gecko/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 "ipc/AutoOpenSurface.h"
#include "mozilla/layers/PLayers.h"
#include "mozilla/layers/ShadowLayers.h"
#include "mozilla/layers/CompositorTypes.h" // for TextureInfo
#include "mozilla/layers/Effects.h"

#include "CanvasLayerComposite.h"
#include "ImageHost.h"
#include "gfx2DGlue.h"

using namespace mozilla;
using namespace mozilla::layers;

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

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

  CleanupResources();
}

void CanvasLayerComposite::SetCompositableHost(CompositableHost* aHost) {
  mImageHost = static_cast<ImageHost*>(aHost);
}

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

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

void
CanvasLayerComposite::RenderLayer(const nsIntPoint& aOffset,
                                  const nsIntRect& aClipRect)
{
  if (!mImageHost) {
    return;
  }

  mCompositor->MakeCurrent();

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

  EffectChain effectChain;
  LayerManagerComposite::AddMaskEffect(mMaskLayer, effectChain);
  gfx::Matrix4x4 transform;
  ToMatrix4x4(GetEffectiveTransform(), transform);
  gfx::Rect clipRect(aClipRect.x, aClipRect.y, aClipRect.width, aClipRect.height);

  mImageHost->Composite(effectChain,
                        GetEffectiveOpacity(),
                        transform,
                        gfx::Point(aOffset.x, aOffset.y),
                        gfx::ToFilter(filter),
                        clipRect);
}

CompositableHost*
CanvasLayerComposite::GetCompositableHost() {
  return mImageHost.get();
}

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

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