Bug 1352863 - Propagate the visible region from Layer to HitTestingTreeNode. r=kats

The propagation happens via LayerMetricsWrapper or WebRenderScrollDataWrapper.

MozReview-Commit-ID: GBZUnNn3zjN

--HG--
extra : rebase_source : 4c63269480154a95d5faedf1b4972f7d3373cb5a

gfx/layers/LayerMetricsWrapper.h

@@ -334,6 +334,19 @@ public:
     return EventRegions();
   }
 
+  LayerIntRegion GetVisibleRegion() const
+  {
+    MOZ_ASSERT(IsValid());
+
+    if (AtBottomLayer()) {
+      return mLayer->GetVisibleRegion();
+    }
+
+    return ViewAs<LayerPixel>(
+        TransformBy(mLayer->GetTransformTyped(), mLayer->GetVisibleRegion()),
+        PixelCastJustification::MovingDownToChildren);
+  }
+
   bool HasTransformAnimation() const
   {
     MOZ_ASSERT(IsValid());

gfx/layers/apz/src/APZCTreeManager.cpp

@@ -626,6 +626,7 @@ APZCTreeManager::PrepareNodeForLayer(const ScrollNode& aLayer,
     AttachNodeToTree(node, aParent, aNextSibling);
     node->SetHitTestData(
         GetEventRegions(aLayer),
+        aLayer.GetVisibleRegion(),
         aLayer.GetTransformTyped(),
         aLayer.GetClipRect() ? Some(ParentLayerIntRegion(*aLayer.GetClipRect())) : Nothing(),
         GetEventRegionsOverride(aParent, aLayer));
@@ -737,6 +738,7 @@ APZCTreeManager::PrepareNodeForLayer(const ScrollNode& aLayer,
     ParentLayerIntRegion clipRegion = ComputeClipRegion(state->mController, aLayer);
     node->SetHitTestData(
         GetEventRegions(aLayer),
+        aLayer.GetVisibleRegion(),
         aLayer.GetTransformTyped(),
         Some(clipRegion),
         GetEventRegionsOverride(aParent, aLayer));
@@ -811,6 +813,7 @@ APZCTreeManager::PrepareNodeForLayer(const ScrollNode& aLayer,
     ParentLayerIntRegion clipRegion = ComputeClipRegion(state->mController, aLayer);
     node->SetHitTestData(
         GetEventRegions(aLayer),
+        aLayer.GetVisibleRegion(),
         aLayer.GetTransformTyped(),
         Some(clipRegion),
         GetEventRegionsOverride(aParent, aLayer));

gfx/layers/apz/src/HitTestingTreeNode.cpp

@@ -249,11 +249,13 @@ HitTestingTreeNode::GetLayersId() const
 
 void
 HitTestingTreeNode::SetHitTestData(const EventRegions& aRegions,
+                                   const LayerIntRegion& aVisibleRegion,
                                    const CSSTransformMatrix& aTransform,
                                    const Maybe<ParentLayerIntRegion>& aClipRegion,
                                    const EventRegionsOverride& aOverride)
 {
   mEventRegions = aRegions;
+  mVisibleRegion = aVisibleRegion;
   mTransform = aTransform;
   mClipRegion = aClipRegion;
   mOverride = aOverride;
@@ -324,6 +326,12 @@ HitTestingTreeNode::GetTransform() const
   return mTransform;
 }
 
+const LayerIntRegion&
+HitTestingTreeNode::GetVisibleRegion() const
+{
+  return mVisibleRegion;
+}
+
 void
 HitTestingTreeNode::Dump(const char* aPrefix) const
 {

gfx/layers/apz/src/HitTestingTreeNode.h

@@ -86,6 +86,7 @@ public:
   /* Hit test related methods */
 
   void SetHitTestData(const EventRegions& aRegions,
+                      const LayerIntRegion& aVisibleRegion,
                       const CSSTransformMatrix& aTransform,
                       const Maybe<ParentLayerIntRegion>& aClipRegion,
                       const EventRegionsOverride& aOverride);
@@ -120,6 +121,7 @@ public:
   /* Returns the mOverride flag. */
   EventRegionsOverride GetEventRegionsOverride() const;
   const CSSTransformMatrix& GetTransform() const;
+  const LayerIntRegion& GetVisibleRegion() const;
 
   /* Debug helpers */
   void Dump(const char* aPrefix = "") const;
@@ -162,6 +164,8 @@ private:
    */
   EventRegions mEventRegions;
 
+  LayerIntRegion mVisibleRegion;
+
   /* This is the transform from layer L. This does NOT include any async
    * transforms. */
   CSSTransformMatrix mTransform;

gfx/layers/wr/WebRenderScrollData.cpp

@@ -37,6 +37,7 @@ WebRenderLayerScrollData::Initialize(WebRenderScrollData& aOwner,
   mTransform = aLayer->GetTransform();
   mTransformIsPerspective = aLayer->GetTransformIsPerspective();
   mEventRegions = aLayer->GetEventRegions();
+  mVisibleRegion = aLayer->GetVisibleRegion();
   mReferentId = aLayer->AsRefLayer()
       ? Some(aLayer->AsRefLayer()->GetReferentId())
       : Nothing();
@@ -71,6 +72,12 @@ WebRenderLayerScrollData::GetScrollMetadata(const WebRenderScrollData& aOwner,
   return aOwner.GetScrollMetadata(mScrollIds[aIndex]);
 }
 
+CSSTransformMatrix
+WebRenderLayerScrollData::GetTransformTyped() const
+{
+  return ViewAs<CSSTransformMatrix>(GetTransform());
+}
+
 WebRenderScrollData::WebRenderScrollData()
   : mIsFirstPaint(false)
 {

gfx/layers/wr/WebRenderScrollData.h

@@ -49,8 +49,10 @@ public:
 
   bool IsScrollInfoLayer() const { return mIsScrollInfoLayer; }
   gfx::Matrix4x4 GetTransform() const { return mTransform; }
+  CSSTransformMatrix GetTransformTyped() const;
   bool GetTransformIsPerspective() const { return mTransformIsPerspective; }
   EventRegions GetEventRegions() const { return mEventRegions; }
+  const LayerIntRegion& GetVisibleRegion() const { return mVisibleRegion; }
   Maybe<uint64_t> GetReferentId() const { return mReferentId; }
   EventRegionsOverride GetEventRegionsOverride() const { return mEventRegionsOverride; }
   const ScrollThumbData& GetScrollThumbData() const { return mScrollThumbData; }
@@ -81,6 +83,7 @@ private:
   gfx::Matrix4x4 mTransform;
   bool mTransformIsPerspective;
   EventRegions mEventRegions;
+  LayerIntRegion mVisibleRegion;
   Maybe<uint64_t> mReferentId;
   EventRegionsOverride mEventRegionsOverride;
   ScrollThumbData mScrollThumbData;
@@ -175,6 +178,7 @@ struct ParamTraits<mozilla::layers::WebRenderLayerScrollData>
     WriteParam(aMsg, aParam.mTransform);
     WriteParam(aMsg, aParam.mTransformIsPerspective);
     WriteParam(aMsg, aParam.mEventRegions);
+    WriteParam(aMsg, aParam.mVisibleRegion);
     WriteParam(aMsg, aParam.mReferentId);
     WriteParam(aMsg, aParam.mEventRegionsOverride);
     WriteParam(aMsg, aParam.mScrollThumbData);
@@ -193,6 +197,7 @@ struct ParamTraits<mozilla::layers::WebRenderLayerScrollData>
         && ReadParam(aMsg, aIter, &aResult->mTransform)
         && ReadParam(aMsg, aIter, &aResult->mTransformIsPerspective)
         && ReadParam(aMsg, aIter, &aResult->mEventRegions)
+        && ReadParam(aMsg, aIter, &aResult->mVisibleRegion)
         && ReadParam(aMsg, aIter, &aResult->mReferentId)
         && ReadParam(aMsg, aIter, &aResult->mEventRegionsOverride)
         && ReadParam(aMsg, aIter, &aResult->mScrollThumbData)

gfx/layers/wr/WebRenderScrollDataWrapper.h

@@ -257,6 +257,19 @@ public:
     return EventRegions();
   }
 
+  LayerIntRegion GetVisibleRegion() const
+  {
+    MOZ_ASSERT(IsValid());
+
+    if (AtBottomLayer()) {
+      return mLayer->GetVisibleRegion();
+    }
+
+    return ViewAs<LayerPixel>(
+        TransformBy(mLayer->GetTransformTyped(), mLayer->GetVisibleRegion()),
+        PixelCastJustification::MovingDownToChildren);
+  }
+
   Maybe<uint64_t> GetReferentId() const
   {
     MOZ_ASSERT(IsValid());