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OGRGeometryCollection Class Reference

#include <ogr_geometry.h>

Inheritance diagram for OGRGeometryCollection:

OGRGeometry OGRMultiLineString OGRMultiPoint OGRMultiPolygon List of all members.

Public Member Functions

 OGRGeometryCollection ()
virtual const char * getGeometryName ()
virtual OGRwkbGeometryType getGeometryType ()
virtual OGRGeometryclone ()
virtual void empty ()
virtual OGRErr transform (OGRCoordinateTransformation *poCT)
virtual void flattenTo2D ()
virtual int WkbSize ()
virtual OGRErr importFromWkb (unsigned char *, int=-1)
virtual OGRErr exportToWkb (OGRwkbByteOrder, unsigned char *)
virtual OGRErr importFromWkt (char **)
virtual OGRErr exportToWkt (char **ppszDstText)
virtual int getDimension ()
virtual int getCoordinateDimension ()
virtual void getEnvelope (OGREnvelope *psEnvelope)
int getNumGeometries ()
OGRGeometrygetGeometryRef (int)
virtual OGRBoolean Equal (OGRGeometry *)
virtual OGRErr addGeometry (OGRGeometry *)
virtual OGRErr addGeometryDirectly (OGRGeometry *)
virtual OGRErr removeGeometry (int iIndex, int bDelete=TRUE)

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.


Constructor & Destructor Documentation

OGRGeometryCollection::OGRGeometryCollection  ) 
 

Create an empty geometry collection.


Member Function Documentation

OGRErr OGRGeometryCollection::addGeometry 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.

Reimplemented in OGRMultiPolygon, OGRMultiPoint, and OGRMultiLineString.

OGRGeometry * OGRGeometryCollection::clone  )  [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.

Reimplemented in OGRMultiPolygon, OGRMultiPoint, and OGRMultiLineString.

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::Equal OGRGeometry poOther  )  [virtual]
 

Returns two if two geometries are equivalent.

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

Returns:
TRUE if equivalent or FALSE otherwise.

Implements OGRGeometry.

OGRErr OGRGeometryCollection::exportToWkb OGRwkbByteOrder  eByteOrder,
unsigned char *  pabyData
[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().

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.
Returns:
Currently OGRERR_NONE is always returned.

Implements OGRGeometry.

OGRErr OGRGeometryCollection::exportToWkt char **  ppszDstText  )  [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.
Returns:
Currently OGRERR_NONE is always returned.

Implements OGRGeometry.

Reimplemented in OGRMultiPolygon, OGRMultiPoint, 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.

int OGRGeometryCollection::getCoordinateDimension  )  [virtual]
 

Get the dimension of the coordinates in this object.

This method corresponds to the SFCOM IGeometry::GetDimension() method.

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

Returns:
in practice this always returns 2 indicating that coordinates are specified within a two dimensional space.

Implements OGRGeometry.

int OGRGeometryCollection::getDimension  )  [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.

void OGRGeometryCollection::getEnvelope OGREnvelope psEnvelope  )  [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.

const char * OGRGeometryCollection::getGeometryName  )  [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 OGRMultiPolygon, OGRMultiPoint, 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  )  [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 OGRMultiPolygon, OGRMultiPoint, and OGRMultiLineString.

int OGRGeometryCollection::getNumGeometries  ) 
 

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
[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.
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 OGRMultiPolygon, OGRMultiPoint, and OGRMultiLineString.

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.

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  )  [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:
Generated on Thu Nov 13 00:06:52 2003 for OGR by doxygen 1.3.4