image/imgFrame.h
author cku <cku@mozilla.com>
Thu, 18 May 2017 22:03:41 +0200
changeset 359088 bbf16eb4f821b2d535826141f9f33f3eb49a54c6
parent 349286 ad48fee41646a4f58e37954c42548b21aa150dcb
child 403442 87ba2465c82e5b354d8f4aafe37deba610cf192b
permissions -rw-r--r--
Bug 1351440 - Part 2. Encapsulate DrawResult and imgIContainer::FLAG_* into imgDrawingParams, and pass it to PaintSVG. r=jwatt The DrawResult return was not in fact anything to do with the success or failure of that method, but was actually passing out a very specific piece of information about the success or failure of any imagelib drawing that may not have occurred under the various PaintSVG calls. The signature of PaintSVG is changed from DrawResult PaintSVG(...., uint32 flags); to void PaintSVG(...., imgDrawingParams& aPackage); imgDrawingParams wraps DrawResult and imgIContainer::FLAG_* as a pack, pass through PaintSVG to imagelib draw calls under beneath. MozReview-Commit-ID: IOq2evUAOQF

/* -*- 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_imgFrame_h
#define mozilla_image_imgFrame_h

#include "mozilla/Maybe.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/Monitor.h"
#include "mozilla/Move.h"
#include "FrameTimeout.h"
#include "gfxDrawable.h"
#include "imgIContainer.h"
#include "MainThreadUtils.h"
#include "nsAutoPtr.h"

namespace mozilla {
namespace image {

class ImageRegion;
class DrawableFrameRef;
class RawAccessFrameRef;

enum class BlendMethod : int8_t {
  // All color components of the frame, including alpha, overwrite the current
  // contents of the frame's output buffer region.
  SOURCE,

  // The frame should be composited onto the output buffer based on its alpha,
  // using a simple OVER operation.
  OVER
};

enum class DisposalMethod : int8_t {
  CLEAR_ALL = -1,  // Clear the whole image, revealing what's underneath.
  NOT_SPECIFIED,   // Leave the frame and let the new frame draw on top.
  KEEP,            // Leave the frame and let the new frame draw on top.
  CLEAR,           // Clear the frame's area, revealing what's underneath.
  RESTORE_PREVIOUS // Restore the previous (composited) frame.
};

enum class Opacity : uint8_t {
  FULLY_OPAQUE,
  SOME_TRANSPARENCY
};

/**
 * AnimationData contains all of the information necessary for using an imgFrame
 * as part of an animation.
 *
 * It includes pointers to the raw image data of the underlying imgFrame, but
 * does not own that data. A RawAccessFrameRef for the underlying imgFrame must
 * outlive the AnimationData for it to remain valid.
 */
struct AnimationData
{
  AnimationData(uint8_t* aRawData, uint32_t aPaletteDataLength,
                FrameTimeout aTimeout, const nsIntRect& aRect,
                BlendMethod aBlendMethod, const Maybe<gfx::IntRect>& aBlendRect,
                DisposalMethod aDisposalMethod, bool aHasAlpha)
    : mRawData(aRawData)
    , mPaletteDataLength(aPaletteDataLength)
    , mTimeout(aTimeout)
    , mRect(aRect)
    , mBlendMethod(aBlendMethod)
    , mBlendRect(aBlendRect)
    , mDisposalMethod(aDisposalMethod)
    , mHasAlpha(aHasAlpha)
  { }

  uint8_t* mRawData;
  uint32_t mPaletteDataLength;
  FrameTimeout mTimeout;
  nsIntRect mRect;
  BlendMethod mBlendMethod;
  Maybe<gfx::IntRect> mBlendRect;
  DisposalMethod mDisposalMethod;
  bool mHasAlpha;
};

class imgFrame
{
  typedef gfx::Color Color;
  typedef gfx::DataSourceSurface DataSourceSurface;
  typedef gfx::DrawTarget DrawTarget;
  typedef gfx::SamplingFilter SamplingFilter;
  typedef gfx::IntPoint IntPoint;
  typedef gfx::IntRect IntRect;
  typedef gfx::IntSize IntSize;
  typedef gfx::SourceSurface SourceSurface;
  typedef gfx::SurfaceFormat SurfaceFormat;

public:
  MOZ_DECLARE_REFCOUNTED_TYPENAME(imgFrame)
  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(imgFrame)

  imgFrame();

  /**
   * Initialize this imgFrame with an empty surface and prepare it for being
   * written to by a decoder.
   *
   * This is appropriate for use with decoded images, but it should not be used
   * when drawing content into an imgFrame, as it may use a different graphics
   * backend than normal content drawing.
   */
  nsresult InitForDecoder(const nsIntSize& aImageSize,
                          const nsIntRect& aRect,
                          SurfaceFormat aFormat,
                          uint8_t aPaletteDepth = 0,
                          bool aNonPremult = false,
                          bool aIsAnimated = false);

  nsresult InitForAnimator(const nsIntSize& aSize,
                           SurfaceFormat aFormat)
  {
    return InitForDecoder(aSize, nsIntRect(0, 0, aSize.width, aSize.height),
                          aFormat, 0, false, true);
  }


  /**
   * Initialize this imgFrame with a new surface and draw the provided
   * gfxDrawable into it.
   *
   * This is appropriate to use when drawing content into an imgFrame, as it
   * uses the same graphics backend as normal content drawing. The downside is
   * that the underlying surface may not be stored in a volatile buffer on all
   * platforms, and raw access to the surface (using RawAccessRef()) may be much
   * more expensive than in the InitForDecoder() case.
   *
   * aBackend specifies the DrawTarget backend type this imgFrame is supposed
   *          to be drawn to.
   */
  nsresult InitWithDrawable(gfxDrawable* aDrawable,
                            const nsIntSize& aSize,
                            const SurfaceFormat aFormat,
                            SamplingFilter aSamplingFilter,
                            uint32_t aImageFlags,
                            gfx::BackendType aBackend);

  DrawableFrameRef DrawableRef();
  RawAccessFrameRef RawAccessRef();

  /**
   * Make this imgFrame permanently available for raw access.
   *
   * This is irrevocable, and should be avoided whenever possible, since it
   * prevents this imgFrame from being optimized and makes it impossible for its
   * volatile buffer to be freed.
   *
   * It is an error to call this without already holding a RawAccessFrameRef to
   * this imgFrame.
   */
  void SetRawAccessOnly();

  bool Draw(gfxContext* aContext, const ImageRegion& aRegion,
            SamplingFilter aSamplingFilter, uint32_t aImageFlags,
            float aOpacity);

  nsresult ImageUpdated(const nsIntRect& aUpdateRect);

  /**
   * Mark this imgFrame as completely decoded, and set final options.
   *
   * You must always call either Finish() or Abort() before releasing the last
   * RawAccessFrameRef pointing to an imgFrame.
   *
   * @param aFrameOpacity    Whether this imgFrame is opaque.
   * @param aDisposalMethod  For animation frames, how this imgFrame is cleared
   *                         from the compositing frame before the next frame is
   *                         displayed.
   * @param aTimeout         For animation frames, the timeout before the next
   *                         frame is displayed.
   * @param aBlendMethod     For animation frames, a blending method to be used
   *                         when compositing this frame.
   * @param aBlendRect       For animation frames, if present, the subrect in
   *                         which @aBlendMethod applies. Outside of this
   *                         subrect, BlendMethod::OVER is always used.
   * @param aFinalize        Finalize the underlying surface (e.g. so that it
   *                         may be marked as read only if possible).
   */
  void Finish(Opacity aFrameOpacity = Opacity::SOME_TRANSPARENCY,
              DisposalMethod aDisposalMethod = DisposalMethod::KEEP,
              FrameTimeout aTimeout = FrameTimeout::FromRawMilliseconds(0),
              BlendMethod aBlendMethod = BlendMethod::OVER,
              const Maybe<IntRect>& aBlendRect = Nothing(),
              bool aFinalize = true);

  /**
   * Mark this imgFrame as aborted. This informs the imgFrame that if it isn't
   * completely decoded now, it never will be.
   *
   * You must always call either Finish() or Abort() before releasing the last
   * RawAccessFrameRef pointing to an imgFrame.
   */
  void Abort();

  /**
   * Returns true if this imgFrame has been aborted.
   */
  bool IsAborted() const;

  /**
   * Returns true if this imgFrame is completely decoded.
   */
  bool IsFinished() const;

  /**
   * Blocks until this imgFrame is either completely decoded, or is marked as
   * aborted.
   *
   * Note that calling this on the main thread _blocks the main thread_. Be very
   * careful in your use of this method to avoid excessive main thread jank or
   * deadlock.
   */
  void WaitUntilFinished() const;

  /**
   * Returns the number of bytes per pixel this imgFrame requires.  This is a
   * worst-case value that does not take into account the effects of format
   * changes caused by Optimize(), since an imgFrame is not optimized throughout
   * its lifetime.
   */
  uint32_t GetBytesPerPixel() const { return GetIsPaletted() ? 1 : 4; }

  IntSize GetImageSize() const { return mImageSize; }
  IntRect GetRect() const { return mFrameRect; }
  IntSize GetSize() const { return mFrameRect.Size(); }
  void GetImageData(uint8_t** aData, uint32_t* length) const;
  uint8_t* GetImageData() const;

  bool GetIsPaletted() const;
  void GetPaletteData(uint32_t** aPalette, uint32_t* length) const;
  uint32_t* GetPaletteData() const;
  uint8_t GetPaletteDepth() const { return mPaletteDepth; }

  AnimationData GetAnimationData() const;

  bool GetCompositingFailed() const;
  void SetCompositingFailed(bool val);

  void SetOptimizable();

  void FinalizeSurface();
  already_AddRefed<SourceSurface> GetSourceSurface();

  void AddSizeOfExcludingThis(MallocSizeOf aMallocSizeOf, size_t& aHeapSizeOut,
                              size_t& aNonHeapSizeOut,
                              size_t& aSharedHandlesOut) const;

private: // methods

  ~imgFrame();

  nsresult LockImageData();
  nsresult UnlockImageData();
  nsresult Optimize(gfx::DrawTarget* aTarget);

  void AssertImageDataLocked() const;

  bool AreAllPixelsWritten() const;
  nsresult ImageUpdatedInternal(const nsIntRect& aUpdateRect);
  void GetImageDataInternal(uint8_t** aData, uint32_t* length) const;
  uint32_t GetImageBytesPerRow() const;
  uint32_t GetImageDataLength() const;
  void FinalizeSurfaceInternal();
  already_AddRefed<SourceSurface> GetSourceSurfaceInternal();

  uint32_t PaletteDataLength() const
  {
    return mPaletteDepth ? (size_t(1) << mPaletteDepth) * sizeof(uint32_t)
                         : 0;
  }

  struct SurfaceWithFormat {
    RefPtr<gfxDrawable> mDrawable;
    SurfaceFormat mFormat;
    SurfaceWithFormat() { }
    SurfaceWithFormat(gfxDrawable* aDrawable, SurfaceFormat aFormat)
      : mDrawable(aDrawable), mFormat(aFormat)
    { }
    bool IsValid() { return !!mDrawable; }
  };

  SurfaceWithFormat SurfaceForDrawing(bool               aDoPartialDecode,
                                      bool               aDoTile,
                                      ImageRegion&       aRegion,
                                      SourceSurface*     aSurface);

private: // data
  friend class DrawableFrameRef;
  friend class RawAccessFrameRef;
  friend class UnlockImageDataRunnable;

  //////////////////////////////////////////////////////////////////////////////
  // Thread-safe mutable data, protected by mMonitor.
  //////////////////////////////////////////////////////////////////////////////

  mutable Monitor mMonitor;

  /**
   * Surface which contains either a weak or a strong reference to its
   * underlying data buffer. If it is a weak reference, and there are no strong
   * references, the buffer may be released due to events such as low memory.
   */
  RefPtr<DataSourceSurface> mRawSurface;

  /**
   * Refers to the same data as mRawSurface, but when set, it guarantees that
   * we hold a strong reference to the underlying data buffer.
   */
  RefPtr<DataSourceSurface> mLockedSurface;

  /**
   * Optimized copy of mRawSurface for the DrawTarget that will render it. This
   * is unused if the DrawTarget is able to render DataSourceSurface buffers
   * directly.
   */
  RefPtr<SourceSurface> mOptSurface;

  nsIntRect mDecoded;

  //! Number of RawAccessFrameRefs currently alive for this imgFrame.
  int32_t mLockCount;

  //! The timeout for this frame.
  FrameTimeout mTimeout;

  DisposalMethod mDisposalMethod;
  BlendMethod    mBlendMethod;
  Maybe<IntRect> mBlendRect;
  SurfaceFormat  mFormat;

  bool mAborted;
  bool mFinished;
  bool mOptimizable;


  //////////////////////////////////////////////////////////////////////////////
  // Effectively const data, only mutated in the Init methods.
  //////////////////////////////////////////////////////////////////////////////

  IntSize      mImageSize;
  IntRect      mFrameRect;

  // The palette and image data for images that are paletted, since Cairo
  // doesn't support these images.
  // The paletted data comes first, then the image data itself.
  // Total length is PaletteDataLength() + GetImageDataLength().
  uint8_t*     mPalettedImageData;
  uint8_t      mPaletteDepth;

  bool mNonPremult;


  //////////////////////////////////////////////////////////////////////////////
  // Main-thread-only mutable data.
  //////////////////////////////////////////////////////////////////////////////

  bool mCompositingFailed;
};

/**
 * A reference to an imgFrame that holds the imgFrame's surface in memory,
 * allowing drawing. If you have a DrawableFrameRef |ref| and |if (ref)| returns
 * true, then calls to Draw() and GetSourceSurface() are guaranteed to succeed.
 */
class DrawableFrameRef final
{
  typedef gfx::DataSourceSurface DataSourceSurface;

public:
  DrawableFrameRef() { }

  explicit DrawableFrameRef(imgFrame* aFrame)
    : mFrame(aFrame)
  {
    MOZ_ASSERT(aFrame);
    MonitorAutoLock lock(aFrame->mMonitor);

    // Paletted images won't have a surface so there is no strong reference
    // to hold on to. Since Draw() and GetSourceSurface() calls will not work
    // in that case, we should be using RawAccessFrameRef exclusively instead.
    // See FrameAnimator::GetRawFrame for an example of this behaviour.
    if (aFrame->mRawSurface) {
      mRef = new DataSourceSurface::ScopedMap(aFrame->mRawSurface,
                                              DataSourceSurface::READ_WRITE);
      if (!mRef->IsMapped()) {
        mFrame = nullptr;
        mRef = nullptr;
      }
    } else {
      MOZ_ASSERT(aFrame->mOptSurface || aFrame->GetIsPaletted());
    }
  }

  DrawableFrameRef(DrawableFrameRef&& aOther)
    : mFrame(aOther.mFrame.forget())
    , mRef(Move(aOther.mRef))
  { }

  DrawableFrameRef& operator=(DrawableFrameRef&& aOther)
  {
    MOZ_ASSERT(this != &aOther, "Self-moves are prohibited");
    mFrame = aOther.mFrame.forget();
    mRef = Move(aOther.mRef);
    return *this;
  }

  explicit operator bool() const { return bool(mFrame); }

  imgFrame* operator->()
  {
    MOZ_ASSERT(mFrame);
    return mFrame;
  }

  const imgFrame* operator->() const
  {
    MOZ_ASSERT(mFrame);
    return mFrame;
  }

  imgFrame* get() { return mFrame; }
  const imgFrame* get() const { return mFrame; }

  void reset()
  {
    mFrame = nullptr;
    mRef = nullptr;
  }

private:
  DrawableFrameRef(const DrawableFrameRef& aOther) = delete;

  RefPtr<imgFrame> mFrame;
  nsAutoPtr<DataSourceSurface::ScopedMap> mRef;
};

/**
 * A reference to an imgFrame that holds the imgFrame's surface in memory in a
 * format appropriate for access as raw data. If you have a RawAccessFrameRef
 * |ref| and |if (ref)| is true, then calls to GetImageData() and
 * GetPaletteData() are guaranteed to succeed. This guarantee is stronger than
 * DrawableFrameRef, so everything that a valid DrawableFrameRef guarantees is
 * also guaranteed by a valid RawAccessFrameRef.
 *
 * This may be considerably more expensive than is necessary just for drawing,
 * so only use this when you need to read or write the raw underlying image data
 * that the imgFrame holds.
 *
 * Once all an imgFrame's RawAccessFrameRefs go out of scope, new
 * RawAccessFrameRefs cannot be created.
 */
class RawAccessFrameRef final
{
public:
  RawAccessFrameRef() { }

  explicit RawAccessFrameRef(imgFrame* aFrame)
    : mFrame(aFrame)
  {
    MOZ_ASSERT(mFrame, "Need a frame");

    if (NS_FAILED(mFrame->LockImageData())) {
      mFrame->UnlockImageData();
      mFrame = nullptr;
    }
  }

  RawAccessFrameRef(RawAccessFrameRef&& aOther)
    : mFrame(aOther.mFrame.forget())
  { }

  ~RawAccessFrameRef()
  {
    if (mFrame) {
      mFrame->UnlockImageData();
    }
  }

  RawAccessFrameRef& operator=(RawAccessFrameRef&& aOther)
  {
    MOZ_ASSERT(this != &aOther, "Self-moves are prohibited");

    if (mFrame) {
      mFrame->UnlockImageData();
    }

    mFrame = aOther.mFrame.forget();

    return *this;
  }

  explicit operator bool() const { return bool(mFrame); }

  imgFrame* operator->()
  {
    MOZ_ASSERT(mFrame);
    return mFrame.get();
  }

  const imgFrame* operator->() const
  {
    MOZ_ASSERT(mFrame);
    return mFrame;
  }

  imgFrame* get() { return mFrame; }
  const imgFrame* get() const { return mFrame; }

  void reset()
  {
    if (mFrame) {
      mFrame->UnlockImageData();
    }
    mFrame = nullptr;
  }

private:
  RawAccessFrameRef(const RawAccessFrameRef& aOther) = delete;

  RefPtr<imgFrame> mFrame;
};

void MarkSurfaceShared(gfx::SourceSurface* aSurface);

} // namespace image
} // namespace mozilla

#endif // mozilla_image_imgFrame_h