QgsMapToPixel Class Reference

Perform transforms between map coordinates and device coordinates. More...

#include <qgsmaptopixel.h>

Public Member Functions
	QgsMapToPixel (double mapUnitsPerPixel, double centerX, double centerY, int widthPixels, int heightPixels, double rotation)
	Constructor. More...
	QgsMapToPixel (double mapUnitsPerPixel)
	Constructor. More...
	QgsMapToPixel ()
	Constructor. More...
int	mapHeight () const
	Return current map height in pixels. More...
double	mapRotation () const
	Return current map rotation in degrees. More...
double	mapUnitsPerPixel () const
	Return current map units per pixel. More...
int	mapWidth () const
	Return current map width in pixels The information is only known if setRotation was used. More...
void	setMapRotation (double degrees, double cx, double cy)
	Set map rotation in degrees (clockwise) More...
void	setMapUnitsPerPixel (double mapUnitsPerPixel)
	Set map units per pixel. More...
void	setParameters (double mapUnitsPerPixel, double centerX, double centerY, int widthPixels, int heightPixels, double rotation)
	Set parameters for use in transforming coordinates. More...
QString	showParameters () const
	String representation of the parameters used in the transform. More...
QgsPointXY	toMapCoordinates (int x, int y) const
QgsPointXY	toMapCoordinates (QPoint p) const
	Transform device coordinates to map (world) coordinates. More...
QgsPointXY	toMapCoordinatesF (double x, double y) const
	Transform device coordinates to map (world) coordinates. More...
QgsPointXY	toMapPoint (double x, double y) const
QgsPointXY	transform (const QgsPointXY &p) const
	Transform the point from map (world) coordinates to device coordinates. More...
void	transform (QgsPointXY *p) const
QgsPointXY	transform (qreal x, qreal y) const
	Transform the point specified by x,y from map (world) coordinates to device coordinates. More...
QTransform	transform () const
void	transformInPlace (double &x, double &y) const
	Transform device coordinates to map coordinates. More...
void	transformInPlace (float &x, float &y) const
template<class T >
void	transformInPlace (QVector< T > &x, QVector< T > &y) const
	Transform device coordinates to map coordinates. More...
double	xCenter () const
	Returns the center x-coordinate for the transform. More...
double	yCenter () const
	Returns the center y-coordinate for the transform. More...

Static Public Member Functions
static QgsMapToPixel	fromScale (double scale, QgsUnitTypes::DistanceUnit mapUnits, double dpi=96)
	Returns a new QgsMapToPixel created using a specified scale and distance unit. More...

Detailed Description

Perform transforms between map coordinates and device coordinates.

This class can convert device coordinates to map coordinates and vice versa.

Definition at line 36 of file qgsmaptopixel.h.

Constructor & Destructor Documentation

QgsMapToPixel() [1/3]

QgsMapToPixel::QgsMapToPixel	(	double	mapUnitsPerPixel,
		double	centerX,
		double	centerY,
		int	widthPixels,
		int	heightPixels,
		double	rotation
	)

Constructor.

Parameters

mapUnitsPerPixel	Map units per pixel
centerX	X coordinate of map center, in geographical units
centerY	Y coordinate of map center, in geographical units
widthPixels	Output width, in pixels
heightPixels	Output height, in pixels
rotation	clockwise rotation in degrees

Since

QGIS 2.8

Definition at line 28 of file qgsmaptopixel.cpp.

QgsMapToPixel() [2/3]

QgsMapToPixel::QgsMapToPixel

(

double

mapUnitsPerPixel

)

Constructor.

Parameters

mapUnitsPerPixel

Map units per pixel

Definition at line 47 of file qgsmaptopixel.cpp.

QgsMapToPixel() [3/3]

QgsMapToPixel::QgsMapToPixel

(

)

Constructor.

Use setParameters to fill

Definition at line 64 of file qgsmaptopixel.cpp.

Member Function Documentation

fromScale()

QgsMapToPixel QgsMapToPixel::fromScale ( double  scale, QgsUnitTypes::DistanceUnit  mapUnits, double  dpi = 96  )

static

Returns a new QgsMapToPixel created using a specified scale and distance unit.

Parameters

scale	map scale denominator, e.g. 1000.0 for a 1:1000 map.
dpi	screen DPI
mapUnits	map units

Returns

matching QgsMapToPixel

Since

QGIS 3.0

Definition at line 57 of file qgsmaptopixel.cpp.

mapHeight()

int QgsMapToPixel::mapHeight

(

)

const

Return current map height in pixels.

Since

QGIS 2.8

Definition at line 69 of file qgsmaptopixel.cpp.

mapRotation()

double QgsMapToPixel::mapRotation

(

)

const

Return current map rotation in degrees.

Since

QGIS 2.8

Definition at line 159 of file qgsmaptopixel.cpp.

mapUnitsPerPixel()

double QgsMapToPixel::mapUnitsPerPixel

(

)

const

Return current map units per pixel.

Definition at line 129 of file qgsmaptopixel.cpp.

mapWidth()

int QgsMapToPixel::mapWidth

(

)

const

Return current map width in pixels The information is only known if setRotation was used.

Since

QGIS 2.8

Definition at line 74 of file qgsmaptopixel.cpp.

setMapRotation()

void QgsMapToPixel::setMapRotation	(	double	degrees,
		double	cx,
		double	cy
	)

Set map rotation in degrees (clockwise)

Parameters

degrees	clockwise rotation in degrees
cx	X ordinate of map center in geographical units
cy	Y ordinate of map center in geographical units

Since

QGIS 2.8

Definition at line 134 of file qgsmaptopixel.cpp.

setMapUnitsPerPixel()

void QgsMapToPixel::setMapUnitsPerPixel

(

double

mapUnitsPerPixel

)

Set map units per pixel.

Parameters

mapUnitsPerPixel

Map units per pixel

Definition at line 119 of file qgsmaptopixel.cpp.

setParameters()

void QgsMapToPixel::setParameters	(	double	mapUnitsPerPixel,
		double	centerX,
		double	centerY,
		int	widthPixels,
		int	heightPixels,
		double	rotation
	)

Set parameters for use in transforming coordinates.

Parameters

mapUnitsPerPixel	Map units per pixel
centerX	X coordinate of map center, in geographical units
centerY	Y coordinate of map center, in geographical units
widthPixels	Output width, in pixels
heightPixels	Output height, in pixels
rotation	clockwise rotation in degrees

Since

QGIS 2.8

Definition at line 164 of file qgsmaptopixel.cpp.

showParameters()

QString QgsMapToPixel::showParameters

(

)

const

String representation of the parameters used in the transform.

Definition at line 202 of file qgsmaptopixel.cpp.

toMapCoordinates() [1/2]

QgsPointXY QgsMapToPixel::toMapCoordinates	(	int	x,
		int	y
	)		const

Definition at line 109 of file qgsmaptopixel.cpp.

toMapCoordinates() [2/2]

QgsPointXY QgsMapToPixel::toMapCoordinates

(

QPoint

p

)

const

Transform device coordinates to map (world) coordinates.

Parameters

p	Point to be converted to map cooordinates

Returns

QgsPointXY in map coorndiates

Definition at line 103 of file qgsmaptopixel.cpp.

toMapCoordinatesF()

QgsPointXY QgsMapToPixel::toMapCoordinatesF	(	double	x,
		double	y
	)		const

Transform device coordinates to map (world) coordinates.

Definition at line 114 of file qgsmaptopixel.cpp.

toMapPoint()

QgsPointXY QgsMapToPixel::toMapPoint	(	double	x,
		double	y
	)		const

Definition at line 91 of file qgsmaptopixel.cpp.

transform() [1/4]

QgsPointXY QgsMapToPixel::transform

(

const QgsPointXY &

p

)

const

Transform the point from map (world) coordinates to device coordinates.

Parameters

p	Point to transform

Returns

QgsPointXY in device coordinates

Definition at line 218 of file qgsmaptopixel.cpp.

transform() [2/4]

void QgsMapToPixel::transform

(

QgsPointXY *

p

)

const

Definition at line 226 of file qgsmaptopixel.cpp.

transform() [3/4]

QgsPointXY QgsMapToPixel::transform	(	qreal	x,
		qreal	y
	)		const

Transform the point specified by x,y from map (world) coordinates to device coordinates.

Parameters

x	x cordinate o point to transform
y	y coordinate of point to transform

Returns

QgsPointXY in device coordinates

Definition at line 212 of file qgsmaptopixel.cpp.

transform() [4/4]

QTransform QgsMapToPixel::transform

(

)

const

Definition at line 253 of file qgsmaptopixel.cpp.

transformInPlace() [1/3]

void QgsMapToPixel::transformInPlace	(	double &	x,
		double &	y
	)		const

Transform device coordinates to map coordinates.

Modifies the given coordinates in place. Intended as a fast way to do the transform.

Definition at line 234 of file qgsmaptopixel.cpp.

transformInPlace() [2/3]

void QgsMapToPixel::transformInPlace	(	float &	x,
		float &	y
	)		const

Note

not available in Python bindings

Definition at line 245 of file qgsmaptopixel.cpp.

transformInPlace() [3/3]

template<class T >

void QgsMapToPixel::transformInPlace ( QVector< T > &  x, QVector< T > &  y  ) const

inline

Transform device coordinates to map coordinates.

Modifies the given coordinates in place. Intended as a fast way to do the transform.

Note

not available in Python bindings

Definition at line 112 of file qgsmaptopixel.h.

xCenter()

double QgsMapToPixel::xCenter ( ) const

inline

Returns the center x-coordinate for the transform.

See also

yCenter()

Since

QGIS 3.0

Definition at line 193 of file qgsmaptopixel.h.

yCenter()

double QgsMapToPixel::yCenter ( ) const

inline

Returns the center y-coordinate for the transform.

See also

xCenter()

Since

QGIS 3.0

Definition at line 200 of file qgsmaptopixel.h.

---

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

• /tmp/buildd/qgis-3.0.2+14stretch/src/core/qgsmaptopixel.h
• /tmp/buildd/qgis-3.0.2+14stretch/src/core/qgsmaptopixel.cpp