QgsPainting Class Reference

Contains miscellaneous painting utility functions. More...

#include <qgspainting.h>

Static Public Member Functions
static void	applyScaleFixForQPictureDpi (QPainter *painter)
	Applies a workaround to a painter to avoid an issue with incorrect scaling when drawing QPictures.
static void	drawPicture (QPainter *painter, const QPointF &point, const QPicture &picture)
	Draws a picture onto a painter, correctly applying workarounds to avoid issues with incorrect scaling.
static bool	drawTriangleUsingTexture (QPainter *painter, const QPolygonF &triangle, const QImage &textureImage, float textureX1, float textureY1, float textureX2, float textureY2, float textureX3, float textureY3)
	Draws a triangle onto a painter using a mapped texture image.
static Qgis::BlendMode	getBlendModeEnum (QPainter::CompositionMode blendMode)
	Returns a Qgis::BlendMode corresponding to a QPainter::CompositionMode.
static QPainter::CompositionMode	getCompositionMode (Qgis::BlendMode blendMode)
	Returns a QPainter::CompositionMode corresponding to a Qgis::BlendMode.
static bool	isClippingMode (Qgis::BlendMode mode)
	Returns true if mode is a clipping blend mode.
static int	qtDefaultDpiX ()
	Returns the default Qt horizontal DPI.
static int	qtDefaultDpiY ()
	Returns the default Qt vertical DPI.
static QTransform	triangleToTriangleTransform (double inX1, double inY1, double inX2, double inY2, double inX3, double inY3, double outX1, double outY1, double outX2, double outY2, double outX3, double outY3, bool &ok)
	Calculates the QTransform which maps the triangle defined by the points (inX1, inY1), (inY2, inY2), (inX3, inY3) to the triangle defined by (outX1, outY1), (outY2, outY2), (outX3, outY3).

Detailed Description

Contains miscellaneous painting utility functions.

Definition at line 31 of file qgspainting.h.

Member Function Documentation

applyScaleFixForQPictureDpi()

void QgsPainting::applyScaleFixForQPictureDpi ( QPainter *  painter )

static

Applies a workaround to a painter to avoid an issue with incorrect scaling when drawing QPictures.

Note

This is a low-level method, which alters the painter state and relies on the caller saving/restoring painter state accordingly. Consider using the high-level drawPicture() method instead.

See also

drawPicture()

Since

QGIS 3.40

Definition at line 236 of file qgspainting.cpp.

drawPicture()

void QgsPainting::drawPicture ( QPainter *  painter, const QPointF &  point, const QPicture &  picture  )

static

Draws a picture onto a painter, correctly applying workarounds to avoid issues with incorrect scaling.

See also

applyScaleFixForQPictureDpi()

Since

QGIS 3.40

Definition at line 246 of file qgspainting.cpp.

drawTriangleUsingTexture()

bool QgsPainting::drawTriangleUsingTexture ( QPainter *  painter, const QPolygonF &  triangle, const QImage &  textureImage, float  textureX1, float  textureY1, float  textureX2, float  textureY2, float  textureX3, float  textureY3  )

static

Draws a triangle onto a painter using a mapped texture image.

The triangle will be rendered using the portion of the texture image described by the triangle (textureX1, textureY1), (textureX2, textureY2), (textureX3, textureY3). Texture coordinates should be in the range 0-1 (as a fraction of the image size), where (0, 0) coorresponds to the top-left of the texture image.

The caller must ensure that triangle is a closed QPolygonF consisting of 4 vertices (the 3 triangle vertices + the first vertex again to close the polygon).

Returns true if the triangle could be rendered, or false if it could not (e.g. when the described points are co-linear).

Since

QGIS 3.34

Definition at line 198 of file qgspainting.cpp.

getBlendModeEnum()

Qgis::BlendMode QgsPainting::getBlendModeEnum ( QPainter::CompositionMode  blendMode )

static

Returns a Qgis::BlendMode corresponding to a QPainter::CompositionMode.

See also

getCompositionMode()

Definition at line 84 of file qgspainting.cpp.

getCompositionMode()

QPainter::CompositionMode QgsPainting::getCompositionMode ( Qgis::BlendMode  blendMode )

static

Returns a QPainter::CompositionMode corresponding to a Qgis::BlendMode.

See also

getBlendModeEnum

Definition at line 24 of file qgspainting.cpp.

isClippingMode()

bool QgsPainting::isClippingMode ( Qgis::BlendMode  mode )

static

Returns true if mode is a clipping blend mode.

Since

QGIS 3.30

Definition at line 143 of file qgspainting.cpp.

qtDefaultDpiX()

int QgsPainting::qtDefaultDpiX ( )

static

Returns the default Qt horizontal DPI.

Note

This method proxies the internal Qt qt_defaultDpiX() function.

See also

qtDefaultDpiY()

Since

QGIS 3.40

Definition at line 226 of file qgspainting.cpp.

qtDefaultDpiY()

int QgsPainting::qtDefaultDpiY ( )

static

Returns the default Qt vertical DPI.

Note

This method proxies the internal Qt qt_defaultDpiY() function.

See also

qtDefaultDpiX()

Since

QGIS 3.40

Definition at line 231 of file qgspainting.cpp.

triangleToTriangleTransform()

QTransform QgsPainting::triangleToTriangleTransform ( double  inX1, double  inY1, double  inX2, double  inY2, double  inX3, double  inY3, double  outX1, double  outY1, double  outX2, double  outY2, double  outX3, double  outY3, bool &  ok  )

static

Calculates the QTransform which maps the triangle defined by the points (inX1, inY1), (inY2, inY2), (inX3, inY3) to the triangle defined by (outX1, outY1), (outY2, outY2), (outX3, outY3).

Parameters

inX1	source triangle vertex 1 x-coordinate
inY1	source triangle vertex 1 y-coordinate
inX2	source triangle vertex 2 x-coordinate
inY2	source triangle vertex 2 y-coordinate
inX3	source triangle vertex 3 x-coordinate
inY3	source triangle vertex 3 y-coordinate
outX1	destination triangle vertex 1 x-coordinate
outY1	destination triangle vertex 1 y-coordinate
outX2	destination triangle vertex 2 x-coordinate
outY2	destination triangle vertex 2 y-coordinate
outX3	destination triangle vertex 3 x-coordinate
outY3	destination triangle vertex 3 y-coordinate
ok	will be set to true if the transform could be determined.

Returns

Calculated transform (if possible)

Since

QGIS 3.34

Definition at line 178 of file qgspainting.cpp.

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

• /build/qgis-3.41.0+git20241201+3c143d501a8+99sid/src/core/painting/qgspainting.h
• /build/qgis-3.41.0+git20241201+3c143d501a8+99sid/src/core/painting/qgspainting.cpp