Raster data container. More...

#include <qgsrasterblock.h>

Public Member Functions
	QgsRasterBlock ()
	QgsRasterBlock (QGis::DataType theDataType, int theWidth, int theHeight)
	Constructor which allocates data block in memory.
	QgsRasterBlock (QGis::DataType theDataType, int theWidth, int theHeight, double theNoDataValue)
	Constructor which allocates data block in memory.
virtual	~QgsRasterBlock ()
bool	reset (QGis::DataType theDataType, int theWidth, int theHeight)
	Reset block.
bool	reset (QGis::DataType theDataType, int theWidth, int theHeight, double theNoDataValue)
	Reset block.
bool	isValid () const
	Returns true if the block is valid (correctly filled with data).
void	setValid (bool valid)
	Mark block as valid or invalid.
bool	isEmpty () const
	Returns true if block is empty, i.e.
int	dataTypeSize () const
QGis::DataType	dataType () const
	Returns data type.
bool	hasNoDataValue () const
	True if the block has no data value.
bool	hasNoData () const
	Returns true if the block may contain no data.
double	noDataValue () const
	Return no data value.
double	value (int row, int column) const
	Read a single value if type of block is numeric.
double	value (qgssize index) const
	Read a single value if type of block is numeric.
QRgb	color (int row, int column) const
	Read a single color.
QRgb	color (qgssize index) const
	Read a single value.
bool	isNoData (int row, int column)
	Check if value at position is no data.
bool	isNoData (qgssize index)
	Check if value at position is no data.
bool	setValue (int row, int column, double value)
	Set value on position.
bool	setValue (qgssize index, double value)
	Set value on index (indexed line by line)
bool	setColor (int row, int column, QRgb color)
	Set color on position.
bool	setColor (qgssize index, QRgb color)
	Set color on index (indexed line by line)
bool	setIsNoData (int row, int column)
	Set no data on pixel.
bool	setIsNoData (qgssize index)
	Set no data on pixel.
bool	setIsNoData ()
	Set the whole block to no data.
bool	setIsNoDataExcept (const QRect &theExceptRect)
	Set the whole block to no data except specified rectangle.
char *	bits (int row, int column)
	Get pointer to data.
char *	bits (qgssize index)
	Get pointer to data.
char *	bits ()
	Get pointer to data.
bool	convert (QGis::DataType destDataType)
	Convert data to different type.
QImage	image () const
	Get image if type is color.
bool	setImage (const QImage *image)
	set image.
void	applyNoDataValues (const QgsRasterRangeList &rangeList)
void	applyScaleOffset (double scale, double offset)
	apply band scale and offset to raster block values @note added in 2.3
QgsError	error () const
	Get error.
void	setError (const QgsError &theError)
	Set error.

Static Public Member Functions
static int	typeSize (int dataType)
static bool	typeIsNumeric (QGis::DataType type)
	Returns true if data type is numeric.
static bool	typeIsColor (QGis::DataType type)
	Returns true if data type is color.
static QGis::DataType	typeWithNoDataValue (QGis::DataType dataType, double *noDataValue)
	For given data type returns wider type and sets no data value.
static QByteArray	valueBytes (QGis::DataType theDataType, double theValue)
	Get byte array representing a value.
static QString	printValue (double value)
	Print double value with all necessary significant digits.
static double	readValue (void *data, QGis::DataType type, qgssize index)
static void	writeValue (void *data, QGis::DataType type, qgssize index, double value)
static QRect	subRect (const QgsRectangle &theExtent, int theWidth, int theHeight, const QgsRectangle &theSubExtent)
	For theExtent and theWidht, theHeight find rectangle covered by subextent.

Detailed Description

Raster data container.

Constructor & Destructor Documentation

QgsRasterBlock::QgsRasterBlock ( )

QgsRasterBlock::QgsRasterBlock	(	QGis::DataType	theDataType,
		int	theWidth,
		int	theHeight
	)

Constructor which allocates data block in memory.

Parameters

theDataType	raster data type
theWidth	width of data matrix
theHeight	height of data matrix

Note: not available in python bindings (use variant with theNoDataValue)

QgsRasterBlock::QgsRasterBlock	(	QGis::DataType	theDataType,
		int	theWidth,
		int	theHeight,
		double	theNoDataValue
	)

Constructor which allocates data block in memory.

Parameters

theDataType	raster data type
theWidth	width of data matrix
theHeight	height of data matrix
theNoDataValue	the value representing no data (NULL)

QgsRasterBlock::~QgsRasterBlock ( )

virtual

Member Function Documentation

void QgsRasterBlock::applyNoDataValues ( const QgsRasterRangeList & rangeList )

void QgsRasterBlock::applyScaleOffset	(	double	scale,
		double	offset
	)

apply band scale and offset to raster block values @note added in 2.3

char * QgsRasterBlock::bits	(	int	row,
		int	column
	)

Get pointer to data.

Parameters

row	row index
column	column index

Returns: pointer to data

Note: not available in python bindings

char * QgsRasterBlock::bits ( qgssize index )

Get pointer to data.

Parameters

index data matrix index (long type in Python)

Returns: pointer to data

Note: not available in python bindings

char * QgsRasterBlock::bits ( )

Get pointer to data.

Returns: pointer to data

Note: not available in python bindings

QRgb QgsRasterBlock::color	(	int	row,
		int	column
	)		const

Read a single color.

Parameters

row	row index
column	column index

Returns: color

QRgb QgsRasterBlock::color ( qgssize index ) const

Read a single value.

Parameters

index data matrix index (long type in Python)

Returns: color

bool QgsRasterBlock::convert ( QGis::DataType destDataType )

Convert data to different type.

Parameters

destDataType dest data type

Returns: true on success

QGis::DataType QgsRasterBlock::dataType ( ) const

inline

Returns data type.

int QgsRasterBlock::dataTypeSize ( ) const

inline

QgsError QgsRasterBlock::error ( ) const

inline

Get error.

bool QgsRasterBlock::hasNoData ( ) const

Returns true if the block may contain no data.

It does not guarantee that it really contains any no data. It can be used to speed up processing. Not the difference between this method and hasNoDataValue().

Returns: true if the block may contain no data

bool QgsRasterBlock::hasNoDataValue ( ) const

inline

True if the block has no data value.

Returns: true if the block has no data value

QImage QgsRasterBlock::image ( ) const

Get image if type is color.

Returns: image

bool QgsRasterBlock::isEmpty ( ) const

Returns true if block is empty, i.e.

its size is 0 (zero rows or cols). This method does not return true if size is not zero and all values are 'no data' (null).

bool QgsRasterBlock::isNoData	(	int	row,
		int	column
	)

Check if value at position is no data.

Parameters

row	row index
column	column index

Returns: true if value is no data

bool QgsRasterBlock::isNoData ( qgssize index )

Check if value at position is no data.

Parameters

index data matrix index (long type in Python)

Returns: true if value is no data

bool QgsRasterBlock::isValid ( ) const

inline

Returns true if the block is valid (correctly filled with data).

An empty block may still be valid (if zero size block was requested). If the block is not valid, error may be retrieved by error() method.

double QgsRasterBlock::noDataValue ( ) const

inline

Return no data value.

If the block does not have a no data value the returned value is undefined.

Returns: No data value

QString QgsRasterBlock::printValue ( double value )

static

Print double value with all necessary significant digits.

   It is ensured that conversion back to double gives the same number.

Parameters

value the value to be printed

Returns: string representing the value

double QgsRasterBlock::readValue	(	void *	data,
		QGis::DataType	type,
		qgssize	index
	)

inlinestatic

bool QgsRasterBlock::reset	(	QGis::DataType	theDataType,
		int	theWidth,
		int	theHeight
	)

Reset block.

Parameters

theDataType	raster data type
theWidth	width of data matrix
theHeight	height of data matrix

Returns: true on success

Note: not available in python bindings (use variant with theNoDataValue)

bool QgsRasterBlock::reset	(	QGis::DataType	theDataType,
		int	theWidth,
		int	theHeight,
		double	theNoDataValue
	)

Reset block.

Parameters

theDataType	raster data type
theWidth	width of data matrix
theHeight	height of data matrix
theNoDataValue	the value representing no data (NULL)

Returns: true on success

bool QgsRasterBlock::setColor	(	int	row,
		int	column,
		QRgb	color
	)

Set color on position.

Parameters

row	row index
column	column index
color	the color to be set, QRgb value

Returns: true on success

bool QgsRasterBlock::setColor	(	qgssize	index,
		QRgb	color
	)

Set color on index (indexed line by line)

Parameters

index	data matrix index (long type in Python)
color	the color to be set, QRgb value

Returns: true on success

void QgsRasterBlock::setError ( const QgsError & theError )

inline

Set error.

bool QgsRasterBlock::setImage ( const QImage * image )

set image.

Parameters

image image

Returns: true on success

bool QgsRasterBlock::setIsNoData	(	int	row,
		int	column
	)

Set no data on pixel.

Parameters

row	row index
column	column index

Returns: true on success

bool QgsRasterBlock::setIsNoData ( qgssize index )

Set no data on pixel.

Parameters

index data matrix index (long type in Python)

Returns: true on success

bool QgsRasterBlock::setIsNoData ( )

Set the whole block to no data.

Returns: true on success

bool QgsRasterBlock::setIsNoDataExcept ( const QRect & theExceptRect )

Set the whole block to no data except specified rectangle.

Returns: true on success

void QgsRasterBlock::setValid ( bool valid )

inline

Mark block as valid or invalid.

bool QgsRasterBlock::setValue	(	int	row,
		int	column,
		double	value
	)

Set value on position.

Parameters

row	row index
column	column index
value	the value to be set

Returns: true on success

bool QgsRasterBlock::setValue	(	qgssize	index,
		double	value
	)

Set value on index (indexed line by line)

Parameters

index	data matrix index (long type in Python)
value	the value to be set

Returns: true on success

QRect QgsRasterBlock::subRect	(	const QgsRectangle &	theExtent,
		int	theWidth,
		int	theHeight,
		const QgsRectangle &	theSubExtent
	)

static

For theExtent and theWidht, theHeight find rectangle covered by subextent.

The output rect has x oriented from left to right and y from top to bottom (upper-left to lower-right orientation).

Parameters

theExtent	extent, usually the larger
theWidth	numbers of columns in theExtent
theHeight	numbers of rows in theExtent
theSubExtent	extent, usually smaller than theExtent

Returns: the rectangle covered by sub extent

bool QgsRasterBlock::typeIsColor ( QGis::DataType type )

static

Returns true if data type is color.

bool QgsRasterBlock::typeIsNumeric ( QGis::DataType type )

static

Returns true if data type is numeric.

static int QgsRasterBlock::typeSize ( int dataType )

inlinestatic

QGis::DataType QgsRasterBlock::typeWithNoDataValue	(	QGis::DataType	dataType,
		double *	noDataValue
	)

static

For given data type returns wider type and sets no data value.

double QgsRasterBlock::value	(	int	row,
		int	column
	)		const

Read a single value if type of block is numeric.

If type is color, returned value is undefined.

Parameters

row	row index
column	column index

Returns: value

double QgsRasterBlock::value ( qgssize index ) const

inline

Read a single value if type of block is numeric.

If type is color, returned value is undefined.

Parameters

index data matrix index (long type in Python)

Returns: value

QByteArray QgsRasterBlock::valueBytes	(	QGis::DataType	theDataType,
		double	theValue
	)

static

Get byte array representing a value.

Parameters

theDataType	data type
theValue	value

Returns: byte array representing the value

void QgsRasterBlock::writeValue	(	void *	data,
		QGis::DataType	type,
		qgssize	index,
		double	value
	)

inlinestatic

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

/tmp/buildd/qgis-2.6.0+wheezy1/src/core/raster/qgsrasterblock.h
/tmp/buildd/qgis-2.6.0+wheezy1/src/core/raster/qgsrasterblock.cpp

Public Member Functions

Static Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation