image doc is still a work in progress. Update online version to latest; updating include header is still a ways off. Remove SkPaint::flatten() example since parameter is not publicly accessible. Minor changes to fix typedef and std::function references. TBR=rmistry@google.com Docs-Preview: https://skia.org/?cl=87120 Bug: skia:6898 Change-Id: I3553bc5fca97c5997aa61ea034b5ca10cb10df75 Reviewed-on: https://skia-review.googlesource.com/87120 Reviewed-by: Cary Clark <caryclark@skia.org> Commit-Queue: Cary Clark <caryclark@skia.org>
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SkImage Reference
Image
Class SkImage
Image describes a two dimensional array of pixels to draw. The pixels may be unencoded in a Raster Bitmap, encoded in a Picture or compressed data stream, or located in GPU memory as a GPU Texture.
Image cannot be modified after it is created. Image may allocate additional storage as needed; for instance, an encoded Image may decode when drawn.
Image width and height are greater than zero. Creating an Image with zero width or height returns Image equal to nullptr.
Image may be created from Bitmap, Pixmap, Surface, Picture, encoded streams, GPU Texture, YUV ColorSpace data, or hardware buffer. Encoded streams supported include BMP, GIF, HEIF, ICO, JPEG, PNG, WBMP, WebP. Supported encodings details vary with platform.
Raster Image
Raster Image pixels are unencoded in a Raster Bitmap. These pixels may be read directly and in most cases written to, although edited pixels may not be drawn if Image has been copied internally.
Texture Image
Texture Image are located on GPU and pixels are not accessible. Texture Image are allocated optimally for best performance. Raster Image may be drawn to GPU Surface, but pixels are uploaded from CPU to GPU downgrading performance.
Lazy Image
Lazy Image defer allocating buffer for Image pixels and decoding stream until Image is drawn. Lazy Image caches result if possible to speed up repeated drawing.
Overview
Subtopics
topics | description |
---|
Member Functions
description | function |
---|---|
MakeBackendTextureFromSkImage | Creates GPU Texture from Image. |
MakeCrossContextFromEncoded | Creates Image from encoded data, and uploads to GPU. |
MakeFromAHardwareBuffer | Creates Image from Android hardware buffer. |
MakeFromAdoptedTexture | Creates Image from GPU Texture, managed internally. |
MakeFromBitmap | Creates Image from Bitmap, sharing or copying pixels. |
MakeFromDeferredTextureImageData | |
MakeFromEncoded | Creates Image from encoded data. |
MakeFromGenerator | Creates Image from a stream of data. |
MakeFromNV12TexturesCopy | Creates Image from YUV ColorSpace data in two planes. |
MakeFromPicture | Creates Image from Picture. |
MakeFromRaster | Creates Image from Pixmap, with release. |
MakeFromTexture | Creates Image from GPU Texture, managed externally. |
MakeFromYUVTexturesCopy | Creates Image from YUV ColorSpace data in three planes. |
MakeRasterCopy | Creates Image from Pixmap and copied pixels. |
MakeRasterData | Creates Image from Image Info and shared pixels. |
alphaType | Returns Alpha Type. |
asLegacyBitmap | Returns as Raster Bitmap. |
bounds | Returns width and height as Rectangle. |
colorSpace | Returns Color Space. |
dimensions | Returns width and height. |
encodeToData | Returns encoded Image as SkData. |
getDeferredTextureImageData | |
getTexture | Deprecated. |
getTextureHandle | Returns GPU reference to Image as texture. |
height | Returns pixel row count. |
isAlphaOnly | Returns if pixels represent a transparency mask. |
isLazyGenerated | Returns if Image is created as needed. |
isOpaque | Returns if Alpha Type is kOpaque SkAlphaType. |
isTextureBacked | Returns if Image was created from GPU Texture. |
isValid | Returns if Image can draw to Raster Surface or GPU Context. |
makeColorSpace | Creates Image matching Color Space if possible. |
makeNonTextureImage | Creates Image without dependency on GPU Texture. |
makeRasterImage | Creates Image compatible with Raster Surface if possible. |
makeShader | Creates Shader, Paint element that can tile Image. |
makeSubset | Creates Image containing part of original. |
makeTextureImage | Creates Image matching Color Space if possible. |
makeWithFilter | Creates filtered, clipped Image. |
peekPixels | Returns Pixmap if possible. |
readPixels | Copies and converts pixels. |
refColorSpace | Returns Image Info Color Space. |
refEncodedData | Returns Image encoded in SkData if present. |
scalePixels | Scales and converts one Image to another. |
toString | Converts Image to machine readable form. |
uniqueID | Identifier for Image. |
width | Returns pixel column count. |
MakeRasterCopy
static sk_sp<SkImage> MakeRasterCopy(const SkPixmap& pixmap)
Creates Image from Pixmap and copy of pixels. Since pixels are copied, Pixmap pixels may be modified or deleted without affecting Image.
Image is returned if Pixmap is valid. Valid Pixmap parameters include: dimensions are greater than zero; each dimension fits in 29 bits; Color Type and Alpha Type are valid, and Color Type is not kUnknown SkColorType; row bytes are large enough to hold one row of pixels; pixel address is not nullptr.
Parameters
pixmap | Image Info, pixel address, and row bytes |
Return Value
copy of Pixmap pixels, or nullptr
Example
See Also
MakeRasterData MakeFromGenerator
MakeRasterData
static sk_sp<SkImage> MakeRasterData(const Info& info, sk_sp<SkData> pixels, size_t rowBytes)
Creates Image from Image Info, sharing pixels.
Image is returned if Image Info is valid. Valid Image Info parameters include: dimensions are greater than zero; each dimension fits in 29 bits; Color Type and Alpha Type are valid, and Color Type is not kUnknown SkColorType; rowBytes are large enough to hold one row of pixels; pixels is not nullptr, and contains enough data for Image.
Parameters
info | contains width, height, Alpha Type, Color Type, Color Space |
pixels | address or pixel storage |
rowBytes | size of pixel row or larger |
Return Value
Image sharing pixels, or nullptr
Example
See Also
MakeRasterCopy MakeFromGenerator
Caller data passed to RasterReleaseProc; may be nullptr.
See Also
MakeFromRaster RasterReleaseProc
Function called when Image no longer shares pixels. ReleaseContext is provided by caller when Image is created, and may be nullptr.
See Also
MakeFromRaster
static sk_sp<SkImage> MakeFromRaster(const SkPixmap& pixmap, RasterReleaseProc rasterReleaseProc, ReleaseContext releaseContext)
Creates Image from pixmap, sharing Pixmap pixels. Pixels must remain valid and unchanged until rasterReleaseProc is called. rasterReleaseProc is passed releaseContext when Image is deleted or no longer refers to pixmap pixels.
Pass nullptr for rasterReleaseProc to share Pixmap without requiring a callback when Image is released. Pass nullptr for releaseContext if rasterReleaseProc does not require state.
Image is returned if pixmap is valid. Valid Pixmap parameters include: dimensions are greater than zero; each dimension fits in 29 bits; Color Type and Alpha Type are valid, and Color Type is not kUnknown SkColorType; row bytes are large enough to hold one row of pixels; pixel address is not nullptr.
Parameters
pixmap | Image Info, pixel address, and row bytes |
rasterReleaseProc | function called when pixels can be released; or nullptr |
releaseContext | state passed to rasterReleaseProc; or nullptr |
Return Value
Example
Example Output
before reset: 0
after reset: 1
See Also
MakeRasterCopy MakeRasterData MakeFromGenerator RasterReleaseProc ReleaseContext
MakeFromBitmap
static sk_sp<SkImage> MakeFromBitmap(const SkBitmap& bitmap)
Creates Image from bitmap, sharing or copying bitmap pixels. If the bitmap is marked immutable, and its pixel memory is shareable, it may be shared instead of copied.
Image is returned if bitmap is valid. Valid Bitmap parameters include: dimensions are greater than zero; each dimension fits in 29 bits; Color Type and Alpha Type are valid, and Color Type is not kUnknown SkColorType; row bytes are large enough to hold one row of pixels; pixel address is not nullptr.
Parameters
bitmap | Image Info, row bytes, and pixels |
Return Value
created Image, or nullptr
Example
See Also
MakeFromRaster MakeRasterCopy MakeFromGenerator MakeRasterData
MakeFromGenerator
static sk_sp<SkImage> MakeFromGenerator(std::unique_ptr<SkImageGenerator> imageGenerator, const SkIRect* subset = nullptr)
Creates Image from data returned by imageGenerator. Generated data is owned by Image and may not be shared or accessed.
subset allows selecting a portion of the full image. Pass nullptr to select the entire image; otherwise, subset must be contained by image bounds.
Image is returned if generator data is valid. Valid data parameters vary by type of data and platform.
imageGenerator may wrap Picture data, codec data, or custom data.
Parameters
imageGenerator | stock or custom routines to retrieve Image |
subset | bounds of returned Image; may be nullptr |
Return Value
created Image, or nullptr
Example
See Also
MakeFromEncoded
static sk_sp<SkImage> MakeFromEncoded(sk_sp<SkData> encoded, const SkIRect* subset = nullptr)
Creates Image from encoded data. subset allows selecting a portion of the full image. Pass nullptr to select the entire image; otherwise, subset must be contained by image bounds.
Image is returned if format of the encoded data is recognized and supported. Recognized formats vary by platfrom.
Parameters
encoded | data of Image to decode |
subset | bounds of returned Image; may be nullptr |
Return Value
created Image, or nullptr
Example
See Also
MakeFromTexture
static sk_sp<SkImage> MakeFromTexture(GrContext* context, const GrBackendTexture& backendTexture, GrSurfaceOrigin origin, SkAlphaType alphaType, sk_sp<SkColorSpace> colorSpace)
Deprecated.
Parameters
context | GPU Context |
backendTexture | texture residing on GPU |
origin | one of: kBottomLeft GrSurfaceOrigin, kTopLeft GrSurfaceOrigin |
alphaType | one of: kUnknown SkAlphaType, kOpaque SkAlphaType, kPremul SkAlphaType, kUnpremul SkAlphaType |
colorSpace | range of colors; may be nullptr |
Return Value
created Image, or nullptr
See Also
MakeFromAdoptedTexture SkSurface::MakeFromBackendTexture
static sk_sp<SkImage> MakeFromTexture(GrContext* context, const GrBackendTexture& backendTexture, GrSurfaceOrigin origin, SkAlphaType alphaType, sk_sp<SkColorSpace> colorSpace, TextureReleaseProc textureReleaseProc, ReleaseContext releaseContext)
Deprecated.
Parameters
context | GPU Context |
backendTexture | texture residing on GPU |
origin | one of: kBottomLeft GrSurfaceOrigin, kTopLeft GrSurfaceOrigin |
alphaType | one of: kUnknown SkAlphaType, kOpaque SkAlphaType, kPremul SkAlphaType, kUnpremul SkAlphaType |
colorSpace | range of colors; may be nullptr |
textureReleaseProc | function called when texture can be released |
releaseContext | state passed to textureReleaseProc |
Return Value
created Image, or nullptr
See Also
MakeFromAdoptedTexture SkSurface::MakeFromBackendTexture
static sk_sp<SkImage> MakeFromTexture(GrContext* context, const GrBackendTexture& backendTexture, GrSurfaceOrigin origin, SkColorType colorType, SkAlphaType alphaType, sk_sp<SkColorSpace> colorSpace)
Creates Image from GPU Texture associated with context. Caller is responsible for managing the lifetime of GPU Texture.
Image is returned if format of backendTexture is recognized and supported. Recognized formats vary by GPU back-end.
Parameters
context | GPU Context |
backendTexture | texture residing on GPU |
origin | one of: kBottomLeft GrSurfaceOrigin, kTopLeft GrSurfaceOrigin |
colorType | one of: kUnknown SkColorType, kAlpha 8 SkColorType, kRGB 565 SkColorType, kARGB 4444 SkColorType, kRGBA 8888 SkColorType, kBGRA 8888 SkColorType, kGray 8 SkColorType, kRGBA F16 SkColorType |
alphaType | one of: kUnknown SkAlphaType, kOpaque SkAlphaType, kPremul SkAlphaType, kUnpremul SkAlphaType |
colorSpace | range of colors; may be nullptr |
Return Value
created Image, or nullptr
Example
See Also
MakeFromAdoptedTexture SkSurface::MakeFromBackendTexture
static sk_sp<SkImage> MakeFromTexture(GrContext* context, const GrBackendTexture& backendTexture, GrSurfaceOrigin origin, SkColorType colorType, SkAlphaType alphaType, sk_sp<SkColorSpace> colorSpace, TextureReleaseProc textureReleaseProc, ReleaseContext releaseContext)
Creates Image from GPU Texture associated with context. GPU Texture must stay valid and unchanged until textureReleaseProc is called. textureReleaseProc is passed releaseContext when Image is deleted or no longer refers to texture.
Image is returned if format of backendTexture is recognized and supported. Recognized formats vary by GPU back-end.
Parameters
context | GPU Context |
backendTexture | texture residing on GPU |
origin | one of: kBottomLeft GrSurfaceOrigin, kTopLeft GrSurfaceOrigin |
colorType | one of: kUnknown SkColorType, kAlpha 8 SkColorType, kRGB 565 SkColorType, kARGB 4444 SkColorType, kRGBA 8888 SkColorType, kBGRA 8888 SkColorType, kGray 8 SkColorType, kRGBA F16 SkColorType |
alphaType | one of: kUnknown SkAlphaType, kOpaque SkAlphaType, kPremul SkAlphaType, kUnpremul SkAlphaType |
colorSpace | range of colors; may be nullptr |
textureReleaseProc | function called when texture can be released |
releaseContext | state passed to textureReleaseProc |
Return Value
created Image, or nullptr
Example
See Also
MakeFromAdoptedTexture SkSurface::MakeFromBackendTexture
MakeCrossContextFromEncoded
static sk_sp<SkImage> MakeCrossContextFromEncoded(GrContext* context, sk_sp<SkData> data, bool buildMips, SkColorSpace* dstColorSpace)
Creates Image from encoded data. Image is uploaded to GPU back-end using context.
Created Image is available to other GPU contexts, and is available across thread boundaries. All contexts must be in the same GPU Share Group, or otherwise share resources.
When Image is no longer referenced, context releases texture memory asynchronously.
Texture decoded from data is uploaded to match Surface created with dstColorSpace. Color Space of Image is determined by encoded data.
Image is returned if format of data is recognized and supported, and if context supports moving resources. Recognized formats vary by platform and GPU back-end.
Image is returned using MakeFromEncoded if context is nullptr or does not support moving resources between contexts.
Parameters
context | GPU Context |
data | Image to decode |
buildMips | create Image as Mip Map if true |
dstColorSpace | range of colors of matching Surface on GPU |
Return Value
created Image, or nullptr
Example
See Also
MakeCrossContextFromPixmap
static sk_sp<SkImage> MakeCrossContextFromPixmap(GrContext* context, const SkPixmap& pixmap, bool buildMips, SkColorSpace* dstColorSpace)
Creates Image from pixmap. Image is uploaded to GPU back-end using context.
Created Image is available to other GPU contexts, and is available across thread boundaries. All contexts must be in the same GPU Share Group, or otherwise share resources.
When Image is no longer referenced, context releases texture memory asynchronously.
Texture created from pixmap is uploaded to match Surface created with dstColorSpace. Color Space of Image is determined by pixmap.colorSpace.
Image is returned referring to GPU back-end if context is not nullptr, format of data is recognized and supported, and if context supports moving resources between contexts. Otherwise, pixmap pixel data is copied and Image as returned in raster format if possible; nullptr may be returned. Recognized GPU formats vary by platform and GPU back-end.
Parameters
context | GPU Context |
pixmap | Image Info, pixel address, and row bytes |
buildMips | create Image as Mip Map if true |
dstColorSpace | range of colors of matching Surface on GPU |
Return Value
created Image, or nullptr
Example
See Also
MakeFromAdoptedTexture
static sk_sp<SkImage> MakeFromAdoptedTexture(GrContext* context, const GrBackendTexture& backendTexture, GrSurfaceOrigin surfaceOrigin, SkAlphaType alphaType = kPremul_SkAlphaType, sk_sp<SkColorSpace> colorSpace = nullptr)
Deprecated.
Parameters
context | GPU Context |
backendTexture | texture residing on GPU |
surfaceOrigin | one of: kBottomLeft GrSurfaceOrigin, kTopLeft GrSurfaceOrigin |
alphaType | one of: kUnknown SkAlphaType, kOpaque SkAlphaType, kPremul SkAlphaType, kUnpremul SkAlphaType |
colorSpace | range of colors; may be nullptr |
Return Value
created Image, or nullptr
See Also
MakeFromTexture MakeFromYUVTexturesCopy
static sk_sp<SkImage> MakeFromAdoptedTexture(GrContext* context, const GrBackendTexture& backendTexture, GrSurfaceOrigin surfaceOrigin, SkColorType colorType, SkAlphaType alphaType = kPremul_SkAlphaType, sk_sp<SkColorSpace> colorSpace = nullptr)
Creates Image from backendTexture associated with context. backendTexture and returned Image are managed internally, and are released when no longer needed.
Image is returned if format of backendTexture is recognized and supported. Recognized formats vary by GPU back-end.
Parameters
context | GPU Context |
backendTexture | texture residing on GPU |
surfaceOrigin | one of: kBottomLeft GrSurfaceOrigin, kTopLeft GrSurfaceOrigin |
colorType | one of: kUnknown SkColorType, kAlpha 8 SkColorType, kRGB 565 SkColorType, kARGB 4444 SkColorType, kRGBA 8888 SkColorType, kBGRA 8888 SkColorType, kGray 8 SkColorType, kRGBA F16 SkColorType |
alphaType | one of: kUnknown SkAlphaType, kOpaque SkAlphaType, kPremul SkAlphaType, kUnpremul SkAlphaType |
colorSpace | range of colors; may be nullptr |
Return Value
created Image, or nullptr
Example
See Also
MakeFromTexture MakeFromYUVTexturesCopy
MakeFromYUVTexturesCopy
static sk_sp<SkImage> MakeFromYUVTexturesCopy(GrContext* context, SkYUVColorSpace yuvColorSpace, const GrBackendObject yuvTextureHandles[3], const SkISize yuvSizes[3], GrSurfaceOrigin surfaceOrigin, sk_sp<SkColorSpace> colorSpace = nullptr)
Creates Image from copy of yuvTextureHandles, an array of textures on GPU. yuvTextureHandles contain pixels for YUV planes of Image. yuvSizes conain dimensions for each pixel plane. Dimensions must be greater than zero but may differ from plane to plane. Returned Image has the dimensions yuvSizes[0]. yuvColorSpace describes how YUV colors convert to RGB colors.
Parameters
context | GPU Context |
yuvColorSpace | one of: kJPEG SkYUVColorSpace, kRec601 SkYUVColorSpace, kRec709 SkYUVColorSpace |
yuvTextureHandles | array of YUV textures on GPU |
yuvSizes | dimensions of YUV textures |
surfaceOrigin | one of: kBottomLeft GrSurfaceOrigin, kTopLeft GrSurfaceOrigin |
colorSpace | range of colors; may be nullptr |
Return Value
created Image, or nullptr
See Also
static sk_sp<SkImage> MakeFromYUVTexturesCopy(GrContext* context, SkYUVColorSpace yuvColorSpace, const GrBackendTexture yuvTextureHandles[3], const SkISize yuvSizes[3], GrSurfaceOrigin surfaceOrigin, sk_sp<SkColorSpace> colorSpace = nullptr)
Creates Image from copy of yuvTextureHandles, an array of textures on GPU. yuvTextureHandles contain pixels for YUV planes of Image. yuvSizes conain dimensions for each pixel plane. Dimensions must be greater than zero but may differ from plane to plane. Returned Image has the dimensions yuvSizes[0]. yuvColorSpace describes how YUV colors convert to RGB colors.
Parameters
context | GPU Context |
yuvColorSpace | one of: kJPEG SkYUVColorSpace, kRec601 SkYUVColorSpace, kRec709 SkYUVColorSpace |
yuvTextureHandles | array of YUV textures on GPU |
yuvSizes | dimensions of YUV textures |
surfaceOrigin | one of: kBottomLeft GrSurfaceOrigin, kTopLeft GrSurfaceOrigin |
colorSpace | range of colors; may be nullptr |
Return Value
created Image, or nullptr
See Also
MakeFromNV12TexturesCopy
static sk_sp<SkImage> MakeFromNV12TexturesCopy(GrContext* context, SkYUVColorSpace yuvColorSpace, const GrBackendObject nv12TextureHandles[2], const SkISize nv12Sizes[2], GrSurfaceOrigin surfaceOrigin, sk_sp<SkColorSpace> colorSpace = nullptr)
Creates Image from copy of nv12TextureHandles, an array of textures on GPU. nv12TextureHandles[0] contains pixels for YUV Component Y plane. nv12TextureHandles[1] contains pixels for YUV Component U plane, followed by pixels for YUV Component V plane. nv12Sizes conain dimensions for each pixel plane. Dimensions must be greater than zero but may differ from plane to plane. Returned Image has the dimensions nv12Sizes[0]. yuvColorSpace describes how YUV colors convert to RGB colors.
Parameters
context | GPU Context |
yuvColorSpace | one of: kJPEG SkYUVColorSpace, kRec601 SkYUVColorSpace, kRec709 SkYUVColorSpace |
nv12TextureHandles | array of YUV textures on GPU |
nv12Sizes | dimensions of YUV textures |
surfaceOrigin | one of: kBottomLeft GrSurfaceOrigin, kTopLeft GrSurfaceOrigin |
colorSpace | range of colors; may be nullptr |
Return Value
created Image, or nullptr
See Also
static sk_sp<SkImage> MakeFromNV12TexturesCopy(GrContext* context, SkYUVColorSpace yuvColorSpace, const GrBackendTexture nv12TextureHandles[2], const SkISize nv12Sizes[2], GrSurfaceOrigin surfaceOrigin, sk_sp<SkColorSpace> colorSpace = nullptr)
Creates Image from copy of nv12TextureHandles, an array of textures on GPU. nv12TextureHandles[0] contains pixels for YUV Component Y plane. nv12TextureHandles[1] contains pixels for YUV Component U plane, followed by pixels for YUV Component V plane. nv12Sizes conain dimensions for each pixel plane. Dimensions must be greater than zero but may differ from plane to plane. Returned Image has the dimensions nv12Sizes[0]. yuvColorSpace describes how YUV colors convert to RGB colors.
Parameters
context | GPU Context |
yuvColorSpace | one of: kJPEG SkYUVColorSpace, kRec601 SkYUVColorSpace, kRec709 SkYUVColorSpace |
nv12TextureHandles | array of YUV textures on GPU |
nv12Sizes | dimensions of YUV textures |
surfaceOrigin | one of: kBottomLeft GrSurfaceOrigin, kTopLeft GrSurfaceOrigin |
colorSpace | range of colors; may be nullptr |
Return Value
created Image, or nullptr
See Also
Enum SkImage::BitDepth
enum class BitDepth { kU8, kF16, };
Constants
SkImage::kU8 | 0 | Use 8 bits per Color ARGB component using unsigned integer format. |
SkImage::kF16 | 1 | Use 16 bits per Color ARGB component using half-precision floating point format. |
See Also
MakeFromPicture
static sk_sp<SkImage> MakeFromPicture(sk_sp<SkPicture> picture, const SkISize& dimensions, const SkMatrix* matrix, const SkPaint* paint, BitDepth bitDepth, sk_sp<SkColorSpace> colorSpace)
Creates Image from picture. Returned Image width and height are set by dimensions. Image draws picture with matrix and paint, set to bitDepth and colorSpace.
If matrix is nullptr, draws with identity Matrix. If paint is nullptr, draws with default Paint. colorSpace may be nullptr.
Parameters
picture | stream of drawing commands |
dimensions | width and height |
matrix | Matrix to rotate, scale, translate, and so on; may be nullptr |
paint | Paint to apply transparency, filtering, and so on; may be nullptr |
bitDepth | 8 bit integer or 16 bit float: per component |
colorSpace | range of colors; may be nullptr |
Return Value
created Image, or nullptr
Example
See Also
MakeFromAHardwareBuffer
static sk_sp<SkImage> MakeFromAHardwareBuffer(AHardwareBuffer* hardwareBuffer, SkAlphaType alphaType = kPremul_SkAlphaType, sk_sp<SkColorSpace> colorSpace = nullptr)
Creates Image from Android hardware buffer. Returned Image takes a reference on the buffer.
Only available on Android, when __ANDROID API is defined to be 26 or greater.
Parameters
hardwareBuffer | AHardwareBuffer Android hardware buffer |
alphaType | one of: kUnknown SkAlphaType, kOpaque SkAlphaType, kPremul SkAlphaType, kUnpremul SkAlphaType |
colorSpace | range of colors; may be nullptr |
Return Value
created Image, or nullptr
See Also
width
int width() const
Returns pixel count in each row.
Return Value
Example
See Also
height
int height() const
Returns pixel row count.
Return Value
Example
See Also
dimensions
SkISize dimensions() const
Returns ISize { width, height }.
Return Value
integral size of width and height
Example
See Also
bounds
SkIRect bounds() const
Returns IRect { 0, 0, width, height }.
Return Value
integral rectangle from origin to width and height
Example
See Also
uniqueID
uint32_t uniqueID() const
Returns value unique to image. Image contents cannot change after Image is created. Any operation to create a new Image will receive generate a new unique number.
Return Value
unique identifier
Example
See Also
alphaType
SkAlphaType alphaType() const
Returns Alpha Type, one of: kUnknown SkAlphaType, kOpaque SkAlphaType, kPremul SkAlphaType, kUnpremul SkAlphaType.
Alpha Type returned was a parameter to an Image constructor, or was parsed from encoded data.
Return Value
Alpha Type in Image
Example
See Also
colorSpace
SkColorSpace* colorSpace() const
Returns Color Space, the range of colors, associated with Image. The reference count of Color Space is unchanged. The returned Color Space is immutable.
Color Space returned was a parameter to an Image constructor, or was parsed from encoded data. Color Space may be ignored when drawing Image, and when drawing into Surface constructed with Color Space.
Return Value
Color Space in Image, or nullptr
Example
See Also
incomplete
refColorSpace
sk_sp<SkColorSpace> refColorSpace() const
Return Value
incomplete
Example
See Also
incomplete
isAlphaOnly
bool isAlphaOnly() const
Returns true if Image pixels represent transparency only. If true, each pixel is packed in 8 bits as defined by kAlpha 8 SkColorType.
Return Value
true if pixels represent a transparency mask
Example
See Also
incomplete
isOpaque
bool isOpaque() const
Returns if all pixels ignore any Alpha value and are treated as fully opaque.
Return Value
true if Alpha Type is kOpaque SkAlphaType
Example
See Also
incomplete
makeShader
sk_sp<SkShader> makeShader(SkShader::TileMode tileMode1, SkShader::TileMode tileMode2, const SkMatrix* localMatrix = nullptr) const
Parameters
tileMode1 | incomplete |
tileMode2 | incomplete |
localMatrix | incomplete |
Return Value
incomplete
Example
See Also
incomplete
sk_sp<SkShader> makeShader(const SkMatrix* localMatrix = nullptr) const
Helper version of
Parameters
localMatrix | incomplete |
Return Value
incomplete
Example
See Also
incomplete
peekPixels
bool peekPixels(SkPixmap* pixmap) const
If the image has direct access to its pixels (i.e. they are in local RAM) return true, and if not null, return in the pixmap parameter the info about the images pixels. On failure, return false and ignore the pixmap parameter.
Parameters
pixmap | incomplete |
Return Value
incomplete
Example
See Also
incomplete
getTexture
GrTexture* getTexture() const
Deprecated.
isTextureBacked
bool isTextureBacked() const
Returns true if the image is texture backed.
Return Value
incomplete
Example
See Also
incomplete
isValid
bool isValid(GrContext* context) const
Returns true if Image can be drawn. If context is nullptr, tests if Image draws on Raster Surface; Otherwise, tests if Image draws on GPU Surface associated with context.
Texture-backed images may become invalid if their underlying GrContext is abandoned. Some generator-backed images may be invalid for CPU and/or GPU.
Parameters
context | GPU Context |
Return Value
incomplete
Example
See Also
incomplete
getTextureHandle
GrBackendObject getTextureHandle(bool flushPendingGrContextIO, GrSurfaceOrigin* origin = nullptr) const
Retrieves the back-end API handle of texture. If flushPendingGrContextIO is true, complete deferred I/O operations.
If origin in not nullptr, copies location of content drawn into Image.
Parameters
flushPendingGrContextIO | flag to flush outstanding requests |
origin | storage for one of: kTopLeft GrSurfaceOrigin, kBottomLeft GrSurfaceOrigin; or nullptr |
Return Value
back-end API texture handle
Example
See Also
incomplete
Enum SkImage::CachingHint
enum CachingHint { kAllow CachingHint, kDisallow CachingHint, };
Hints to image calls where the system might cache computed intermediates (e.g. the results of decoding or a read-back from the GPU. Passing kAllow CachingHint signals that the system's default behavior is fine. Passing kDisallow CachingHint signals that caching should be avoided.
Constants
SkImage::kAllow_CachingHint | 0 | |
SkImage::kDisallow_CachingHint | 1 |
Example
See Also
incomplete
readPixels
bool readPixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRowBytes, int srcX, int srcY, CachingHint cachingHint = kAllow_CachingHint) const
Copy the pixels from the image into the specified buffer (dstPixels + dstRowBytes), converting them into the requested format (dstInfo). The image pixels are read starting at the specified (srcX, srcY) location. dstInfo and (srcX, srcY) offset specifies a source rectangle:
SkRect srcR; srcR.setXYWH(srcX, srcY, dstInfo.width(), dstInfo.height);
The source rectangle is intersected with the bounds of the image. If this intersection is not empty, then we have two sets of pixels (of equal size). Replace dstPixels with the corresponding Image pixels, performing any Color Type/Alpha Type transformations needed (in the case where Image and dstInfo have different Color Types or Alpha Types). This call can fail, returning false, for several reasons: if source rectangle does not intersect the image bounds; if the requested Color Type/Alpha Type cannot be converted from the image's types.
Parameters
dstInfo | incomplete |
dstPixels | incomplete |
dstRowBytes | incomplete |
srcX | incomplete |
srcY | incomplete |
cachingHint | incomplete |
Return Value
incomplete
Example
See Also
incomplete
bool readPixels(const SkPixmap& dst, int srcX, int srcY, CachingHint cachingHint = kAllow_CachingHint) const
Parameters
dst | incomplete |
srcX | incomplete |
srcY | incomplete |
cachingHint | incomplete |
Return Value
incomplete
Example
See Also
incomplete
scalePixels
bool scalePixels(const SkPixmap& dst, SkFilterQuality filterQuality, CachingHint cachingHint = kAllow_CachingHint) const
Copies Image pixels into dst, converting to dst Color Type and Alpha Type. If the conversion cannot be performed, false is returned. If dst dimensions differ from Image dimensions, Image is scaled, applying filterQuality.
Parameters
dst | incomplete |
filterQuality | incomplete |
cachingHint | incomplete |
Return Value
incomplete
Example
See Also
incomplete
encodeToData
sk_sp<SkData> encodeToData(SkEncodedImageFormat encodedImageFormat, int quality) const
Encodes Image pixels, returning result as SkData.
Returns nullptr if encoding fails, or encodedImageFormat is not supported.
Parameters
encodedImageFormat | incomplete |
quality | incomplete |
Return Value
encoded Image, or nullptr
Example
See Also
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sk_sp<SkData> encodeToData() const
Encodes Image and returns result as SkData. Will reuse existing encoded data if present, as returned by refEncodedData. If encoded data is missing or invalid, Image is encoded as PNG.
Returns nullptr if existing encoded data is missing or invalid and encoding fails.
Return Value
incomplete
Example
See Also
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refEncodedData
sk_sp<SkData> refEncodedData() const
If the image already has its contents in encoded form (e.g. PNG or JPEG), return that as SkData. If the image does not already has its contents in encoded form, return nullptr.
To force the image to return its contents as encoded data, call encodeToData.
Return Value
incomplete
Example
See Also
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toString
const char* toString(SkString* string) const
Parameters
string | incomplete |
Return Value
incomplete
Example
See Also
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makeSubset
sk_sp<SkImage> makeSubset(const SkIRect& subset) const
Return a new image that is a subset of this image. The underlying implementation may share the pixels, or it may make a copy. If subset does not intersect the bounds of this image, or the copy/share cannot be made, nullptr will be returned.
Parameters
subset | incomplete |
Return Value
incomplete
Example
See Also
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makeTextureImage
sk_sp<SkImage> makeTextureImage(GrContext* context, SkColorSpace* dstColorSpace) const
Ensures that an image is backed by a texture (when GrContext is non-null), suitable for use with surfaces that have the supplied destination color space. If no transformation is required, the returned image may be the same as this image. If this image is from a different GrContext, this will fail.
Parameters
context | GPU Context |
dstColorSpace | incomplete |
Return Value
incomplete
Example
See Also
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makeNonTextureImage
sk_sp<SkImage> makeNonTextureImage() const
Creates raster Image if Image contains GPU Texture and raster Image , this will make a raster copy of it (or nullptr if reading back the pixels fails). Otherwise, it returns the original image.
Return Value
incomplete
Example
See Also
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makeRasterImage
sk_sp<SkImage> makeRasterImage() const
If the image is texture-backed this will make a raster copy of it (or nullptr if reading back the pixels fails). Otherwise, it returns the original image.
Return Value
incomplete
Example
See Also
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makeWithFilter
sk_sp<SkImage> makeWithFilter(const SkImageFilter* filter, const SkIRect& subset, const SkIRect& clipBounds, SkIRect* outSubset, SkIPoint* offset) const
Apply a given image filter to this image, and return the filtered result. The subset represents the active portion of this image. The return value is similarly an SkImage, with an active subset (outSubset). This is usually used with texture-backed images, where the texture may be approx-match and thus larger than the required size. clipBounds constrains the device-space extent of the image, stored in outSubset. offset is storage, set to the amount to translate the result when drawn. If the result image cannot be created, or the result would be transparent black, null is returned, in which case the offset and outSubset parameters should be ignored by the caller.
Parameters
filter | incomplete |
subset | incomplete |
clipBounds | incomplete |
outSubset | incomplete |
offset | incomplete |
Return Value
incomplete
Example
See Also
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Struct SkImage::DeferredTextureImageUsageParams
struct DeferredTextureImageUsageParams { DeferredTextureImageUsageParams(const SkMatrix matrix, const SkFilterQuality quality, int preScaleMipLevel); SkMatrix fMatrix; SkFilterQuality fQuality; int fPreScaleMipLevel; };
DeferredTextureImageUsageParams
DeferredTextureImageUsageParams(const SkMatrix matrix, const SkFilterQuality quality, int preScaleMipLevel)
Parameters
matrix | incomplete |
quality | incomplete |
preScaleMipLevel | incomplete |
Return Value
incomplete
Example
See Also
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Example
See Also
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getDeferredTextureImageData
size_t getDeferredTextureImageData(const GrContextThreadSafeProxy& contextThreadSafeProxy, const DeferredTextureImageUsageParams deferredTextureImageUsageParams[], int paramCnt, void* buffer, SkColorSpace* dstColorSpace = nullptr, SkColorType dstColorType = kN32_SkColorType) const
This method allows clients to capture the data necessary to turn a SkImage into a texture- backed image. If the original image is codec-backed this will decode into a format optimized for the context represented by the proxy. This method is thread safe with respect to the GrContext whence the proxy came. Clients allocate and manage the storage of the deferred texture data and control its lifetime. No cleanup is required, thus it is safe to simply free the memory out from under the data.
The same method is used both for getting the size necessary for pre-uploaded texture data and for retrieving the data. The params array represents the set of draws over which to optimize the pre-upload data.
When called with a null buffer this returns the size that the client must allocate in order to create deferred texture data for this image (or zero if this is an inappropriate candidate). The buffer allocated by the client should be 8 byte aligned.
When buffer is not null this fills in the deferred texture data for this image in the provided buffer (assuming this is an appropriate candidate image and the buffer is appropriately aligned). Upon success the size written is returned, otherwise 0.
dstColorSpace is the color space of the surface where this texture will ultimately be used. If the method determines that mip-maps are needed, this helps determine the correct strategy for building them (gamma-correct or not).
dstColorType is the color type of the surface where this texture will ultimately be used. This determines the format with which the image will be uploaded to the GPU. If dstColorType does not support color spaces (low bit depth types such as kARGB 4444 SkColorType), then dstColorSpace must be null.
Parameters
contextThreadSafeProxy | incomplete |
deferredTextureImageUsageParams | incomplete |
paramCnt | incomplete |
buffer | incomplete |
dstColorSpace | incomplete |
dstColorType | incomplete |
Return Value
incomplete
Example
See Also
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MakeFromDeferredTextureImageData
static sk_sp<SkImage> MakeFromDeferredTextureImageData(GrContext* context, const void* data, SkBudgeted budgeted)
Returns a texture-backed image from data produced in SkImage::getDeferredTextureImageData. The context must be the context that provided the proxy passed to getDeferredTextureImageData.
Parameters
context | GPU Context |
data | incomplete |
budgeted | incomplete |
Return Value
incomplete
Example
See Also
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MakeBackendTextureFromSkImage
static bool MakeBackendTextureFromSkImage(GrContext* context, sk_sp<SkImage> image, GrBackendTexture* backendTexture, BackendTextureReleaseProc* backendTextureReleaseProc)
Creates a GrBackendTexture from the provided SkImage. Returns true on success. The GrBackendTexture and BackendTextureReleaseProc are populated on success. It is the callers responsibility to call the BackendTextureReleaseProc once they have deleted the texture. Note that the BackendTextureReleaseProc allows Skia to clean up auxiliary data related to the GrBackendTexture, and is not a substitute for the client deleting the GrBackendTexture themselves.
If image is both texture backed and singly referenced; that is, its only reference was transferred using std::move(): image is returned in backendTexture without conversion or making a copy.
If the SkImage is not texture backed, this function will generate a texture with the image's contents and return that.
Parameters
context | GPU Context |
image | incomplete |
backendTexture | incomplete |
backendTextureReleaseProc | incomplete |
Return Value
incomplete
Example
See Also
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Enum SkImage::LegacyBitmapMode
enum LegacyBitmapMode { kRO LegacyBitmapMode, kRW LegacyBitmapMode, };
Helper functions to convert to SkBitmap
Constants
SkImage::kRO_LegacyBitmapMode | 0 | |
SkImage::kRW_LegacyBitmapMode | 1 |
Example
See Also
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asLegacyBitmap
bool asLegacyBitmap(SkBitmap* bitmap, LegacyBitmapMode legacyBitmapMode) const
Creates raster Bitmap with same pixels as Image. If legacyBitmapMode is kRO LegacyBitmapMode, returned bitmap is read-only and immutable. Returns true if Bitmap is stored in bitmap. Returns false and resets bitmap if Bitmap write did not succeed.
Parameters
bitmap | storage for legacy Bitmap |
legacyBitmapMode | one of: kRO LegacyBitmapMode, kRW LegacyBitmapMode |
Return Value
true if Bitmap was created
Example
See Also
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isLazyGenerated
bool isLazyGenerated() const
Returns true if Image is backed by an image-generator or other service that creates and caches its pixels or texture on-demand.
Return Value
true if Image is created as needed
Example
See Also
incomplete
makeColorSpace
sk_sp<SkImage> makeColorSpace(sk_sp<SkColorSpace> target, SkTransferFunctionBehavior premulBehavior) const
If target is supported, returns an SkImage in target color space. Otherwise, returns nullptr. This will leave the image as is if it already in target color space. Otherwise, it will convert the pixels from Image color space to target color space. If this->colorSpace is nullptr, Image color space will be treated as sRGB.
If premulBehavior is SkTransferFunctionBehavior::kRespect: converts Image pixels to a linear space before converting to match destination Color Type and Color Space. If premulBehavior is SkTransferFunctionBehavior::kIgnore: Image pixels are treated as if they are linear, regardless of how they are encoded.
Parameters
target | incomplete |
premulBehavior | incomplete |
Return Value
incomplete
Example
See Also
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