryCollection &  operator= (const OGRGeometryCollection &other) 
Assignment operator.  
virtual const char *  getGeometryName () const 
Fetch WKT name for geometry type.  
virtual OGRwkbGeometryType  getGeometryType () const 
Fetch geometry type.  
virtual OGRGeometry *  clone () const 
Make a copy of this object.  
virtual void  empty () 
Clear geometry information.  
virtual OGRErr  transform (OGRCoordinateTransformation *poCT) 
Apply arbitrary coordinate transformation to geometry.  
virtual void  flattenTo2D () 
Convert geometry to strictly 2D.  
virtual OGRBoolean  IsEmpty () const 
Returns TRUE (nonzero) if the object has no points.  
virtual void  segmentize (double dfMaxLength) 
Add intermediate vertices to a geometry.  
virtual OGRBoolean  hasCurveGeometry (int bLookForNonLinear=FALSE) const 
virtual OGRGeometry *  getCurveGeometry (const char *const *papszOptions=NULL) const 
virtual OGRGeometry *  getLinearGeometry (double dfMaxAngleStepSizeDegrees=0, const char *const *papszOptions=NULL) const 
virtual int  WkbSize () const 
Returns size of related binary representation.  
virtual OGRErr  importFromWkb (unsigned char *, int=1, OGRwkbVariant=wkbVariantOldOgc) 
Assign geometry from well known binary data.  
virtual OGRErr  exportToWkb (OGRwkbByteOrder, unsigned char *, OGRwkbVariant=wkbVariantOldOgc) const 
Convert a geometry into well known binary format.  
virtual OGRErr  importFromWkt (char **) 
Assign geometry from well known text data.  
virtual OGRErr  exportToWkt (char **ppszDstText, OGRwkbVariant=wkbVariantOldOgc) const 
Convert a geometry into well known text format.  
virtual double  get_Length () const 
Compute the length of a multicurve.  
virtual double  get_Area () const 
Compute area of geometry collection.  
virtual int  getDimension () const 
Get the dimension of this object.  
virtual void  getEnvelope (OGREnvelope *psEnvelope) const 
Computes and returns the bounding envelope for this geometry in the passed psEnvelope structure.  
virtual void  getEnvelope (OGREnvelope3D *psEnvelope) const 
Computes and returns the bounding envelope (3D) for this geometry in the passed psEnvelope structure.  
int  getNumGeometries () const 
Fetch number of geometries in container.  
OGRGeometry *  getGeometryRef (int) 
Fetch geometry from container.  
const OGRGeometry *  getGeometryRef (int) const 
virtual OGRBoolean  Equals (OGRGeometry *) const 
Returns TRUE if two geometries are equivalent.  
virtual void  setCoordinateDimension (int nDimension) 
Set the coordinate dimension.  
virtual OGRErr  addGeometry (const OGRGeometry *) 
Add a geometry to the container.  
virtual OGRErr  addGeometryDirectly (OGRGeometry *) 
Add a geometry directly to the container.  
virtual OGRErr  removeGeometry (int iIndex, int bDelete=TRUE) 
Remove a geometry from the container.  
void  closeRings () 
Force rings to be closed.  
virtual void  swapXY () 
Swap x and y coordinates.  
Protected Member Functions  
OGRErr  exportToWktInternal (char **ppszDstText, OGRwkbVariant eWkbVariant, const char *pszSkipPrefix) const 
virtual OGRBoolean  isCompatibleSubType (OGRwkbGeometryType) const 
Static Protected Member Functions  
static OGRGeometryCollection *  TransferMembersAndDestroy (OGRGeometryCollection *poSrc, OGRGeometryCollection *poDst) 
Protected Attributes  
int  nGeomCount 
OGRGeometry **  papoGeoms 
A collection of 1 or more geometry objects.
All geometries must share a common spatial reference system, and Subclasses may impose additional restrictions on the contents.
OGRGeometryCollection::OGRGeometryCollection  (  const OGRGeometryCollection &  other  ) 
Copy constructor.
Note: before GDAL 2.1, only the default implementation of the constructor existed, which could be unsafe to use.
OGRErr OGRGeometryCollection::addGeometry  (  const OGRGeometry *  poNewGeom  )  [virtual] 
Add a geometry to the container.
Some subclasses of OGRGeometryCollection restrict the types of geometry that can be added, and may return an error. The passed geometry is cloned to make an internal copy.
There is no SFCOM analog to this method.
This method is the same as the C function OGR_G_AddGeometry().
poNewGeom  geometry to add to the container. 
OGRErr OGRGeometryCollection::addGeometryDirectly  (  OGRGeometry *  poNewGeom  )  [virtual] 
Add a geometry directly to the container.
Some subclasses of OGRGeometryCollection restrict the types of geometry that can be added, and may return an error. Ownership of the passed geometry is taken by the container rather than cloning as addGeometry() does.
This method is the same as the C function OGR_G_AddGeometryDirectly().
There is no SFCOM analog to this method.
poNewGeom  geometry to add to the container. 
OGRGeometry * OGRGeometryCollection::clone  (  )  const [virtual] 
Make a copy of this object.
This method relates to the SFCOM IGeometry::clone() method.
This method is the same as the C function OGR_G_Clone().
Implements OGRGeometry.
void OGRGeometryCollection::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.
void OGRGeometryCollection::empty  (  )  [virtual] 
Clear geometry information.
This restores the geometry to it's initial state after construction, and before assignment of actual geometry.
This method relates to the SFCOM IGeometry::Empty() method.
This method is the same as the C function OGR_G_Empty().
Implements OGRGeometry.
OGRBoolean OGRGeometryCollection::Equals  (  OGRGeometry *  poOtherGeom  )  const [virtual] 
Returns TRUE if two geometries are equivalent.
This method is the same as the C function OGR_G_Equals().
Implements OGRGeometry.
OGRErr OGRGeometryCollection::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.
eByteOrder  One of wkbXDR or wkbNDR indicating MSB or LSB byte order respectively.  
pabyData  a buffer into which the binary representation is written. This buffer must be at least OGRGeometry::WkbSize() byte in size.  
eWkbVariant  What 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. 
Implements OGRGeometry.
OGRErr OGRGeometryCollection::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().
ppszDstText  a text buffer is allocated by the program, and assigned to the passed pointer. After use, *ppszDstText should be freed with OGRFree().  
eWkbVariant  the specification that must be conformed too :

Implements OGRGeometry.
Reimplemented in OGRMultiSurface, OGRMultiPolygon, OGRMultiPoint, OGRMultiCurve, and OGRMultiLineString.
void OGRGeometryCollection::flattenTo2D  (  )  [virtual] 
Convert geometry to strictly 2D.
In a sense this converts all Z coordinates to 0.0.
This method is the same as the C function OGR_G_FlattenTo2D().
Implements OGRGeometry.
double OGRGeometryCollection::get_Area  (  )  const [virtual] 
Compute area of geometry collection.
The area is computed as the sum of the areas of all members in this collection.
double OGRGeometryCollection::get_Length  (  )  const [virtual] 
Compute the length of a multicurve.
The length is computed as the sum of the length of all members in this collection.
int OGRGeometryCollection::getDimension  (  )  const [virtual] 
Get the dimension of this object.
This method corresponds to the SFCOM IGeometry::GetDimension() method. It indicates the dimension of the object, but does not indicate the dimension of the underlying space (as indicated by OGRGeometry::getCoordinateDimension()).
This method is the same as the C function OGR_G_GetDimension().
Implements OGRGeometry.
Reimplemented in OGRMultiSurface, OGRMultiPoint, and OGRMultiCurve.
void OGRGeometryCollection::getEnvelope  (  OGREnvelope *  psEnvelope  )  const [virtual] 
Computes and returns the bounding envelope for this geometry in the passed psEnvelope structure.
This method is the same as the C function OGR_G_GetEnvelope().
psEnvelope  the structure in which to place the results. 
Implements OGRGeometry.
void OGRGeometryCollection::getEnvelope  (  OGREnvelope3D *  psEnvelope  )  const [virtual] 
Computes and returns the bounding envelope (3D) for this geometry in the passed psEnvelope structure.
This method is the same as the C function OGR_G_GetEnvelope3D().
psEnvelope  the structure in which to place the results. 
Implements OGRGeometry.
const char * OGRGeometryCollection::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().
Implements OGRGeometry.
Reimplemented in OGRMultiSurface, OGRMultiPolygon, OGRMultiPoint, OGRMultiCurve, and OGRMultiLineString.
OGRGeometry * OGRGeometryCollection::getGeometryRef  (  int  i  ) 
Fetch geometry from container.
This method returns a pointer to an geometry within the container. The returned geometry remains owned by the container, and should not be modified. The pointer is only valid untill the next change to the geometry container. Use IGeometry::clone() to make a copy.
This method relates to the SFCOM IGeometryCollection::get_Geometry() method.
i  the index of the geometry to fetch, between 0 and getNumGeometries()  1. 
OGRwkbGeometryType OGRGeometryCollection::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().
Implements OGRGeometry.
Reimplemented in OGRMultiSurface, OGRMultiPolygon, OGRMultiPoint, OGRMultiCurve, and OGRMultiLineString.
int OGRGeometryCollection::getNumGeometries  (  )  const 
Fetch number of geometries in container.
This method relates to the SFCOM IGeometryCollect::get_NumGeometries() method.
OGRErr OGRGeometryCollection::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().
pabyData  the binary input data.  
nSize  the size of pabyData in bytes, or zero if not known.  
eWkbVariant  if wkbVariantPostGIS1, special interpretation is done for curve geometries code 
Implements OGRGeometry.
OGRErr OGRGeometryCollection::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().
ppszInput  pointer to a pointer to the source text. The pointer is updated to pointer after the consumed text. 
Implements OGRGeometry.
Reimplemented in OGRMultiSurface, OGRMultiPoint, and OGRMultiCurve.
OGRBoolean OGRGeometryCollection::IsEmpty  (  )  const [virtual] 
Returns TRUE (nonzero) if the object has no points.
Normally this returns FALSE except between when an object is instantiated and points have been assigned.
This method relates to the SFCOM IGeometry::IsEmpty() method.
Implements OGRGeometry.
OGRGeometryCollection & OGRGeometryCollection::operator=  (  const OGRGeometryCollection &  other  ) 
Assignment operator.
Note: before GDAL 2.1, only the default implementation of the operator existed, which could be unsafe to use.
OGRErr OGRGeometryCollection::removeGeometry  (  int  iGeom,  
int  bDelete = TRUE  
)  [virtual] 
Remove a geometry from the container.
Removing a geometry will cause the geometry count to drop by one, and all "higher" geometries will shuffle down one in index.
There is no SFCOM analog to this method.
This method is the same as the C function OGR_G_RemoveGeometry().
iGeom  the index of the geometry to delete. A value of 1 is a special flag meaning that all geometries should be removed.  
bDelete  if TRUE the geometry will be deallocated, otherwise it will not. The default is TRUE as the container is considered to own the geometries in it. 
void OGRGeometryCollection::segmentize  (  double  dfMaxLength  )  [virtual] 
Add intermediate vertices to a geometry.
This method modifies the geometry to add intermediate vertices if necessary so that the maximum length between 2 consecutives vertices is lower than dfMaxLength.
dfMaxLength  maximum length between 2 consecutives vertices. 
Reimplemented from OGRGeometry.
void OGRGeometryCollection::setCoordinateDimension  (  int  nNewDimension  )  [virtual] 
Set the coordinate dimension.
This method sets the explicit coordinate dimension. Setting the coordinate dimension of a geometry to 2 should zero out any existing Z values. Setting the dimension of a geometry collection will not necessarily affect the children geometries.
nNewDimension  New coordinate dimension value, either 2 or 3. 
Reimplemented from OGRGeometry.
void OGRGeometryCollection::swapXY  (  )  [virtual] 
OGRErr OGRGeometryCollection::transform  (  OGRCoordinateTransformation *  poCT  )  [virtual] 
Apply arbitrary coordinate transformation to geometry.
This method will transform the coordinates of a geometry from their current spatial reference system to a new target spatial reference system. Normally this means reprojecting the vectors, but it could include datum shifts, and changes of units.
Note that this method does not require that the geometry already have a spatial reference system. It will be assumed that they can be treated as having the source spatial reference system of the OGRCoordinateTransformation object, and the actual SRS of the geometry will be ignored. On successful completion the output OGRSpatialReference of the OGRCoordinateTransformation will be assigned to the geometry.
This method is the same as the C function OGR_G_Transform().
poCT  the transformation to apply. 
Implements OGRGeometry.
int OGRGeometryCollection::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().
Implements OGRGeometry.