ogrgeometry.cpp

mitab,读取MapInfo的地图文件

 * 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().
 *
 * @param poCT the transformation to apply.
 *
 * @return OGRERR_NONE on success or an error code.
 */

/************************************************************************/
/*                          OGR_G_Transform()                           */
/************************************************************************/
/**
 * Apply arbitrary coordinate transformation to geometry.
 *
 * This function 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 function 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 function is the same as the CPP method OGRGeometry::transform.
 *
 * @param hGeom handle on the geometry to apply the transform to.
 * @param hTransform handle on the transformation to apply.
 *
 * @return OGRERR_NONE on success or an error code.
 */

OGRErr OGR_G_Transform( OGRGeometryH hGeom, 
                        OGRCoordinateTransformationH hTransform )

{
    return ((OGRGeometry *) hGeom)->transform(
        (OGRCoordinateTransformation *) hTransform );
}

/**
 * \fn int OGRGeometry::getDimension() const;
 *
 * 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().
 *
 * @return 0 for points, 1 for lines and 2 for surfaces.
 */

/************************************************************************/
/*                         OGR_G_GetDimension()                         */
/************************************************************************/
/**
 *
 * Get the dimension of this geometry.
 *
 * This function corresponds to the SFCOM IGeometry::GetDimension() method.
 * It indicates the dimension of the geometry, but does not indicate the
 * dimension of the underlying space (as indicated by
 * OGR_G_GetCoordinateDimension() function).
 *
 * This function is the same as the CPP method OGRGeometry::getDimension().
 *
 * @param hGeom handle on the geometry to get the dimension from.
 * @return 0 for points, 1 for lines and 2 for surfaces.
 */

int OGR_G_GetDimension( OGRGeometryH hGeom )

{
    return ((OGRGeometry *) hGeom)->getDimension();
}

/************************************************************************/
/*                       getCoordinateDimension()                       */
/************************************************************************/
/**
 * 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().
 *
 * @return in practice this always returns 2 indicating that coordinates are
 * specified within a two dimensional space.
 */

int OGRGeometry::getCoordinateDimension() const

{
    return nCoordDimension;
}

/************************************************************************/
/*                    OGR_G_GetCoordinateDimension()                    */
/************************************************************************/
/**
 *
 * Get the dimension of the coordinates in this geometry.
 *
 * This function corresponds to the SFCOM IGeometry::GetDimension() method.
 *
 * This function is the same as the CPP method 
 * OGRGeometry::getCoordinateDimension().
 *
 * @param hGeom handle on the geometry to get the dimension of the 
 * coordinates from.
 * @return in practice this always returns 2 indicating that coordinates are
 * specified within a two dimensional space.
 */

int OGR_G_GetCoordinateDimension( OGRGeometryH hGeom )

{
    return ((OGRGeometry *) hGeom)->getCoordinateDimension();
}

/************************************************************************/
/*                       setCoordinateDimension()                       */
/************************************************************************/

/**
 * 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. 
 *
 * @param nNewDimension New coordinate dimension value, either 2 or 3.
 */

void OGRGeometry::setCoordinateDimension( int nNewDimension )

{
    nCoordDimension = nNewDimension;
}

/************************************************************************/
/*                    OGR_G_SetCoordinateDimension()                    */
/************************************************************************/

void OGR_G_SetCoordinateDimension( OGRGeometryH hGeom, int nNewDimension)

{
    ((OGRGeometry *) hGeom)->setCoordinateDimension( nNewDimension );
}


/**
 * \fn OGRBoolean OGRGeometry::IsEmpty() const;
 *
 * 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.
 *
 * NOTE: This method is hardcoded to return FALSE at this time.
 *
 * @return TRUE if object is empty, otherwise FALSE.
 */

/**
 * \fn OGRBoolean OGRGeometry::IsSimple() const;
 *
 * Returns TRUE if the geometry is simple.
 * 
 * Returns TRUE if the geometry has no anomalous geometric points, such
 * as self intersection or self tangency. The description of each
 * instantiable geometric class will include the specific conditions that
 * cause an instance of that class to be classified as not simple.
 *
 * This method relates to the SFCOM IGeometry::IsSimple() method.
 *
 * NOTE: This method is hardcoded to return TRUE at this time.
 *
 * @return TRUE if object is simple, otherwise FALSE.
 */

/**
 * \fn int OGRGeometry::Equals( OGRGeometry *poOtherGeom ) const;
 *
 * Returns two if two geometries are equivalent.
 *
 * This method is the same as the C function OGR_G_Equal().
 *
 * @return TRUE if equivalent or FALSE otherwise.
 */


// Backward compatibility method.

int OGRGeometry::Equal( OGRGeometry *poOtherGeom ) const
{
    return Equals( poOtherGeom );
}

/************************************************************************/
/*                            OGR_G_Equals()                            */
/************************************************************************/

/**
 * Returns two if two geometries are equivalent.
 *
 * This function is the same as the CPP method OGRGeometry::Equals() method.
 *
 * @param hGeom handle on the first geometry.
 * @param hOther handle on the other geometry to test against.
 * @return TRUE if equivalent or FALSE otherwise.
 */

int OGR_G_Equals( OGRGeometryH hGeom, OGRGeometryH hOther )

{
    return ((OGRGeometry *) hGeom)->Equals( (OGRGeometry *) hOther );
}

int OGR_G_Equal( OGRGeometryH hGeom, OGRGeometryH hOther )

{
    return ((OGRGeometry *) hGeom)->Equals( (OGRGeometry *) hOther );
}


/**
 * \fn int OGRGeometry::WkbSize() const;
 *
 * 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().
 *
 * @return size of binary representation in bytes.
 */

/************************************************************************/
/*                           OGR_G_WkbSize()                            */
/************************************************************************/
/**
 * Returns size of related binary representation.
 *
 * This function 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 function relates to the SFCOM IWks::WkbSize() method.
 *
 * This function is the same as the CPP method OGRGeometry::WkbSize().
 *
 * @param hGeom handle on the geometry to get the binary size from.
 * @return size of binary representation in bytes.
 */

int OGR_G_WkbSize( OGRGeometryH hGeom )

{
    return ((OGRGeometry *) hGeom)->WkbSize();
}

/**
 * \fn void OGRGeometry::getEnvelope(OGREnvelope *psEnvelope) const;
 *
 * 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().
 *
 * @param psEnvelope the structure in which to place the results.
 */

/************************************************************************/
/*                         OGR_G_GetEnvelope()                          */
/************************************************************************/
/**
 * Computes and returns the bounding envelope for this geometry in the
 * passed psEnvelope structure.
 *
 * This function is the same as the CPP method OGRGeometry::getEnvelope().
 *
 * @param hGeom handle of the geometry to get envelope from.
 * @param psEnvelope the structure in which to place the results.
 */

void OGR_G_GetEnvelope( OGRGeometryH hGeom, OGREnvelope *psEnvelope )

{
    ((OGRGeometry *) hGeom)->getEnvelope( psEnvelope );
}

/**
 * \fn OGRErr OGRGeometry::importFromWkb( unsigned char * pabyData, int nSize);
 *
 * 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().
 *
 * @param pabyData the binary input data.
 * @param nSize the size of pabyData in bytes, or zero if not known.
 *
 * @return OGRERR_NONE if all goes well, otherwise any of
 * OGRERR_NOT_ENOUGH_DATA, OGRERR_UNSUPPORTED_GEOMETRY_TYPE, or
 * OGRERR_CORRUPT_DATA may be returned.
 */

/************************************************************************/
/*                        OGR_G_ImportFromWkb()                         */
/************************************************************************/
/**
 * 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 function relates to the SFCOM IWks::ImportFromWKB() method.
 *
 * This function is the same as the CPP method OGRGeometry::importFromWkb().
 *
 * @param hGeom handle on the geometry to assign the well know binary data to.
 * @param pabyData the binary input data.
 * @param nSize the size of pabyData in bytes, or zero if not known.
 *
 * @return 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 OGR_G_ImportFromWkb( OGRGeometryH hGeom, 
                            unsigned char *pabyData, int nSize )

{
    return ((OGRGeometry *) hGeom)->importFromWkb( pabyData, nSize );
}

/**
 * \fn OGRErr OGRGeometry::exportToWkb( OGRwkbByteOrder eByteOrder,
                                        unsigned char * pabyData ) const;
 *
 * 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().
 *
 * @param eByteOrder One of wkbXDR or wkbNDR indicating MSB or LSB byte order
 *               respectively.
 * @param pabyData a buffer into which the binary representation is
 *                      written.  This buffer must be at least
 *                      OGRGeometry::WkbSize() byte in size.
 *
 * @return Currently OGRERR_NONE is always returned.
 */

/************************************************************************/
/*                         OGR_G_ExportToWkb()                          */
/************************************************************************/
/**
 * Convert a geometry into well known binary format.
 *
 * This function relates to the SFCOM IWks::ExportToWKB() method.
 *
 * This function is the same as the CPP method OGRGeometry::exportToWkb().
 *
 * @param hGeom handle on the geometry to convert to a well know binary 
 * data from.
 * @param eOrder One of wkbXDR or wkbNDR indicating MSB or LSB byte order
 *               respectively.
 * @param pabyDstBuffer a buffer into which the binary representation is
 *                      written.  This buffer must be at least