/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- * * This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ #ifndef mozilla_image_decoders_nsPNGDecoder_h #define mozilla_image_decoders_nsPNGDecoder_h #include "Decoder.h" #include "png.h" #include "qcms.h" #include "StreamingLexer.h" #include "SurfacePipe.h" namespace mozilla { namespace image { class RasterImage; class nsPNGDecoder : public Decoder { public: virtual ~nsPNGDecoder(); /// @return true if this PNG is a valid ICO resource. bool IsValidICO() const; protected: nsresult InitInternal() override; LexerResult DoDecode(SourceBufferIterator& aIterator, IResumable* aOnResume) override; Maybe<Telemetry::ID> SpeedHistogram() const override; private: friend class DecoderFactory; // Decoders should only be instantiated via DecoderFactory. explicit nsPNGDecoder(RasterImage* aImage); /// The information necessary to create a frame. struct FrameInfo { gfx::SurfaceFormat mFormat; gfx::IntRect mFrameRect; bool mIsInterlaced; }; nsresult CreateFrame(const FrameInfo& aFrameInfo); void EndImageFrame(); enum class TransparencyType { eNone, eAlpha, eFrameRect }; TransparencyType GetTransparencyType(gfx::SurfaceFormat aFormat, const gfx::IntRect& aFrameRect); void PostHasTransparencyIfNeeded(TransparencyType aTransparencyType); void PostInvalidationIfNeeded(); void WriteRow(uint8_t* aRow); // Convenience methods to make interacting with StreamingLexer from inside // a libpng callback easier. void DoTerminate(png_structp aPNGStruct, TerminalState aState); void DoYield(png_structp aPNGStruct); enum class State { PNG_DATA, FINISHED_PNG_DATA }; LexerTransition<State> ReadPNGData(const char* aData, size_t aLength); LexerTransition<State> FinishedPNGData(); StreamingLexer<State> mLexer; // The next lexer state transition. We need to store it here because we can't // directly return arbitrary values from libpng callbacks. LexerTransition<State> mNextTransition; // We yield to the caller every time we finish decoding a frame. When this // happens, we need to allocate the next frame after returning from the yield. // |mNextFrameInfo| is used to store the information needed to allocate the // next frame. Maybe<FrameInfo> mNextFrameInfo; // The length of the last chunk of data passed to ReadPNGData(). We use this // to arrange to arrive back at the correct spot in the data after yielding. size_t mLastChunkLength; public: png_structp mPNG; png_infop mInfo; nsIntRect mFrameRect; uint8_t* mCMSLine; uint8_t* interlacebuf; qcms_profile* mInProfile; qcms_transform* mTransform; gfx::SurfaceFormat format; // whether CMS or premultiplied alpha are forced off uint32_t mCMSMode; uint8_t mChannels; uint8_t mPass; bool mFrameIsHidden; bool mDisablePremultipliedAlpha; struct AnimFrameInfo { AnimFrameInfo(); #ifdef PNG_APNG_SUPPORTED AnimFrameInfo(png_structp aPNG, png_infop aInfo); #endif DisposalMethod mDispose; BlendMethod mBlend; int32_t mTimeout; }; AnimFrameInfo mAnimInfo; SurfacePipe mPipe; /// The SurfacePipe used to write to the output surface. // The number of frames we've finished. uint32_t mNumFrames; // libpng callbacks // We put these in the class so that they can access protected members. static void PNGAPI info_callback(png_structp png_ptr, png_infop info_ptr); static void PNGAPI row_callback(png_structp png_ptr, png_bytep new_row, png_uint_32 row_num, int pass); #ifdef PNG_APNG_SUPPORTED static void PNGAPI frame_info_callback(png_structp png_ptr, png_uint_32 frame_num); #endif static void PNGAPI end_callback(png_structp png_ptr, png_infop info_ptr); static void PNGAPI error_callback(png_structp png_ptr, png_const_charp error_msg); static void PNGAPI warning_callback(png_structp png_ptr, png_const_charp warning_msg); // This is defined in the PNG spec as an invariant. We use it to // do manual validation without libpng. static const uint8_t pngSignatureBytes[]; }; } // namespace image } // namespace mozilla #endif // mozilla_image_decoders_nsPNGDecoder_h