| /* |
| * 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; |
| |
| //#define SK_SUPPORT_LEGACY_OPTIONLESS_GET_PIXELS |
| |
| /** |
| * 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. |
| */ |
| #ifdef SK_SUPPORT_LEGACY_BOOL_ONGETINFO |
| SkImageInfo getInfo(); |
| bool getInfo(SkImageInfo* info) { |
| if (info) { |
| *info = this->getInfo(); |
| } |
| return true; |
| } |
| #else |
| const SkImageInfo& getInfo() const { return fInfo; } |
| #endif |
| |
| /** |
| * Used to describe the result of a call to getPixels(). |
| * |
| * Result is the union of possible results from subclasses. |
| */ |
| enum Result { |
| /** |
| * General return value for success. |
| */ |
| kSuccess, |
| /** |
| * The input is incomplete. A partial image was generated. |
| */ |
| kIncompleteInput, |
| /** |
| * The generator cannot convert to match the request, ignoring |
| * dimensions. |
| */ |
| kInvalidConversion, |
| /** |
| * The generator cannot scale to requested size. |
| */ |
| kInvalidScale, |
| /** |
| * Parameters (besides info) are invalid. e.g. NULL pixels, rowBytes |
| * too small, etc. |
| */ |
| kInvalidParameters, |
| /** |
| * The input did not contain a valid image. |
| */ |
| kInvalidInput, |
| /** |
| * Fulfilling this request requires rewinding the input, which is not |
| * supported for this input. |
| */ |
| kCouldNotRewind, |
| /** |
| * This method is not implemented by this generator. |
| */ |
| kUnimplemented, |
| }; |
| |
| /** |
| * Whether or not the memory passed to getPixels is zero initialized. |
| */ |
| enum ZeroInitialized { |
| /** |
| * The memory passed to getPixels is zero initialized. The SkCodec |
| * may take advantage of this by skipping writing zeroes. |
| */ |
| kYes_ZeroInitialized, |
| /** |
| * The memory passed to getPixels has not been initialized to zero, |
| * so the SkCodec must write all zeroes to memory. |
| * |
| * This is the default. It will be used if no Options struct is used. |
| */ |
| kNo_ZeroInitialized, |
| }; |
| |
| /** |
| * Additional options to pass to getPixels. |
| */ |
| struct Options { |
| Options() |
| : fZeroInitialized(kNo_ZeroInitialized) {} |
| |
| ZeroInitialized fZeroInitialized; |
| }; |
| |
| /** |
| * 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 Result kSuccess, or another value explaining the type of failure. |
| */ |
| Result getPixels(const SkImageInfo& info, void* pixels, size_t rowBytes, const Options*, |
| SkPMColor ctable[], int* ctableCount); |
| |
| /** |
| * Simplified version of getPixels() that asserts that info is NOT kIndex8_SkColorType and |
| * uses the default Options. |
| */ |
| Result 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* NewFromData(SkData*); |
| |
| protected: |
| #ifdef SK_SUPPORT_LEGACY_BOOL_ONGETINFO |
| SkImageGenerator() : fInfo(SkImageInfo::MakeUnknown(0, 0) ) {} |
| virtual bool onGetInfo(SkImageInfo* info); |
| #endif |
| SkImageGenerator(const SkImageInfo& info) : fInfo(info) {} |
| |
| virtual SkData* onRefEncodedData(); |
| |
| #ifdef SK_SUPPORT_LEGACY_OPTIONLESS_GET_PIXELS |
| virtual Result onGetPixels(const SkImageInfo& info, |
| void* pixels, size_t rowBytes, |
| SkPMColor ctable[], int* ctableCount); |
| #endif |
| virtual Result onGetPixels(const SkImageInfo& info, |
| void* pixels, size_t rowBytes, const Options&, |
| 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; |
| }; |
| |
| #endif // SkImageGenerator_DEFINED |