OGRGeometryFactory Class Reference

#include <ogr_geometry.h>

List of all members.

Static Public Member Functions

static OGRErr createFromWkb (unsigned char *, OGRSpatialReference *, OGRGeometry **, int=-1)
static OGRErr createFromWkt (char **, OGRSpatialReference *, OGRGeometry **)
static OGRGeometrycreateFromGML (const char *)
static void destroyGeometry (OGRGeometry *)
static OGRGeometrycreateGeometry (OGRwkbGeometryType)
static OGRGeometryforceToPolygon (OGRGeometry *)
static OGRGeometryforceToMultiPolygon (OGRGeometry *)
static OGRGeometryforceToMultiPoint (OGRGeometry *)
static OGRGeometryforceToMultiLineString (OGRGeometry *)
static int haveGEOS ()


Detailed Description

Create geometry objects from well known text/binary.


Member Function Documentation

OGRGeometry * OGRGeometryFactory::createFromGML const char *  pszData  )  [static]
 

Create geometry from GML.

This method translates a fragment of GML containing only the geometry portion into a corresponding OGRGeometry. There are many limitations on the forms of GML geometries supported by this parser, but they are too numerous to list here.

The C function OGR_G_CreateFromGML() is the same as this method.

Parameters:
pszData The GML fragment for the geometry.
Returns:
a geometry on succes, or NULL on error.

OGRErr OGRGeometryFactory::createFromWkb unsigned char *  pabyData,
OGRSpatialReference poSR,
OGRGeometry **  ppoReturn,
int  nBytes = -1
[static]
 

Create a geometry object of the appropriate type from it's well known binary representation.

Note that if nBytes is passed as zero, no checking can be done on whether the pabyData is sufficient. This can result in a crash if the input data is corrupt. This function returns no indication of the number of bytes from the data source actually used to represent the returned geometry object. Use OGRGeometry::WkbSize() on the returned geometry to establish the number of bytes it required in WKB format.

Also note that this is a static method, and that there is no need to instantiate an OGRGeometryFactory object.

The C function OGR_G_CreateFromWkb() is the same as this method.

Parameters:
pabyData pointer to the input BLOB data.
poSR pointer to the spatial reference to be assigned to the created geometry object. This may be NULL.
ppoReturn the newly created geometry object will be assigned to the indicated pointer on return. This will be NULL in case of failure.
nBytes the number of bytes available in pabyData, or zero if it isn't 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.

OGRErr OGRGeometryFactory::createFromWkt char **  ppszData,
OGRSpatialReference poSR,
OGRGeometry **  ppoReturn
[static]
 

Create a geometry object of the appropriate type from it's well known text representation.

The C function OGR_G_CreateFromWkt() is the same as this method.

Parameters:
ppszData input zero terminated string containing well known text representation of the geometry to be created. The pointer is updated to point just beyond that last character consumed.
poSR pointer to the spatial reference to be assigned to the created geometry object. This may be NULL.
ppoReturn the newly created geometry object will be assigned to the indicated pointer on return. This will be NULL if the method fails.
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.

OGRGeometry * OGRGeometryFactory::createGeometry OGRwkbGeometryType  eGeometryType  )  [static]
 

Create an empty geometry of desired type.

This is equivelent to allocating the desired geometry with new, but the allocation is guaranteed to take place in the context of the GDAL/OGR heap.

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

Parameters:
eGeometryType the type code of the geometry class to be instantiated.
Returns:
the newly create geometry or NULL on failure.

void OGRGeometryFactory::destroyGeometry OGRGeometry poGeom  )  [static]
 

Destroy geometry object.

Equivalent to invoking delete on a geometry, but it guaranteed to take place within the context of the GDAL/OGR heap.

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

Parameters:
poGeom the geometry to deallocate.

OGRGeometry * OGRGeometryFactory::forceToMultiLineString OGRGeometry poGeom  )  [static]
 

Convert to multilinestring.

Tries to force the provided geometry to be a multilinestring. Currently this just effects a change on linestrings. The passed in geometry is consumed and a new one returned (or potentially the same one).

Returns:
new geometry.

OGRGeometry * OGRGeometryFactory::forceToMultiPoint OGRGeometry poGeom  )  [static]
 

Convert to multipoint.

Tries to force the provided geometry to be a multipoint. Currently this just effects a change on points. The passed in geometry is consumed and a new one returned (or potentially the same one).

Returns:
new geometry.

OGRGeometry * OGRGeometryFactory::forceToMultiPolygon OGRGeometry poGeom  )  [static]
 

Convert to multipolygon.

Tries to force the provided geometry to be a multipolygon. Currently this just effects a change on polygons. The passed in geometry is consumed and a new one returned (or potentially the same one).

Returns:
new geometry.

OGRGeometry * OGRGeometryFactory::forceToPolygon OGRGeometry poGeom  )  [static]
 

Convert to polygon.

Tries to force the provided geometry to be a polygon. Currently this just effects a change on multipolygons. The passed in geometry is consumed and a new one returned (or potentially the same one).

Returns:
new geometry.

int OGRGeometryFactory::haveGEOS  )  [static]
 

Test if GEOS enabled.

This static method returns TRUE if GEOS support is built into OGR, otherwise it returns FALSE.

Returns:
TRUE if available, otherwise FALSE.


The documentation for this class was generated from the following files:
Generated on Mon Jan 9 18:03:32 2006 for OGR by  doxygen 1.4.6