Esempio n. 1
0
void
ClientThebesLayer::PaintThebes()
{
  PROFILER_LABEL("ClientThebesLayer", "PaintThebes");
  NS_ASSERTION(ClientManager()->InDrawing(),
               "Can only draw in drawing phase");
  
  //TODO: This is going to copy back pixels that we might end up
  // drawing over anyway. It would be nice if we could avoid
  // this duplication.
  mContentClient->SyncFrontBufferToBackBuffer();

  bool canUseOpaqueSurface = CanUseOpaqueSurface();
  ContentType contentType =
    canUseOpaqueSurface ? GFX_CONTENT_COLOR :
                          GFX_CONTENT_COLOR_ALPHA;

  {
    uint32_t flags = 0;
#ifndef MOZ_WIDGET_ANDROID
    if (ClientManager()->CompositorMightResample()) {
      flags |= ThebesLayerBuffer::PAINT_WILL_RESAMPLE;
    }
    if (!(flags & ThebesLayerBuffer::PAINT_WILL_RESAMPLE)) {
      if (MayResample()) {
        flags |= ThebesLayerBuffer::PAINT_WILL_RESAMPLE;
      }
    }
#endif
    PaintState state =
      mContentClient->BeginPaintBuffer(this, contentType, flags);
    mValidRegion.Sub(mValidRegion, state.mRegionToInvalidate);

    if (state.mContext) {
      // The area that became invalid and is visible needs to be repainted
      // (this could be the whole visible area if our buffer switched
      // from RGB to RGBA, because we might need to repaint with
      // subpixel AA)
      state.mRegionToInvalidate.And(state.mRegionToInvalidate,
                                    GetEffectiveVisibleRegion());
      nsIntRegion extendedDrawRegion = state.mRegionToDraw;
      SetAntialiasingFlags(this, state.mContext);

      PaintBuffer(state.mContext,
                  state.mRegionToDraw, extendedDrawRegion, state.mRegionToInvalidate,
                  state.mDidSelfCopy, state.mClip);
      MOZ_LAYERS_LOG_IF_SHADOWABLE(this, ("Layer::Mutated(%p) PaintThebes", this));
      Mutated();
    } else {
      // It's possible that state.mRegionToInvalidate is nonempty here,
      // if we are shrinking the valid region to nothing. So use mRegionToDraw
      // instead.
      NS_WARN_IF_FALSE(state.mRegionToDraw.IsEmpty(),
                       "No context when we have something to draw, resource exhaustion?");
    }
  }
}
void
ClientThebesLayer::PaintThebes()
{
  PROFILER_LABEL("ClientThebesLayer", "PaintThebes");
  NS_ASSERTION(ClientManager()->InDrawing(),
               "Can only draw in drawing phase");
  
  {
    mContentClient->PrepareFrame();

    uint32_t flags = 0;
#ifndef MOZ_WIDGET_ANDROID
    if (ClientManager()->CompositorMightResample()) {
      flags |= RotatedContentBuffer::PAINT_WILL_RESAMPLE;
    }
    if (!(flags & RotatedContentBuffer::PAINT_WILL_RESAMPLE)) {
      if (MayResample()) {
        flags |= RotatedContentBuffer::PAINT_WILL_RESAMPLE;
      }
    }
#endif
    PaintState state =
      mContentClient->BeginPaintBuffer(this, flags);
    mValidRegion.Sub(mValidRegion, state.mRegionToInvalidate);

    if (DrawTarget* target = mContentClient->BorrowDrawTargetForPainting(this, state)) {
      // The area that became invalid and is visible needs to be repainted
      // (this could be the whole visible area if our buffer switched
      // from RGB to RGBA, because we might need to repaint with
      // subpixel AA)
      state.mRegionToInvalidate.And(state.mRegionToInvalidate,
                                    GetEffectiveVisibleRegion());
      SetAntialiasingFlags(this, target);

      nsRefPtr<gfxContext> ctx = gfxContext::ContextForDrawTarget(target);
      PaintBuffer(ctx,
                  state.mRegionToDraw, state.mRegionToDraw, state.mRegionToInvalidate,
                  state.mDidSelfCopy, state.mClip);
      MOZ_LAYERS_LOG_IF_SHADOWABLE(this, ("Layer::Mutated(%p) PaintThebes", this));
      Mutated();
      ctx = nullptr;
      mContentClient->ReturnDrawTargetToBuffer(target);
    } else {
      // It's possible that state.mRegionToInvalidate is nonempty here,
      // if we are shrinking the valid region to nothing. So use mRegionToDraw
      // instead.
      NS_WARN_IF_FALSE(state.mRegionToDraw.IsEmpty(),
                       "No context when we have something to draw, resource exhaustion?");
    }
  }
}
Esempio n. 3
0
void
ClientPaintedLayer::PaintThebes(nsTArray<ReadbackProcessor::Update>* aReadbackUpdates)
{
  AUTO_PROFILER_LABEL("ClientPaintedLayer::PaintThebes", GRAPHICS);

  NS_ASSERTION(ClientManager()->InDrawing(),
               "Can only draw in drawing phase");

  mContentClient->BeginPaint();

  uint32_t flags = GetPaintFlags();

  PaintState state = mContentClient->BeginPaintBuffer(this, flags);
  if (!UpdatePaintRegion(state)) {
    return;
  }

  bool didUpdate = false;
  RotatedContentBuffer::DrawIterator iter;
  while (DrawTarget* target = mContentClient->BorrowDrawTargetForPainting(state, &iter)) {
    if (!target || !target->IsValid()) {
      if (target) {
        mContentClient->ReturnDrawTargetToBuffer(target);
      }
      continue;
    }

    SetAntialiasingFlags(this, target);

    RefPtr<gfxContext> ctx = gfxContext::CreatePreservingTransformOrNull(target);
    MOZ_ASSERT(ctx); // already checked the target above

    ClientManager()->GetPaintedLayerCallback()(this,
                                              ctx,
                                              iter.mDrawRegion,
                                              iter.mDrawRegion,
                                              state.mClip,
                                              state.mRegionToInvalidate,
                                              ClientManager()->GetPaintedLayerCallbackData());

    ctx = nullptr;
    mContentClient->ReturnDrawTargetToBuffer(target);
    didUpdate = true;
  }

  mContentClient->EndPaint(aReadbackUpdates);

  if (didUpdate) {
    UpdateContentClient(state);
  }
}
Esempio n. 4
0
void
SetAntialiasingFlags(Layer* aLayer, gfxContext* aTarget)
{
  if (!aTarget->IsCairo()) {
    SetAntialiasingFlags(aLayer, aTarget->GetDrawTarget());
    return;
  }

  bool permitSubpixelAA = !(aLayer->GetContentFlags() & Layer::CONTENT_DISABLE_SUBPIXEL_AA);
  nsRefPtr<gfxASurface> surface = aTarget->CurrentSurface();
  if (surface->GetContentType() != gfxContentType::COLOR_ALPHA) {
    // Destination doesn't have alpha channel; no need to set any special flags
    surface->SetSubpixelAntialiasingEnabled(permitSubpixelAA);
    return;
  }

  const nsIntRect& bounds = aLayer->GetVisibleRegion().GetBounds();
  permitSubpixelAA &= !(aLayer->GetContentFlags() & Layer::CONTENT_COMPONENT_ALPHA) ||
      surface->GetOpaqueRect().Contains(
      aTarget->UserToDevice(gfxRect(bounds.x, bounds.y, bounds.width, bounds.height)));
  surface->SetSubpixelAntialiasingEnabled(permitSubpixelAA);
}
Esempio n. 5
0
void
BasicThebesLayer::PaintThebes(gfxContext* aContext,
                              Layer* aMaskLayer,
                              LayerManager::DrawThebesLayerCallback aCallback,
                              void* aCallbackData,
                              ReadbackProcessor* aReadback)
{
  PROFILER_LABEL("BasicThebesLayer", "PaintThebes");
  NS_ASSERTION(BasicManager()->InDrawing(),
               "Can only draw in drawing phase");
  nsRefPtr<gfxASurface> targetSurface = aContext->CurrentSurface();

  if (!mContentClient) {
    // we pass a null pointer for the Forwarder argument, which means
    // this will not have a ContentHost on the other side.
    mContentClient = new ContentClientBasic(nullptr, BasicManager());
  }

  nsTArray<ReadbackProcessor::Update> readbackUpdates;
  if (aReadback && UsedForReadback()) {
    aReadback->GetThebesLayerUpdates(this, &readbackUpdates);
  }
  //TODO: This is going to copy back pixels that we might end up
  // drawing over anyway. It would be nice if we could avoid
  // this duplication.
  mContentClient->SyncFrontBufferToBackBuffer();

  bool canUseOpaqueSurface = CanUseOpaqueSurface();
  ContentType contentType =
    canUseOpaqueSurface ? gfxASurface::CONTENT_COLOR :
                          gfxASurface::CONTENT_COLOR_ALPHA;
  float opacity = GetEffectiveOpacity();
  
  if (!BasicManager()->IsRetained()) {
    NS_ASSERTION(readbackUpdates.IsEmpty(), "Can't do readback for non-retained layer");

    mValidRegion.SetEmpty();
    mContentClient->Clear();

    nsIntRegion toDraw = IntersectWithClip(GetEffectiveVisibleRegion(), aContext);

    RenderTraceInvalidateStart(this, "FFFF00", toDraw.GetBounds());

    if (!toDraw.IsEmpty() && !IsHidden()) {
      if (!aCallback) {
        BasicManager()->SetTransactionIncomplete();
        return;
      }

      aContext->Save();

      bool needsClipToVisibleRegion = GetClipToVisibleRegion();
      bool needsGroup =
          opacity != 1.0 || GetOperator() != gfxContext::OPERATOR_OVER || aMaskLayer;
      nsRefPtr<gfxContext> groupContext;
      if (needsGroup) {
        groupContext =
          BasicManager()->PushGroupForLayer(aContext, this, toDraw,
                                            &needsClipToVisibleRegion);
        if (GetOperator() != gfxContext::OPERATOR_OVER) {
          needsClipToVisibleRegion = true;
        }
      } else {
        groupContext = aContext;
      }
      SetAntialiasingFlags(this, groupContext);
      aCallback(this, groupContext, toDraw, CLIP_NONE, nsIntRegion(), aCallbackData);
      if (needsGroup) {
        BasicManager()->PopGroupToSourceWithCachedSurface(aContext, groupContext);
        if (needsClipToVisibleRegion) {
          gfxUtils::ClipToRegion(aContext, toDraw);
        }
        AutoSetOperator setOperator(aContext, GetOperator());
        PaintWithMask(aContext, opacity, aMaskLayer);
      }

      aContext->Restore();
    }

    RenderTraceInvalidateEnd(this, "FFFF00");
    return;
  }

  {
    uint32_t flags = 0;
#ifndef MOZ_WIDGET_ANDROID
    if (BasicManager()->CompositorMightResample()) {
      flags |= ThebesLayerBuffer::PAINT_WILL_RESAMPLE;
    }
    if (!(flags & ThebesLayerBuffer::PAINT_WILL_RESAMPLE)) {
      if (MayResample()) {
        flags |= ThebesLayerBuffer::PAINT_WILL_RESAMPLE;
      }
    }
#endif
    if (mDrawAtomically) {
      flags |= ThebesLayerBuffer::PAINT_NO_ROTATION;
    }
    PaintState state =
      mContentClient->BeginPaintBuffer(this, contentType, flags);
    mValidRegion.Sub(mValidRegion, state.mRegionToInvalidate);

    if (state.mContext) {
      // The area that became invalid and is visible needs to be repainted
      // (this could be the whole visible area if our buffer switched
      // from RGB to RGBA, because we might need to repaint with
      // subpixel AA)
      state.mRegionToInvalidate.And(state.mRegionToInvalidate,
                                    GetEffectiveVisibleRegion());
      nsIntRegion extendedDrawRegion = state.mRegionToDraw;
      SetAntialiasingFlags(this, state.mContext);

      RenderTraceInvalidateStart(this, "FFFF00", state.mRegionToDraw.GetBounds());

      PaintBuffer(state.mContext,
                  state.mRegionToDraw, extendedDrawRegion, state.mRegionToInvalidate,
                  state.mDidSelfCopy,
                  state.mClip,
                  aCallback, aCallbackData);
      MOZ_LAYERS_LOG_IF_SHADOWABLE(this, ("Layer::Mutated(%p) PaintThebes", this));
      Mutated();

      RenderTraceInvalidateEnd(this, "FFFF00");
    } else {
      // It's possible that state.mRegionToInvalidate is nonempty here,
      // if we are shrinking the valid region to nothing. So use mRegionToDraw
      // instead.
      NS_WARN_IF_FALSE(state.mRegionToDraw.IsEmpty(),
                       "No context when we have something to draw, resource exhaustion?");
    }
  }

  if (BasicManager()->IsTransactionIncomplete())
    return;

  gfxRect clipExtents;
  clipExtents = aContext->GetClipExtents();

  // Pull out the mask surface and transform here, because the mask
  // is internal to basic layers
  AutoMaskData mask;
  gfxASurface* maskSurface = nullptr;
  const gfxMatrix* maskTransform = nullptr;
  if (GetMaskData(aMaskLayer, &mask)) {
    maskSurface = mask.GetSurface();
    maskTransform = &mask.GetTransform();
  }

  if (!IsHidden() && !clipExtents.IsEmpty()) {
    AutoSetOperator setOperator(aContext, GetOperator());
    mContentClient->DrawTo(this, aContext, opacity, maskSurface, maskTransform);
  }

  for (uint32_t i = 0; i < readbackUpdates.Length(); ++i) {
    ReadbackProcessor::Update& update = readbackUpdates[i];
    nsIntPoint offset = update.mLayer->GetBackgroundLayerOffset();
    nsRefPtr<gfxContext> ctx =
      update.mLayer->GetSink()->BeginUpdate(update.mUpdateRect + offset,
                                            update.mSequenceCounter);
    if (ctx) {
      NS_ASSERTION(opacity == 1.0, "Should only read back opaque layers");
      ctx->Translate(gfxPoint(offset.x, offset.y));
      mContentClient->DrawTo(this, ctx, 1.0, maskSurface, maskTransform);
      update.mLayer->GetSink()->EndUpdate(ctx, update.mUpdateRect + offset);
    }
  }
}
Esempio n. 6
0
/***
 * If we can, let's paint this ClientPaintedLayer's contents off the main thread.
 * The essential idea is that we ask the ContentClient for a DrawTarget and record
 * the moz2d commands. On the Paint Thread, we replay those commands to the
 * destination draw target. There are a couple of lifetime issues here though:
 *
 * 1) TextureClient owns the underlying buffer and DrawTarget. Because of this
 *    we have to keep the TextureClient and DrawTarget alive but trick the
 *    TextureClient into thinking it's already returned the DrawTarget
 *    since we iterate through different Rects to get DrawTargets*. If
 *    the TextureClient goes away, the DrawTarget and thus buffer can too.
 * 2) When ContentClient::EndPaint happens, it flushes the DrawTarget. We have
 *    to Reflush on the Paint Thread
 * 3) DrawTarget API is NOT thread safe. We get around this by recording
 *    on the main thread and painting on the paint thread. Logically,
 *    ClientLayerManager will force a flushed paint and block the main thread
 *    if we have another transaction. Thus we have a gap between when the main
 *    thread records, the paint thread paints, and we block the main thread
 *    from trying to paint again. The underlying API however is NOT thread safe.
 *  4) We have both "sync" and "async" OMTP. Sync OMTP means we paint on the main thread
 *     but block the main thread while the paint thread paints. Async OMTP doesn't block
 *     the main thread. Sync OMTP is only meant to be used as a debugging tool.
 */
bool
ClientPaintedLayer::PaintOffMainThread()
{
  mContentClient->BeginAsyncPaint();

  uint32_t flags = GetPaintFlags();

  PaintState state = mContentClient->BeginPaintBuffer(this, flags);
  if (!UpdatePaintRegion(state)) {
    return false;
  }

  bool didUpdate = false;
  RotatedContentBuffer::DrawIterator iter;

  // Debug Protip: Change to BorrowDrawTargetForPainting if using sync OMTP.
  while (RefPtr<CapturedPaintState> captureState =
          mContentClient->BorrowDrawTargetForRecording(state, &iter))
  {
    DrawTarget* target = captureState->mTarget;
    if (!target || !target->IsValid()) {
      if (target) {
        mContentClient->ReturnDrawTargetToBuffer(target);
      }
      continue;
    }

    RefPtr<DrawTargetCapture> captureDT =
      Factory::CreateCaptureDrawTarget(target->GetBackendType(),
                                       target->GetSize(),
                                       target->GetFormat());

    captureDT->SetTransform(captureState->mTargetTransform);
    SetAntialiasingFlags(this, captureDT);

    RefPtr<gfxContext> ctx = gfxContext::CreatePreservingTransformOrNull(captureDT);
    MOZ_ASSERT(ctx); // already checked the target above

    ClientManager()->GetPaintedLayerCallback()(this,
                                              ctx,
                                              iter.mDrawRegion,
                                              iter.mDrawRegion,
                                              state.mClip,
                                              state.mRegionToInvalidate,
                                              ClientManager()->GetPaintedLayerCallbackData());

    ctx = nullptr;

    captureState->mCapture = captureDT.forget();
    PaintThread::Get()->PaintContents(captureState,
                                      RotatedContentBuffer::PrepareDrawTargetForPainting);

    mContentClient->ReturnDrawTargetToBuffer(target);

    didUpdate = true;
  }
  mContentClient->EndPaint(nullptr);

  if (didUpdate) {
    UpdateContentClient(state);
  }
  return true;
}
Esempio n. 7
0
void
BasicThebesLayer::PaintThebes(gfxContext* aContext,
                              Layer* aMaskLayer,
                              LayerManager::DrawThebesLayerCallback aCallback,
                              void* aCallbackData,
                              ReadbackProcessor* aReadback)
{
  PROFILER_LABEL("BasicThebesLayer", "PaintThebes");
  NS_ASSERTION(BasicManager()->InDrawing(),
               "Can only draw in drawing phase");

  nsTArray<ReadbackProcessor::Update> readbackUpdates;
  if (aReadback && UsedForReadback()) {
    aReadback->GetThebesLayerUpdates(this, &readbackUpdates);
  }

  float opacity = GetEffectiveOpacity();
  CompositionOp effectiveOperator = GetEffectiveOperator(this);

  if (!BasicManager()->IsRetained()) {
    NS_ASSERTION(readbackUpdates.IsEmpty(), "Can't do readback for non-retained layer");

    mValidRegion.SetEmpty();
    mContentClient->Clear();

    nsIntRegion toDraw = IntersectWithClip(GetEffectiveVisibleRegion(), aContext);

    RenderTraceInvalidateStart(this, "FFFF00", toDraw.GetBounds());

    if (!toDraw.IsEmpty() && !IsHidden()) {
      if (!aCallback) {
        BasicManager()->SetTransactionIncomplete();
        return;
      }

      aContext->Save();

      bool needsClipToVisibleRegion = GetClipToVisibleRegion();
      bool needsGroup = opacity != 1.0 ||
                        effectiveOperator != CompositionOp::OP_OVER ||
                        aMaskLayer;
      nsRefPtr<gfxContext> groupContext;
      if (needsGroup) {
        groupContext =
          BasicManager()->PushGroupForLayer(aContext, this, toDraw,
                                            &needsClipToVisibleRegion);
        if (effectiveOperator != CompositionOp::OP_OVER) {
          needsClipToVisibleRegion = true;
        }
      } else {
        groupContext = aContext;
      }
      SetAntialiasingFlags(this, groupContext);
      aCallback(this, groupContext, toDraw, DrawRegionClip::CLIP_NONE, nsIntRegion(), aCallbackData);
      if (needsGroup) {
        BasicManager()->PopGroupToSourceWithCachedSurface(aContext, groupContext);
        if (needsClipToVisibleRegion) {
          gfxUtils::ClipToRegion(aContext, toDraw);
        }
        AutoSetOperator setOptimizedOperator(aContext, ThebesOp(effectiveOperator));
        PaintWithMask(aContext, opacity, aMaskLayer);
      }

      aContext->Restore();
    }

    RenderTraceInvalidateEnd(this, "FFFF00");
    return;
  }

  if (BasicManager()->IsTransactionIncomplete())
    return;

  gfxRect clipExtents;
  clipExtents = aContext->GetClipExtents();

  // Pull out the mask surface and transform here, because the mask
  // is internal to basic layers
  AutoMoz2DMaskData mask;
  SourceSurface* maskSurface = nullptr;
  Matrix maskTransform;
  if (GetMaskData(aMaskLayer, &mask)) {
    maskSurface = mask.GetSurface();
    maskTransform = mask.GetTransform();
  }

  if (!IsHidden() && !clipExtents.IsEmpty()) {
    mContentClient->DrawTo(this, aContext->GetDrawTarget(), opacity,
                           GetOperator(),
                           maskSurface, &maskTransform);
  }

  for (uint32_t i = 0; i < readbackUpdates.Length(); ++i) {
    ReadbackProcessor::Update& update = readbackUpdates[i];
    nsIntPoint offset = update.mLayer->GetBackgroundLayerOffset();
    nsRefPtr<gfxContext> ctx =
      update.mLayer->GetSink()->BeginUpdate(update.mUpdateRect + offset,
                                            update.mSequenceCounter);
    if (ctx) {
      NS_ASSERTION(opacity == 1.0, "Should only read back opaque layers");
      ctx->Translate(gfxPoint(offset.x, offset.y));
      mContentClient->DrawTo(this, ctx->GetDrawTarget(), 1.0,
                             CompositionOpForOp(ctx->CurrentOperator()),
                             maskSurface, &maskTransform);
      update.mLayer->GetSink()->EndUpdate(ctx, update.mUpdateRect + offset);
    }
  }
}
Esempio n. 8
0
void
BasicThebesLayer::Validate(LayerManager::DrawThebesLayerCallback aCallback,
                           void* aCallbackData)
{
  if (!mContentClient) {
    // This client will have a null Forwarder, which means it will not have
    // a ContentHost on the other side.
    mContentClient = new ContentClientBasic();
  }

  if (!BasicManager()->IsRetained()) {
    return;
  }

  uint32_t flags = 0;
#ifndef MOZ_WIDGET_ANDROID
  if (BasicManager()->CompositorMightResample()) {
    flags |= RotatedContentBuffer::PAINT_WILL_RESAMPLE;
  }
  if (!(flags & RotatedContentBuffer::PAINT_WILL_RESAMPLE)) {
    if (MayResample()) {
      flags |= RotatedContentBuffer::PAINT_WILL_RESAMPLE;
    }
  }
#endif
  if (mDrawAtomically) {
    flags |= RotatedContentBuffer::PAINT_NO_ROTATION;
  }
  PaintState state =
    mContentClient->BeginPaintBuffer(this, flags);
  mValidRegion.Sub(mValidRegion, state.mRegionToInvalidate);

  if (DrawTarget* target = mContentClient->BorrowDrawTargetForPainting(state)) {
    // The area that became invalid and is visible needs to be repainted
    // (this could be the whole visible area if our buffer switched
    // from RGB to RGBA, because we might need to repaint with
    // subpixel AA)
    state.mRegionToInvalidate.And(state.mRegionToInvalidate,
                                  GetEffectiveVisibleRegion());
    SetAntialiasingFlags(this, target);

    RenderTraceInvalidateStart(this, "FFFF00", state.mRegionToDraw.GetBounds());

    nsRefPtr<gfxContext> ctx = gfxContext::ContextForDrawTarget(target);
    PaintBuffer(ctx,
                state.mRegionToDraw, state.mRegionToDraw, state.mRegionToInvalidate,
                state.mDidSelfCopy,
                state.mClip,
                aCallback, aCallbackData);
    MOZ_LAYERS_LOG_IF_SHADOWABLE(this, ("Layer::Mutated(%p) PaintThebes", this));
    Mutated();
    ctx = nullptr;
    mContentClient->ReturnDrawTargetToBuffer(target);

    RenderTraceInvalidateEnd(this, "FFFF00");
  } else {
    // It's possible that state.mRegionToInvalidate is nonempty here,
    // if we are shrinking the valid region to nothing. So use mRegionToDraw
    // instead.
    NS_WARN_IF_FALSE(state.mRegionToDraw.IsEmpty(),
                     "No context when we have something to draw, resource exhaustion?");
  }
}
Esempio n. 9
0
void
ClientThebesLayer::PaintThebes()
{
    PROFILER_LABEL("ClientThebesLayer", "PaintThebes");
    NS_ASSERTION(ClientManager()->InDrawing(),
                 "Can only draw in drawing phase");

    uint32_t flags = RotatedContentBuffer::PAINT_CAN_DRAW_ROTATED;
#ifndef MOZ_WIDGET_ANDROID
    if (ClientManager()->CompositorMightResample()) {
        flags |= RotatedContentBuffer::PAINT_WILL_RESAMPLE;
    }
    if (!(flags & RotatedContentBuffer::PAINT_WILL_RESAMPLE)) {
        if (MayResample()) {
            flags |= RotatedContentBuffer::PAINT_WILL_RESAMPLE;
        }
    }
#endif
    PaintState state =
        mContentClient->BeginPaintBuffer(this, flags);
    mValidRegion.Sub(mValidRegion, state.mRegionToInvalidate);

    if (!state.mRegionToDraw.IsEmpty() && !ClientManager()->GetThebesLayerCallback()) {
        ClientManager()->SetTransactionIncomplete();
        return;
    }

    // The area that became invalid and is visible needs to be repainted
    // (this could be the whole visible area if our buffer switched
    // from RGB to RGBA, because we might need to repaint with
    // subpixel AA)
    state.mRegionToInvalidate.And(state.mRegionToInvalidate,
                                  GetEffectiveVisibleRegion());

    bool didUpdate = false;
    RotatedContentBuffer::DrawIterator iter;
    while (DrawTarget* target = mContentClient->BorrowDrawTargetForPainting(state, &iter)) {
        SetAntialiasingFlags(this, target);

        nsRefPtr<gfxContext> ctx = gfxContext::ContextForDrawTarget(target);

        ClientManager()->GetThebesLayerCallback()(this,
                ctx,
                iter.mDrawRegion,
                state.mClip,
                state.mRegionToInvalidate,
                ClientManager()->GetThebesLayerCallbackData());

        ctx = nullptr;
        mContentClient->ReturnDrawTargetToBuffer(target);
        didUpdate = true;
    }

    if (didUpdate) {
        Mutated();

        mValidRegion.Or(mValidRegion, state.mRegionToDraw);

        ContentClientRemote* contentClientRemote = static_cast<ContentClientRemote*>(mContentClient.get());
        MOZ_ASSERT(contentClientRemote->GetIPDLActor());

        // Hold(this) ensures this layer is kept alive through the current transaction
        // The ContentClient assumes this layer is kept alive (e.g., in CreateBuffer),
        // so deleting this Hold for whatever reason will break things.
        ClientManager()->Hold(this);
        contentClientRemote->Updated(state.mRegionToDraw,
                                     mVisibleRegion,
                                     state.mDidSelfCopy);
    }
}