Skia-based Canvas implementation. More...

#include </d/a/AeonGUI/AeonGUI/include/aeongui/SkiaCanvas.hpp>

Inheritance diagram for AeonGUI::SkiaCanvas:

Collaboration diagram for AeonGUI::SkiaCanvas:

Public Member Functions
	SkiaCanvas ()
	Construct an empty (zero-size) SkiaCanvas.
	SkiaCanvas (uint32_t aWidth, uint32_t aHeight)
	Construct a SkiaCanvas with the given viewport dimensions.
void	ResizeViewport (uint32_t aWidth, uint32_t aHeight) final
	Resize the rendering viewport.
const uint8_t *	GetPixels () const final
	Get a pointer to the raw pixel data.
size_t	GetWidth () const final
	Get the width of the canvas in pixels.
size_t	GetHeight () const final
	Get the height of the canvas in pixels.
size_t	GetStride () const final
	Get the stride (bytes per row) of the pixel buffer.
void	Clear () final
	Clear the canvas to transparent.
void	Draw (const Path &aPath) final
	Draw a path using the current fill and stroke settings.
void	DrawImage (const uint8_t *aPixels, size_t aImageWidth, size_t aImageHeight, size_t aImageStride, double aX, double aY, double aWidth, double aHeight, double aOpacity) final
	Draw a raster image.
void	DrawText (const std::string &aText, double aX, double aY, const std::string &aFontFamily, double aFontSize, int aFontWeight, int aFontStyle) final
double	MeasureText (const std::string &aText, const std::string &aFontFamily, double aFontSize, int aFontWeight, int aFontStyle) const final
void	DrawTextOnPath (const std::string &aText, const Path &aPath, double aStartOffset, const std::string &aFontFamily, double aFontSize, int aFontWeight, int aFontStyle, bool aReverse=false, bool aClosed=false) final
void	SetFillColor (const ColorAttr &aColor) final
	Set the fill color.
const ColorAttr &	GetFillColor () const final
	Get the current fill color.
void	SetStrokeColor (const ColorAttr &aColor) final
	Set the stroke color.
const ColorAttr &	GetStrokeColor () const final
	Get the current stroke color.
void	SetStrokeWidth (double aWidth) final
	Set the stroke width.
double	GetStrokeWidth () const final
	Get the current stroke width.
void	SetStrokeOpacity (double aWidth) final
	Set the stroke opacity.
double	GetStrokeOpacity () const final
	Get the current stroke opacity.
void	SetFillOpacity (double aWidth) final
	Set the fill opacity.
double	GetFillOpacity () const final
	Get the current fill opacity.
void	SetOpacity (double aWidth) final
	Set the global opacity.
double	GetOpacity () const final
	Get the current global opacity.
void	SetViewBox (const ViewBox &aViewBox, const PreserveAspectRatio &aPreserveAspectRatio) final
	Set the SVG viewBox and preserveAspectRatio.
void	SetTransform (const Matrix2x3 &aMatrix) final
	Replace the current transformation matrix.
void	Transform (const Matrix2x3 &aMatrix) final
	Pre-multiply the current transformation matrix.
void	Save () final
	Save the current graphics state (transform, clipping, etc.).
void	Restore () final
	Restore the previously saved graphics state.
void *	GetNativeSurface () const final
	Get the native rendering surface handle.
void	PushGroup () final
	Begin an offscreen group for filter/compositing.
void	PopGroup () final
	End an offscreen group and composite back.
void	ApplyDropShadow (double aDx, double aDy, double aStdDeviationX, double aStdDeviationY, const Color &aFloodColor, double aFloodOpacity) final
	Apply a drop-shadow filter to the current group content.
uint8_t	PickAtPoint (double aX, double aY) const final
	Read the pick ID at the given viewport coordinates.
void	ResetPick () final
	Clear the pick buffer and reset for a new frame.
void	SetClipRect (double aX, double aY, double aWidth, double aHeight) final
	Set a device-space clip rectangle on both render and pick surfaces.
std::unique_ptr< Path >	CreatePath () const final
	Create a new Path object suitable for this canvas backend.
Public Member Functions inherited from AeonGUI::Canvas
void	SetHitTesting (bool aHitTesting)
	Enable or disable hit-testing mode.
bool	IsHitTesting () const
	Query whether the canvas is in hit-testing mode.
void	SetPickId (uint8_t aPickId)
	Set the current pick ID for subsequent Draw calls.
virtual	~Canvas ()=0
	Virtual destructor.
const PickBounds &	GetPickBounds (uint8_t aId) const
	Get the cached device-space bounds for a pick ID.

Additional Inherited Members
Protected Attributes inherited from AeonGUI::Canvas
bool	mHitTesting {false}
	True when in hit-testing mode.
uint8_t	mPickId {0}
	Current pick ID for Draw calls.
std::array< PickBounds, 256 >	mPickBounds {}
	Cached device-space bounds per pick ID.

Detailed Description

Skia-based Canvas implementation.

Renders 2D geometry, text, and images into a CPU-side pixel buffer using Google Skia. Selected at build time with -DAEONGUI_BACKEND=Skia.

Constructor & Destructor Documentation

◆ SkiaCanvas()

AeonGUI::SkiaCanvas::SkiaCanvas	(	uint32_t	aWidth,
		uint32_t	aHeight )

Construct a SkiaCanvas with the given viewport dimensions.

Parameters

aWidth	Viewport width in pixels.
aHeight	Viewport height in pixels.

Member Function Documentation

◆ ApplyDropShadow()

void AeonGUI::SkiaCanvas::ApplyDropShadow	(	double	aDx,
		double	aDy,
		double	aStdDeviationX,
		double	aStdDeviationY,
		const Color &	aFloodColor,
		double	aFloodOpacity )

finalvirtual

Apply a drop-shadow filter to the current group content.

Must be called between PushGroup() and PopGroup(). The implementation captures the group, creates a blurred shadow, offsets it, and composites it under the original content.

Parameters

aDx	Horizontal offset of the shadow.
aDy	Vertical offset of the shadow.
aStdDeviationX	Horizontal Gaussian blur standard deviation.
aStdDeviationY	Vertical Gaussian blur standard deviation.
aFloodColor	Shadow color.
aFloodOpacity	Shadow opacity [0.0, 1.0].

Implements AeonGUI::Canvas.

◆ Clear()

void AeonGUI::SkiaCanvas::Clear ( )

finalvirtual

Clear the canvas to transparent.

Implements AeonGUI::Canvas.

◆ CreatePath()

std::unique_ptr< Path > AeonGUI::SkiaCanvas::CreatePath ( ) const

finalvirtual

Create a new Path object suitable for this canvas backend.

Returns: A new empty Path instance.

Implements AeonGUI::Canvas.

◆ Draw()

void AeonGUI::SkiaCanvas::Draw ( const Path & aPath )

finalvirtual

Draw a path using the current fill and stroke settings.

Parameters

aPath The path to draw.

Implements AeonGUI::Canvas.

◆ DrawImage()

void AeonGUI::SkiaCanvas::DrawImage	(	const uint8_t *	aPixels,
		size_t	aImageWidth,
		size_t	aImageHeight,
		size_t	aImageStride,
		double	aX,
		double	aY,
		double	aWidth,
		double	aHeight,
		double	aOpacity )

finalvirtual

Draw a raster image.

Parameters

aPixels	Pointer to source BGRA pixel data.
aImageWidth	Width of the source image in pixels.
aImageHeight	Height of the source image in pixels.
aImageStride	Stride of the source image in bytes.
aX	Destination X coordinate.
aY	Destination Y coordinate.
aWidth	Destination width in user units.
aHeight	Destination height in user units.
aOpacity	Opacity for the image [0.0, 1.0].

Implements AeonGUI::Canvas.

◆ DrawText()

void AeonGUI::SkiaCanvas::DrawText	(	const std::string &	aText,
		double	aX,
		double	aY,
		const std::string &	aFontFamily,
		double	aFontSize,
		int	aFontWeight,
		int	aFontStyle )

finalvirtual

Draw text at the given position using the specified font description and size.

Parameters

aText	The UTF-8 text string to render.
aX	The x coordinate for the text start position.
aY	The y coordinate for the text baseline.
aFontFamily	Font family name (e.g. "sans-serif").
aFontSize	Font size in CSS pixels.
aFontWeight	CSS font weight (400 = normal, 700 = bold).
aFontStyle	0 = normal, 1 = italic, 2 = oblique.

Implements AeonGUI::Canvas.

◆ DrawTextOnPath()

void AeonGUI::SkiaCanvas::DrawTextOnPath	(	const std::string &	aText,
		const Path &	aPath,
		double	aStartOffset,
		const std::string &	aFontFamily,
		double	aFontSize,
		int	aFontWeight,
		int	aFontStyle,
		bool	aReverse = false,
		bool	aClosed = false )

finalvirtual

Draw text along a path. Each glyph is positioned and rotated to follow the path.

Parameters

aText	The UTF-8 text string to render.
aPath	The path to follow.
aStartOffset	Starting distance along the path in user units.
aFontFamily	Font family name.
aFontSize	Font size in CSS pixels.
aFontWeight	CSS font weight (400 = normal, 700 = bold).
aFontStyle	0 = normal, 1 = italic, 2 = oblique.
aReverse	If true, render glyph order against the path direction.
aClosed	If true, treat the path as closed for offset wrapping.

Implements AeonGUI::Canvas.

◆ GetFillColor()

const ColorAttr & AeonGUI::SkiaCanvas::GetFillColor ( ) const

finalvirtual

Get the current fill color.

Returns: Reference to the current fill color.

Implements AeonGUI::Canvas.

◆ GetFillOpacity()

double AeonGUI::SkiaCanvas::GetFillOpacity ( ) const

finalvirtual

Get the current fill opacity.

Returns: Opacity in [0.0, 1.0].

Implements AeonGUI::Canvas.

◆ GetHeight()

size_t AeonGUI::SkiaCanvas::GetHeight ( ) const

finalvirtual

Get the height of the canvas in pixels.

Returns: Height in pixels.

Implements AeonGUI::Canvas.

◆ GetNativeSurface()

void * AeonGUI::SkiaCanvas::GetNativeSurface ( ) const

finalvirtual

Get the native rendering surface handle.

Returns: Pointer to the underlying surface (e.g. cairo_surface_t).

Implements AeonGUI::Canvas.

◆ GetOpacity()

double AeonGUI::SkiaCanvas::GetOpacity ( ) const

finalvirtual

Get the current global opacity.

Returns: Opacity in [0.0, 1.0].

Implements AeonGUI::Canvas.

◆ GetPixels()

const uint8_t * AeonGUI::SkiaCanvas::GetPixels ( ) const

finalvirtual

Get a pointer to the raw pixel data.

Returns: Pointer to BGRA pixel data, or nullptr if empty.

Implements AeonGUI::Canvas.

◆ GetStride()

size_t AeonGUI::SkiaCanvas::GetStride ( ) const

finalvirtual

Get the stride (bytes per row) of the pixel buffer.

Returns: Stride in bytes.

Implements AeonGUI::Canvas.

◆ GetStrokeColor()

const ColorAttr & AeonGUI::SkiaCanvas::GetStrokeColor ( ) const

finalvirtual

Get the current stroke color.

Returns: Reference to the current stroke color.

Implements AeonGUI::Canvas.

◆ GetStrokeOpacity()

double AeonGUI::SkiaCanvas::GetStrokeOpacity ( ) const

finalvirtual

Get the current stroke opacity.

Returns: Opacity in [0.0, 1.0].

Implements AeonGUI::Canvas.

◆ GetStrokeWidth()

double AeonGUI::SkiaCanvas::GetStrokeWidth ( ) const

finalvirtual

Get the current stroke width.

Returns: Stroke width in user units.

Implements AeonGUI::Canvas.

◆ GetWidth()

size_t AeonGUI::SkiaCanvas::GetWidth ( ) const

finalvirtual

Get the width of the canvas in pixels.

Returns: Width in pixels.

Implements AeonGUI::Canvas.

◆ MeasureText()

double AeonGUI::SkiaCanvas::MeasureText	(	const std::string &	aText,
		const std::string &	aFontFamily,
		double	aFontSize,
		int	aFontWeight,
		int	aFontStyle ) const

finalvirtual

Measure the width of text with the given font parameters.

Parameters

aText	The UTF-8 text string to measure.
aFontFamily	Font family name.
aFontSize	Font size in CSS pixels.
aFontWeight	CSS font weight.
aFontStyle	Font style (0=normal, 1=italic, 2=oblique).

Returns: The logical width in CSS pixels.

Implements AeonGUI::Canvas.

◆ PickAtPoint()

uint8_t AeonGUI::SkiaCanvas::PickAtPoint	(	double	aX,
		double	aY ) const

finalvirtual

Read the pick ID at the given viewport coordinates.

Parameters

aX	X coordinate in viewport pixels.
aY	Y coordinate in viewport pixels.

Returns: Pick ID at that pixel, or 0 if empty / out of bounds.

Implements AeonGUI::Canvas.

◆ PopGroup()

void AeonGUI::SkiaCanvas::PopGroup ( )

finalvirtual

End an offscreen group and composite back.

Pops the group pushed by PushGroup() and paints it back to the underlying surface.

Implements AeonGUI::Canvas.

◆ PushGroup()

void AeonGUI::SkiaCanvas::PushGroup ( )

finalvirtual

Begin an offscreen group for filter/compositing.

All subsequent drawing is redirected to a temporary surface. Call PopGroup() to retrieve and composite the result.

Implements AeonGUI::Canvas.

◆ ResetPick()

void AeonGUI::SkiaCanvas::ResetPick ( )

finalvirtual

Clear the pick buffer and reset for a new frame.

Implements AeonGUI::Canvas.

◆ ResizeViewport()

void AeonGUI::SkiaCanvas::ResizeViewport	(	uint32_t	aWidth,
		uint32_t	aHeight )

finalvirtual

Resize the rendering viewport.

Parameters

aWidth	New width in pixels.
aHeight	New height in pixels.

Implements AeonGUI::Canvas.

◆ Restore()

void AeonGUI::SkiaCanvas::Restore ( )

finalvirtual

Restore the previously saved graphics state.

Implements AeonGUI::Canvas.

◆ Save()

void AeonGUI::SkiaCanvas::Save ( )

finalvirtual

Save the current graphics state (transform, clipping, etc.).

Implements AeonGUI::Canvas.

◆ SetClipRect()

void AeonGUI::SkiaCanvas::SetClipRect	(	double	aX,
		double	aY,
		double	aWidth,
		double	aHeight )

finalvirtual

Set a device-space clip rectangle on both render and pick surfaces.

Must be called between Save() and Restore().

Parameters

aX	X of clip rect (device pixels).
aY	Y of clip rect (device pixels).
aWidth	Width (device pixels).
aHeight	Height (device pixels).

Implements AeonGUI::Canvas.

◆ SetFillColor()

void AeonGUI::SkiaCanvas::SetFillColor ( const ColorAttr & aColor )

finalvirtual

Set the fill color.

Parameters

aColor The fill color to set.

Implements AeonGUI::Canvas.

◆ SetFillOpacity()

void AeonGUI::SkiaCanvas::SetFillOpacity ( double aWidth )

finalvirtual

Set the fill opacity.

Parameters

aWidth Opacity value in the range [0.0, 1.0].

Implements AeonGUI::Canvas.

◆ SetOpacity()

void AeonGUI::SkiaCanvas::SetOpacity ( double aWidth )

finalvirtual

Set the global opacity.

Parameters

aWidth Opacity value in the range [0.0, 1.0].

Implements AeonGUI::Canvas.

◆ SetStrokeColor()

void AeonGUI::SkiaCanvas::SetStrokeColor ( const ColorAttr & aColor )

finalvirtual

Set the stroke color.

Parameters

aColor The stroke color to set.

Implements AeonGUI::Canvas.

◆ SetStrokeOpacity()

void AeonGUI::SkiaCanvas::SetStrokeOpacity ( double aWidth )

finalvirtual

Set the stroke opacity.

Parameters

aWidth Opacity value in the range [0.0, 1.0].

Implements AeonGUI::Canvas.

◆ SetStrokeWidth()

void AeonGUI::SkiaCanvas::SetStrokeWidth ( double aWidth )

finalvirtual

Set the stroke width.

Parameters

aWidth The stroke width in user units.

Implements AeonGUI::Canvas.

◆ SetTransform()

void AeonGUI::SkiaCanvas::SetTransform ( const Matrix2x3 & aMatrix )

finalvirtual

Replace the current transformation matrix.

Parameters

aMatrix The new 2x3 transformation matrix.

Implements AeonGUI::Canvas.

◆ SetViewBox()

void AeonGUI::SkiaCanvas::SetViewBox	(	const ViewBox &	aViewBox,
		const PreserveAspectRatio &	aPreserveAspectRatio )

finalvirtual

Set the SVG viewBox and preserveAspectRatio.

Parameters

aViewBox	The viewBox rectangle.
aPreserveAspectRatio	How to align and scale.

Implements AeonGUI::Canvas.

◆ Transform()

void AeonGUI::SkiaCanvas::Transform ( const Matrix2x3 & aMatrix )

finalvirtual

Pre-multiply the current transformation matrix.

Parameters

aMatrix The matrix to concatenate.

Implements AeonGUI::Canvas.

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

/d/a/AeonGUI/AeonGUI/include/aeongui/SkiaCanvas.hpp
/d/a/AeonGUI/AeonGUI/core/SkiaCanvas.cpp

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ SkiaCanvas()

Member Function Documentation

◆ ApplyDropShadow()

◆ Clear()

◆ CreatePath()

◆ Draw()

◆ DrawImage()

◆ DrawText()

◆ DrawTextOnPath()

◆ GetFillColor()

◆ GetFillOpacity()

◆ GetHeight()

◆ GetNativeSurface()

◆ GetOpacity()

◆ GetPixels()

◆ GetStride()

◆ GetStrokeColor()

◆ GetStrokeOpacity()

◆ GetStrokeWidth()

◆ GetWidth()

◆ MeasureText()

◆ PickAtPoint()

◆ PopGroup()

◆ PushGroup()

◆ ResetPick()

◆ ResizeViewport()

◆ Restore()

◆ Save()

◆ SetClipRect()

◆ SetFillColor()

◆ SetFillOpacity()

◆ SetOpacity()

◆ SetStrokeColor()

◆ SetStrokeOpacity()

◆ SetStrokeWidth()

◆ SetTransform()

◆ SetViewBox()

◆ Transform()