| /* |
| * Copyright 2013 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef SkImageGenerator_DEFINED |
| #define SkImageGenerator_DEFINED |
| |
| #include "SkColor.h" |
| #include "SkImageInfo.h" |
| |
| class SkBitmap; |
| class SkData; |
| class SkImageGenerator; |
| class SkMatrix; |
| class SkPaint; |
| class SkPicture; |
| |
| /** |
| * Takes ownership of SkImageGenerator. If this method fails for |
| * whatever reason, it will return false and immediatetely delete |
| * the generator. If it succeeds, it will modify destination |
| * bitmap. |
| * |
| * If generator is NULL, will safely return false. |
| * |
| * If this fails or when the SkDiscardablePixelRef that is |
| * installed into destination is destroyed, it will call |
| * SkDELETE() on the generator. Therefore, generator should be |
| * allocated with SkNEW() or SkNEW_ARGS(). |
| * |
| * @param destination Upon success, this bitmap will be |
| * configured and have a pixelref installed. |
| * |
| * @return true iff successful. |
| */ |
| SK_API bool SkInstallDiscardablePixelRef(SkImageGenerator*, SkBitmap* destination); |
| |
| /** |
| * On success, installs a discardable pixelref into destination, based on encoded data. |
| * Regardless of success or failure, the caller must still balance their ownership of encoded. |
| */ |
| SK_API bool SkInstallDiscardablePixelRef(SkData* encoded, SkBitmap* destination); |
| |
| /** |
| * An interface that allows a purgeable PixelRef (such as a |
| * SkDiscardablePixelRef) to decode and re-decode an image as needed. |
| */ |
| class SK_API SkImageGenerator : public SkNoncopyable { |
| public: |
| /** |
| * The PixelRef which takes ownership of this SkImageGenerator |
| * will call the image generator's destructor. |
| */ |
| virtual ~SkImageGenerator() { } |
| |
| /** |
| * Return a ref to the encoded (i.e. compressed) representation, |
| * of this data. |
| * |
| * If non-NULL is returned, the caller is responsible for calling |
| * unref() on the data when it is finished. |
| */ |
| SkData* refEncodedData() { return this->onRefEncodedData(); } |
| |
| /** |
| * Return the ImageInfo associated with this generator. |
| */ |
| const SkImageInfo& getInfo() const { return fInfo; } |
| |
| /** |
| * 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. If the generator cannot perform this scale, |
| * it will return kInvalidScale. |
| * |
| * If info is kIndex8_SkColorType, then the caller must provide storage for up to 256 |
| * SkPMColor values in ctable. On success the generator must copy N colors into that storage, |
| * (where N is the logical number of table entries) and set ctableCount to N. |
| * |
| * If info is not kIndex8_SkColorType, then the last two parameters may be NULL. If ctableCount |
| * is not null, it will be set to 0. |
| * |
| * @return true on success. |
| */ |
| bool getPixels(const SkImageInfo& info, void* pixels, size_t rowBytes, |
| SkPMColor ctable[], int* ctableCount); |
| |
| /** |
| * Simplified version of getPixels() that asserts that info is NOT kIndex8_SkColorType and |
| * uses the default Options. |
| */ |
| bool getPixels(const SkImageInfo& info, void* pixels, size_t rowBytes); |
| |
| /** |
| * If planes or rowBytes is NULL or if any entry in planes is NULL or if any entry in rowBytes |
| * is 0, this imagegenerator should output the sizes and return true if it can efficiently |
| * return YUV planar data. If it cannot, it should return false. Note that either planes and |
| * rowBytes are both fully defined and non NULL/non 0 or they are both NULL or have NULL or 0 |
| * entries only. Having only partial planes/rowBytes information is not supported. |
| * |
| * If all planes and rowBytes entries are non NULL or non 0, then it should copy the |
| * associated YUV data into those planes of memory supplied by the caller. It should validate |
| * that the sizes match what it expected. If the sizes do not match, it should return false. |
| */ |
| bool getYUV8Planes(SkISize sizes[3], void* planes[3], size_t rowBytes[3], |
| SkYUVColorSpace* colorSpace); |
| |
| /** |
| * If the default image decoder system can interpret the specified (encoded) data, then |
| * this returns a new ImageGenerator for it. Otherwise this returns NULL. Either way |
| * the caller is still responsible for managing their ownership of the data. |
| */ |
| static SkImageGenerator* NewFromEncoded(SkData*); |
| |
| /** Return a new image generator backed by the specified picture. If the size is empty or |
| * the picture is NULL, this returns NULL. |
| * The optional matrix and paint arguments are passed to drawPicture() at rasterization |
| * time. |
| */ |
| static SkImageGenerator* NewFromPicture(const SkISize&, const SkPicture*, const SkMatrix*, |
| const SkPaint*); |
| |
| protected: |
| SkImageGenerator(const SkImageInfo& info) : fInfo(info) {} |
| |
| virtual SkData* onRefEncodedData(); |
| |
| virtual bool onGetPixels(const SkImageInfo& info, void* pixels, size_t rowBytes, |
| SkPMColor ctable[], int* ctableCount); |
| virtual bool onGetYUV8Planes(SkISize sizes[3], void* planes[3], size_t rowBytes[3]); |
| virtual bool onGetYUV8Planes(SkISize sizes[3], void* planes[3], size_t rowBytes[3], |
| SkYUVColorSpace* colorSpace); |
| |
| private: |
| const SkImageInfo fInfo; |
| |
| // This is our default impl, which may be different on different platforms. |
| // It is called from NewFromEncoded() after it has checked for any runtime factory. |
| // The SkData will never be NULL, as that will have been checked by NewFromEncoded. |
| static SkImageGenerator* NewFromEncodedImpl(SkData*); |
| }; |
| |
| #endif // SkImageGenerator_DEFINED |