C++ LayerComposite::GetShadowVisibleRegion方法代码示例

void
LayerManagerComposite::ApplyOcclusionCulling(Layer* aLayer, nsIntRegion& aOpaqueRegion)
{
  nsIntRegion localOpaque;
  Matrix transform2d;
  bool isTranslation = false;
  // If aLayer has a simple transform (only an integer translation) then we
  // can easily convert aOpaqueRegion into pre-transform coordinates and include
  // that region.
  if (aLayer->GetLocalTransform().Is2D(&transform2d)) {
    if (transform2d.IsIntegerTranslation()) {
      isTranslation = true;
      localOpaque = aOpaqueRegion;
      localOpaque.MoveBy(-transform2d._31, -transform2d._32);
    }
  }

  // Subtract any areas that we know to be opaque from our
  // visible region.
  LayerComposite *composite = aLayer->AsLayerComposite();
  if (!localOpaque.IsEmpty()) {
    nsIntRegion visible = composite->GetShadowVisibleRegion();
    visible.Sub(visible, localOpaque);
    composite->SetShadowVisibleRegion(visible);
  }

  // Compute occlusions for our descendants (in front-to-back order) and allow them to
  // contribute to localOpaque.
  for (Layer* child = aLayer->GetLastChild(); child; child = child->GetPrevSibling()) {
    ApplyOcclusionCulling(child, localOpaque);
  }

  // If we have a simple transform, then we can add our opaque area into
  // aOpaqueRegion.
  if (isTranslation &&
      !aLayer->HasMaskLayers() &&
      aLayer->GetLocalOpacity() == 1.0f) {
    if (aLayer->GetContentFlags() & Layer::CONTENT_OPAQUE) {
      localOpaque.Or(localOpaque, composite->GetFullyRenderedRegion());
    }
    localOpaque.MoveBy(transform2d._31, transform2d._32);
    const Maybe<ParentLayerIntRect>& clip = aLayer->GetEffectiveClipRect();
    if (clip) {
      localOpaque.And(localOpaque, ParentLayerIntRect::ToUntyped(*clip));
    }
    aOpaqueRegion.Or(aOpaqueRegion, localOpaque);
  }
}

static void
BuildBackgroundPatternFor(ContainerLayer* aContainer,
                          Layer* aShadowRoot,
                          const ViewConfig& aConfig,
                          const gfxRGBA& aColor,
                          LayerManager* aManager,
                          nsIFrame* aFrame)
{
  LayerComposite* shadowRoot = aShadowRoot->AsLayerComposite();
  gfxMatrix t;
  if (!shadowRoot->GetShadowTransform().Is2D(&t)) {
    return;
  }

  // Get the rect bounding the shadow content, transformed into the
  // same space as |aFrame|
  nsIntRect contentBounds = shadowRoot->GetShadowVisibleRegion().GetBounds();
  gfxRect contentVis(contentBounds.x, contentBounds.y,
                     contentBounds.width, contentBounds.height);
  gfxRect localContentVis(t.Transform(contentVis));
  // Round *in* here because this area is punched out of the background
  localContentVis.RoundIn();
  nsIntRect localIntContentVis(localContentVis.X(), localContentVis.Y(),
                               localContentVis.Width(), localContentVis.Height());

  // Get the frame's rect
  nscoord auPerDevPixel = aFrame->PresContext()->AppUnitsPerDevPixel();
  nsIntRect frameRect = aFrame->GetRect().ToOutsidePixels(auPerDevPixel);

  // If the shadow tree covers the frame rect, don't bother building
  // the background, it wouldn't be visible
  if (localIntContentVis.Contains(frameRect)) {
    return;
  }
  nsRefPtr<ColorLayer> layer = aManager->CreateColorLayer();
  layer->SetColor(aColor);

  // The visible area of the background is the frame's area minus the
  // content area
  nsIntRegion bgRgn(frameRect);
  bgRgn.Sub(bgRgn, localIntContentVis);
  bgRgn.MoveBy(-frameRect.TopLeft());
  layer->SetVisibleRegion(bgRgn);

  aContainer->InsertAfter(layer, nullptr);
}

//.........这里部分代码省略.........
    }

    if (!surface) {
      return;
    }

    compositor->SetRenderTarget(surface);
  } else {
    surface = previousTarget;
    aContainer->mSupportsComponentAlphaChildren = (aContainer->GetContentFlags() & Layer::CONTENT_OPAQUE) ||
      (aContainer->GetParent() && aContainer->GetParent()->SupportsComponentAlphaChildren());
  }

  nsAutoTArray<Layer*, 12> children;
  aContainer->SortChildrenBy3DZOrder(children);

  /**
   * Render this container's contents.
   */
  for (uint32_t i = 0; i < children.Length(); i++) {
    LayerComposite* layerToRender = static_cast<LayerComposite*>(children.ElementAt(i)->ImplData());

    if (layerToRender->GetLayer()->GetEffectiveVisibleRegion().IsEmpty() &&
        !layerToRender->GetLayer()->AsContainerLayer()) {
      continue;
    }

    if (i + 1 < children.Length() &&
        layerToRender->GetLayer()->GetEffectiveTransform().IsIdentity()) {
      LayerComposite* nextLayer = static_cast<LayerComposite*>(children.ElementAt(i + 1)->ImplData());
      nsIntRect nextLayerOpaqueRect;
      if (nextLayer && nextLayer->GetLayer()) {
        nextLayerOpaqueRect = GetOpaqueRect(nextLayer->GetLayer());
      }
      if (!nextLayerOpaqueRect.IsEmpty()) {
        nsIntRegion visibleRegion;
        visibleRegion.Sub(layerToRender->GetShadowVisibleRegion(), nextLayerOpaqueRect);
        layerToRender->SetShadowVisibleRegion(visibleRegion);
        if (visibleRegion.IsEmpty()) {
          continue;
        }
      }
    }

    nsIntRect clipRect = layerToRender->GetLayer()->
        CalculateScissorRect(aClipRect, &aManager->GetWorldTransform());
    if (clipRect.IsEmpty()) {
      continue;
    }

    if (layerToRender->HasLayerBeenComposited()) {
      // Composer2D will compose this layer so skip GPU composition
      // this time & reset composition flag for next composition phase
      layerToRender->SetLayerComposited(false);
    } else {
      layerToRender->RenderLayer(clipRect);
    }
    // invariant: our GL context should be current here, I don't think we can
    // assert it though
  }

  if (needsSurface) {
    // Unbind the current surface and rebind the previous one.
#ifdef MOZ_DUMP_PAINTING
    if (gfxUtils::sDumpPainting) {
      nsRefPtr<gfxImageSurface> surf = surface->Dump(aManager->GetCompositor());
      WriteSnapshotToDumpFile(aContainer, surf);
    }
#endif

    compositor->SetRenderTarget(previousTarget);
    EffectChain effectChain;
    LayerManagerComposite::AutoAddMaskEffect autoMaskEffect(aContainer->GetMaskLayer(),
                                                            effectChain,
                                                            !aContainer->GetTransform().CanDraw2D());

    effectChain.mPrimaryEffect = new EffectRenderTarget(surface);

    gfx::Matrix4x4 transform;
    ToMatrix4x4(aContainer->GetEffectiveTransform(), transform);

    gfx::Rect rect(visibleRect.x, visibleRect.y, visibleRect.width, visibleRect.height);
    gfx::Rect clipRect(aClipRect.x, aClipRect.y, aClipRect.width, aClipRect.height);
    aManager->GetCompositor()->DrawQuad(rect, clipRect, effectChain, opacity,
                                        transform);
  }

  if (aContainer->GetFrameMetrics().IsScrollable()) {
    gfx::Matrix4x4 transform;
    ToMatrix4x4(aContainer->GetEffectiveTransform(), transform);

    const FrameMetrics& frame = aContainer->GetFrameMetrics();
    LayerRect layerBounds = ScreenRect(frame.mCompositionBounds) * ScreenToLayerScale(1.0);
    gfx::Rect rect(layerBounds.x, layerBounds.y, layerBounds.width, layerBounds.height);
    gfx::Rect clipRect(aClipRect.x, aClipRect.y, aClipRect.width, aClipRect.height);
    aManager->GetCompositor()->DrawDiagnostics(DIAGNOSTIC_CONTAINER,
                                               rect, clipRect,
                                               transform);
  }
}

//.........这里部分代码省略.........
  // from our ancestors.
  LayerComposite* composite = static_cast<LayerComposite*>(aLayer->AsHostLayer());
  Maybe<ParentLayerIntRect> layerClip = composite->GetShadowClipRect();
  MOZ_ASSERT(!layerClip || !aLayer->Combines3DTransformWithAncestors(),
             "The layer with a clip should not participate "
             "a 3D rendering context");
  Maybe<ParentLayerIntRect> outsideClip =
    IntersectMaybeRects(layerClip, aClipFromAncestors);

  // Convert the combined clip into our pre-transform coordinate space, so
  // that it can later be intersected with our visible region.
  // If our transform is a perspective, there's no meaningful insideClip rect
  // we can compute (it would need to be a cone).
  Maybe<LayerIntRect> insideClip;
  if (outsideClip && !transform.HasPerspectiveComponent()) {
    Matrix4x4 inverse = transform;
    if (inverse.Invert()) {
      Maybe<LayerRect> insideClipFloat =
        UntransformBy(ViewAs<ParentLayerToLayerMatrix4x4>(inverse),
                      ParentLayerRect(*outsideClip),
                      LayerRect::MaxIntRect());
      if (insideClipFloat) {
        insideClipFloat->RoundOut();
        LayerIntRect insideClipInt;
        if (insideClipFloat->ToIntRect(&insideClipInt)) {
          insideClip = Some(insideClipInt);
        }
      }
    }
  }

  Maybe<ParentLayerIntRect> ancestorClipForChildren;
  if (insideClip) {
    ancestorClipForChildren =
      Some(ViewAs<ParentLayerPixel>(*insideClip, PixelCastJustification::MovingDownToChildren));
  }

  // Save the value of localOpaque, which currently stores the region obscured
  // by siblings (and uncles and such), before our descendants contribute to it.
  nsIntRegion obscured = localOpaque;

  // Recurse on our descendants, in front-to-back order. In this process:
  //  - Occlusions are computed for them, and they contribute to localOpaque.
  //  - They recalculate their visible regions, taking ancestorClipForChildren
  //    into account, and accumulate them into descendantsVisibleRegion.
  LayerIntRegion descendantsVisibleRegion;
  bool hasPreserve3DChild = false;
  for (Layer* child = aLayer->GetLastChild(); child; child = child->GetPrevSibling()) {
    PostProcessLayers(child, localOpaque, descendantsVisibleRegion, ancestorClipForChildren);
    if (child->Extend3DContext()) {
      hasPreserve3DChild = true;
    }
  }

  // Recalculate our visible region.
  LayerIntRegion visible = composite->GetShadowVisibleRegion();

  // If we have descendants, throw away the visible region stored on this
  // layer, and use the region accumulated by our descendants instead.
  if (aLayer->GetFirstChild() && !hasPreserve3DChild) {
    visible = descendantsVisibleRegion;
  }

  // Subtract any areas that we know to be opaque.
  if (!obscured.IsEmpty()) {
    visible.SubOut(LayerIntRegion::FromUnknownRegion(obscured));
  }

  // Clip the visible region using the combined clip.
  if (insideClip) {
    visible.AndWith(*insideClip);
  }
  composite->SetShadowVisibleRegion(visible);

  // Transform the newly calculated visible region into our parent's space,
  // apply our clip to it (if any), and accumulate it into |aVisibleRegion|
  // for the caller to use.
  ParentLayerIntRegion visibleParentSpace = TransformBy(
      ViewAs<LayerToParentLayerMatrix4x4>(transform), visible);
  if (const Maybe<ParentLayerIntRect>& clipRect = composite->GetShadowClipRect()) {
    visibleParentSpace.AndWith(*clipRect);
  }
  aVisibleRegion.OrWith(ViewAs<LayerPixel>(visibleParentSpace,
      PixelCastJustification::MovingDownToChildren));

  // If we have a simple transform, then we can add our opaque area into
  // aOpaqueRegion.
  if (integerTranslation &&
      !aLayer->HasMaskLayers() &&
      aLayer->IsOpaqueForVisibility()) {
    if (aLayer->IsOpaque()) {
      localOpaque.OrWith(composite->GetFullyRenderedRegion());
    }
    localOpaque.MoveBy(*integerTranslation);
    if (layerClip) {
      localOpaque.AndWith(layerClip->ToUnknownRect());
    }
    aOpaqueRegion.OrWith(localOpaque);
  }
}

//.........这里部分代码省略.........
        compositor->DrawQuad(compositor->ClipRectInLayersCoordinates(clipRect),
            clipRect, effectChain, opacity, Matrix4x4());
      }
    }
  }

  /**
   * Render this container's contents.
   */
  for (uint32_t i = 0; i < children.Length(); i++) {
    LayerComposite* layerToRender = static_cast<LayerComposite*>(children.ElementAt(i)->ImplData());

    if (layerToRender->GetLayer()->GetEffectiveVisibleRegion().IsEmpty() &&
        !layerToRender->GetLayer()->AsContainerLayer()) {
      continue;
    }

    nsIntRect clipRect = layerToRender->GetLayer()->
        CalculateScissorRect(aClipRect, &aManager->GetWorldTransform());
    if (clipRect.IsEmpty()) {
      continue;
    }

    nsIntRegion savedVisibleRegion;
    bool restoreVisibleRegion = false;
    if (i + 1 < children.Length() &&
        layerToRender->GetLayer()->GetEffectiveTransform().IsIdentity()) {
      LayerComposite* nextLayer = static_cast<LayerComposite*>(children.ElementAt(i + 1)->ImplData());
      nsIntRect nextLayerOpaqueRect;
      if (nextLayer && nextLayer->GetLayer()) {
        nextLayerOpaqueRect = GetOpaqueRect(nextLayer->GetLayer());
      }
      if (!nextLayerOpaqueRect.IsEmpty()) {
        savedVisibleRegion = layerToRender->GetShadowVisibleRegion();
        nsIntRegion visibleRegion;
        visibleRegion.Sub(savedVisibleRegion, nextLayerOpaqueRect);
        if (visibleRegion.IsEmpty()) {
          continue;
        }
        layerToRender->SetShadowVisibleRegion(visibleRegion);
        restoreVisibleRegion = true;
      }
    }

    if (layerToRender->HasLayerBeenComposited()) {
      // Composer2D will compose this layer so skip GPU composition
      // this time & reset composition flag for next composition phase
      layerToRender->SetLayerComposited(false);
      nsIntRect clearRect = layerToRender->GetClearRect();
      if (!clearRect.IsEmpty()) {
        // Clear layer's visible rect on FrameBuffer with transparent pixels
        gfx::Rect fbRect(clearRect.x, clearRect.y, clearRect.width, clearRect.height);
        compositor->ClearRect(fbRect);
        layerToRender->SetClearRect(nsIntRect(0, 0, 0, 0));
      }
    } else {
      layerToRender->RenderLayer(clipRect);
    }

    if (restoreVisibleRegion) {
      // Restore the region in case it's not covered by opaque content next time
      layerToRender->SetShadowVisibleRegion(savedVisibleRegion);
    }

    if (gfxPrefs::LayersScrollGraph()) {
      DrawVelGraph(clipRect, aManager, layerToRender->GetLayer());

void
LayerManagerComposite::PostProcessLayers(Layer* aLayer,
                                         nsIntRegion& aOpaqueRegion,
                                         LayerIntRegion& aVisibleRegion)
{
  nsIntRegion localOpaque;
  Matrix transform2d;
  Maybe<nsIntPoint> integerTranslation;
  // If aLayer has a simple transform (only an integer translation) then we
  // can easily convert aOpaqueRegion into pre-transform coordinates and include
  // that region.
  if (aLayer->GetLocalTransform().Is2D(&transform2d)) {
    if (transform2d.IsIntegerTranslation()) {
      integerTranslation = Some(TruncatedToInt(transform2d.GetTranslation()));
      localOpaque = aOpaqueRegion;
      localOpaque.MoveBy(-*integerTranslation);
    }
  }

  // Save the value of localOpaque, which currently stores the region obscured
  // by siblings (and uncles and such), before our descendants contribute to it.
  nsIntRegion obscured = localOpaque;

  // Recurse on our descendants, in front-to-back order. In this process:
  //  - Occlusions are computed for them, and they contribute to localOpaque.
  //  - They recalculate their visible regions, and accumulate them into
  //    descendantsVisibleRegion.
  LayerIntRegion descendantsVisibleRegion;
  for (Layer* child = aLayer->GetLastChild(); child; child = child->GetPrevSibling()) {
    PostProcessLayers(child, localOpaque, descendantsVisibleRegion);
  }

  // Recalculate our visible region.
  LayerComposite* composite = aLayer->AsLayerComposite();
  LayerIntRegion visible = composite->GetShadowVisibleRegion();

  // If we have descendants, throw away the visible region stored on this
  // layer, and use the region accumulated by our descendants instead.
  if (aLayer->GetFirstChild()) {
    visible = descendantsVisibleRegion;
  }

  // Subtract any areas that we know to be opaque.
  if (!obscured.IsEmpty()) {
    visible.SubOut(LayerIntRegion::FromUnknownRegion(obscured));
  }

  composite->SetShadowVisibleRegion(visible);

  // Transform the newly calculated visible region into our parent's space,
  // apply our clip to it (if any), and accumulate it into |aVisibleRegion|
  // for the caller to use.
  ParentLayerIntRegion visibleParentSpace = TransformTo<ParentLayerPixel>(
      aLayer->GetLocalTransform(), visible);
  if (const Maybe<ParentLayerIntRect>& clipRect = composite->GetShadowClipRect()) {
    visibleParentSpace.AndWith(*clipRect);
  }
  aVisibleRegion.OrWith(ViewAs<LayerPixel>(visibleParentSpace,
      PixelCastJustification::MovingDownToChildren));

  // If we have a simple transform, then we can add our opaque area into
  // aOpaqueRegion.
  if (integerTranslation &&
      !aLayer->HasMaskLayers() &&
      aLayer->IsOpaqueForVisibility()) {
    if (aLayer->GetContentFlags() & Layer::CONTENT_OPAQUE) {
      localOpaque.OrWith(composite->GetFullyRenderedRegion());
    }
    localOpaque.MoveBy(*integerTranslation);
    const Maybe<ParentLayerIntRect>& clip = aLayer->GetEffectiveClipRect();
    if (clip) {
      localOpaque.AndWith(clip->ToUnknownRect());
    }
    aOpaqueRegion.OrWith(localOpaque);
  }
}