juce::LowLevelGraphicsContext Class Reference

Detailed Description

Interface class for graphics context objects, used internally by the Graphics class.

Users are not supposed to create instances of this class directly - do your drawing via the Graphics object instead.

It's a base class for different types of graphics context, that may perform software-based or OS-accelerated rendering.

E.g. the LowLevelGraphicsSoftwareRenderer renders onto an image in memory, but other subclasses could render directly to a windows HDC, a Quartz context, or an OpenGL context.

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

• juce_graphics/contexts/juce_LowLevelGraphicsContext.h

Public Member Functions
virtual	~LowLevelGraphicsContext ()=default
virtual bool	isVectorDevice () const =0
	Returns true if this device is vector-based, e.g.
virtual void	setOrigin (Point< int >)=0
	Moves the origin to a new position.
virtual void	addTransform (const AffineTransform &)=0
virtual float	getPhysicalPixelScaleFactor () const =0
virtual bool	clipToRectangle (const Rectangle< int > &)=0
virtual bool	clipToRectangleList (const RectangleList< int > &)=0
virtual void	excludeClipRectangle (const Rectangle< int > &)=0
virtual void	clipToPath (const Path &, const AffineTransform &)=0
virtual void	clipToImageAlpha (const Image &, const AffineTransform &)=0
virtual bool	clipRegionIntersects (const Rectangle< int > &)=0
virtual Rectangle< int >	getClipBounds () const =0
virtual bool	isClipEmpty () const =0
virtual void	saveState ()=0
virtual void	restoreState ()=0
virtual void	beginTransparencyLayer (float opacity)=0
virtual void	endTransparencyLayer ()=0
virtual void	setFill (const FillType &)=0
virtual void	setOpacity (float)=0
virtual void	setInterpolationQuality (Graphics::ResamplingQuality)=0
virtual void	fillAll ()
virtual void	fillRect (const Rectangle< int > &, bool replaceExistingContents)=0
virtual void	fillRect (const Rectangle< float > &)=0
virtual void	fillRectList (const RectangleList< float > &)=0
virtual void	fillPath (const Path &, const AffineTransform &)=0
virtual void	drawRect (const Rectangle< float > &rect, float lineThickness)
virtual void	strokePath (const Path &path, const PathStrokeType &strokeType, const AffineTransform &transform)
virtual void	drawImage (const Image &, const AffineTransform &)=0
virtual void	drawLine (const Line< float > &)=0
virtual void	drawLineWithThickness (const Line< float > &line, float lineThickness)
virtual void	setFont (const Font &)=0
virtual const Font &	getFont ()=0
virtual void	drawGlyphs (Span< const uint16_t >, Span< const Point< float > >, const AffineTransform &)=0
	Uses the current font to draw the provided glyph numbers.
virtual std::unique_ptr< ImageType >	getPreferredImageTypeForTemporaryImages () const =0
	Returns the optimal ImageType for creating temporary images in this GraphicsContext.
virtual void	drawRoundedRectangle (const Rectangle< float > &r, float cornerSize, float lineThickness)
virtual void	fillRoundedRectangle (const Rectangle< float > &r, float cornerSize)
virtual void	drawEllipse (const Rectangle< float > &area, float lineThickness)
virtual void	fillEllipse (const Rectangle< float > &area)
virtual uint64_t	getFrameId () const =0
	Returns an integer that uniquely identifies the current frame.

Protected Member Functions
	LowLevelGraphicsContext ()=default

Constructors and Destructors

LowLevelGraphicsContext()

juce::LowLevelGraphicsContext::LowLevelGraphicsContext ( )

protecteddefault

~LowLevelGraphicsContext()

virtual juce::LowLevelGraphicsContext::~LowLevelGraphicsContext ( )

virtualdefault

Member Functions

isVectorDevice()

virtual bool juce::LowLevelGraphicsContext::isVectorDevice ( ) const

pure virtual

Returns true if this device is vector-based, e.g.

a printer.

setOrigin()

virtual void juce::LowLevelGraphicsContext::setOrigin ( Point< int > )

pure virtual

Moves the origin to a new position.

The coordinates are relative to the current origin, and indicate the new position of (0, 0).

addTransform()

virtual void juce::LowLevelGraphicsContext::addTransform ( const AffineTransform & )

pure virtual

getPhysicalPixelScaleFactor()

virtual float juce::LowLevelGraphicsContext::getPhysicalPixelScaleFactor ( ) const

pure virtual

Referenced by strokePath().

clipToRectangle()

virtual bool juce::LowLevelGraphicsContext::clipToRectangle ( const Rectangle< int > & )

pure virtual

clipToRectangleList()

virtual bool juce::LowLevelGraphicsContext::clipToRectangleList ( const RectangleList< int > & )

pure virtual

excludeClipRectangle()

virtual void juce::LowLevelGraphicsContext::excludeClipRectangle ( const Rectangle< int > & )

pure virtual

clipToPath()

virtual void juce::LowLevelGraphicsContext::clipToPath ( const Path & , const AffineTransform &  )

pure virtual

clipToImageAlpha()

virtual void juce::LowLevelGraphicsContext::clipToImageAlpha ( const Image & , const AffineTransform &  )

pure virtual

clipRegionIntersects()

virtual bool juce::LowLevelGraphicsContext::clipRegionIntersects ( const Rectangle< int > & )

pure virtual

getClipBounds()

virtual Rectangle< int > juce::LowLevelGraphicsContext::getClipBounds ( ) const

pure virtual

Referenced by fillAll().

isClipEmpty()

virtual bool juce::LowLevelGraphicsContext::isClipEmpty ( ) const

pure virtual

saveState()

virtual void juce::LowLevelGraphicsContext::saveState ( )

pure virtual

restoreState()

virtual void juce::LowLevelGraphicsContext::restoreState ( )

pure virtual

beginTransparencyLayer()

virtual void juce::LowLevelGraphicsContext::beginTransparencyLayer ( float opacity )

pure virtual

endTransparencyLayer()

virtual void juce::LowLevelGraphicsContext::endTransparencyLayer ( )

pure virtual

setFill()

virtual void juce::LowLevelGraphicsContext::setFill ( const FillType & )

pure virtual

setOpacity()

virtual void juce::LowLevelGraphicsContext::setOpacity ( float )

pure virtual

setInterpolationQuality()

virtual void juce::LowLevelGraphicsContext::setInterpolationQuality ( Graphics::ResamplingQuality )

pure virtual

fillAll()

virtual void juce::LowLevelGraphicsContext::fillAll ( )

inlinevirtual

References fillRect(), and getClipBounds().

fillRect() [1/2]

virtual void juce::LowLevelGraphicsContext::fillRect ( const Rectangle< int > & , bool replaceExistingContents )

pure virtual

Referenced by fillAll().

fillRect() [2/2]

virtual void juce::LowLevelGraphicsContext::fillRect ( const Rectangle< float > & )

pure virtual

fillRectList()

virtual void juce::LowLevelGraphicsContext::fillRectList ( const RectangleList< float > & )

pure virtual

Referenced by drawRect().

fillPath()

virtual void juce::LowLevelGraphicsContext::fillPath ( const Path & , const AffineTransform &  )

pure virtual

Referenced by drawEllipse(), drawLineWithThickness(), fillEllipse(), fillRoundedRectangle(), and strokePath().

drawRect()

virtual void juce::LowLevelGraphicsContext::drawRect ( const Rectangle< float > & rect, float lineThickness )

inlinevirtual

References juce::RectangleList< ValueType >::addWithoutMerging(), and fillRectList().

strokePath()

virtual void juce::LowLevelGraphicsContext::strokePath ( const Path & path, const PathStrokeType & strokeType, const AffineTransform & transform )

inlinevirtual

References juce::PathStrokeType::createStrokedPath(), fillPath(), and getPhysicalPixelScaleFactor().

Referenced by drawEllipse(), and drawRoundedRectangle().

drawImage()

virtual void juce::LowLevelGraphicsContext::drawImage ( const Image & , const AffineTransform &  )

pure virtual

drawLine()

virtual void juce::LowLevelGraphicsContext::drawLine ( const Line< float > & )

pure virtual

drawLineWithThickness()

virtual void juce::LowLevelGraphicsContext::drawLineWithThickness ( const Line< float > & line, float lineThickness )

inlinevirtual

References juce::Path::addLineSegment(), and fillPath().

setFont()

virtual void juce::LowLevelGraphicsContext::setFont ( const Font & )

pure virtual

getFont()

virtual const Font & juce::LowLevelGraphicsContext::getFont ( )

pure virtual

drawGlyphs()

virtual void juce::LowLevelGraphicsContext::drawGlyphs ( Span< const uint16_t > , Span< const Point< float > > , const AffineTransform &  )

pure virtual

Uses the current font to draw the provided glyph numbers.

getPreferredImageTypeForTemporaryImages()

virtual std::unique_ptr< ImageType > juce::LowLevelGraphicsContext::getPreferredImageTypeForTemporaryImages ( ) const

pure virtual

Returns the optimal ImageType for creating temporary images in this GraphicsContext.

While this typically matches the GraphicsContext's native ImageType, certain scenarios may benefit from using a different format for temporary operations (e.g., for performance, memory efficiency, or specific rendering requirements).

Returns

A unique_ptr to the recommended ImageType instance for temporary images

drawRoundedRectangle()

virtual void juce::LowLevelGraphicsContext::drawRoundedRectangle ( const Rectangle< float > & r, float cornerSize, float lineThickness )

inlinevirtual

References juce::Path::addRoundedRectangle(), and strokePath().

fillRoundedRectangle()

virtual void juce::LowLevelGraphicsContext::fillRoundedRectangle ( const Rectangle< float > & r, float cornerSize )

inlinevirtual

References juce::Path::addRoundedRectangle(), and fillPath().

drawEllipse()

virtual void juce::LowLevelGraphicsContext::drawEllipse ( const Rectangle< float > & area, float lineThickness )

inlinevirtual

References juce::Path::addEllipse(), juce::approximatelyEqual(), juce::Rectangle< ValueType >::expanded(), fillPath(), juce::Rectangle< ValueType >::getHeight(), juce::Rectangle< ValueType >::getWidth(), juce::Rectangle< ValueType >::reduced(), juce::Path::setUsingNonZeroWinding(), and strokePath().

fillEllipse()

virtual void juce::LowLevelGraphicsContext::fillEllipse ( const Rectangle< float > & area )

inlinevirtual

References juce::Path::addEllipse(), and fillPath().

getFrameId()

virtual uint64_t juce::LowLevelGraphicsContext::getFrameId ( ) const

pure virtual

Returns an integer that uniquely identifies the current frame.

Useful for debugging/logging.