OGR: OGRPoint Class Reference

# OGRPoint Class Reference

`#include <ogr_geometry.h>`

Inheritance diagram for OGRPoint:

List of all members.

## Public Member Functions
| OGRPoint ()
virtual int | WkbSize () const
virtual OGRErr | importFromWkb (unsigned char *, int=-1)
virtual OGRErr | exportToWkb (OGRwkbByteOrder, unsigned char *) const
virtual OGRErr | importFromWkt (char **)
virtual OGRErr | exportToWkt (char **ppszDstText) const
virtual int | getDimension () const
virtual OGRGeometry * | clone () const
virtual void | empty ()
virtual void | getEnvelope (OGREnvelope *psEnvelope) const
virtual OGRBoolean | IsEmpty () const
double | getX () const
double | getY () const
double | getZ () const
virtual void | setCoordinateDimension (int nDimension)
void | setX (double xIn)
void | setY (double yIn)
void | setZ (double zIn)
virtual OGRBoolean | Equals (OGRGeometry *) const
virtual const char * | getGeometryName () const
virtual OGRwkbGeometryType | getGeometryType () const
virtual OGRErr | transform (OGRCoordinateTransformation *poCT)
virtual void | flattenTo2D ()

## Detailed Description

Point class.

Implements SFCOM IPoint methods.

## Constructor & Destructor Documentation

OGRPoint::OGRPoint | ( |  | ) |

Create a (0,0) point.

References empty().

Referenced by clone().

## Member Function Documentation

OGRGeometry * OGRPoint::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.

References OGRGeometry::assignSpatialReference(), OGRGeometry::getSpatialReference(), OGRPoint(), and setCoordinateDimension().

void OGRPoint::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.

Referenced by importFromWkt(), and OGRPoint().

OGRBoolean OGRPoint::Equals | ( | OGRGeometry * | poOtherGeom | ) | const`[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.

References getGeometryType(), OGRGeometry::getGeometryType(), getX(), getY(), and getZ().

OGRErr OGRPoint::exportToWkb | ( | OGRwkbByteOrder | eByteOrder,
|  | unsigned char * | pabyData |
| ) |  |  | 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().

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.

References getGeometryType().

OGRErr OGRPoint::exportToWkt | ( | char ** | ppszDstText | ) | 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.

Returns:
  Currently OGRERR_NONE is always returned.

Implements OGRGeometry.

void OGRPoint::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 OGRPoint::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.

void OGRPoint::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.

References getX(), and getY().

const char * OGRPoint::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.

OGRwkbGeometryType OGRPoint::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.

References wkbPoint, and wkbPoint25D.

Referenced by OGRPolygon::Centroid(), Equals(), exportToWkb(), and OGRPolygon::PointOnSurface().

double OGRPoint::getX | ( |  | ) | const`[inline]`

Fetch X coordinate.

Relates to the SFCOM IPoint::get_X() method.

Returns:
  the X coordinate of this point.

Referenced by OGRLineString::addPoint(), OGRPolygon::Centroid(), Equals(), OGRMultiPoint::exportToWkt(), OGRCurve::get_IsClosed(), getEnvelope(), OGRPolygon::PointOnSurface(), and OGRLineString::setPoint().

double OGRPoint::getY | ( |  | ) | const`[inline]`

Fetch Y coordinate.

Relates to the SFCOM IPoint::get_Y() method.

Returns:
  the Y coordinate of this point.

Referenced by OGRLineString::addPoint(), OGRPolygon::Centroid(), Equals(), OGRMultiPoint::exportToWkt(), OGRCurve::get_IsClosed(), getEnvelope(), OGRPolygon::PointOnSurface(), and OGRLineString::setPoint().

double OGRPoint::getZ | ( |  | ) | const`[inline]`

Fetch Z coordinate.

Relates to the SFCOM IPoint::get_Z() method.

Returns:
  the Z coordinate of this point, or zero if it is a 2D point.

Referenced by OGRLineString::addPoint(), Equals(), OGRMultiPoint::exportToWkt(), and OGRLineString::setPoint().

OGRErr OGRPoint::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.

References wkbPoint.

OGRErr OGRPoint::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.

References empty().

OGRBoolean OGRPoint::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.

Referenced by OGRMultiPoint::exportToWkt().

void OGRPoint::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.

Referenced by clone().

void OGRPoint::setX | ( | double | xIn | ) | `[inline]`

Assign point X coordinate.

There is no corresponding SFCOM method.

Referenced by OGRPolygon::Centroid(), OGRLineString::getPoint(), OGRPolygon::PointOnSurface(), and OGRLineString::Value().

void OGRPoint::setY | ( | double | yIn | ) | `[inline]`

Assign point Y coordinate.

There is no corresponding SFCOM method.

Referenced by OGRPolygon::Centroid(), OGRLineString::getPoint(), OGRPolygon::PointOnSurface(), and OGRLineString::Value().

void OGRPoint::setZ | ( | double | zIn | ) | `[inline]`

Assign point Z coordinate. Calling this method will force the geometry coordinate dimension to 3D (wkbPoint|wkbZ).

There is no corresponding SFCOM method.

Referenced by OGRLineString::getPoint(), and OGRLineString::Value().

OGRErr OGRPoint::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.

References OGRGeometry::assignSpatialReference(), OGRCoordinateTransformation::GetTargetCS(), and OGRCoordinateTransformation::Transform().

int OGRPoint::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:

- ogr_geometry.h
- ogrpoint.cpp

Generated for GDAL by 1.5.9.