| /* |
| * Copyright 2017 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef SkFrameHolder_DEFINED |
| #define SkFrameHolder_DEFINED |
| |
| #include "include/codec/SkCodec.h" |
| #include "include/codec/SkCodecAnimation.h" |
| #include "include/core/SkRect.h" |
| #include "include/core/SkTypes.h" |
| #include "include/private/SkEncodedInfo.h" |
| #include "include/private/SkNoncopyable.h" |
| |
| /** |
| * Base class for a single frame of an animated image. |
| * |
| * Separate from SkCodec::FrameInfo, which is a pared down |
| * interface that only contains the info the client needs. |
| */ |
| class SkFrame : public SkNoncopyable { |
| public: |
| SkFrame(int id) |
| : fId(id) |
| , fHasAlpha(false) |
| , fRequiredFrame(kUninitialized) |
| , fDisposalMethod(SkCodecAnimation::DisposalMethod::kKeep) |
| , fDuration(0) |
| , fBlend(SkCodecAnimation::Blend::kSrcOver) |
| { |
| fRect.setEmpty(); |
| } |
| |
| virtual ~SkFrame() {} |
| |
| /** |
| * An explicit move constructor, as |
| * https://en.cppreference.com/w/cpp/language/move_constructor says that |
| * there is no implicit move constructor if there are user-declared |
| * destructors, and we have one, immediately above. |
| * |
| * Without a move constructor, it is harder to use an SkFrame, or an |
| * SkFrame subclass, inside a std::vector. |
| */ |
| SkFrame(SkFrame&&) = default; |
| |
| /** |
| * 0-based index of the frame in the image sequence. |
| */ |
| int frameId() const { return fId; } |
| |
| /** |
| * How this frame reports its alpha. |
| * |
| * This only considers the rectangle of this frame, and |
| * considers it to have alpha even if it is opaque once |
| * blended with the frame behind it. |
| */ |
| SkEncodedInfo::Alpha reportedAlpha() const { |
| return this->onReportedAlpha(); |
| } |
| |
| /** |
| * Cached value representing whether the frame has alpha, |
| * after compositing with the prior frame. |
| */ |
| bool hasAlpha() const { return fHasAlpha; } |
| |
| /** |
| * Cache whether the finished frame has alpha. |
| */ |
| void setHasAlpha(bool alpha) { fHasAlpha = alpha; } |
| |
| /** |
| * Whether enough of the frame has been read to determine |
| * fRequiredFrame and fHasAlpha. |
| */ |
| bool reachedStartOfData() const { return fRequiredFrame != kUninitialized; } |
| |
| /** |
| * The frame this one depends on. |
| * |
| * Must not be called until fRequiredFrame has been set properly. |
| */ |
| int getRequiredFrame() const { |
| SkASSERT(this->reachedStartOfData()); |
| return fRequiredFrame; |
| } |
| |
| /** |
| * Set the frame that this frame depends on. |
| */ |
| void setRequiredFrame(int req) { fRequiredFrame = req; } |
| |
| /** |
| * Set the rectangle that is updated by this frame. |
| */ |
| void setXYWH(int x, int y, int width, int height) { |
| fRect.setXYWH(x, y, width, height); |
| } |
| |
| /** |
| * The rectangle that is updated by this frame. |
| */ |
| SkIRect frameRect() const { return fRect; } |
| |
| int xOffset() const { return fRect.x(); } |
| int yOffset() const { return fRect.y(); } |
| int width() const { return fRect.width(); } |
| int height() const { return fRect.height(); } |
| |
| SkCodecAnimation::DisposalMethod getDisposalMethod() const { |
| return fDisposalMethod; |
| } |
| |
| void setDisposalMethod(SkCodecAnimation::DisposalMethod disposalMethod) { |
| fDisposalMethod = disposalMethod; |
| } |
| |
| /** |
| * Set the duration (in ms) to show this frame. |
| */ |
| void setDuration(int duration) { |
| fDuration = duration; |
| } |
| |
| /** |
| * Duration in ms to show this frame. |
| */ |
| int getDuration() const { |
| return fDuration; |
| } |
| |
| void setBlend(SkCodecAnimation::Blend blend) { |
| fBlend = blend; |
| } |
| |
| SkCodecAnimation::Blend getBlend() const { |
| return fBlend; |
| } |
| |
| /** |
| * Fill in the FrameInfo with details from this object. |
| */ |
| void fillIn(SkCodec::FrameInfo*, bool fullyReceived) const; |
| |
| protected: |
| virtual SkEncodedInfo::Alpha onReportedAlpha() const = 0; |
| |
| private: |
| inline static constexpr int kUninitialized = -2; |
| |
| const int fId; |
| bool fHasAlpha; |
| int fRequiredFrame; |
| SkIRect fRect; |
| SkCodecAnimation::DisposalMethod fDisposalMethod; |
| int fDuration; |
| SkCodecAnimation::Blend fBlend; |
| }; |
| |
| /** |
| * Base class for an object which holds the SkFrames of an |
| * image sequence. |
| */ |
| class SkFrameHolder : public SkNoncopyable { |
| public: |
| SkFrameHolder() |
| : fScreenWidth(0) |
| , fScreenHeight(0) |
| {} |
| |
| virtual ~SkFrameHolder() {} |
| |
| /** |
| * Size of the image. Each frame will be contained in |
| * these dimensions (possibly after clipping). |
| */ |
| int screenWidth() const { return fScreenWidth; } |
| int screenHeight() const { return fScreenHeight; } |
| |
| /** |
| * Compute the opacity and required frame, based on |
| * the frame's reportedAlpha and how it blends |
| * with prior frames. |
| */ |
| void setAlphaAndRequiredFrame(SkFrame*); |
| |
| /** |
| * Return the frame with frameId i. |
| */ |
| const SkFrame* getFrame(int i) const { |
| return this->onGetFrame(i); |
| } |
| |
| protected: |
| int fScreenWidth; |
| int fScreenHeight; |
| |
| virtual const SkFrame* onGetFrame(int i) const = 0; |
| }; |
| |
| #endif // SkFrameHolder_DEFINED |