A paint effect which blurs a source picture, using a number of different blur methods. More...

#include <qgsblureffect.h>

Inheritance diagram for QgsBlurEffect:

Public Types
enum	BlurMethod { StackBlur , GaussianBlur }
	Available blur methods (algorithms) More...

Public Types inherited from QgsPaintEffect
enum	DrawMode { Modifier , Render , ModifyAndRender }
	Drawing modes for effects. More...

Public Member Functions
	QgsBlurEffect ()=default
	Constructor for QgsBlurEffect. More...

QPainter::CompositionMode	blendMode () const
	Returns the blend mode for the effect. More...

double	blurLevel () const
	Returns the blur level (radius) More...

const QgsMapUnitScale &	blurMapUnitScale () const
	Returns the map unit scale used for the blur strength (radius). More...

BlurMethod	blurMethod () const
	Returns the blur method (algorithm) used for performing the blur. More...

Qgis::RenderUnit	blurUnit () const
	Returns the units used for the blur level (radius). More...

QgsBlurEffect *	clone () const override
	Duplicates an effect by creating a deep copy of the effect. More...

double	opacity () const
	Returns the opacity for the effect. More...

QVariantMap	properties () const override
	Returns the properties describing the paint effect encoded in a string format. More...

void	readProperties (const QVariantMap &props) override
	Reads a string map of an effect's properties and restores the effect to the state described by the properties map. More...

void	setBlendMode (const QPainter::CompositionMode mode)
	Sets the blend mode for the effect. More...

void	setBlurLevel (const double level)
	Sets blur level (radius) More...

void	setBlurMapUnitScale (const QgsMapUnitScale &scale)
	Sets the map unit scale used for the blur strength (radius). More...

void	setBlurMethod (const BlurMethod method)
	Sets the blur method (algorithm) to use for performing the blur. More...

void	setBlurUnit (const Qgis::RenderUnit unit)
	Sets the units used for the blur level (radius). More...

void	setOpacity (const double opacity)
	Sets the opacity for the effect. More...

QString	type () const override
	Returns the effect type. More...

Public Member Functions inherited from QgsPaintEffect
	QgsPaintEffect ()=default
	Constructor for QgsPaintEffect. More...

	QgsPaintEffect (const QgsPaintEffect &other)

virtual	~QgsPaintEffect ()

virtual void	begin (QgsRenderContext &context)
	Begins intercepting paint operations to a render context. More...

virtual QgsPaintEffect *	clone () const =0
	Duplicates an effect by creating a deep copy of the effect. More...

DrawMode	drawMode () const
	Returns the draw mode for the effect. More...

bool	enabled () const
	Returns whether the effect is enabled. More...

virtual void	end (QgsRenderContext &context)
	Ends interception of paint operations to a render context, and draws the result to the render context after being modified by the effect. More...

virtual QVariantMap	properties () const =0
	Returns the properties describing the paint effect encoded in a string format. More...

virtual bool	readProperties (const QDomElement &element)
	Restores the effect to the state described by a DOM element. More...

virtual void	readProperties (const QVariantMap &props)=0
	Reads a string map of an effect's properties and restores the effect to the state described by the properties map. More...

virtual void	render (QPicture &picture, QgsRenderContext &context)
	Renders a picture using the effect. More...

virtual bool	saveProperties (QDomDocument &doc, QDomElement &element) const
	Saves the current state of the effect to a DOM element. More...

void	setDrawMode (DrawMode drawMode)
	Sets the draw mode for the effect. More...

void	setEnabled (bool enabled)
	Sets whether the effect is enabled. More...

virtual QString	type () const =0
	Returns the effect type. More...

Static Public Member Functions
static QgsPaintEffect *	create (const QVariantMap &map)
	Creates a new QgsBlurEffect effect from a properties string map. More...

Protected Member Functions
QRectF	boundingRect (const QRectF &rect, const QgsRenderContext &context) const override
	Returns the bounding rect required for drawing the effect. More...

void	draw (QgsRenderContext &context) override
	Handles drawing of the effect's result on to the specified render context. More...

Protected Member Functions inherited from QgsPaintEffect
virtual QRectF	boundingRect (const QRectF &rect, const QgsRenderContext &context) const
	Returns the bounding rect required for drawing the effect. More...

virtual void	draw (QgsRenderContext &context)=0
	Handles drawing of the effect's result on to the specified render context. More...

void	drawSource (QPainter &painter)
	Draws the source QPicture onto the specified painter. More...

void	fixQPictureDpi (QPainter *painter) const
	Applies a workaround to a QPainter to avoid an issue with incorrect scaling when drawing QPictures. More...

QPointF	imageOffset (const QgsRenderContext &context) const
	Returns the offset which should be used when drawing the source image on to a destination render context. More...

const QPicture *	source () const
	Returns the source QPicture. More...

QImage *	sourceAsImage (QgsRenderContext &context)
	Returns the source QPicture rendered to a new QImage. More...

Additional Inherited Members
Protected Attributes inherited from QgsPaintEffect
DrawMode	mDrawMode = ModifyAndRender

bool	mEnabled = true

bool	requiresQPainterDpiFix = true

Detailed Description

A paint effect which blurs a source picture, using a number of different blur methods.

Definition at line 36 of file qgsblureffect.h.

Member Enumeration Documentation

◆ BlurMethod

enum QgsBlurEffect::BlurMethod

Available blur methods (algorithms)

Enumerator
StackBlur	Stack blur, a fast but low quality blur. Valid blur level values are between 0 - 16.
GaussianBlur	Gaussian blur, a slower but high quality blur. Blur level values are the distance in pixels for the blur operation.

Definition at line 42 of file qgsblureffect.h.

Constructor & Destructor Documentation

◆ QgsBlurEffect()

QgsBlurEffect::QgsBlurEffect ( )

default

Constructor for QgsBlurEffect.

Member Function Documentation

◆ blendMode()

QPainter::CompositionMode QgsBlurEffect::blendMode ( ) const

inline

Returns the blend mode for the effect.

Returns: blend mode used for drawing the effect on to a destination paint device

See also: setBlendMode

Definition at line 171 of file qgsblureffect.h.

◆ blurLevel()

double QgsBlurEffect::blurLevel ( ) const

inline

Returns the blur level (radius)

Returns: blur level. Depending on the current blurMethod(), this parameter has different effects

See also: setBlurLevel; blurUnit; blurMapUnitScale; blurMethod

Definition at line 85 of file qgsblureffect.h.

◆ blurMapUnitScale()

const QgsMapUnitScale & QgsBlurEffect::blurMapUnitScale ( ) const

inline

Returns the map unit scale used for the blur strength (radius).

Returns: map unit scale for blur strength

See also: setBlurMapUnitScale; blurLevel; blurUnit

Since: QGIS 3.4.9

Definition at line 125 of file qgsblureffect.h.

◆ blurMethod()

BlurMethod QgsBlurEffect::blurMethod ( ) const

inline

Returns the blur method (algorithm) used for performing the blur.

Returns: blur method

See also: setBlurMethod

Definition at line 139 of file qgsblureffect.h.

◆ blurUnit()

Qgis::RenderUnit QgsBlurEffect::blurUnit ( ) const

inline

Returns the units used for the blur level (radius).

Returns: units for blur level

See also: setBlurUnit; blurLevel; blurMapUnitScale

Since: QGIS 3.4.9

Definition at line 105 of file qgsblureffect.h.

◆ boundingRect()

QRectF QgsBlurEffect::boundingRect	(	const QRectF &	rect,
		const QgsRenderContext &	context
	)		const

overrideprotectedvirtual

Returns the bounding rect required for drawing the effect.

This method can be used to expand the bounding rect of a source picture to account for offset or blurring effects.

Parameters

rect	original source bounding rect
context	destination render context

Returns: modified bounding rect

See also: sourceAsImage

Reimplemented from QgsPaintEffect.

Definition at line 143 of file qgsblureffect.cpp.

◆ clone()

QgsBlurEffect * QgsBlurEffect::clone ( ) const

overridevirtual

Duplicates an effect by creating a deep copy of the effect.

Returns: clone of paint effect

Implements QgsPaintEffect.

Definition at line 137 of file qgsblureffect.cpp.

◆ create()

QgsPaintEffect * QgsBlurEffect::create ( const QVariantMap & map )

static

Creates a new QgsBlurEffect effect from a properties string map.

Parameters

map	encoded properties string map

Returns: new QgsBlurEffect

Definition at line 24 of file qgsblureffect.cpp.

◆ draw()

void QgsBlurEffect::draw ( QgsRenderContext & context )

overrideprotectedvirtual

Handles drawing of the effect's result on to the specified render context.

Derived classes must reimplement this method to apply any transformations to the source QPicture and draw the result using the context's painter.

Parameters

context destination render context

See also: drawSource

Implements QgsPaintEffect.

Definition at line 31 of file qgsblureffect.cpp.

◆ opacity()

double QgsBlurEffect::opacity ( ) const

inline

Returns the opacity for the effect.

Returns: opacity value between 0 and 1 inclusive, where 0 is fully transparent and 1 is fully opaque

See also: setOpacity()

Definition at line 155 of file qgsblureffect.h.

◆ properties()

QVariantMap QgsBlurEffect::properties ( ) const

overridevirtual

Returns the properties describing the paint effect encoded in a string format.

Returns: string map of properties, in the form property key, value

See also: readProperties; saveProperties

Implements QgsPaintEffect.

Definition at line 77 of file qgsblureffect.cpp.

◆ readProperties()

void QgsBlurEffect::readProperties ( const QVariantMap & props )

overridevirtual

Reads a string map of an effect's properties and restores the effect to the state described by the properties map.

Parameters

props effect properties encoded in a string map

See also: properties

Implements QgsPaintEffect.

Definition at line 91 of file qgsblureffect.cpp.

◆ setBlendMode()

void QgsBlurEffect::setBlendMode ( const QPainter::CompositionMode mode )

inline

Sets the blend mode for the effect.

Parameters

mode	blend mode used for drawing the effect on to a destination paint device

See also: blendMode

Definition at line 163 of file qgsblureffect.h.

◆ setBlurLevel()

void QgsBlurEffect::setBlurLevel ( const double level )

inline

Sets blur level (radius)

Parameters

level blur level. Depending on the current blurMethod(), this parameter has different effects

See also: blurLevel; setBlurUnit; setBlurMapUnitScale; setBlurMethod

Definition at line 74 of file qgsblureffect.h.

◆ setBlurMapUnitScale()

void QgsBlurEffect::setBlurMapUnitScale ( const QgsMapUnitScale & scale )

inline

Sets the map unit scale used for the blur strength (radius).

Parameters

scale map unit scale for blur strength

See also: blurMapUnitScale; setBlurLevel; setBlurUnit

Since: QGIS 3.4.9

Definition at line 115 of file qgsblureffect.h.

◆ setBlurMethod()

void QgsBlurEffect::setBlurMethod ( const BlurMethod method )

inline

Sets the blur method (algorithm) to use for performing the blur.

Parameters

method blur method

See also: blurMethod

Definition at line 132 of file qgsblureffect.h.

◆ setBlurUnit()

void QgsBlurEffect::setBlurUnit ( const Qgis::RenderUnit unit )

inline

Sets the units used for the blur level (radius).

Parameters

unit	units for blur level

See also: blurUnit; setBlurLevel; setBlurMapUnitScale

Since: QGIS 3.4.9

Definition at line 95 of file qgsblureffect.h.

◆ setOpacity()

void QgsBlurEffect::setOpacity ( const double opacity )

inline

Sets the opacity for the effect.

Parameters

opacity double between 0 and 1 inclusive, where 0 is fully transparent and 1 is fully opaque

See also: opacity()

Definition at line 147 of file qgsblureffect.h.

◆ type()

QString QgsBlurEffect::type ( ) const

inlineoverridevirtual

Returns the effect type.

Returns: unique string representation of the effect type

Implements QgsPaintEffect.

Definition at line 60 of file qgsblureffect.h.

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

/build/qgis-3.37.0+git20240325+fdefdf9c27f+17bookworm/src/core/effects/qgsblureffect.h
/build/qgis-3.37.0+git20240325+fdefdf9c27f+17bookworm/src/core/effects/qgsblureffect.cpp

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ BlurMethod

Constructor & Destructor Documentation

◆ QgsBlurEffect()

Member Function Documentation

◆ blendMode()

◆ blurLevel()

◆ blurMapUnitScale()

◆ blurMethod()

◆ blurUnit()

◆ boundingRect()

◆ clone()

◆ create()

◆ draw()

◆ opacity()

◆ properties()

◆ readProperties()

◆ setBlendMode()

◆ setBlurLevel()

◆ setBlurMapUnitScale()

◆ setBlurMethod()

◆ setBlurUnit()

◆ setOpacity()

◆ type()