A graphics context, used for drawing a component or image. More...

#include <juce_GraphicsContext.h>

Classes
class	ScopedSaveState
	Uses RAII to save and restore the state of a graphics context. More...

Public Types
enum	ResamplingQuality { lowResamplingQuality = 0 , mediumResamplingQuality = 1 , highResamplingQuality = 2 }
	Types of rendering quality that can be specified when drawing images. More...

Public Member Functions
	Graphics (const Image &imageToDrawOnto)
	Creates a Graphics object to draw directly onto the given image.

void	setColour (Colour newColour)
	Changes the current drawing colour.

void	setOpacity (float newOpacity)
	Changes the opacity to use with the current colour.

void	setGradientFill (const ColourGradient &gradient)
	Sets the context to use a gradient for its fill pattern.

void	setGradientFill (ColourGradient &&gradient)
	Sets the context to use a gradient for its fill pattern.

void	setTiledImageFill (const Image &imageToUse, int anchorX, int anchorY, float opacity)
	Sets the context to use a tiled image pattern for filling.

void	setFillType (const FillType &newFill)
	Changes the current fill settings.

void	setFont (const Font &newFont)
	Changes the font to use for subsequent text-drawing functions.

void	setFont (float newFontHeight)
	Changes the size of the currently-selected font.

Font	getCurrentFont () const
	Returns the currently selected font.

void	drawSingleLineText (const String &text, int startX, int baselineY, Justification justification=Justification::left) const
	Draws a one-line text string.

void	drawMultiLineText (const String &text, int startX, int baselineY, int maximumLineWidth, Justification justification=Justification::left, float leading=0.0f) const
	Draws text across multiple lines.

void	drawText (const String &text, int x, int y, int width, int height, Justification justificationType, bool useEllipsesIfTooBig=true) const
	Draws a line of text within a specified rectangle.

void	drawText (const String &text, Rectangle< int > area, Justification justificationType, bool useEllipsesIfTooBig=true) const
	Draws a line of text within a specified rectangle.

void	drawText (const String &text, Rectangle< float > area, Justification justificationType, bool useEllipsesIfTooBig=true) const
	Draws a line of text within a specified rectangle.

void	drawFittedText (const String &text, int x, int y, int width, int height, Justification justificationFlags, int maximumNumberOfLines, float minimumHorizontalScale=0.0f) const
	Tries to draw a text string inside a given space.

void	drawFittedText (const String &text, Rectangle< int > area, Justification justificationFlags, int maximumNumberOfLines, float minimumHorizontalScale=0.0f) const
	Tries to draw a text string inside a given space.

void	fillAll () const
	Fills the context's entire clip region with the current colour or brush.

void	fillAll (Colour colourToUse) const
	Fills the context's entire clip region with a given colour.

void	fillRect (Rectangle< int > rectangle) const
	Fills a rectangle with the current colour or brush.

void	fillRect (Rectangle< float > rectangle) const
	Fills a rectangle with the current colour or brush.

void	fillRect (int x, int y, int width, int height) const
	Fills a rectangle with the current colour or brush.

void	fillRect (float x, float y, float width, float height) const
	Fills a rectangle with the current colour or brush.

void	fillRectList (const RectangleList< float > &rectangles) const
	Fills a set of rectangles using the current colour or brush.

void	fillRectList (const RectangleList< int > &rectangles) const
	Fills a set of rectangles using the current colour or brush.

void	fillRoundedRectangle (float x, float y, float width, float height, float cornerSize) const
	Uses the current colour or brush to fill a rectangle with rounded corners.

void	fillRoundedRectangle (Rectangle< float > rectangle, float cornerSize) const
	Uses the current colour or brush to fill a rectangle with rounded corners.

void	fillCheckerBoard (Rectangle< float > area, float checkWidth, float checkHeight, Colour colour1, Colour colour2) const
	Fills a rectangle with a checkerboard pattern, alternating between two colours.

void	drawRect (int x, int y, int width, int height, int lineThickness=1) const
	Draws a rectangular outline, using the current colour or brush.

void	drawRect (float x, float y, float width, float height, float lineThickness=1.0f) const
	Draws a rectangular outline, using the current colour or brush.

void	drawRect (Rectangle< int > rectangle, int lineThickness=1) const
	Draws a rectangular outline, using the current colour or brush.

void	drawRect (Rectangle< float > rectangle, float lineThickness=1.0f) const
	Draws a rectangular outline, using the current colour or brush.

void	drawRoundedRectangle (float x, float y, float width, float height, float cornerSize, float lineThickness) const
	Uses the current colour or brush to draw the outline of a rectangle with rounded corners.

void	drawRoundedRectangle (Rectangle< float > rectangle, float cornerSize, float lineThickness) const
	Uses the current colour or brush to draw the outline of a rectangle with rounded corners.

void	fillEllipse (float x, float y, float width, float height) const
	Fills an ellipse with the current colour or brush.

void	fillEllipse (Rectangle< float > area) const
	Fills an ellipse with the current colour or brush.

void	drawEllipse (float x, float y, float width, float height, float lineThickness) const
	Draws an elliptical stroke using the current colour or brush.

void	drawEllipse (Rectangle< float > area, float lineThickness) const
	Draws an elliptical stroke using the current colour or brush.

void	drawLine (float startX, float startY, float endX, float endY) const
	Draws a line between two points.

void	drawLine (float startX, float startY, float endX, float endY, float lineThickness) const
	Draws a line between two points with a given thickness.

void	drawLine (Line< float > line) const
	Draws a line between two points.

void	drawLine (Line< float > line, float lineThickness) const
	Draws a line between two points with a given thickness.

void	drawDashedLine (Line< float > line, const float *dashLengths, int numDashLengths, float lineThickness=1.0f, int dashIndexToStartFrom=0) const
	Draws a dashed line using a custom set of dash-lengths.

void	drawVerticalLine (int x, float top, float bottom) const
	Draws a vertical line of pixels at a given x position.

void	drawHorizontalLine (int y, float left, float right) const
	Draws a horizontal line of pixels at a given y position.

void	fillPath (const Path &path) const
	Fills a path using the currently selected colour or brush.

void	fillPath (const Path &path, const AffineTransform &transform) const
	Fills a path using the currently selected colour or brush, and adds a transform.

void	strokePath (const Path &path, const PathStrokeType &strokeType, const AffineTransform &transform={}) const
	Draws a path's outline using the currently selected colour or brush.

void	drawArrow (Line< float > line, float lineThickness, float arrowheadWidth, float arrowheadLength) const
	Draws a line with an arrowhead at its end.

void	setImageResamplingQuality (ResamplingQuality newQuality)
	Changes the quality that will be used when resampling images.

void	drawImageAt (const Image &imageToDraw, int topLeftX, int topLeftY, bool fillAlphaChannelWithCurrentBrush=false) const
	Draws an image.

void	drawImage (const Image &imageToDraw, int destX, int destY, int destWidth, int destHeight, int sourceX, int sourceY, int sourceWidth, int sourceHeight, bool fillAlphaChannelWithCurrentBrush=false) const
	Draws part of an image, rescaling it to fit in a given target region.

void	drawImageTransformed (const Image &imageToDraw, const AffineTransform &transform, bool fillAlphaChannelWithCurrentBrush=false) const
	Draws an image, having applied an affine transform to it.

void	drawImage (const Image &imageToDraw, Rectangle< float > targetArea, RectanglePlacement placementWithinTarget=RectanglePlacement::stretchToFit, bool fillAlphaChannelWithCurrentBrush=false) const
	Draws an image to fit within a designated rectangle.

void	drawImageWithin (const Image &imageToDraw, int destX, int destY, int destWidth, int destHeight, RectanglePlacement placementWithinTarget, bool fillAlphaChannelWithCurrentBrush=false) const
	Draws an image to fit within a designated rectangle.

Rectangle< int >	getClipBounds () const
	Returns the position of the bounding box for the current clipping region.

bool	clipRegionIntersects (Rectangle< int > area) const
	Checks whether a rectangle overlaps the context's clipping region.

bool	reduceClipRegion (int x, int y, int width, int height)
	Intersects the current clipping region with another region.

bool	reduceClipRegion (Rectangle< int > area)
	Intersects the current clipping region with another region.

bool	reduceClipRegion (const RectangleList< int > &clipRegion)
	Intersects the current clipping region with a rectangle list region.

bool	reduceClipRegion (const Path &path, const AffineTransform &transform=AffineTransform())
	Intersects the current clipping region with a path.

bool	reduceClipRegion (const Image &image, const AffineTransform &transform)
	Intersects the current clipping region with an image's alpha-channel.

void	excludeClipRegion (Rectangle< int > rectangleToExclude)
	Excludes a rectangle to stop it being drawn into.

bool	isClipEmpty () const
	Returns true if no drawing can be done because the clip region is zero.

void	saveState ()
	Saves the current graphics state on an internal stack.

void	restoreState ()
	Restores a graphics state that was previously saved with saveState().

void	beginTransparencyLayer (float layerOpacity)
	Begins rendering to an off-screen bitmap which will later be flattened onto the current context with the given opacity.

void	endTransparencyLayer ()
	Completes a drawing operation to a temporary semi-transparent buffer.

void	setOrigin (Point< int > newOrigin)
	Moves the position of the context's origin.

void	setOrigin (int newOriginX, int newOriginY)
	Moves the position of the context's origin.

void	addTransform (const AffineTransform &transform)
	Adds a transformation which will be performed on all the graphics operations that the context subsequently performs.

void	resetToDefaultState ()
	Resets the current colour, brush, and font to default settings.

bool	isVectorDevice () const
	Returns true if this context is drawing to a vector-based device, such as a printer.

	Graphics (LowLevelGraphicsContext &) noexcept
	Create a graphics that draws with a given low-level renderer.

LowLevelGraphicsContext &	getInternalContext () const noexcept

Detailed Description

A graphics context, used for drawing a component or image.

When a Component needs painting, a Graphics context is passed to its Component::paint() method, and this you then call methods within this object to actually draw the component's content.

A Graphics can also be created from an image, to allow drawing directly onto that image.

See also: Component::paint

Member Enumeration Documentation

◆ ResamplingQuality

enum Graphics::ResamplingQuality

Types of rendering quality that can be specified when drawing images.

See also: Graphics::setImageResamplingQuality

Enumerator
lowResamplingQuality	Just uses a nearest-neighbour algorithm for resampling.
mediumResamplingQuality	Uses bilinear interpolation for upsampling and area-averaging for downsampling.
highResamplingQuality	Uses bicubic interpolation for upsampling and area-averaging for downsampling.

Constructor & Destructor Documentation

◆ Graphics() [1/2]

Graphics::Graphics ( const Image & imageToDrawOnto )

explicit

Creates a Graphics object to draw directly onto the given image.

The graphics object that is created will be set up to draw onto the image, with the context's clipping area being the entire size of the image, and its origin being the image's origin. To draw into a subsection of an image, use the reduceClipRegion() and setOrigin() methods.

Obviously you shouldn't delete the image before this context is deleted.

◆ Graphics() [2/2]

Graphics::Graphics ( LowLevelGraphicsContext & )

noexcept

Create a graphics that draws with a given low-level renderer.

This method is intended for use only by people who know what they're doing. Note that the LowLevelGraphicsContext will NOT be deleted by this object.

Member Function Documentation

◆ setColour()

void Graphics::setColour ( Colour newColour )

Changes the current drawing colour.

This sets the colour that will now be used for drawing operations - it also sets the opacity to that of the colour passed-in.

If a brush is being used when this method is called, the brush will be deselected, and any subsequent drawing will be done with a solid colour brush instead.

See also: setOpacity

◆ setOpacity()

void Graphics::setOpacity ( float newOpacity )

Changes the opacity to use with the current colour.

If a solid colour is being used for drawing, this changes its opacity to this new value (i.e. it doesn't multiply the colour's opacity by this amount).

If a gradient is being used, this will have no effect on it.

A value of 0.0 is completely transparent, 1.0 is completely opaque.

◆ setGradientFill() [1/2]

void Graphics::setGradientFill ( const ColourGradient & gradient )

Sets the context to use a gradient for its fill pattern.

◆ setGradientFill() [2/2]

void Graphics::setGradientFill ( ColourGradient && gradient )

Sets the context to use a gradient for its fill pattern.

◆ setTiledImageFill()

void Graphics::setTiledImageFill	(	const Image &	imageToUse,
		int	anchorX,
		int	anchorY,
		float	opacity )

Sets the context to use a tiled image pattern for filling.

Make sure that you don't delete this image while it's still being used by this context!

◆ setFillType()

void Graphics::setFillType ( const FillType & newFill )

Changes the current fill settings.

See also: setColour, setGradientFill, setTiledImageFill

◆ setFont() [1/2]

void Graphics::setFont ( const Font & newFont )

Changes the font to use for subsequent text-drawing functions.

See also: drawSingleLineText, drawMultiLineText, drawText, drawFittedText

◆ setFont() [2/2]

void Graphics::setFont ( float newFontHeight )

Changes the size of the currently-selected font.

This is a convenient shortcut that changes the context's current font to a different size. The typeface won't be changed.

See also: Font

◆ getCurrentFont()

Font Graphics::getCurrentFont ( ) const

Returns the currently selected font.

◆ drawSingleLineText()

void Graphics::drawSingleLineText	(	const String &	text,
		int	startX,
		int	baselineY,
		Justification	justification = Justification::left ) const

Draws a one-line text string.

This will use the current colour (or brush) to fill the text. The font is the last one specified by setFont().

Parameters

text	the string to draw
startX	the position to draw the left-hand edge of the text
baselineY	the position of the text's baseline
justification	the horizontal flags indicate which end of the text string is anchored at the specified point.

See also: drawMultiLineText, drawText, drawFittedText, GlyphArrangement::addLineOfText

◆ drawMultiLineText()

void Graphics::drawMultiLineText	(	const String &	text,
		int	startX,
		int	baselineY,
		int	maximumLineWidth,
		Justification	justification = Justification::left,
		float	leading = 0.0f ) const

Draws text across multiple lines.

This will break the text onto a new line where there's a new-line or carriage-return character, or at a word-boundary when the text becomes wider than the size specified by the maximumLineWidth parameter. New-lines will be vertically separated by the specified leading.

See also: setFont, drawSingleLineText, drawFittedText, GlyphArrangement::addJustifiedText

◆ drawText() [1/3]

void Graphics::drawText	(	const String &	text,
		int	x,
		int	y,
		int	width,
		int	height,
		Justification	justificationType,
		bool	useEllipsesIfTooBig = true ) const

Draws a line of text within a specified rectangle.

The text will be positioned within the rectangle based on the justification flags passed-in. If the string is too long to fit inside the rectangle, it will either be truncated or will have ellipsis added to its end (if the useEllipsesIfTooBig flag is true).

See also: drawSingleLineText, drawFittedText, drawMultiLineText, GlyphArrangement::addJustifiedText

◆ drawText() [2/3]

void Graphics::drawText	(	const String &	text,
		Rectangle< int >	area,
		Justification	justificationType,
		bool	useEllipsesIfTooBig = true ) const

Draws a line of text within a specified rectangle.

The text will be positioned within the rectangle based on the justification flags passed-in. If the string is too long to fit inside the rectangle, it will either be truncated or will have ellipsis added to its end (if the useEllipsesIfTooBig flag is true).

See also: drawSingleLineText, drawFittedText, drawMultiLineText, GlyphArrangement::addJustifiedText

◆ drawText() [3/3]

void Graphics::drawText	(	const String &	text,
		Rectangle< float >	area,
		Justification	justificationType,
		bool	useEllipsesIfTooBig = true ) const

Draws a line of text within a specified rectangle.

The text will be positioned within the rectangle based on the justification flags passed-in. If the string is too long to fit inside the rectangle, it will either be truncated or will have ellipsis added to its end (if the useEllipsesIfTooBig flag is true).

See also: drawSingleLineText, drawFittedText, drawMultiLineText, GlyphArrangement::addJustifiedText

◆ drawFittedText() [1/2]

void Graphics::drawFittedText	(	const String &	text,
		int	x,
		int	y,
		int	width,
		int	height,
		Justification	justificationFlags,
		int	maximumNumberOfLines,
		float	minimumHorizontalScale = 0.0f ) const

Tries to draw a text string inside a given space.

This does its best to make the given text readable within the specified rectangle, so it's useful for labelling things.

If the text is too big, it'll be squashed horizontally or broken over multiple lines if the maximumLinesToUse value allows this. If the text just won't fit into the space, it'll cram as much as possible in there, and put some ellipsis at the end to show that it's been truncated.

A Justification parameter lets you specify how the text is laid out within the rectangle, both horizontally and vertically.

The minimumHorizontalScale parameter specifies how much the text can be squashed horizontally to try to squeeze it into the space. If you don't want any horizontal scaling to occur, you can set this value to 1.0f. Pass 0 if you want it to use a default value.

See also: GlyphArrangement::addFittedText

◆ drawFittedText() [2/2]

void Graphics::drawFittedText	(	const String &	text,
		Rectangle< int >	area,
		Justification	justificationFlags,
		int	maximumNumberOfLines,
		float	minimumHorizontalScale = 0.0f ) const

Tries to draw a text string inside a given space.

This does its best to make the given text readable within the specified rectangle, so it's useful for labelling things.

If the text is too big, it'll be squashed horizontally or broken over multiple lines if the maximumLinesToUse value allows this. If the text just won't fit into the space, it'll cram as much as possible in there, and put some ellipsis at the end to show that it's been truncated.

A Justification parameter lets you specify how the text is laid out within the rectangle, both horizontally and vertically.

The minimumHorizontalScale parameter specifies how much the text can be squashed horizontally to try to squeeze it into the space. If you don't want any horizontal scaling to occur, you can set this value to 1.0f. Pass 0 if you want it to use a default value.

See also: GlyphArrangement::addFittedText

◆ fillAll() [1/2]

void Graphics::fillAll ( ) const

Fills the context's entire clip region with the current colour or brush.

(See also the fillAll (Colour) method which is a quick way of filling it with a given colour).

◆ fillAll() [2/2]

void Graphics::fillAll ( Colour colourToUse ) const

Fills the context's entire clip region with a given colour.

This leaves the context's current colour and brush unchanged, it just uses the specified colour temporarily.

◆ fillRect() [1/4]

void Graphics::fillRect ( Rectangle< int > rectangle ) const

Fills a rectangle with the current colour or brush.

See also: drawRect, fillRoundedRectangle

◆ fillRect() [2/4]

void Graphics::fillRect ( Rectangle< float > rectangle ) const

Fills a rectangle with the current colour or brush.

See also: drawRect, fillRoundedRectangle

◆ fillRect() [3/4]

void Graphics::fillRect	(	int	x,
		int	y,
		int	width,
		int	height ) const

Fills a rectangle with the current colour or brush.

See also: drawRect, fillRoundedRectangle

◆ fillRect() [4/4]

void Graphics::fillRect	(	float	x,
		float	y,
		float	width,
		float	height ) const

Fills a rectangle with the current colour or brush.

See also: drawRect, fillRoundedRectangle

◆ fillRectList() [1/2]

void Graphics::fillRectList ( const RectangleList< float > & rectangles ) const

Fills a set of rectangles using the current colour or brush.

If you have a lot of rectangles to draw, it may be more efficient to create a RectangleList and use this method than to call fillRect() multiple times.

◆ fillRectList() [2/2]

void Graphics::fillRectList ( const RectangleList< int > & rectangles ) const

Fills a set of rectangles using the current colour or brush.

If you have a lot of rectangles to draw, it may be more efficient to create a RectangleList and use this method than to call fillRect() multiple times.

◆ fillRoundedRectangle() [1/2]

void Graphics::fillRoundedRectangle	(	float	x,
		float	y,
		float	width,
		float	height,
		float	cornerSize ) const

Uses the current colour or brush to fill a rectangle with rounded corners.

See also: drawRoundedRectangle, Path::addRoundedRectangle

◆ fillRoundedRectangle() [2/2]

void Graphics::fillRoundedRectangle	(	Rectangle< float >	rectangle,
		float	cornerSize ) const

Uses the current colour or brush to fill a rectangle with rounded corners.

See also: drawRoundedRectangle, Path::addRoundedRectangle

◆ fillCheckerBoard()

void Graphics::fillCheckerBoard	(	Rectangle< float >	area,
		float	checkWidth,
		float	checkHeight,
		Colour	colour1,
		Colour	colour2 ) const

Fills a rectangle with a checkerboard pattern, alternating between two colours.

◆ drawRect() [1/4]

void Graphics::drawRect	(	int	x,
		int	y,
		int	width,
		int	height,
		int	lineThickness = 1 ) const

Draws a rectangular outline, using the current colour or brush.

The lines are drawn inside the given rectangle, and greater line thicknesses extend inwards.

See also: fillRect

◆ drawRect() [2/4]

void Graphics::drawRect	(	float	x,
		float	y,
		float	width,
		float	height,
		float	lineThickness = 1.0f ) const

Draws a rectangular outline, using the current colour or brush.

The lines are drawn inside the given rectangle, and greater line thicknesses extend inwards.

See also: fillRect

◆ drawRect() [3/4]

void Graphics::drawRect	(	Rectangle< int >	rectangle,
		int	lineThickness = 1 ) const

Draws a rectangular outline, using the current colour or brush.

The lines are drawn inside the given rectangle, and greater line thicknesses extend inwards.

See also: fillRect

◆ drawRect() [4/4]

void Graphics::drawRect	(	Rectangle< float >	rectangle,
		float	lineThickness = 1.0f ) const

Draws a rectangular outline, using the current colour or brush.

The lines are drawn inside the given rectangle, and greater line thicknesses extend inwards.

See also: fillRect

◆ drawRoundedRectangle() [1/2]

void Graphics::drawRoundedRectangle	(	float	x,
		float	y,
		float	width,
		float	height,
		float	cornerSize,
		float	lineThickness ) const

Uses the current colour or brush to draw the outline of a rectangle with rounded corners.

See also: fillRoundedRectangle, Path::addRoundedRectangle

◆ drawRoundedRectangle() [2/2]

void Graphics::drawRoundedRectangle	(	Rectangle< float >	rectangle,
		float	cornerSize,
		float	lineThickness ) const

Uses the current colour or brush to draw the outline of a rectangle with rounded corners.

See also: fillRoundedRectangle, Path::addRoundedRectangle

◆ fillEllipse() [1/2]

void Graphics::fillEllipse	(	float	x,
		float	y,
		float	width,
		float	height ) const

Fills an ellipse with the current colour or brush.

The ellipse is drawn to fit inside the given rectangle.

See also: drawEllipse, Path::addEllipse

◆ fillEllipse() [2/2]

void Graphics::fillEllipse ( Rectangle< float > area ) const

Fills an ellipse with the current colour or brush.

The ellipse is drawn to fit inside the given rectangle.

See also: drawEllipse, Path::addEllipse

◆ drawEllipse() [1/2]

void Graphics::drawEllipse	(	float	x,
		float	y,
		float	width,
		float	height,
		float	lineThickness ) const

Draws an elliptical stroke using the current colour or brush.

See also: fillEllipse, Path::addEllipse

◆ drawEllipse() [2/2]

void Graphics::drawEllipse	(	Rectangle< float >	area,
		float	lineThickness ) const

Draws an elliptical stroke using the current colour or brush.

See also: fillEllipse, Path::addEllipse

◆ drawLine() [1/4]

void Graphics::drawLine	(	float	startX,
		float	startY,
		float	endX,
		float	endY ) const

Draws a line between two points.

The line is 1 pixel wide and drawn with the current colour or brush. TIP: If you're trying to draw horizontal or vertical lines, don't use this - it's better to use fillRect() instead unless you really need an angled line.

◆ drawLine() [2/4]

void Graphics::drawLine	(	float	startX,
		float	startY,
		float	endX,
		float	endY,
		float	lineThickness ) const

Draws a line between two points with a given thickness.

TIP: If you're trying to draw horizontal or vertical lines, don't use this - it's better to use fillRect() instead unless you really need an angled line.

See also: Path::addLineSegment

◆ drawLine() [3/4]

void Graphics::drawLine ( Line< float > line ) const

Draws a line between two points.

The line is 1 pixel wide and drawn with the current colour or brush. TIP: If you're trying to draw horizontal or vertical lines, don't use this - it's better to use fillRect() instead unless you really need an angled line.

◆ drawLine() [4/4]

void Graphics::drawLine	(	Line< float >	line,
		float	lineThickness ) const

Draws a line between two points with a given thickness.

See also: Path::addLineSegment TIP: If you're trying to draw horizontal or vertical lines, don't use this - it's better to use fillRect() instead unless you really need an angled line.

◆ drawDashedLine()

void Graphics::drawDashedLine	(	Line< float >	line,
		const float *	dashLengths,
		int	numDashLengths,
		float	lineThickness = 1.0f,
		int	dashIndexToStartFrom = 0 ) const

Draws a dashed line using a custom set of dash-lengths.

Parameters

line	the line to draw
dashLengths	a series of lengths to specify the on/off lengths - e.g. { 4, 5, 6, 7 } will draw a line of 4 pixels, skip 5 pixels, draw 6 pixels, skip 7 pixels, and then repeat.
numDashLengths	the number of elements in the array (this must be an even number).
lineThickness	the thickness of the line to draw
dashIndexToStartFrom	the index in the dash-length array to use for the first segment

See also: PathStrokeType::createDashedStroke

◆ drawVerticalLine()

void Graphics::drawVerticalLine	(	int	x,
		float	top,
		float	bottom ) const

Draws a vertical line of pixels at a given x position.

The x position is an integer, but the top and bottom of the line can be sub-pixel positions, and these will be anti-aliased if necessary.

The bottom parameter must be greater than or equal to the top parameter.

◆ drawHorizontalLine()

void Graphics::drawHorizontalLine	(	int	y,
		float	left,
		float	right ) const

Draws a horizontal line of pixels at a given y position.

The y position is an integer, but the left and right ends of the line can be sub-pixel positions, and these will be anti-aliased if necessary.

The right parameter must be greater than or equal to the left parameter.

◆ fillPath() [1/2]

void Graphics::fillPath ( const Path & path ) const

Fills a path using the currently selected colour or brush.

◆ fillPath() [2/2]

void Graphics::fillPath	(	const Path &	path,
		const AffineTransform &	transform ) const

Fills a path using the currently selected colour or brush, and adds a transform.

◆ strokePath()

void Graphics::strokePath	(	const Path &	path,
		const PathStrokeType &	strokeType,
		const AffineTransform &	transform = {} ) const

Draws a path's outline using the currently selected colour or brush.

◆ drawArrow()

void Graphics::drawArrow	(	Line< float >	line,
		float	lineThickness,
		float	arrowheadWidth,
		float	arrowheadLength ) const

Draws a line with an arrowhead at its end.

Parameters

line	the line to draw
lineThickness	the thickness of the line
arrowheadWidth	the width of the arrow head (perpendicular to the line)
arrowheadLength	the length of the arrow head (along the length of the line)

◆ setImageResamplingQuality()

void Graphics::setImageResamplingQuality ( ResamplingQuality newQuality )

Changes the quality that will be used when resampling images.

By default a Graphics object will be set to mediumRenderingQuality.

See also: Graphics::drawImage, Graphics::drawImageTransformed, Graphics::drawImageWithin

◆ drawImageAt()

void Graphics::drawImageAt	(	const Image &	imageToDraw,
		int	topLeftX,
		int	topLeftY,
		bool	fillAlphaChannelWithCurrentBrush = false ) const

Draws an image.

This will draw the whole of an image, positioning its top-left corner at the given coordinates, and keeping its size the same. This is the simplest image drawing method - the others give more control over the scaling and clipping of the images.

Images are composited using the context's current opacity, so if you don't want it to be drawn semi-transparently, be sure to call setOpacity (1.0f) (or setColour() with an opaque colour) before drawing images.

◆ drawImage() [1/2]

void Graphics::drawImage	(	const Image &	imageToDraw,
		int	destX,
		int	destY,
		int	destWidth,
		int	destHeight,
		int	sourceX,
		int	sourceY,
		int	sourceWidth,
		int	sourceHeight,
		bool	fillAlphaChannelWithCurrentBrush = false ) const

Draws part of an image, rescaling it to fit in a given target region.

The specified area of the source image is rescaled and drawn to fill the specified destination rectangle.

Images are composited using the context's current opacity, so if you don't want it to be drawn semi-transparently, be sure to call setOpacity (1.0f) (or setColour() with an opaque colour) before drawing images.

Parameters

imageToDraw	the image to overlay
destX	the left of the destination rectangle
destY	the top of the destination rectangle
destWidth	the width of the destination rectangle
destHeight	the height of the destination rectangle
sourceX	the left of the rectangle to copy from the source image
sourceY	the top of the rectangle to copy from the source image
sourceWidth	the width of the rectangle to copy from the source image
sourceHeight	the height of the rectangle to copy from the source image
fillAlphaChannelWithCurrentBrush	if true, then instead of drawing the source image's pixels, the source image's alpha channel is used as a mask with which to fill the destination using the current colour or brush. (If the source is has no alpha channel, then it will just fill the target with a solid rectangle)

See also: setImageResamplingQuality, drawImageAt, drawImageWithin, fillAlphaMap

◆ drawImageTransformed()

void Graphics::drawImageTransformed	(	const Image &	imageToDraw,
		const AffineTransform &	transform,
		bool	fillAlphaChannelWithCurrentBrush = false ) const

Draws an image, having applied an affine transform to it.

This lets you throw the image around in some wacky ways, rotate it, shear, scale it, etc.

Images are composited using the context's current opacity, so if you don't want it to be drawn semi-transparently, be sure to call setOpacity (1.0f) (or setColour() with an opaque colour) before drawing images.

If fillAlphaChannelWithCurrentBrush is set to true, then the image's RGB channels are ignored and it is filled with the current brush, masked by its alpha channel.

If you want to render only a subsection of an image, use Image::getClippedImage() to create the section that you need.

See also: setImageResamplingQuality, drawImage

◆ drawImage() [2/2]

void Graphics::drawImage	(	const Image &	imageToDraw,
		Rectangle< float >	targetArea,
		RectanglePlacement	placementWithinTarget = RectanglePlacement::stretchToFit,
		bool	fillAlphaChannelWithCurrentBrush = false ) const

Draws an image to fit within a designated rectangle.

Parameters

imageToDraw	the source image to draw
targetArea	the target rectangle to fit it into
placementWithinTarget	this specifies how the image should be positioned within the target rectangle - see the RectanglePlacement class for more details about this.
fillAlphaChannelWithCurrentBrush	if true, then instead of drawing the image, just its alpha channel will be used as a mask with which to draw with the current brush or colour. This is similar to fillAlphaMap(), and see also drawImage()

See also: drawImage, drawImageTransformed, drawImageAt, RectanglePlacement

◆ drawImageWithin()

void Graphics::drawImageWithin	(	const Image &	imageToDraw,
		int	destX,
		int	destY,
		int	destWidth,
		int	destHeight,
		RectanglePlacement	placementWithinTarget,
		bool	fillAlphaChannelWithCurrentBrush = false ) const

Draws an image to fit within a designated rectangle.

If the image is too big or too small for the space, it will be rescaled to fit as nicely as it can do without affecting its aspect ratio. It will then be placed within the target rectangle according to the justification flags specified.

Parameters

imageToDraw	the source image to draw
destX	top-left of the target rectangle to fit it into
destY	top-left of the target rectangle to fit it into
destWidth	size of the target rectangle to fit the image into
destHeight	size of the target rectangle to fit the image into
placementWithinTarget	this specifies how the image should be positioned within the target rectangle - see the RectanglePlacement class for more details about this.
fillAlphaChannelWithCurrentBrush	if true, then instead of drawing the image, just its alpha channel will be used as a mask with which to draw with the current brush or colour. This is similar to fillAlphaMap(), and see also drawImage()

See also: setImageResamplingQuality, drawImage, drawImageTransformed, drawImageAt, RectanglePlacement

◆ getClipBounds()

Rectangle< int > Graphics::getClipBounds ( ) const

Returns the position of the bounding box for the current clipping region.

See also: clipRegionIntersects

◆ clipRegionIntersects()

bool Graphics::clipRegionIntersects ( Rectangle< int > area ) const

Checks whether a rectangle overlaps the context's clipping region.

If this returns false, no part of the given area can be drawn onto, so this method can be used to optimise a component's paint() method, by letting it avoid drawing complex objects that aren't within the region being repainted.

◆ reduceClipRegion() [1/5]

bool Graphics::reduceClipRegion	(	int	x,
		int	y,
		int	width,
		int	height )

Intersects the current clipping region with another region.

Returns: true if the resulting clipping region is non-zero in size

See also: setOrigin, clipRegionIntersects

◆ reduceClipRegion() [2/5]

bool Graphics::reduceClipRegion ( Rectangle< int > area )

Intersects the current clipping region with another region.

Returns: true if the resulting clipping region is non-zero in size

See also: setOrigin, clipRegionIntersects

◆ reduceClipRegion() [3/5]

bool Graphics::reduceClipRegion ( const RectangleList< int > & clipRegion )

Intersects the current clipping region with a rectangle list region.

Returns: true if the resulting clipping region is non-zero in size

See also: setOrigin, clipRegionIntersects

◆ reduceClipRegion() [4/5]

bool Graphics::reduceClipRegion	(	const Path &	path,
		const AffineTransform &	transform = AffineTransform() )

Intersects the current clipping region with a path.

Returns: true if the resulting clipping region is non-zero in size

See also: reduceClipRegion

◆ reduceClipRegion() [5/5]

bool Graphics::reduceClipRegion	(	const Image &	image,
		const AffineTransform &	transform )

Intersects the current clipping region with an image's alpha-channel.

The current clipping path is intersected with the area covered by this image's alpha-channel, after the image has been transformed by the specified matrix.

Parameters

image	the image whose alpha-channel should be used. If the image doesn't have an alpha-channel, it is treated as entirely opaque.
transform	a matrix to apply to the image

Returns: true if the resulting clipping region is non-zero in size

See also: reduceClipRegion

◆ excludeClipRegion()

void Graphics::excludeClipRegion ( Rectangle< int > rectangleToExclude )

Excludes a rectangle to stop it being drawn into.

◆ isClipEmpty()

bool Graphics::isClipEmpty ( ) const

Returns true if no drawing can be done because the clip region is zero.

◆ saveState()

void Graphics::saveState ( )

Saves the current graphics state on an internal stack.

To restore the state, use restoreState().

See also: ScopedSaveState

◆ restoreState()

void Graphics::restoreState ( )

Restores a graphics state that was previously saved with saveState().

See also: ScopedSaveState

◆ beginTransparencyLayer()

void Graphics::beginTransparencyLayer ( float layerOpacity )

Begins rendering to an off-screen bitmap which will later be flattened onto the current context with the given opacity.

The context uses an internal stack of temporary image layers to do this. When you've finished drawing to the layer, call endTransparencyLayer() to complete the operation and composite the finished layer. Every call to beginTransparencyLayer() MUST be matched by a corresponding call to endTransparencyLayer()!

This call also saves the current state, and endTransparencyLayer() restores it.

◆ endTransparencyLayer()

void Graphics::endTransparencyLayer ( )

Completes a drawing operation to a temporary semi-transparent buffer.

See beginTransparencyLayer() for more details.

◆ setOrigin() [1/2]

void Graphics::setOrigin ( Point< int > newOrigin )

Moves the position of the context's origin.

This changes the position that the context considers to be (0, 0) to the specified position.

So if you call setOrigin with (100, 100), then the position that was previously referred to as (100, 100) will subsequently be considered to be (0, 0).

See also: reduceClipRegion, addTransform

◆ setOrigin() [2/2]

void Graphics::setOrigin	(	int	newOriginX,
		int	newOriginY )

Moves the position of the context's origin.

This changes the position that the context considers to be (0, 0) to the specified position.

So if you call setOrigin (100, 100), then the position that was previously referred to as (100, 100) will subsequently be considered to be (0, 0).

See also: reduceClipRegion, addTransform

◆ addTransform()

void Graphics::addTransform ( const AffineTransform & transform )

Adds a transformation which will be performed on all the graphics operations that the context subsequently performs.

After calling this, all the coordinates that are passed into the context will be transformed by this matrix.

See also: setOrigin

◆ resetToDefaultState()

void Graphics::resetToDefaultState ( )

Resets the current colour, brush, and font to default settings.

◆ isVectorDevice()

bool Graphics::isVectorDevice ( ) const

Returns true if this context is drawing to a vector-based device, such as a printer.

◆ getInternalContext()

LowLevelGraphicsContext & Graphics::getInternalContext ( ) const

noexcept

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

juce_GraphicsContext.h

Classes

Public Types

Public Member Functions

Detailed Description

Member Enumeration Documentation

◆ ResamplingQuality

Constructor & Destructor Documentation

◆ Graphics() [1/2]

◆ Graphics() [2/2]

Member Function Documentation

◆ setColour()

◆ setOpacity()

◆ setGradientFill() [1/2]

◆ setGradientFill() [2/2]

◆ setTiledImageFill()

◆ setFillType()

◆ setFont() [1/2]

◆ setFont() [2/2]

◆ getCurrentFont()

◆ drawSingleLineText()

◆ drawMultiLineText()

◆ drawText() [1/3]

◆ drawText() [2/3]

◆ drawText() [3/3]

◆ drawFittedText() [1/2]

◆ drawFittedText() [2/2]

◆ fillAll() [1/2]

◆ fillAll() [2/2]

◆ fillRect() [1/4]

◆ fillRect() [2/4]

◆ fillRect() [3/4]

◆ fillRect() [4/4]

◆ fillRectList() [1/2]

◆ fillRectList() [2/2]

◆ fillRoundedRectangle() [1/2]

◆ fillRoundedRectangle() [2/2]

◆ fillCheckerBoard()

◆ drawRect() [1/4]

◆ drawRect() [2/4]

◆ drawRect() [3/4]

◆ drawRect() [4/4]

◆ drawRoundedRectangle() [1/2]

◆ drawRoundedRectangle() [2/2]

◆ fillEllipse() [1/2]

◆ fillEllipse() [2/2]

◆ drawEllipse() [1/2]

◆ drawEllipse() [2/2]

◆ drawLine() [1/4]

◆ drawLine() [2/4]

◆ drawLine() [3/4]

◆ drawLine() [4/4]

◆ drawDashedLine()

◆ drawVerticalLine()

◆ drawHorizontalLine()

◆ fillPath() [1/2]

◆ fillPath() [2/2]

◆ strokePath()

◆ drawArrow()

◆ setImageResamplingQuality()

◆ drawImageAt()

◆ drawImage() [1/2]

◆ drawImageTransformed()

◆ drawImage() [2/2]

◆ drawImageWithin()

◆ getClipBounds()

◆ clipRegionIntersects()

◆ reduceClipRegion() [1/5]

◆ reduceClipRegion() [2/5]

◆ reduceClipRegion() [3/5]

◆ reduceClipRegion() [4/5]

◆ reduceClipRegion() [5/5]

◆ excludeClipRegion()

◆ isClipEmpty()

◆ saveState()

◆ restoreState()

◆ beginTransparencyLayer()

◆ endTransparencyLayer()

◆ setOrigin() [1/2]

◆ setOrigin() [2/2]

◆ addTransform()