gecko-dev/gfx/layers/composite/CanvasLayerComposite.cpp

/* -*- Mode: C++; tab-width: 20; 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/. */

#include "CanvasLayerComposite.h"
#include "composite/CompositableHost.h"  // for CompositableHost
#include "gfx2DGlue.h"                  // for ToFilter, ToMatrix4x4
#include "GraphicsFilter.h"             // for GraphicsFilter
#include "gfxUtils.h"                   // for gfxUtils, etc
#include "mozilla/gfx/Matrix.h"         // for Matrix4x4
#include "mozilla/gfx/Point.h"          // for Point
#include "mozilla/gfx/Rect.h"           // for Rect
#include "mozilla/layers/Compositor.h"  // for Compositor
#include "mozilla/layers/Effects.h"     // for EffectChain
#include "mozilla/mozalloc.h"           // for operator delete
#include "nsAString.h"
#include "nsAutoPtr.h"                  // for nsRefPtr
#include "nsISupportsImpl.h"            // for MOZ_COUNT_CTOR, etc
#include "nsPoint.h"                    // for nsIntPoint
#include "nsString.h"                   // for nsAutoCString

using namespace mozilla;
using namespace mozilla::layers;
using namespace mozilla::gfx;

CanvasLayerComposite::CanvasLayerComposite(LayerManagerComposite* aManager)
  : CanvasLayer(aManager, nullptr)
  , LayerComposite(aManager)
  , mImageHost(nullptr)
{
  MOZ_COUNT_CTOR(CanvasLayerComposite);
  mImplData = static_cast<LayerComposite*>(this);
}

CanvasLayerComposite::~CanvasLayerComposite()
{
  MOZ_COUNT_DTOR(CanvasLayerComposite);

  CleanupResources();
}

bool
CanvasLayerComposite::SetCompositableHost(CompositableHost* aHost)
{
  switch (aHost->GetType()) {
    case BUFFER_IMAGE_SINGLE:
    case BUFFER_IMAGE_BUFFERED:
    case COMPOSITABLE_IMAGE:
      mImageHost = aHost;
      return true;
    default:
      return false;
  }

}

Layer*
CanvasLayerComposite::GetLayer()
{
  return this;
}

LayerRenderState
CanvasLayerComposite::GetRenderState()
{
  if (mDestroyed || !mImageHost || !mImageHost->IsAttached()) {
    return LayerRenderState();
  }
  return mImageHost->GetRenderState();
}

void
CanvasLayerComposite::RenderLayer(const nsIntRect& aClipRect)
{
  if (!mImageHost || !mImageHost->IsAttached()) {
    return;
  }

  mCompositor->MakeCurrent();

#ifdef MOZ_DUMP_PAINTING
  if (gfxUtils::sDumpPainting) {
    RefPtr<gfx::DataSourceSurface> surf = mImageHost->GetAsSurface();
    WriteSnapshotToDumpFile(this, surf);
  }
#endif

  GraphicsFilter filter = mFilter;
#ifdef ANDROID
  // Bug 691354
  // Using the LINEAR filter we get unexplained artifacts.
  // Use NEAREST when no scaling is required.
  Matrix matrix;
  bool is2D = GetEffectiveTransform().Is2D(&matrix);
  if (is2D && !ThebesMatrix(matrix).HasNonTranslationOrFlip()) {
    filter = GraphicsFilter::FILTER_NEAREST;
  }
#endif

  EffectChain effectChain(this);

  LayerManagerComposite::AutoAddMaskEffect autoMaskEffect(mMaskLayer, effectChain);
  gfx::Rect clipRect(aClipRect.x, aClipRect.y, aClipRect.width, aClipRect.height);

  mImageHost->Composite(effectChain,
                        GetEffectiveOpacity(),
                        GetEffectiveTransform(),
                        gfx::ToFilter(filter),
                        clipRect);
  mImageHost->BumpFlashCounter();
}

CompositableHost*
CanvasLayerComposite::GetCompositableHost()
{
  if ( mImageHost && mImageHost->IsAttached()) {
    return mImageHost.get();
  }

  return nullptr;
}

void
CanvasLayerComposite::CleanupResources()
{
  if (mImageHost) {
    mImageHost->Detach(this);
  }
  mImageHost = nullptr;
}

nsACString&
CanvasLayerComposite::PrintInfo(nsACString& aTo, const char* aPrefix)
{
  CanvasLayer::PrintInfo(aTo, aPrefix);
  aTo += "\n";
  if (mImageHost && mImageHost->IsAttached()) {
    nsAutoCString pfx(aPrefix);
    pfx += "  ";
    mImageHost->PrintInfo(aTo, pfx.get());
  }
  return aTo;
}