gecko-dev/gfx/layers/basic/BasicImages.cpp

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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/. */

#include <stdint.h>          // for uint8_t, uint32_t
#include "BasicLayers.h"     // for BasicLayerManager
#include "ImageContainer.h"  // for PlanarYCbCrImage, etc
#include "ImageTypes.h"      // for ImageFormat, etc
#include "cairo.h"           // for cairo_user_data_key_t
#include "gfxASurface.h"     // for gfxASurface, etc
#include "gfxPlatform.h"     // for gfxPlatform, gfxImageFormat
#include "gfxUtils.h"        // for gfxUtils
#include "mozilla/CheckedInt.h"
#include "mozilla/mozalloc.h"  // for operator delete[], etc
#include "mozilla/RefPtr.h"
#include "mozilla/UniquePtr.h"
#include "nsCOMPtr.h"           // for already_AddRefed
#include "nsDebug.h"            // for NS_ERROR, NS_ASSERTION
#include "nsISupportsImpl.h"    // for Image::Release, etc
#include "nsThreadUtils.h"      // for NS_IsMainThread
#include "mozilla/gfx/Point.h"  // for IntSize
#include "mozilla/gfx/DataSurfaceHelpers.h"
#include "gfx2DGlue.h"
#include "YCbCrUtils.h"  // for YCbCr conversions

namespace mozilla {
namespace layers {

class BasicPlanarYCbCrImage : public RecyclingPlanarYCbCrImage {
 public:
  BasicPlanarYCbCrImage(const gfx::IntSize& aScaleHint,
                        gfxImageFormat aOffscreenFormat,
                        BufferRecycleBin* aRecycleBin)
      : RecyclingPlanarYCbCrImage(aRecycleBin),
        mScaleHint(aScaleHint),
        mStride(0),
        mDelayedConversion(false) {
    SetOffscreenFormat(aOffscreenFormat);
  }

  ~BasicPlanarYCbCrImage() {
    if (mDecodedBuffer) {
      // Right now this only happens if the Image was never drawn, otherwise
      // this will have been tossed away at surface destruction.
      mRecycleBin->RecycleBuffer(std::move(mDecodedBuffer),
                                 mSize.height * mStride);
    }
  }

  virtual bool CopyData(const Data& aData) override;
  virtual void SetDelayedConversion(bool aDelayed) override {
    mDelayedConversion = aDelayed;
  }

  already_AddRefed<gfx::SourceSurface> GetAsSourceSurface() override;

  virtual size_t SizeOfIncludingThis(
      MallocSizeOf aMallocSizeOf) const override {
    return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
  }

  virtual size_t SizeOfExcludingThis(
      MallocSizeOf aMallocSizeOf) const override {
    size_t size = RecyclingPlanarYCbCrImage::SizeOfExcludingThis(aMallocSizeOf);
    size += aMallocSizeOf(mDecodedBuffer.get());
    return size;
  }

 private:
  UniquePtr<uint8_t[]> mDecodedBuffer;
  gfx::IntSize mScaleHint;
  int mStride;
  bool mDelayedConversion;
};

class BasicImageFactory : public ImageFactory {
 public:
  BasicImageFactory() = default;

  virtual RefPtr<PlanarYCbCrImage> CreatePlanarYCbCrImage(
      const gfx::IntSize& aScaleHint, BufferRecycleBin* aRecycleBin) override {
    return new BasicPlanarYCbCrImage(
        aScaleHint, gfxPlatform::GetPlatform()->GetOffscreenFormat(),
        aRecycleBin);
  }
};

bool BasicPlanarYCbCrImage::CopyData(const Data& aData) {
  RecyclingPlanarYCbCrImage::CopyData(aData);

  if (mDelayedConversion) {
    return false;
  }

  // Do some sanity checks to prevent integer overflow
  if (aData.mYSize.width > PlanarYCbCrImage::MAX_DIMENSION ||
      aData.mYSize.height > PlanarYCbCrImage::MAX_DIMENSION) {
    NS_ERROR("Illegal image source width or height");
    return false;
  }

  gfx::SurfaceFormat format =
      gfx::ImageFormatToSurfaceFormat(GetOffscreenFormat());

  gfx::IntSize size(mScaleHint);
  gfx::GetYCbCrToRGBDestFormatAndSize(aData, format, size);
  if (size.width > PlanarYCbCrImage::MAX_DIMENSION ||
      size.height > PlanarYCbCrImage::MAX_DIMENSION) {
    NS_ERROR("Illegal image dest width or height");
    return false;
  }

  mStride = gfx::StrideForFormatAndWidth(format, size.width);
  mozilla::CheckedInt32 requiredBytes =
      mozilla::CheckedInt32(size.height) * mozilla::CheckedInt32(mStride);
  if (!requiredBytes.isValid()) {
    // invalid size
    return false;
  }
  mDecodedBuffer = AllocateBuffer(requiredBytes.value());
  if (!mDecodedBuffer) {
    // out of memory
    return false;
  }

  gfx::ConvertYCbCrToRGB(aData, format, size, mDecodedBuffer.get(), mStride);
  SetOffscreenFormat(gfx::SurfaceFormatToImageFormat(format));
  mSize = size;

  return true;
}

already_AddRefed<gfx::SourceSurface>
BasicPlanarYCbCrImage::GetAsSourceSurface() {
  NS_ASSERTION(NS_IsMainThread(), "Must be main thread");

  if (mSourceSurface) {
    RefPtr<gfx::SourceSurface> surface(mSourceSurface);
    return surface.forget();
  }

  if (!mDecodedBuffer) {
    return PlanarYCbCrImage::GetAsSourceSurface();
  }

  gfxImageFormat format = GetOffscreenFormat();

  RefPtr<gfx::SourceSurface> surface;
  {
    // Create a DrawTarget so that we can own the data inside mDecodeBuffer.
    // We create the target out of mDecodedBuffer, and get a snapshot from it.
    // The draw target is destroyed on scope exit and the surface owns the data.
    RefPtr<gfx::DrawTarget> drawTarget = gfxPlatform::CreateDrawTargetForData(
        mDecodedBuffer.get(), mSize, mStride,
        gfx::ImageFormatToSurfaceFormat(format));
    if (!drawTarget) {
      return nullptr;
    }

    surface = drawTarget->Snapshot();
  }

  mRecycleBin->RecycleBuffer(std::move(mDecodedBuffer), mSize.height * mStride);

  mSourceSurface = surface;
  return surface.forget();
}

ImageFactory* BasicLayerManager::GetImageFactory() {
  if (!mFactory) {
    mFactory = new BasicImageFactory();
  }

  return mFactory.get();
}

}  // namespace layers
}  // namespace mozilla