Public Member Functions | Protected Member Functions | Static Protected Member Functions | Protected Attributes

OGRGeometryCollection Class Reference

A collection of 1 or more geometry objects. More...

#include <ogr_geometry.h>

Inheritance diagram for OGRGeometryCollection:
OGRGeometry OGRMultiCurve OGRMultiPoint OGRMultiSurface OGRMultiLineString OGRMultiPolygon

List of all members.

Public Member Functions

 OGRGeometryCollection ()
 Create an empty geometry collection.
virtual const char * getGeometryName () const
 Fetch WKT name for geometry type.
virtual OGRwkbGeometryType getGeometryType () const
 Fetch geometry type.
virtual OGRGeometryclone () 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 (non-zero) 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 OGRGeometrygetCurveGeometry (const char *const *papszOptions=NULL) const
virtual OGRGeometrygetLinearGeometry (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.
OGRGeometrygetGeometryRef (int)
 Fetch geometry from container.
const OGRGeometrygetGeometryRef (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 OGRGeometryCollectionTransferMembersAndDestroy (OGRGeometryCollection *poSrc, OGRGeometryCollection *poDst)

Protected Attributes

int nGeomCount
OGRGeometry ** papoGeoms

Detailed Description

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.


Member Function Documentation

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().

Parameters:
poNewGeom geometry to add to the container.
Returns:
OGRERR_NONE if successful, or OGRERR_UNSUPPORTED_GEOMETRY_TYPE if the geometry type is illegal for the type of geometry 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.

Parameters:
poNewGeom geometry to add to the container.
Returns:
OGRERR_NONE if successful, or OGRERR_UNSUPPORTED_GEOMETRY_TYPE if the geometry type is illegal for the type of geometry 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().

Returns:
a new object instance with the same geometry, and spatial reference system as the original.

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().

Returns:
TRUE if equivalent or FALSE otherwise.

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.

Parameters:
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.
Returns:
Currently OGRERR_NONE is always returned.

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().

Parameters:
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 :

  • 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.

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.

Note:
No warning will be issued if a member of the collection does not support the get_Area method.
Returns:
computed area.
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.

Note:
No warning will be issued if a member of the collection does not support the get_Length method.
Returns:
computed area.
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().

Returns:
0 for points, 1 for lines and 2 for surfaces.

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().

Parameters:
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().

Parameters:
psEnvelope the structure in which to place the results.
Since:
OGR 1.9.0

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().

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.

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.

Parameters:
i the index of the geometry to fetch, between 0 and getNumGeometries() - 1.
Returns:
pointer to requested geometry.
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().

Returns:
the geometry type code.

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.

Returns:
count of children geometries. May be zero.
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().

Parameters:
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
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.

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().

Parameters:
ppszInput pointer 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.

Implements OGRGeometry.

Reimplemented in OGRMultiSurface, OGRMultiPoint, and OGRMultiCurve.

OGRBoolean OGRGeometryCollection::IsEmpty (  )  const [virtual]

Returns TRUE (non-zero) 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.

Returns:
TRUE if object is empty, otherwise FALSE.

Implements OGRGeometry.

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().

Parameters:
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.
Returns:
OGRERR_NONE if successful, or OGRERR_FAILURE if the index is out of range.
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.

Parameters:
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.

Parameters:
nNewDimension New coordinate dimension value, either 2 or 3.

Reimplemented from OGRGeometry.

void OGRGeometryCollection::swapXY (  )  [virtual]

Swap x and y coordinates.

Since:
OGR 1.8.0

Reimplemented from OGRGeometry.

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().

Parameters:
poCT the transformation to apply.
Returns:
OGRERR_NONE on success or an error code.

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().

Returns:
size of binary representation in bytes.

Implements OGRGeometry.


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

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