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Diffstat (limited to 'src/deps/skia/include/codec/SkAndroidCodec.h')
| -rw-r--r-- | src/deps/skia/include/codec/SkAndroidCodec.h | 263 |
1 files changed, 263 insertions, 0 deletions
diff --git a/src/deps/skia/include/codec/SkAndroidCodec.h b/src/deps/skia/include/codec/SkAndroidCodec.h new file mode 100644 index 000000000..11157429f --- /dev/null +++ b/src/deps/skia/include/codec/SkAndroidCodec.h @@ -0,0 +1,263 @@ +/* + * Copyright 2015 Google Inc. + * + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +#ifndef SkAndroidCodec_DEFINED +#define SkAndroidCodec_DEFINED + +#include "include/codec/SkCodec.h" +#include "include/core/SkEncodedImageFormat.h" +#include "include/core/SkStream.h" +#include "include/core/SkTypes.h" + +/** + * Abstract interface defining image codec functionality that is necessary for + * Android. + */ +class SK_API SkAndroidCodec : SkNoncopyable { +public: + /** + * Deprecated. + * + * Now that SkAndroidCodec supports multiframe images, there are multiple + * ways to handle compositing an oriented frame on top of an oriented frame + * with different tradeoffs. SkAndroidCodec now ignores the orientation and + * forces the client to handle it. + */ + enum class ExifOrientationBehavior { + kIgnore, + kRespect, + }; + + /** + * Pass ownership of an SkCodec to a newly-created SkAndroidCodec. + */ + static std::unique_ptr<SkAndroidCodec> MakeFromCodec(std::unique_ptr<SkCodec>); + + /** + * If this stream represents an encoded image that we know how to decode, + * return an SkAndroidCodec that can decode it. Otherwise return NULL. + * + * The SkPngChunkReader handles unknown chunks in PNGs. + * See SkCodec.h for more details. + * + * If NULL is returned, the stream is deleted immediately. Otherwise, the + * SkCodec takes ownership of it, and will delete it when done with it. + */ + static std::unique_ptr<SkAndroidCodec> MakeFromStream(std::unique_ptr<SkStream>, + SkPngChunkReader* = nullptr); + + /** + * If this data represents an encoded image that we know how to decode, + * return an SkAndroidCodec that can decode it. Otherwise return NULL. + * + * The SkPngChunkReader handles unknown chunks in PNGs. + * See SkCodec.h for more details. + */ + static std::unique_ptr<SkAndroidCodec> MakeFromData(sk_sp<SkData>, SkPngChunkReader* = nullptr); + + virtual ~SkAndroidCodec(); + + // TODO: fInfo is now just a cache of SkCodec's SkImageInfo. No need to + // cache and return a reference here, once Android call-sites are updated. + const SkImageInfo& getInfo() const { return fInfo; } + + /** + * Return the ICC profile of the encoded data. + */ + const skcms_ICCProfile* getICCProfile() const { + return fCodec->getEncodedInfo().profile(); + } + + /** + * Format of the encoded data. + */ + SkEncodedImageFormat getEncodedFormat() const { return fCodec->getEncodedFormat(); } + + /** + * @param requestedColorType Color type requested by the client + * + * |requestedColorType| may be overriden. We will default to kF16 + * for high precision images. + * + * In the general case, if it is possible to decode to + * |requestedColorType|, this returns |requestedColorType|. + * Otherwise, this returns a color type that is an appropriate + * match for the the encoded data. + */ + SkColorType computeOutputColorType(SkColorType requestedColorType); + + /** + * @param requestedUnpremul Indicates if the client requested + * unpremultiplied output + * + * Returns the appropriate alpha type to decode to. If the image + * has alpha, the value of requestedUnpremul will be honored. + */ + SkAlphaType computeOutputAlphaType(bool requestedUnpremul); + + /** + * @param outputColorType Color type that the client will decode to. + * @param prefColorSpace Preferred color space to decode to. + * This may not return |prefColorSpace| for a couple reasons. + * (1) Android Principles: 565 must be sRGB, F16 must be + * linear sRGB, transfer function must be parametric. + * (2) Codec Limitations: F16 requires a linear color space. + * + * Returns the appropriate color space to decode to. + */ + sk_sp<SkColorSpace> computeOutputColorSpace(SkColorType outputColorType, + sk_sp<SkColorSpace> prefColorSpace = nullptr); + + /** + * Compute the appropriate sample size to get to |size|. + * + * @param size As an input parameter, the desired output size of + * the decode. As an output parameter, the smallest sampled size + * larger than the input. + * @return the sample size to set AndroidOptions::fSampleSize to decode + * to the output |size|. + */ + int computeSampleSize(SkISize* size) const; + + /** + * Returns the dimensions of the scaled output image, for an input + * sampleSize. + * + * When the sample size divides evenly into the original dimensions, the + * scaled output dimensions will simply be equal to the original + * dimensions divided by the sample size. + * + * When the sample size does not divide even into the original + * dimensions, the codec may round up or down, depending on what is most + * efficient to decode. + * + * Finally, the codec will always recommend a non-zero output, so the output + * dimension will always be one if the sampleSize is greater than the + * original dimension. + */ + SkISize getSampledDimensions(int sampleSize) const; + + /** + * Return (via desiredSubset) a subset which can decoded from this codec, + * or false if the input subset is invalid. + * + * @param desiredSubset in/out parameter + * As input, a desired subset of the original bounds + * (as specified by getInfo). + * As output, if true is returned, desiredSubset may + * have been modified to a subset which is + * supported. Although a particular change may have + * been made to desiredSubset to create something + * supported, it is possible other changes could + * result in a valid subset. If false is returned, + * desiredSubset's value is undefined. + * @return true If the input desiredSubset is valid. + * desiredSubset may be modified to a subset + * supported by the codec. + * false If desiredSubset is invalid (NULL or not fully + * contained within the image). + */ + bool getSupportedSubset(SkIRect* desiredSubset) const; + // TODO: Rename SkCodec::getValidSubset() to getSupportedSubset() + + /** + * Returns the dimensions of the scaled, partial output image, for an + * input sampleSize and subset. + * + * @param sampleSize Factor to scale down by. + * @param subset Must be a valid subset of the original image + * dimensions and a subset supported by SkAndroidCodec. + * getSubset() can be used to obtain a subset supported + * by SkAndroidCodec. + * @return Size of the scaled partial image. Or zero size + * if either of the inputs is invalid. + */ + SkISize getSampledSubsetDimensions(int sampleSize, const SkIRect& subset) const; + + /** + * Additional options to pass to getAndroidPixels(). + */ + // FIXME: It's a bit redundant to name these AndroidOptions when this class is already + // called SkAndroidCodec. On the other hand, it's may be a bit confusing to call + // these Options when SkCodec has a slightly different set of Options. Maybe these + // should be DecodeOptions or SamplingOptions? + struct AndroidOptions : public SkCodec::Options { + AndroidOptions() + : SkCodec::Options() + , fSampleSize(1) + {} + + /** + * The client may provide an integer downscale factor for the decode. + * The codec may implement this downscaling by sampling or another + * method if it is more efficient. + * + * The default is 1, representing no downscaling. + */ + int fSampleSize; + }; + + /** + * Decode into the given pixels, a block of memory of size at + * least (info.fHeight - 1) * rowBytes + (info.fWidth * + * bytesPerPixel) + * + * Repeated calls to this function should give the same results, + * allowing the PixelRef to be immutable. + * + * @param info A description of the format (config, size) + * expected by the caller. This can simply be identical + * to the info returned by getInfo(). + * + * This contract also allows the caller to specify + * different output-configs, which the implementation can + * decide to support or not. + * + * A size that does not match getInfo() implies a request + * to scale or subset. If the codec cannot perform this + * scaling or subsetting, it will return an error code. + * + * The AndroidOptions object is also used to specify any requested scaling or subsetting + * using options->fSampleSize and options->fSubset. If NULL, the defaults (as specified above + * for AndroidOptions) are used. + * + * @return Result kSuccess, or another value explaining the type of failure. + */ + // FIXME: It's a bit redundant to name this getAndroidPixels() when this class is already + // called SkAndroidCodec. On the other hand, it's may be a bit confusing to call + // this getPixels() when it is a slightly different API than SkCodec's getPixels(). + // Maybe this should be decode() or decodeSubset()? + SkCodec::Result getAndroidPixels(const SkImageInfo& info, void* pixels, size_t rowBytes, + const AndroidOptions* options); + + /** + * Simplified version of getAndroidPixels() where we supply the default AndroidOptions as + * specified above for AndroidOptions. It will not perform any scaling or subsetting. + */ + SkCodec::Result getAndroidPixels(const SkImageInfo& info, void* pixels, size_t rowBytes); + + SkCodec::Result getPixels(const SkImageInfo& info, void* pixels, size_t rowBytes) { + return this->getAndroidPixels(info, pixels, rowBytes); + } + + SkCodec* codec() const { return fCodec.get(); } + +protected: + SkAndroidCodec(SkCodec*); + + virtual SkISize onGetSampledDimensions(int sampleSize) const = 0; + + virtual bool onGetSupportedSubset(SkIRect* desiredSubset) const = 0; + + virtual SkCodec::Result onGetAndroidPixels(const SkImageInfo& info, void* pixels, + size_t rowBytes, const AndroidOptions& options) = 0; + +private: + const SkImageInfo fInfo; + std::unique_ptr<SkCodec> fCodec; +}; +#endif // SkAndroidCodec_DEFINED |