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Skia
2DGraphicsLibrary
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Skia
2DGraphicsLibrary
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SkImage is an abstraction for drawing a rectagle of pixels, though the particular type of image could be actually storing its data on the GPU, or as drawing commands (picture or PDF or otherwise), ready to be played back into another canvas. More...
#include <SkImage.h>
Classes | |
| struct | DeferredTextureImageUsageParams |
| Drawing params for which a deferred texture image data should be optimized. More... | |
Public Types | |
| enum | CachingHint { kAllow_CachingHint, kDisallow_CachingHint } |
| Hints to image calls where the system might cache computed intermediates (e.g. More... | |
| enum | LegacyBitmapMode { kRO_LegacyBitmapMode, kRW_LegacyBitmapMode } |
| typedef SkImageInfo | Info |
| typedef void * | ReleaseContext |
| typedef void(* | RasterReleaseProc )(const void *pixels, ReleaseContext) |
| typedef void(* | TextureReleaseProc )(ReleaseContext) |
Public Member Functions | |
| int | width () const |
| int | height () const |
| SkISize | dimensions () const |
| SkIRect | bounds () const |
| uint32_t | uniqueID () const |
| SkAlphaType | alphaType () const |
| bool | isOpaque () const |
| bool | readYUV8Planes (const SkISize[3], void *const planes[3], const size_t rowBytes[3], SkYUVColorSpace) const |
| Extracts YUV planes from the SkImage and stores them in client-provided memory. More... | |
| sk_sp< SkShader > | makeShader (SkShader::TileMode, SkShader::TileMode, const SkMatrix *localMatrix=nullptr) const |
| bool | peekPixels (SkPixmap *pixmap) const |
| If the image has direct access to its pixels (i.e. More... | |
| void | preroll (GrContext *=nullptr) const |
| Some images have to perform preliminary work in preparation for drawing. More... | |
| GrTexture * | getTexture () const |
| bool | isTextureBacked () const |
| Returns true if the image is texture backed. | |
| GrBackendObject | getTextureHandle (bool flushPendingGrContextIO) const |
| Retrieves the backend API handle of the texture. More... | |
| bool | readPixels (const SkImageInfo &dstInfo, void *dstPixels, size_t dstRowBytes, int srcX, int srcY, CachingHint=kAllow_CachingHint) const |
| Copy the pixels from the image into the specified buffer (pixels + rowBytes), converting them into the requested format (dstInfo). More... | |
| bool | readPixels (const SkPixmap &dst, int srcX, int srcY, CachingHint=kAllow_CachingHint) const |
| bool | scalePixels (const SkPixmap &dst, SkFilterQuality, CachingHint=kAllow_CachingHint) const |
| Copy the pixels from this image into the dst pixmap, converting as needed into dst's colortype/alphatype. More... | |
| SkData * | encode (SkImageEncoder::Type, int quality) const |
| Encode the image's pixels and return the result as a new SkData, which the caller must manage (i.e. More... | |
| SkData * | encode (SkPixelSerializer *=nullptr) const |
| Encode the image and return the result as a caller-managed SkData. More... | |
| SkData * | refEncoded () const |
| If the image already has its contents in encoded form (e.g. More... | |
| const char * | toString (SkString *) const |
| sk_sp< SkImage > | makeSubset (const SkIRect &subset) const |
| Return a new image that is a subset of this image. More... | |
| sk_sp< SkImage > | makeTextureImage (GrContext *) const |
| Ensures that an image is backed by a texture (when GrContext is non-null). More... | |
| sk_sp< SkImage > | makeNonTextureImage () const |
| If the image is texture-backed this will make a raster copy of it (or nullptr if reading back the pixels fails). More... | |
| 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. More... | |
| size_t | getDeferredTextureImageData (const GrContextThreadSafeProxy &, const DeferredTextureImageUsageParams[], int paramCnt, void *buffer) const |
| This method allows clients to capture the data necessary to turn a SkImage into a texture- backed image. More... | |
| bool | asLegacyBitmap (SkBitmap *, LegacyBitmapMode) const |
| Attempt to create a bitmap with the same pixels as the image. More... | |
| bool | isLazyGenerated () const |
| Returns true if the image is backed by an image-generator or other src that creates (and caches) its pixels / texture on-demand. | |
 Public Member Functions inherited from SkRefCntBase | |
| SkRefCntBase () | |
| Default construct, initializing the reference count to 1. | |
| virtual | ~SkRefCntBase () |
| Destruct, asserting that the reference count is 1. | |
| int32_t | getRefCnt () const |
| Return the reference count. More... | |
| void | validate () const |
| 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 Member Functions | |
| static sk_sp< SkImage > | MakeRasterCopy (const SkPixmap &) |
| static sk_sp< SkImage > | MakeRasterData (const Info &, sk_sp< SkData > pixels, size_t rowBytes) |
| static sk_sp< SkImage > | MakeFromRaster (const SkPixmap &, RasterReleaseProc, ReleaseContext) |
| Return a new Image referencing the specified pixels. More... | |
| static sk_sp< SkImage > | MakeFromBitmap (const SkBitmap &) |
| Construct a new image from the specified bitmap. More... | |
| static sk_sp< SkImage > | MakeFromGenerator (SkImageGenerator *, const SkIRect *subset=nullptr) |
| Construct a new SkImage based on the given ImageGenerator. More... | |
| static sk_sp< SkImage > | MakeFromEncoded (sk_sp< SkData > encoded, const SkIRect *subset=nullptr) |
| Construct a new SkImage based on the specified encoded data. More... | |
| static sk_sp< SkImage > | MakeFromTexture (GrContext *ctx, const GrBackendTextureDesc &desc) |
| Create a new image from the specified descriptor. More... | |
| static sk_sp< SkImage > | MakeFromTexture (GrContext *ctx, const GrBackendTextureDesc &de, SkAlphaType at) |
| static sk_sp< SkImage > | MakeFromTexture (GrContext *ctx, const GrBackendTextureDesc &desc, SkAlphaType at, TextureReleaseProc trp, ReleaseContext rc) |
| Create a new image from the specified descriptor. More... | |
| static sk_sp< SkImage > | MakeFromTexture (GrContext *, const GrBackendTextureDesc &, SkAlphaType, sk_sp< SkColorSpace >, TextureReleaseProc, ReleaseContext) |
| Create a new image from the specified descriptor. More... | |
| static sk_sp< SkImage > | MakeFromAdoptedTexture (GrContext *, const GrBackendTextureDesc &, SkAlphaType=kPremul_SkAlphaType, sk_sp< SkColorSpace >=nullptr) |
| Create a new image from the specified descriptor. More... | |
| static sk_sp< SkImage > | MakeFromYUVTexturesCopy (GrContext *, SkYUVColorSpace, const GrBackendObject yuvTextureHandles[3], const SkISize yuvSizes[3], GrSurfaceOrigin, sk_sp< SkColorSpace >=nullptr) |
| Create a new image by copying the pixels from the specified y, u, v textures. More... | |
| static sk_sp< SkImage > | MakeFromNV12TexturesCopy (GrContext *, SkYUVColorSpace, const GrBackendObject nv12TextureHandles[2], const SkISize nv12Sizes[2], GrSurfaceOrigin, sk_sp< SkColorSpace >=nullptr) |
| Create a new image by copying the pixels from the specified y and uv textures. More... | |
| static sk_sp< SkImage > | MakeFromPicture (sk_sp< SkPicture >, const SkISize &dimensions, const SkMatrix *, const SkPaint *) |
| static sk_sp< SkImage > | MakeTextureFromPixmap (GrContext *, const SkPixmap &, SkBudgeted budgeted) |
| static sk_sp< SkImage > | MakeFromDeferredTextureImageData (GrContext *, const void *, SkBudgeted) |
| Returns a texture-backed image from data produced in SkImage::getDeferredTextureImageData. More... | |
Protected Member Functions | |
| SkImage (int width, int height, uint32_t uniqueID) | |
| Protected Member Functions inherited from SkRefCntBase | |
| void | internal_dispose_restore_refcnt_to_1 () const |
| Allow subclasses to call this if they've overridden internal_dispose so they can reset fRefCnt before the destructor is called or if they choose not to call the destructor (e.g. More... | |
Private Types | |
| typedef SkRefCnt | INHERITED |
Static Private Member Functions | |
| static sk_sp< SkImage > | MakeTextureFromMipMap (GrContext *, const SkImageInfo &, const GrMipLevel *texels, int mipLevelCount, SkBudgeted) |
Private Attributes | |
| const int | fWidth |
| const int | fHeight |
| const uint32_t | fUniqueID |
SkImage is an abstraction for drawing a rectagle of pixels, though the particular type of image could be actually storing its data on the GPU, or as drawing commands (picture or PDF or otherwise), ready to be played back into another canvas.
The content of SkImage is always immutable, though the actual storage may change, if for example that image can be re-created via encoded data or other means.
SkImage always has a non-zero dimensions. If there is a request to create a new image, either directly or via SkSurface, and either of the requested dimensions are zero, then NULL will be returned.
| enum SkImage::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 signals that the system's default behavior is fine. Passing kDisallow signals that caching should be avoided.
| bool SkImage::asLegacyBitmap | ( | SkBitmap * | , |
| LegacyBitmapMode | |||
| ) | const |
Attempt to create a bitmap with the same pixels as the image.
The result will always be a raster-backed bitmap (texture-backed bitmaps are DEPRECATED, and not supported here).
If the mode is kRO (read-only), the resulting bitmap will be marked as immutable.
On succcess, returns true. On failure, returns false and the bitmap parameter will be reset to empty.
| SkData* SkImage::encode | ( | SkImageEncoder::Type | , |
| int | quality | ||
| ) | const |
Encode the image's pixels and return the result as a new SkData, which the caller must manage (i.e.
call unref() when they are done).
If the image type cannot be encoded, or the requested encoder type is not supported, this will return NULL.
Note: this will attempt to encode the image's pixels in the specified format, even if the image returns a data from refEncoded(). That data will be ignored.
| SkData* SkImage::encode | ( | SkPixelSerializer * | = nullptr | ) | const |
Encode the image and return the result as a caller-managed SkData.
This will attempt to reuse existing encoded data (as returned by refEncoded).
We defer to the SkPixelSerializer both for vetting existing encoded data (useEncodedData) and for encoding the image (encode) when no such data is present or is rejected by the serializer.
If not specified, we use a default serializer which 1) always accepts existing data (in any format) and 2) encodes to PNG.
If no compatible encoded data exists and encoding fails, this method will also fail (return NULL).
| size_t SkImage::getDeferredTextureImageData | ( | const GrContextThreadSafeProxy & | , |
| const DeferredTextureImageUsageParams | [], | ||
| int | paramCnt, | ||
| void * | buffer | ||
| ) | 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.
| GrBackendObject SkImage::getTextureHandle | ( | bool | flushPendingGrContextIO | ) | const |
Retrieves the backend API handle of the texture.
If flushPendingGrContextIO then the GrContext will issue to the backend API any deferred IO operations on the texture before returning.
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Create a new image from the specified descriptor.
Note - Skia will delete or recycle the texture when the image is released.
Will return NULL if the specified descriptor is unsupported.
Construct a new image from the specified bitmap.
If the bitmap is marked immutable, and its pixel memory is shareable, it may be shared instead of copied.
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Returns a texture-backed image from data produced in SkImage::getDeferredTextureImageData.
The context must be the context that provided the proxy passed to getDeferredTextureImageData.
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Construct a new SkImage based on the specified encoded data.
Returns NULL on failure, which can mean that the format of the encoded data was not recognized/supported.
If a subset is specified, it must be contained within the encoded data's bounds.
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Construct a new SkImage based on the given ImageGenerator.
Returns NULL on error. This function will always take ownership of the passed generator.
If a subset is specified, it must be contained within the generator's bounds.
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Create a new image by copying the pixels from the specified y and uv textures.
The data from the textures is immediately ingested into the image and the textures can be modified or deleted after the function returns. The image will have the dimensions of the y texture.
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Return a new Image referencing the specified pixels.
These must remain valid and unchanged until the specified release-proc is called, indicating that Skia no longer has a reference to the pixels.
Returns NULL if the requested pixmap info is unsupported.
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inlinestatic |
Create a new image from the specified descriptor.
Note - the caller is responsible for managing the lifetime of the underlying platform texture.
Will return NULL if the specified descriptor is unsupported.
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inlinestatic |
Create a new image from the specified descriptor.
The underlying platform texture must stay valid and unaltered until the specified release-proc is invoked, indicating that Skia no longer is holding a reference to it.
Will return NULL if the specified descriptor is unsupported.
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Create a new image from the specified descriptor.
The underlying platform texture must stay valid and unaltered until the specified release-proc is invoked, indicating that Skia no longer is holding a reference to it.
Will return NULL if the specified descriptor is unsupported.
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Create a new image by copying the pixels from the specified y, u, v textures.
The data from the textures is immediately ingested into the image and the textures can be modified or deleted after the function returns. The image will have the dimensions of the y texture.
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 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, NULL will be returned.
| sk_sp<SkImage> 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 which may be produced to the given rect.
offset is the amount to translate the resulting image relative to the src when it is drawn. This is an out-param.
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.
| bool SkImage::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.
| void SkImage::preroll | ( | GrContext * | = nullptr | ) | const |
Some images have to perform preliminary work in preparation for drawing.
This can be decoding, uploading to a GPU, or other tasks. These happen automatically when an image is drawn, and often they are cached so that the cost is only paid the first time.
Preroll() can be called before drawing to try to perform this prepatory work ahead of time. For images that have no such work, this returns instantly. Others may do some thing to prepare their cache and then return.
If the image will drawn to a GPU-backed canvas or surface, pass the associated GrContext. If the image will be drawn to any other type of canvas or surface, pass null.
| bool SkImage::readPixels | ( | const SkImageInfo & | dstInfo, |
| void * | dstPixels, | ||
| size_t | dstRowBytes, | ||
| int | srcX, | ||
| int | srcY, | ||
| CachingHint | = kAllow_CachingHint |
||
| ) | const |
Copy the pixels from the image into the specified buffer (pixels + rowBytes), converting them into the requested format (dstInfo).
The image pixels are read starting at the specified (srcX,srcY) location.
The specified ImageInfo and (srcX,srcY) offset specifies a source rectangle
srcR.setXYWH(srcX, srcY, dstInfo.width(), dstInfo.height());
srcR 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 the dst pixels with the corresponding src pixels, performing any colortype/alphatype transformations needed (in the case where the src and dst have different colortypes or alphatypes).
This call can fail, returning false, for several reasons:
| bool SkImage::readYUV8Planes | ( | const SkISize | [3], |
| void *const | planes[3], | ||
| const size_t | rowBytes[3], | ||
| SkYUVColorSpace | |||
| ) | const |
Extracts YUV planes from the SkImage and stores them in client-provided memory.
The sizes planes and rowBytes arrays are ordered [y, u, v].
| SkData* SkImage::refEncoded | ( | ) | const |
If the image already has its contents in encoded form (e.g.
PNG or JPEG), return a ref to that data (which the caller must call unref() on). The caller is responsible for calling unref on the data when they are done.
If the image does not already has its contents in encoded form, return NULL.
Note: to force the image to return its contents as encoded data, try calling encode(...).
| bool SkImage::scalePixels | ( | const SkPixmap & | dst, |
| SkFilterQuality | , | ||
| CachingHint | = kAllow_CachingHint |
||
| ) | const |
Copy the pixels from this image into the dst pixmap, converting as needed into dst's colortype/alphatype.
If the conversion cannot be performed, false is returned.
If dst's dimensions differ from the src dimension, the image will be scaled, applying the specified filter-quality.
