Raster data container. More...

#include <qgsrasterblock.h>

Public Member Functions
	QgsRasterBlock ()

	QgsRasterBlock (Qgis::DataType dataType, int width, int height)
	Constructor which allocates data block in memory. More...

virtual	~QgsRasterBlock ()

void	applyNoDataValues (const QgsRasterRangeList &rangeList)

void	applyScaleOffset (double scale, double offset)
	Apply band scale and offset to raster block values. More...

char *	bits (int row, int column)
	Get pointer to data. More...

char *	bits (qgssize index)
	Get pointer to data. More...

char *	bits ()
	Get pointer to data. More...

QRgb	color (int row, int column) const
	Read a single color. More...

QRgb	color (qgssize index) const
	Read a single value. More...

bool	convert (Qgis::DataType destDataType)
	Convert data to different type. More...

QByteArray	data () const
	Get access to raw data. More...

Qgis::DataType	dataType () const
	Returns data type. More...

int	dataTypeSize () const

QgsError	error () const
	Get error. More...

bool	hasNoData () const
	Returns true if the block may contain no data. More...

bool	hasNoDataValue () const
	True if the block has no data value. More...

int	height () const
	Returns the height (number of rows) of the raster block. More...

QImage	image () const
	Get image if type is color. More...

bool	isEmpty () const
	Returns true if block is empty, i.e. More...

bool	isNoData (int row, int column)
	Check if value at position is no data. More...

bool	isNoData (qgssize index)
	Check if value at position is no data. More...

bool	isValid () const
	Returns true if the block is valid (correctly filled with data). More...

double	noDataValue () const
	Return no data value. More...

bool	reset (Qgis::DataType dataType, int width, int height)
	Reset block. More...

void	resetNoDataValue ()
	Reset no data value: if there was a no data value previously set, it will be discarded. More...

bool	setColor (int row, int column, QRgb color)
	Set color on position. More...

bool	setColor (qgssize index, QRgb color)
	Set color on index (indexed line by line) More...

void	setData (const QByteArray &data, int offset=0)
	Rewrite raw pixel data. More...

void	setError (const QgsError &error)
	Set error. More...

bool	setImage (const QImage *image)
	set image. More...

void	setIsData (int row, int column)
	Remove no data flag on pixel. More...

void	setIsData (qgssize index)
	Remove no data flag on pixel. More...

bool	setIsNoData (int row, int column)
	Set no data on pixel. More...

bool	setIsNoData (qgssize index)
	Set no data on pixel. More...

bool	setIsNoData ()
	Set the whole block to no data. More...

bool	setIsNoDataExcept (QRect exceptRect)
	Set the whole block to no data except specified rectangle. More...

void	setNoDataValue (double noDataValue)
	Sets cell value that will be considered as "no data". More...

void	setValid (bool valid)
	Mark block as valid or invalid. More...

bool	setValue (int row, int column, double value)
	Set value on position. More...

bool	setValue (qgssize index, double value)
	Set value on index (indexed line by line) More...

QString	toString () const

double	value (int row, int column) const
	Read a single value if type of block is numeric. More...

double	value (qgssize index) const
	Read a single value if type of block is numeric. More...

int	width () const
	Returns the width (number of columns) of the raster block. More...

Static Public Member Functions
static QString	printValue (double value)
	Print double value with all necessary significant digits. More...

static QString	printValue (float value)
	Print float value with all necessary significant digits. More...

static double	readValue (void *data, Qgis::DataType type, qgssize index)

static QRect	subRect (const QgsRectangle &extent, int width, int height, const QgsRectangle &subExtent)
	For extent and width, height find rectangle covered by subextent. More...

static bool	typeIsColor (Qgis::DataType type)
	Returns true if data type is color. More...

static bool	typeIsNumeric (Qgis::DataType type)
	Returns true if data type is numeric. More...

static int	typeSize (int dataType)

static Qgis::DataType	typeWithNoDataValue (Qgis::DataType dataType, double *noDataValue)
	For given data type returns wider type and sets no data value. More...

static QByteArray	valueBytes (Qgis::DataType dataType, double value)
	Get byte array representing a value. More...

static void	writeValue (void *data, Qgis::DataType type, qgssize index, double value)

Detailed Description

Raster data container.

Definition at line 36 of file qgsrasterblock.h.

Constructor & Destructor Documentation

◆ QgsRasterBlock() [1/2]

QgsRasterBlock::QgsRasterBlock ( )

Definition at line 30 of file qgsrasterblock.cpp.

◆ QgsRasterBlock() [2/2]

QgsRasterBlock::QgsRasterBlock	(	Qgis::DataType	dataType,
		int	width,
		int	height
	)

Constructor which allocates data block in memory.

Parameters

dataType	raster data type
width	width of data matrix
height	height of data matrix

Definition at line 35 of file qgsrasterblock.cpp.

◆ ~QgsRasterBlock()

QgsRasterBlock::~QgsRasterBlock ( )

virtual

Definition at line 44 of file qgsrasterblock.cpp.

Member Function Documentation

◆ applyNoDataValues()

void QgsRasterBlock::applyNoDataValues ( const QgsRasterRangeList & rangeList )

Definition at line 733 of file qgsrasterblock.cpp.

◆ applyScaleOffset()

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

Apply band scale and offset to raster block values.

Since: QGIS 2.3

Definition at line 720 of file qgsrasterblock.cpp.

◆ bits() [1/3]

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

Definition at line 666 of file qgsrasterblock.cpp.

◆ bits() [2/3]

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

Definition at line 646 of file qgsrasterblock.cpp.

◆ bits() [3/3]

char * QgsRasterBlock::bits ( )

Get pointer to data.

Returns: pointer to data

Note: not available in Python bindings

Definition at line 671 of file qgsrasterblock.cpp.

◆ color() [1/2]

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

Read a single color.

Parameters

row	row index
column	column index

Returns: color

Definition at line 260 of file qgsrasterblock.cpp.

◆ color() [2/2]

QRgb QgsRasterBlock::color ( qgssize index ) const

Read a single value.

Parameters

index data matrix index (long type in Python)

Returns: color

Definition at line 253 of file qgsrasterblock.cpp.

◆ convert()

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

Convert data to different type.

Parameters

destDataType dest data type

Returns: true on success

Definition at line 685 of file qgsrasterblock.cpp.

◆ data()

QByteArray QgsRasterBlock::data ( ) const

Get access to raw data.

The returned QByteArray instance is not a copy of the data: it only refers to the array owned by the QgsRasterBlock, therefore it is only valid while the QgsRasterBlock object still exists. Writing to the returned QByteArray will not affect the original data: a deep copy of the data will be made and only the local copy will be modified.

Note: in Python the method returns ordinary bytes object as the

Since: QGIS 3.0

Definition at line 619 of file qgsrasterblock.cpp.

◆ dataType()

Qgis::DataType QgsRasterBlock::dataType ( ) const

inline

Returns data type.

Definition at line 129 of file qgsrasterblock.h.

◆ dataTypeSize()

int QgsRasterBlock::dataTypeSize ( ) const

inline

Definition at line 117 of file qgsrasterblock.h.

◆ error()

QgsError QgsRasterBlock::error ( ) const

inline

Get error.

Definition at line 386 of file qgsrasterblock.h.

◆ hasNoData()

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

Definition at line 222 of file qgsrasterblock.cpp.

◆ hasNoDataValue()

bool QgsRasterBlock::hasNoDataValue ( ) const

inline

True if the block has no data value.

Returns: true if the block has no data value

See also: noDataValue(), setNoDataValue(), resetNoDataValue()

Definition at line 139 of file qgsrasterblock.h.

◆ height()

int QgsRasterBlock::height ( ) const

inline

Returns the height (number of rows) of the raster block.

See also: width

Since: QGIS 2.10

Definition at line 417 of file qgsrasterblock.h.

◆ image()

QImage QgsRasterBlock::image ( ) const

Get image if type is color.

Returns: image

Definition at line 752 of file qgsrasterblock.cpp.

◆ isEmpty()

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).

Definition at line 130 of file qgsrasterblock.cpp.

◆ isNoData() [1/2]

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

Definition at line 297 of file qgsrasterblock.cpp.

◆ isNoData() [2/2]

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

Definition at line 267 of file qgsrasterblock.cpp.

◆ isValid()

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.

Definition at line 68 of file qgsrasterblock.h.

◆ noDataValue()

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

See also: hasNoDataValue(), setNoDataValue(), resetNoDataValue()

Definition at line 169 of file qgsrasterblock.h.

◆ printValue() [1/2]

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

Definition at line 776 of file qgsrasterblock.cpp.

◆ printValue() [2/2]

QString QgsRasterBlock::printValue ( float value )

static

Print float value with all necessary significant digits.

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

Parameters

value the value to be printed

Returns: string representing the value

Since: QGIS 2.16

Note: not available in Python bindings

Definition at line 815 of file qgsrasterblock.cpp.

◆ readValue()

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

inlinestatic

Note: not available in Python bindings

Definition at line 496 of file qgsrasterblock.h.

◆ reset()

bool QgsRasterBlock::reset	(	Qgis::DataType	dataType,
		int	width,
		int	height
	)

Reset block.

Parameters

dataType	raster data type
width	width of data matrix
height	height of data matrix

Returns: true on success

Definition at line 52 of file qgsrasterblock.cpp.

◆ resetNoDataValue()

void QgsRasterBlock::resetNoDataValue ( )

Reset no data value: if there was a no data value previously set, it will be discarded.

Since: QGIS 3.0

See also: noDataValue(), hasNoDataValue(), setNoDataValue()

Definition at line 233 of file qgsrasterblock.cpp.

◆ setColor() [1/2]

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

Definition at line 323 of file qgsrasterblock.cpp.

◆ setColor() [2/2]

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

Definition at line 328 of file qgsrasterblock.cpp.

◆ setData()

void QgsRasterBlock::setData	(	const QByteArray &	data,
		int	offset = `0`
	)

Rewrite raw pixel data.

If the data array is shorter than the internal array within the raster block object, pixels at the end will stay untouched. If the data array is longer than the internal array, only the initial data from the input array will be used. Optionally it is possible to set non-zero offset (in bytes) if the input data should overwrite data somewhere in the middle of the internal buffer.

Since: QGIS 3.0

Definition at line 629 of file qgsrasterblock.cpp.

◆ setError()

void QgsRasterBlock::setError ( const QgsError & error )

inline

Set error.

Definition at line 389 of file qgsrasterblock.h.

◆ setImage()

bool QgsRasterBlock::setImage ( const QImage * image )

set image.

Parameters

image image

Returns: true on success

Definition at line 761 of file qgsrasterblock.cpp.

◆ setIsData() [1/2]

void QgsRasterBlock::setIsData	(	int	row,
		int	column
	)

Remove no data flag on pixel.

If the raster block does not have an explicit no data value set then an internal map of no data pixels is maintained for the block. In this case it is possible to reset a pixel to flag it as having valid data using this method. This method has no effect for raster blocks with an explicit no data value set.

Parameters

row	row index
column	column index

Since: QGIS 2.10

Definition at line 592 of file qgsrasterblock.cpp.

◆ setIsData() [2/2]

void QgsRasterBlock::setIsData ( qgssize index )

Remove no data flag on pixel.

If the raster block does not have an explicit no data value set then an internal map of no data pixels is maintained for the block. In this case it is possible to reset a pixel to flag it as having valid data using this method. This method has no effect for raster blocks with an explicit no data value set.

Parameters

index data matrix index (long type in Python)

Since: QGIS 2.10

Definition at line 597 of file qgsrasterblock.cpp.

◆ setIsNoData() [1/3]

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

Set no data on pixel.

Parameters

row	row index
column	column index

Returns: true on success

Definition at line 348 of file qgsrasterblock.cpp.

◆ setIsNoData() [2/3]

bool QgsRasterBlock::setIsNoData ( qgssize index )

Set no data on pixel.

Parameters

index data matrix index (long type in Python)

Returns: true on success

Definition at line 353 of file qgsrasterblock.cpp.

◆ setIsNoData() [3/3]

bool QgsRasterBlock::setIsNoData ( )

Set the whole block to no data.

Returns: true on success

Definition at line 380 of file qgsrasterblock.cpp.

◆ setIsNoDataExcept()

bool QgsRasterBlock::setIsNoDataExcept ( QRect exceptRect )

Set the whole block to no data except specified rectangle.

Returns: true on success

Definition at line 432 of file qgsrasterblock.cpp.

◆ setNoDataValue()

void QgsRasterBlock::setNoDataValue ( double noDataValue )

Sets cell value that will be considered as "no data".

Since: QGIS 3.0

See also: noDataValue(), hasNoDataValue(), resetNoDataValue()

Definition at line 227 of file qgsrasterblock.cpp.

◆ setValid()

void QgsRasterBlock::setValid ( bool valid )

inline

Mark block as valid or invalid.

Definition at line 71 of file qgsrasterblock.h.

◆ setValue() [1/2]

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

Definition at line 318 of file qgsrasterblock.cpp.

◆ setValue() [2/2]

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

Definition at line 302 of file qgsrasterblock.cpp.

◆ subRect()

QRect QgsRasterBlock::subRect	(	const QgsRectangle &	extent,
		int	width,
		int	height,
		const QgsRectangle &	subExtent
	)

static

For extent and width, height 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

extent	extent, usually the larger
width	numbers of columns in theExtent
height	numbers of rows in theExtent
subExtent	extent, usually smaller than theExtent

Returns: the rectangle covered by sub extent

Definition at line 920 of file qgsrasterblock.cpp.

◆ toString()

QString QgsRasterBlock::toString ( ) const

Definition at line 914 of file qgsrasterblock.cpp.

◆ typeIsColor()

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

static

Returns true if data type is color.

Definition at line 164 of file qgsrasterblock.cpp.

◆ typeIsNumeric()

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

static

Returns true if data type is numeric.

Definition at line 139 of file qgsrasterblock.cpp.

◆ typeSize()

static int QgsRasterBlock::typeSize ( int dataType )

inlinestatic

Definition at line 81 of file qgsrasterblock.h.

◆ typeWithNoDataValue()

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

static

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

Definition at line 189 of file qgsrasterblock.cpp.

◆ value() [1/2]

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

Definition at line 248 of file qgsrasterblock.cpp.

◆ value() [2/2]

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

Definition at line 567 of file qgsrasterblock.h.

◆ valueBytes()

QByteArray QgsRasterBlock::valueBytes	(	Qgis::DataType	dataType,
		double	value
	)

static

Get byte array representing a value.

Parameters

dataType	data type
value	value

Returns: byte array representing the value

Definition at line 850 of file qgsrasterblock.cpp.

◆ width()

int QgsRasterBlock::width ( ) const

inline

Returns the width (number of columns) of the raster block.

See also: height

Since: QGIS 2.10

Definition at line 410 of file qgsrasterblock.h.

◆ writeValue()

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

inlinestatic

Note: not available in Python bindings

Definition at line 534 of file qgsrasterblock.h.

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

/tmp/buildd/qgis-3.0.2+14stretch/src/core/raster/qgsrasterblock.h
/tmp/buildd/qgis-3.0.2+14stretch/src/core/raster/qgsrasterblock.cpp

Public Member Functions

Static Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ QgsRasterBlock() [1/2]

◆ QgsRasterBlock() [2/2]

◆ ~QgsRasterBlock()

Member Function Documentation

◆ applyNoDataValues()

◆ applyScaleOffset()

◆ bits() [1/3]

◆ bits() [2/3]

◆ bits() [3/3]

◆ color() [1/2]

◆ color() [2/2]

◆ convert()

◆ data()

◆ dataType()

◆ dataTypeSize()

◆ error()

◆ hasNoData()

◆ hasNoDataValue()

◆ height()

◆ image()

◆ isEmpty()

◆ isNoData() [1/2]

◆ isNoData() [2/2]

◆ isValid()

◆ noDataValue()

◆ printValue() [1/2]

◆ printValue() [2/2]

◆ readValue()

◆ reset()

◆ resetNoDataValue()

◆ setColor() [1/2]

◆ setColor() [2/2]

◆ setData()

◆ setError()

◆ setImage()

◆ setIsData() [1/2]

◆ setIsData() [2/2]

◆ setIsNoData() [1/3]

◆ setIsNoData() [2/3]

◆ setIsNoData() [3/3]

◆ setIsNoDataExcept()

◆ setNoDataValue()

◆ setValid()

◆ setValue() [1/2]

◆ setValue() [2/2]

◆ subRect()

◆ toString()

◆ typeIsColor()

◆ typeIsNumeric()

◆ typeSize()

◆ typeWithNoDataValue()

◆ value() [1/2]

◆ value() [2/2]

◆ valueBytes()

◆ width()

◆ writeValue()