GDALProxyDataset Class Reference

Inheritance diagram for GDALProxyDataset:

Public Member Functions
virtual char **	GetMetadata (const char *pszDomain)
virtual CPLErr	SetMetadata (char *papszMetadata, const char pszDomain)
virtual const char *	GetMetadataItem (const char pszName, const char pszDomain)
virtual CPLErr	SetMetadataItem (const char pszName, const char pszValue, const char *pszDomain)
virtual void	FlushCache (void)
virtual const char *	GetProjectionRef (void)
virtual CPLErr	SetProjection (const char *)
virtual CPLErr	GetGeoTransform (double *)
virtual CPLErr	SetGeoTransform (double *)
virtual void *	GetInternalHandle (const char *)
virtual GDALDriver *	GetDriver (void)
virtual char **	GetFileList (void)
virtual int	GetGCPCount ()
virtual const char *	GetGCPProjection ()
virtual const GDAL_GCP *	GetGCPs ()
virtual CPLErr	SetGCPs (int nGCPCount, const GDAL_GCP pasGCPList, const char pszGCPProjection)
virtual CPLErr	AdviseRead (int nXOff, int nYOff, int nXSize, int nYSize, int nBufXSize, int nBufYSize, GDALDataType eDT, int nBandCount, int panBandList, char *papszOptions)
virtual CPLErr	CreateMaskBand (int nFlags)
Protected Member Functions
virtual GDALDataset *	RefUnderlyingDataset ()=0
virtual void	UnrefUnderlyingDataset (GDALDataset *poUnderlyingDataset)
virtual CPLErr	IBuildOverviews (const char , int, int , int, int , GDALProgressFunc, void )
virtual CPLErr	IRasterIO (GDALRWFlag, int, int, int, int, void , int, int, GDALDataType, int, int , int, int, int)

Member Function Documentation

virtual CPLErr GDALProxyDataset::AdviseRead	(	int	nXOff,
		int	nYOff,
		int	nXSize,
		int	nYSize,
		int	nBufXSize,
		int	nBufYSize,
		GDALDataType	eDT,
		int	nBandCount,
		int *	panBandMap,
		char **	papszOptions
	)			`[virtual]`

Advise driver of upcoming read requests.

Some GDAL drivers operate more efficiently if they know in advance what set of upcoming read requests will be made. The AdviseRead() method allows an application to notify the driver of the region and bands of interest, and at what resolution the region will be read.

Many drivers just ignore the AdviseRead() call, but it can dramatically accelerate access via some drivers.

Parameters:

	nXOff	The pixel offset to the top left corner of the region of the band to be accessed. This would be zero to start from the left side.
	nYOff	The line offset to the top left corner of the region of the band to be accessed. This would be zero to start from the top.
	nXSize	The width of the region of the band to be accessed in pixels.
	nYSize	The height of the region of the band to be accessed in lines.
	nBufXSize	the width of the buffer image into which the desired region is to be read, or from which it is to be written.
	nBufYSize	the height of the buffer image into which the desired region is to be read, or from which it is to be written.
	eBufType	the type of the pixel values in the pData data buffer. The pixel values will automatically be translated to/from the GDALRasterBand data type as needed.
	nBandCount	the number of bands being read or written.
	panBandMap	the list of nBandCount band numbers being read/written. Note band numbers are 1 based. This may be NULL to select the first nBandCount bands.
	papszOptions	a list of name=value strings with special control options. Normally this is NULL.

Returns:: CE_Failure if the request is invalid and CE_None if it works or is ignored.

Reimplemented from GDALDataset.

const char int int int int GDALProgressFunc void pProgressData void GDALProxyDataset::FlushCache ( void ) [virtual]

Flush all write cached data to disk.

Any raster (or other GDAL) data written via GDAL calls, but buffered internally will be written to disk.

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

Reimplemented from GDALDataset.

References GDALDataset::FlushCache().

virtual GDALDriver* GDALProxyDataset::GetDriver ( void ) [virtual]

Fetch the driver to which this dataset relates.

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

Returns:: the driver on which the dataset was created with GDALOpen() or GDALCreate().

Reimplemented from GDALDataset.

virtual char** GDALProxyDataset::GetFileList ( void ) [virtual]

Fetch files forming dataset.

Returns a list of files believed to be part of this dataset. If it returns an empty list of files it means there is believed to be no local file system files associated with the dataset (for instance a virtual dataset). The returned file list is owned by the caller and should be deallocated with CSLDestroy().

The returned filenames will normally be relative or absolute paths depending on the path used to originally open the dataset.

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

Returns:: NULL or a NULL terminated array of file names.

Reimplemented from GDALDataset.

virtual int GDALProxyDataset::GetGCPCount ( ) [virtual]

Get number of GCPs.

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

Returns:: number of GCPs for this dataset. Zero if there are none.

Reimplemented from GDALDataset.

virtual const char* GDALProxyDataset::GetGCPProjection ( ) [virtual]

Get output projection for GCPs.

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

The projection string follows the normal rules from GetProjectionRef().

Returns:: internal projection string or "" if there are no GCPs.

Reimplemented from GDALDataset.

Reimplemented in GDALProxyPoolDataset.

virtual const GDAL_GCP* GDALProxyDataset::GetGCPs ( ) [virtual]

Fetch GCPs.

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

Returns:: pointer to internal GCP structure list. It should not be modified, and may change on the next GDAL call.

Reimplemented from GDALDataset.

Reimplemented in GDALProxyPoolDataset.

virtual CPLErr GDALProxyDataset::GetGeoTransform ( double * padfTransform ) [virtual]

Fetch the affine transformation coefficients.

Fetches the coefficients for transforming between pixel/line (P,L) raster space, and projection coordinates (Xp,Yp) space.

   Xp = padfTransform[0] + P*padfTransform[1] + L*padfTransform[2];
   Yp = padfTransform[3] + P*padfTransform[4] + L*padfTransform[5];

In a north up image, padfTransform[1] is the pixel width, and padfTransform[5] is the pixel height. The upper left corner of the upper left pixel is at position (padfTransform[0],padfTransform[3]).

The default transform is (0,1,0,0,0,1) and should be returned even when a CE_Failure error is returned, such as for formats that don't support transformation to projection coordinates.

NOTE: GetGeoTransform() isn't expressive enough to handle the variety of OGC Grid Coverages pixel/line to projection transformation schemes. Eventually this method will be depreciated in favour of a more general scheme.

This method does the same thing as the C GDALGetGeoTransform() function.

Parameters:

padfTransform

an existing six double buffer into which the transformation will be placed.

Returns:: CE_None on success, or CE_Failure if no transform can be fetched.

Reimplemented from GDALDataset.

Reimplemented in GDALProxyPoolDataset.

virtual void* GDALProxyDataset::GetInternalHandle ( const char * ) [virtual]

Fetch a format specific internally meaningful handle.

This method is the same as the C GDALGetInternalHandle() method.

Parameters:

pszHandleName

the handle name desired. The meaningful names will be specific to the file format.

Returns:: the desired handle value, or NULL if not recognised/supported.

Reimplemented from GDALDataset.

Reimplemented in GDALProxyPoolDataset.

virtual char** GDALProxyDataset::GetMetadata ( const char * pszDomain ) [virtual]

Fetch metadata.

The returned string list is owned by the object, and may change at any time. It is formated as a "Name=value" list with the last pointer value being NULL. Use the the CPL StringList functions such as CSLFetchNameValue() to manipulate it.

Note that relatively few formats return any metadata at this time.

This method does the same thing as the C function GDALGetMetadata().

Parameters:

pszDomain

the domain of interest. Use "" or NULL for the default domain.

Returns:: NULL or a string list.

Reimplemented from GDALMajorObject.

Reimplemented in GDALProxyPoolDataset.

virtual const char* GDALProxyDataset::GetMetadataItem	(	const char *	pszName,
		const char *	pszDomain
	)			`[virtual]`

Fetch single metadata item.

The C function GDALGetMetadataItem() does the same thing as this method.

Parameters:

	pszName	the key for the metadata item to fetch.
	pszDomain	the domain to fetch for, use NULL for the default domain.

Returns:: NULL on failure to find the key, or a pointer to an internal copy of the value string on success.

Reimplemented from GDALMajorObject.

Reimplemented in GDALProxyPoolDataset.

virtual const char* GDALProxyDataset::GetProjectionRef ( void ) [virtual]

Fetch the projection definition string for this dataset.

Same as the C function GDALGetProjectionRef().

The returned string defines the projection coordinate system of the image in OpenGIS WKT format. It should be suitable for use with the OGRSpatialReference class.

When a projection definition is not available an empty (but not NULL) string is returned.

Returns:: a pointer to an internal projection reference string. It should not be altered, freed or expected to last for long.

See also:: http://www.gdal.org/ogr/osr_tutorial.html

Reimplemented from GDALDataset.

Reimplemented in GDALProxyPoolDataset.

virtual CPLErr GDALProxyDataset::SetGCPs	(	int	nGCPCount,
		const GDAL_GCP *	pasGCPList,
		const char *	pszGCPProjection
	)			`[virtual]`

Assign GCPs.

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

This method assigns the passed set of GCPs to this dataset, as well as setting their coordinate system. Internally copies are made of the coordinate system and list of points, so the caller remains resposible for deallocating these arguments if appropriate.

Most formats do not support setting of GCPs, even foramts that can handle GCPs. These formats will return CE_Failure.

Parameters:

	nGCPCount	number of GCPs being assigned.
	pasGCPList	array of GCP structures being assign (nGCPCount in array).
	pszGCPProjection	the new OGC WKT coordinate system to assign for the GCP output coordinates. This parameter should be "" if no output coordinate system is known.

Returns:: CE_None on success, CE_Failure on failure (including if action is not supported for this format).

Reimplemented from GDALDataset.

virtual CPLErr GDALProxyDataset::SetGeoTransform ( double * ) [virtual]

Set the affine transformation coefficients.

See GetGeoTransform() for details on the meaning of the padfTransform coefficients.

This method does the same thing as the C GDALSetGeoTransform() function.

Parameters:

padfTransform

a six double buffer containing the transformation coefficients to be written with the dataset.

Returns:: CE_None on success, or CE_Failure if this transform cannot be written.

Reimplemented from GDALDataset.

Reimplemented in GDALProxyPoolDataset.

virtual CPLErr GDALProxyDataset::SetMetadata	(	char **	papszMetadataIn,
		const char *	pszDomain
	)			`[virtual]`

Set metadata.

The C function GDALSetMetadata() does the same thing as this method.

Parameters:

	papszMetadata	the metadata in name=value string list format to apply.
	pszDomain	the domain of interest. Use "" or NULL for the default domain.

Returns:: CE_None on success, CE_Failure on failure and CE_Warning if the metadata has been accepted, but is likely not maintained persistently by the underlying object between sessions.

Reimplemented from GDALMajorObject.

virtual CPLErr GDALProxyDataset::SetMetadataItem	(	const char *	pszName,
		const char *	pszValue,
		const char *	pszDomain
	)			`[virtual]`

Set single metadata item.

The C function GDALSetMetadataItem() does the same thing as this method.

Parameters:

	pszName	the key for the metadata item to fetch.
	pszValue	the value to assign to the key.
	pszDomain	the domain to set within, use NULL for the default domain.

Returns:: CE_None on success, or an error code on failure.

Reimplemented from GDALMajorObject.

virtual CPLErr GDALProxyDataset::SetProjection ( const char * ) [virtual]

Set the projection reference string for this dataset.

The string should be in OGC WKT or PROJ.4 format. An error may occur because of incorrectly specified projection strings, because the dataset is not writable, or because the dataset does not support the indicated projection. Many formats do not support writing projections.

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

Parameters:

pszProjection

projection reference string.

Returns:: CE_Failure if an error occurs, otherwise CE_None.

Reimplemented from GDALDataset.

Reimplemented in GDALProxyPoolDataset.

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

gdal_proxy.h
gdalproxydataset.cpp

GDALProxyDataset Class Reference

Public Member Functions

Protected Member Functions

Member Function Documentation