SkSurface is responsible for managing the pixels that a canvas draws into. More...

#include <SkSurface.h>

Inheritance diagram for SkSurface:

Public Types
enum	ContentChangeMode { kDiscard_ContentChangeMode , kRetain_ContentChangeMode }

enum class	BackendHandleAccess { kFlushRead , kFlushWrite , kDiscardWrite , kFlushRead_BackendHandleAccess = kFlushRead , kFlushWrite_BackendHandleAccess = kFlushWrite , kDiscardWrite_BackendHandleAccess = kDiscardWrite }

using	ReleaseContext = void *
	Caller data passed to TextureReleaseProc; may be nullptr. More...

using	TextureReleaseProc = void(*)(ReleaseContext)
	User function called when supplied texture may be deleted. More...

using	AsyncReadResult = SkImage::AsyncReadResult

using	ReadPixelsContext = void *
	Client-provided context that is passed to client-provided ReadPixelsContext. More...

using	ReadPixelsCallback = void(ReadPixelsContext, std::unique_ptr< const AsyncReadResult >)
	Client-provided callback to asyncRescaleAndReadPixels() or asyncRescaleAndReadPixelsYUV420() that is called when read result is ready or on failure. More...

using	RescaleGamma = SkImage::RescaleGamma
	Controls the gamma that rescaling occurs in for asyncRescaleAndReadPixels() and asyncRescaleAndReadPixelsYUV420(). More...

using	RescaleMode = SkImage::RescaleMode

Public Member Functions
bool	isCompatible (const GrSurfaceCharacterization &characterization) const
	Is this surface compatible with the provided characterization? More...

int	width () const
	Returns pixel count in each row; may be zero or greater. More...

int	height () const
	Returns pixel row count; may be zero or greater. More...

virtual SkImageInfo	imageInfo () const
	Returns an ImageInfo describing the surface. More...

uint32_t	generationID ()
	Returns unique value identifying the content of SkSurface. More...

void	notifyContentWillChange (ContentChangeMode mode)
	Notifies that SkSurface contents will be changed by code outside of Skia. More...

GrRecordingContext *	recordingContext () const
	Returns the recording context being used by the SkSurface. More...

skgpu::graphite::Recorder *	recorder () const
	Returns the recorder being used by the SkSurface. More...

virtual bool	replaceBackendTexture (const GrBackendTexture &backendTexture, GrSurfaceOrigin origin, ContentChangeMode mode=kRetain_ContentChangeMode, TextureReleaseProc=nullptr, ReleaseContext=nullptr)=0
	If the surface was made via MakeFromBackendTexture then it's backing texture may be substituted with a different texture. More...

SkCanvas *	getCanvas ()
	Returns SkCanvas that draws into SkSurface. More...

sk_sp< const SkCapabilities >	capabilities ()
	Returns SkCapabilities that describes the capabilities of the SkSurface's device. More...

sk_sp< SkSurface >	makeSurface (const SkImageInfo &imageInfo)
	Returns a compatible SkSurface, or nullptr. More...

sk_sp< SkSurface >	makeSurface (int width, int height)
	Calls makeSurface(ImageInfo) with the same ImageInfo as this surface, but with the specified width and height. More...

sk_sp< SkImage >	makeImageSnapshot ()
	Returns SkImage capturing SkSurface contents. More...

sk_sp< SkImage >	makeImageSnapshot (const SkIRect &bounds)
	Like the no-parameter version, this returns an image of the current surface contents. More...

void	draw (SkCanvas canvas, SkScalar x, SkScalar y, const SkSamplingOptions &sampling, const SkPaint paint)
	Draws SkSurface contents to canvas, with its top-left corner at (x, y). More...

void	draw (SkCanvas canvas, SkScalar x, SkScalar y, const SkPaint paint=nullptr)

bool	peekPixels (SkPixmap *pixmap)
	Copies SkSurface pixel address, row bytes, and SkImageInfo to SkPixmap, if address is available, and returns true. More...

bool	readPixels (const SkPixmap &dst, int srcX, int srcY)
	Copies SkRect of pixels to dst. More...

bool	readPixels (const SkImageInfo &dstInfo, void *dstPixels, size_t dstRowBytes, int srcX, int srcY)
	Copies SkRect of pixels from SkCanvas into dstPixels. More...

bool	readPixels (const SkBitmap &dst, int srcX, int srcY)
	Copies SkRect of pixels from SkSurface into bitmap. More...

void	asyncRescaleAndReadPixels (const SkImageInfo &info, const SkIRect &srcRect, RescaleGamma rescaleGamma, RescaleMode rescaleMode, ReadPixelsCallback callback, ReadPixelsContext context)
	Makes surface pixel data available to caller, possibly asynchronously. More...

void	asyncRescaleAndReadPixelsYUV420 (SkYUVColorSpace yuvColorSpace, sk_sp< SkColorSpace > dstColorSpace, const SkIRect &srcRect, const SkISize &dstSize, RescaleGamma rescaleGamma, RescaleMode rescaleMode, ReadPixelsCallback callback, ReadPixelsContext context)
	Similar to asyncRescaleAndReadPixels but performs an additional conversion to YUV. More...

void	asyncRescaleAndReadPixelsYUVA420 (SkYUVColorSpace yuvColorSpace, sk_sp< SkColorSpace > dstColorSpace, const SkIRect &srcRect, const SkISize &dstSize, RescaleGamma rescaleGamma, RescaleMode rescaleMode, ReadPixelsCallback callback, ReadPixelsContext context)
	Identical to asyncRescaleAndReadPixelsYUV420 but a fourth plane is returned in the AsyncReadResult passed to 'callback'. More...

void	writePixels (const SkPixmap &src, int dstX, int dstY)
	Copies SkRect of pixels from the src SkPixmap to the SkSurface. More...

void	writePixels (const SkBitmap &src, int dstX, int dstY)
	Copies SkRect of pixels from the src SkBitmap to the SkSurface. More...

const SkSurfaceProps &	props () const
	Returns SkSurfaceProps for surface. More...

bool	wait (int numSemaphores, const GrBackendSemaphore *waitSemaphores, bool deleteSemaphoresAfterWait=true)
	Inserts a list of GPU semaphores that the current GPU-backed API must wait on before executing any more commands on the GPU for this surface. More...

bool	characterize (GrSurfaceCharacterization *characterization) const
	Initializes GrSurfaceCharacterization that can be used to perform GPU back-end processing in a separate thread. More...

bool	unique () const
	May return true if the caller is the only owner. More...

void	ref () const
	Increment the reference count. More...

void	unref () const
	Decrement the reference count. More...

Static Public Attributes
static constexpr BackendHandleAccess	kFlushRead_BackendHandleAccess

static constexpr BackendHandleAccess	kFlushWrite_BackendHandleAccess

static constexpr BackendHandleAccess	kDiscardWrite_BackendHandleAccess

Protected Member Functions
	SkSurface (int width, int height, const SkSurfaceProps *surfaceProps)

	SkSurface (const SkImageInfo &imageInfo, const SkSurfaceProps *surfaceProps)

void	dirtyGenerationID ()

Detailed Description

SkSurface is responsible for managing the pixels that a canvas draws into.

The pixels can be allocated either in CPU memory (a raster surface) or on the GPU (a GrRenderTarget surface). SkSurface takes care of allocating a SkCanvas that will draw into the surface. Call surface->getCanvas() to use that canvas (but don't delete it, it is owned by the surface). SkSurface always has non-zero dimensions. If there is a request for a new surface, and either of the requested dimensions are zero, then nullptr will be returned.

Clients should not subclass SkSurface as there is a lot of internal machinery that is not publicly accessible.

Member Typedef Documentation

◆ AsyncReadResult

using SkSurface::AsyncReadResult = SkImage::AsyncReadResult

◆ ReadPixelsCallback

using SkSurface::ReadPixelsCallback = void(ReadPixelsContext, std::unique_ptr<const AsyncReadResult>)

Client-provided callback to asyncRescaleAndReadPixels() or asyncRescaleAndReadPixelsYUV420() that is called when read result is ready or on failure.

◆ ReadPixelsContext

using SkSurface::ReadPixelsContext = void*

Client-provided context that is passed to client-provided ReadPixelsContext.

◆ ReleaseContext

using SkSurface::ReleaseContext = void*

Caller data passed to TextureReleaseProc; may be nullptr.

◆ RescaleGamma

using SkSurface::RescaleGamma = SkImage::RescaleGamma

Controls the gamma that rescaling occurs in for asyncRescaleAndReadPixels() and asyncRescaleAndReadPixelsYUV420().

◆ RescaleMode

using SkSurface::RescaleMode = SkImage::RescaleMode

◆ TextureReleaseProc

using SkSurface::TextureReleaseProc = void (*)(ReleaseContext)

User function called when supplied texture may be deleted.

Member Enumeration Documentation

◆ BackendHandleAccess

enum SkSurface::BackendHandleAccess

strong

Enumerator
kFlushRead	back-end object is readable
kFlushWrite	back-end object is writable
kDiscardWrite	back-end object must be overwritten
kFlushRead_BackendHandleAccess
kFlushWrite_BackendHandleAccess
kDiscardWrite_BackendHandleAccess

◆ ContentChangeMode

enum SkSurface::ContentChangeMode

Enumerator
kDiscard_ContentChangeMode	discards surface on change
kRetain_ContentChangeMode	preserves surface on change

Constructor & Destructor Documentation

◆ SkSurface() [1/2]

SkSurface::SkSurface	(	int	width,
		int	height,
		const SkSurfaceProps *	surfaceProps
	)

protected

◆ SkSurface() [2/2]

SkSurface::SkSurface	(	const SkImageInfo &	imageInfo,
		const SkSurfaceProps *	surfaceProps
	)

protected

Member Function Documentation

◆ asyncRescaleAndReadPixels()

void SkSurface::asyncRescaleAndReadPixels	(	const SkImageInfo &	info,
		const SkIRect &	srcRect,
		RescaleGamma	rescaleGamma,
		RescaleMode	rescaleMode,
		ReadPixelsCallback	callback,
		ReadPixelsContext	context
	)

Makes surface pixel data available to caller, possibly asynchronously.

It can also rescale the surface pixels.

Currently asynchronous reads are only supported on the GPU backend and only when the underlying 3D API supports transfer buffers and CPU/GPU synchronization primitives. In all other cases this operates synchronously.

Data is read from the source sub-rectangle, is optionally converted to a linear gamma, is rescaled to the size indicated by 'info', is then converted to the color space, color type, and alpha type of 'info'. A 'srcRect' that is not contained by the bounds of the surface causes failure.

When the pixel data is ready the caller's ReadPixelsCallback is called with a AsyncReadResult containing pixel data in the requested color type, alpha type, and color space. The AsyncReadResult will have count() == 1. Upon failure the callback is called with nullptr for AsyncReadResult. For a GPU surface this flushes work but a submit must occur to guarantee a finite time before the callback is called.

The data is valid for the lifetime of AsyncReadResult with the exception that if the SkSurface is GPU-backed the data is immediately invalidated if the context is abandoned or destroyed.

Parameters

info	info of the requested pixels
srcRect	subrectangle of surface to read
rescaleGamma	controls whether rescaling is done in the surface's gamma or whether the source data is transformed to a linear gamma before rescaling.
rescaleMode	controls the technique of the rescaling
callback	function to call with result of the read
context	passed to callback

◆ asyncRescaleAndReadPixelsYUV420()

void SkSurface::asyncRescaleAndReadPixelsYUV420	(	SkYUVColorSpace	yuvColorSpace,
		sk_sp< SkColorSpace >	dstColorSpace,
		const SkIRect &	srcRect,
		const SkISize &	dstSize,
		RescaleGamma	rescaleGamma,
		RescaleMode	rescaleMode,
		ReadPixelsCallback	callback,
		ReadPixelsContext	context
	)

Similar to asyncRescaleAndReadPixels but performs an additional conversion to YUV.

The RGB->YUV conversion is controlled by 'yuvColorSpace'. The YUV data is returned as three planes ordered y, u, v. The u and v planes are half the width and height of the resized rectangle. The y, u, and v values are single bytes. Currently this fails if 'dstSize' width and height are not even. A 'srcRect' that is not contained by the bounds of the surface causes failure.

When the pixel data is ready the caller's ReadPixelsCallback is called with a AsyncReadResult containing the planar data. The AsyncReadResult will have count() == 3. Upon failure the callback is called with nullptr for AsyncReadResult. For a GPU surface this flushes work but a submit must occur to guarantee a finite time before the callback is called.

The data is valid for the lifetime of AsyncReadResult with the exception that if the SkSurface is GPU-backed the data is immediately invalidated if the context is abandoned or destroyed.

Parameters

yuvColorSpace	The transformation from RGB to YUV. Applied to the resized image after it is converted to dstColorSpace.
dstColorSpace	The color space to convert the resized image to, after rescaling.
srcRect	The portion of the surface to rescale and convert to YUV planes.
dstSize	The size to rescale srcRect to
rescaleGamma	controls whether rescaling is done in the surface's gamma or whether the source data is transformed to a linear gamma before rescaling.
rescaleMode	controls the sampling technique of the rescaling
callback	function to call with the planar read result
context	passed to callback

◆ asyncRescaleAndReadPixelsYUVA420()

void SkSurface::asyncRescaleAndReadPixelsYUVA420	(	SkYUVColorSpace	yuvColorSpace,
		sk_sp< SkColorSpace >	dstColorSpace,
		const SkIRect &	srcRect,
		const SkISize &	dstSize,
		RescaleGamma	rescaleGamma,
		RescaleMode	rescaleMode,
		ReadPixelsCallback	callback,
		ReadPixelsContext	context
	)

Identical to asyncRescaleAndReadPixelsYUV420 but a fourth plane is returned in the AsyncReadResult passed to 'callback'.

The fourth plane contains the alpha chanel at the same full resolution as the Y plane.

◆ capabilities()

sk_sp<const SkCapabilities> SkSurface::capabilities ( )

Returns SkCapabilities that describes the capabilities of the SkSurface's device.

Returns: SkCapabilities of SkSurface's device.

◆ characterize()

bool SkSurface::characterize ( GrSurfaceCharacterization * characterization ) const

Initializes GrSurfaceCharacterization that can be used to perform GPU back-end processing in a separate thread.

Typically this is used to divide drawing into multiple tiles. GrDeferredDisplayListRecorder records the drawing commands for each tile.

Return true if SkSurface supports characterization. raster surface returns false.

Parameters

characterization properties for parallel drawing

Returns: true if supported

example: https://fiddle.skia.org/c/@Surface_characterize

◆ dirtyGenerationID()

void SkSurface::dirtyGenerationID ( )

inlineprotected

◆ draw() [1/2]

void SkSurface::draw	(	SkCanvas *	canvas,
		SkScalar	x,
		SkScalar	y,
		const SkPaint *	paint = `nullptr`
	)

inline

◆ draw() [2/2]

void SkSurface::draw	(	SkCanvas *	canvas,
		SkScalar	x,
		SkScalar	y,
		const SkSamplingOptions &	sampling,
		const SkPaint *	paint
	)

Draws SkSurface contents to canvas, with its top-left corner at (x, y).

If SkPaint paint is not nullptr, apply SkColorFilter, alpha, SkImageFilter, and SkBlendMode.

Parameters

canvas	SkCanvas drawn into
x	horizontal offset in SkCanvas
y	vertical offset in SkCanvas
sampling	what technique to use when sampling the surface pixels
paint	SkPaint containing SkBlendMode, SkColorFilter, SkImageFilter, and so on; or nullptr

example: https://fiddle.skia.org/c/@Surface_draw

◆ generationID()

uint32_t SkSurface::generationID ( )

Returns unique value identifying the content of SkSurface.

Returned value changes each time the content changes. Content is changed by drawing, or by calling notifyContentWillChange().

Returns: unique content identifier

example: https://fiddle.skia.org/c/@Surface_notifyContentWillChange

◆ getCanvas()

SkCanvas* SkSurface::getCanvas ( )

Returns SkCanvas that draws into SkSurface.

Subsequent calls return the same SkCanvas. SkCanvas returned is managed and owned by SkSurface, and is deleted when SkSurface is deleted.

Returns: drawing SkCanvas for SkSurface

example: https://fiddle.skia.org/c/@Surface_getCanvas

◆ height()

int SkSurface::height ( ) const

inline

Returns pixel row count; may be zero or greater.

Returns: number of pixel rows

◆ imageInfo()

virtual SkImageInfo SkSurface::imageInfo ( ) const

inlinevirtual

Returns an ImageInfo describing the surface.

◆ isCompatible()

bool SkSurface::isCompatible ( const GrSurfaceCharacterization & characterization ) const

Is this surface compatible with the provided characterization?

This method can be used to determine if an existing SkSurface is a viable destination for an GrDeferredDisplayList.

Parameters

characterization The characterization for which a compatibility check is desired

Returns: true if this surface is compatible with the characterization; false otherwise

◆ makeImageSnapshot() [1/2]

sk_sp<SkImage> SkSurface::makeImageSnapshot ( )

Returns SkImage capturing SkSurface contents.

Subsequent drawing to SkSurface contents are not captured. SkImage allocation is accounted for if SkSurface was created with skgpu::Budgeted::kYes.

Returns: SkImage initialized with SkSurface contents

example: https://fiddle.skia.org/c/@Surface_makeImageSnapshot

◆ makeImageSnapshot() [2/2]

sk_sp<SkImage> SkSurface::makeImageSnapshot ( const SkIRect & bounds )

Like the no-parameter version, this returns an image of the current surface contents.

This variant takes a rectangle specifying the subset of the surface that is of interest. These bounds will be sanitized before being used.

If bounds extends beyond the surface, it will be trimmed to just the intersection of it and the surface.
If bounds does not intersect the surface, then this returns nullptr.
If bounds == the surface, then this is the same as calling the no-parameter variant.

example: https://fiddle.skia.org/c/@Surface_makeImageSnapshot_2

◆ makeSurface() [1/2]

sk_sp<SkSurface> SkSurface::makeSurface ( const SkImageInfo & imageInfo )

Returns a compatible SkSurface, or nullptr.

Returned SkSurface contains the same raster, GPU, or null properties as the original. Returned SkSurface does not share the same pixels.

Returns nullptr if imageInfo width or height are zero, or if imageInfo is incompatible with SkSurface.

Parameters

imageInfo width, height, SkColorType, SkAlphaType, SkColorSpace, of SkSurface; width and height must be greater than zero

Returns: compatible SkSurface or nullptr

example: https://fiddle.skia.org/c/@Surface_makeSurface

◆ makeSurface() [2/2]

sk_sp<SkSurface> SkSurface::makeSurface	(	int	width,
		int	height
	)

Calls makeSurface(ImageInfo) with the same ImageInfo as this surface, but with the specified width and height.

◆ notifyContentWillChange()

void SkSurface::notifyContentWillChange ( ContentChangeMode mode )

Notifies that SkSurface contents will be changed by code outside of Skia.

Subsequent calls to generationID() return a different value.

TODO: Can kRetain_ContentChangeMode be deprecated?

example: https://fiddle.skia.org/c/@Surface_notifyContentWillChange

◆ peekPixels()

bool SkSurface::peekPixels ( SkPixmap * pixmap )

Copies SkSurface pixel address, row bytes, and SkImageInfo to SkPixmap, if address is available, and returns true.

If pixel address is not available, return false and leave SkPixmap unchanged.

pixmap contents become invalid on any future change to SkSurface.

Parameters

pixmap storage for pixel state if pixels are readable; otherwise, ignored

Returns: true if SkSurface has direct access to pixels

example: https://fiddle.skia.org/c/@Surface_peekPixels

◆ props()

const SkSurfaceProps& SkSurface::props ( ) const

inline

Returns SkSurfaceProps for surface.

Returns: LCD striping orientation and setting for device independent fonts

◆ readPixels() [1/3]

bool SkSurface::readPixels	(	const SkBitmap &	dst,
		int	srcX,
		int	srcY
	)

Copies SkRect of pixels from SkSurface into bitmap.

Source SkRect corners are (srcX, srcY) and SkSurface (width(), height()). Destination SkRect corners are (0, 0) and (bitmap.width(), bitmap.height()). Copies each readable pixel intersecting both rectangles, without scaling, converting to bitmap.colorType() and bitmap.alphaType() if required.

Pixels are readable when SkSurface is raster, or backed by a GPU.

The destination pixel storage must be allocated by the caller.

Pixel values are converted only if SkColorType and SkAlphaType do not match. Only pixels within both source and destination rectangles are copied. dst contents outside SkRect intersection are unchanged.

Pass negative values for srcX or srcY to offset pixels across or down destination.

Does not copy, and returns false if:

Source and destination rectangles do not intersect.
SkSurface pixels could not be converted to dst.colorType() or dst.alphaType().
dst pixels could not be allocated.
dst.rowBytes() is too small to contain one row of pixels.

Parameters

dst	storage for pixels copied from SkSurface
srcX	offset into readable pixels on x-axis; may be negative
srcY	offset into readable pixels on y-axis; may be negative

Returns: true if pixels were copied

example: https://fiddle.skia.org/c/@Surface_readPixels_3

◆ readPixels() [2/3]

bool SkSurface::readPixels	(	const SkImageInfo &	dstInfo,
		void *	dstPixels,
		size_t	dstRowBytes,
		int	srcX,
		int	srcY
	)

Copies SkRect of pixels from SkCanvas into dstPixels.

Source SkRect corners are (srcX, srcY) and SkSurface (width(), height()). Destination SkRect corners are (0, 0) and (dstInfo.width(), dstInfo.height()). Copies each readable pixel intersecting both rectangles, without scaling, converting to dstInfo.colorType() and dstInfo.alphaType() if required.

Pixels are readable when SkSurface is raster, or backed by a GPU.

The destination pixel storage must be allocated by the caller.

Pixel values are converted only if SkColorType and SkAlphaType do not match. Only pixels within both source and destination rectangles are copied. dstPixels contents outside SkRect intersection are unchanged.

Pass negative values for srcX or srcY to offset pixels across or down destination.

Does not copy, and returns false if:

Source and destination rectangles do not intersect.
SkSurface pixels could not be converted to dstInfo.colorType() or dstInfo.alphaType().
dstRowBytes is too small to contain one row of pixels.

Parameters

dstInfo	width, height, SkColorType, and SkAlphaType of dstPixels
dstPixels	storage for pixels; dstInfo.height() times dstRowBytes, or larger
dstRowBytes	size of one destination row; dstInfo.width() times pixel size, or larger
srcX	offset into readable pixels on x-axis; may be negative
srcY	offset into readable pixels on y-axis; may be negative

Returns: true if pixels were copied

◆ readPixels() [3/3]

bool SkSurface::readPixels	(	const SkPixmap &	dst,
		int	srcX,
		int	srcY
	)

Copies SkRect of pixels to dst.

Source SkRect corners are (srcX, srcY) and SkSurface (width(), height()). Destination SkRect corners are (0, 0) and (dst.width(), dst.height()). Copies each readable pixel intersecting both rectangles, without scaling, converting to dst.colorType() and dst.alphaType() if required.

Pixels are readable when SkSurface is raster, or backed by a GPU.

The destination pixel storage must be allocated by the caller.

Pixel values are converted only if SkColorType and SkAlphaType do not match. Only pixels within both source and destination rectangles are copied. dst contents outside SkRect intersection are unchanged.

Pass negative values for srcX or srcY to offset pixels across or down destination.

Does not copy, and returns false if:

Source and destination rectangles do not intersect.
SkPixmap pixels could not be allocated.
dst.rowBytes() is too small to contain one row of pixels.

Parameters

dst	storage for pixels copied from SkSurface
srcX	offset into readable pixels on x-axis; may be negative
srcY	offset into readable pixels on y-axis; may be negative

Returns: true if pixels were copied

example: https://fiddle.skia.org/c/@Surface_readPixels

◆ recorder()

skgpu::graphite::Recorder* SkSurface::recorder ( ) const

Returns the recorder being used by the SkSurface.

Returns: the recorder, if available; nullptr otherwise

◆ recordingContext()

GrRecordingContext* SkSurface::recordingContext ( ) const

Returns the recording context being used by the SkSurface.

Returns: the recording context, if available; nullptr otherwise

◆ ref()

void SkRefCntBase::ref ( ) const

inlineinherited

Increment the reference count.

Must be balanced by a call to unref().

◆ replaceBackendTexture()

virtual bool SkSurface::replaceBackendTexture	(	const GrBackendTexture &	backendTexture,
		GrSurfaceOrigin	origin,
		ContentChangeMode	mode = `kRetain_ContentChangeMode`,
		TextureReleaseProc	= `nullptr`,
		ReleaseContext	= `nullptr`
	)

pure virtual

If the surface was made via MakeFromBackendTexture then it's backing texture may be substituted with a different texture.

The contents of the previous backing texture are copied into the new texture. SkCanvas state is preserved. The original sample count is used. The GrBackendFormat and dimensions of replacement texture must match that of the original.

Upon success textureReleaseProc is called when it is safe to delete the texture in the backend API (accounting only for use of the texture by this surface). If SkSurface creation fails textureReleaseProc is called before this function returns.

Parameters

backendTexture	the new backing texture for the surface
mode	Retain or discard current Content
TextureReleaseProc	function called when texture can be released
ReleaseContext	state passed to textureReleaseProc

◆ unique()

bool SkRefCntBase::unique ( ) const

inlineinherited

May return true if the caller is the only owner.

Ensures that all previous owner's actions are complete.

◆ unref()

void SkRefCntBase::unref ( ) const

inlineinherited

Decrement the reference count.

If the reference count is 1 before the decrement, then delete the object. Note that if this is the case, then the object needs to have been allocated via new, and not on the stack.

◆ wait()

bool SkSurface::wait	(	int	numSemaphores,
		const GrBackendSemaphore *	waitSemaphores,
		bool	deleteSemaphoresAfterWait = `true`
	)

Inserts a list of GPU semaphores that the current GPU-backed API must wait on before executing any more commands on the GPU for this surface.

We only guarantee blocking transfer and fragment shader work, but may block earlier stages as well depending on the backend. If this call returns false, then the GPU back-end will not wait on any passed in semaphores, and the client will still own the semaphores, regardless of the value of deleteSemaphoresAfterWait.

If deleteSemaphoresAfterWait is false then Skia will not delete the semaphores. In this case it is the client's responsibility to not destroy or attempt to reuse the semaphores until it knows that Skia has finished waiting on them. This can be done by using finishedProcs on flush calls.

Parameters

numSemaphores	size of waitSemaphores array
waitSemaphores	array of semaphore containers @paramm deleteSemaphoresAfterWait who owns and should delete the semaphores

Returns: true if GPU is waiting on semaphores

◆ width()

int SkSurface::width ( ) const

inline

Returns pixel count in each row; may be zero or greater.

Returns: number of pixel columns

◆ writePixels() [1/2]

void SkSurface::writePixels	(	const SkBitmap &	src,
		int	dstX,
		int	dstY
	)

Copies SkRect of pixels from the src SkBitmap to the SkSurface.

Source SkRect corners are (0, 0) and (src.width(), src.height()). Destination SkRect corners are (dstX, dstY) and (dstX + Surface width(), dstY + Surface height()).

Copies each readable pixel intersecting both rectangles, without scaling, converting to SkSurface colorType() and SkSurface alphaType() if required.

Parameters

src	storage for pixels to copy to SkSurface
dstX	x-axis position relative to SkSurface to begin copy; may be negative
dstY	y-axis position relative to SkSurface to begin copy; may be negative

example: https://fiddle.skia.org/c/@Surface_writePixels_2

◆ writePixels() [2/2]

void SkSurface::writePixels	(	const SkPixmap &	src,
		int	dstX,
		int	dstY
	)

Copies SkRect of pixels from the src SkPixmap to the SkSurface.

Source SkRect corners are (0, 0) and (src.width(), src.height()). Destination SkRect corners are (dstX, dstY) and (dstX + Surface width(), dstY + Surface height()).

Copies each readable pixel intersecting both rectangles, without scaling, converting to SkSurface colorType() and SkSurface alphaType() if required.

Parameters

src	storage for pixels to copy to SkSurface
dstX	x-axis position relative to SkSurface to begin copy; may be negative
dstY	y-axis position relative to SkSurface to begin copy; may be negative

example: https://fiddle.skia.org/c/@Surface_writePixels

Member Data Documentation

◆ kDiscardWrite_BackendHandleAccess

constexpr BackendHandleAccess SkSurface::kDiscardWrite_BackendHandleAccess

staticconstexpr

Initial value:

=

BackendHandleAccess::kDiscardWrite

SkSurface::BackendHandleAccess::kDiscardWrite

@ kDiscardWrite

back-end object must be overwritten

◆ kFlushRead_BackendHandleAccess

constexpr BackendHandleAccess SkSurface::kFlushRead_BackendHandleAccess

staticconstexpr

Initial value:

=

BackendHandleAccess::kFlushRead

SkSurface::BackendHandleAccess::kFlushRead

@ kFlushRead

back-end object is readable

◆ kFlushWrite_BackendHandleAccess

constexpr BackendHandleAccess SkSurface::kFlushWrite_BackendHandleAccess

staticconstexpr

Initial value:

=

BackendHandleAccess::kFlushWrite

SkSurface::BackendHandleAccess::kFlushWrite

@ kFlushWrite

back-end object is writable

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

/CHECKOUT/include/core/SkSurface.h

Public Types

Public Member Functions

Static Public Attributes

Protected Member Functions

Detailed Description

Member Typedef Documentation

◆ AsyncReadResult

◆ ReadPixelsCallback

◆ ReadPixelsContext

◆ ReleaseContext

◆ RescaleGamma

◆ RescaleMode

◆ TextureReleaseProc

Member Enumeration Documentation

◆ BackendHandleAccess

◆ ContentChangeMode

Constructor & Destructor Documentation

◆ SkSurface() [1/2]

◆ SkSurface() [2/2]

Member Function Documentation

◆ asyncRescaleAndReadPixels()

◆ asyncRescaleAndReadPixelsYUV420()

◆ asyncRescaleAndReadPixelsYUVA420()

◆ capabilities()

◆ characterize()

◆ dirtyGenerationID()

◆ draw() [1/2]

◆ draw() [2/2]

◆ generationID()

◆ getCanvas()

◆ height()

◆ imageInfo()

◆ isCompatible()

◆ makeImageSnapshot() [1/2]

◆ makeImageSnapshot() [2/2]

◆ makeSurface() [1/2]

◆ makeSurface() [2/2]

◆ notifyContentWillChange()

◆ peekPixels()

◆ props()

◆ readPixels() [1/3]

◆ readPixels() [2/3]

◆ readPixels() [3/3]

◆ recorder()

◆ recordingContext()

◆ ref()

◆ replaceBackendTexture()

◆ unique()

◆ unref()

◆ wait()

◆ width()

◆ writePixels() [1/2]

◆ writePixels() [2/2]

Member Data Documentation

◆ kDiscardWrite_BackendHandleAccess

◆ kFlushRead_BackendHandleAccess

◆ kFlushWrite_BackendHandleAccess