Account for perspective and preserve-3d in mapToVisualRectInAncestorSpace

third_party/WebKit/Source/core/layout/LayoutObject.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2011 Apple Inc.
  *               All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved.
  *               (http://www.torchmobile.com/)
@@ skipping 1259 matching lines @@
 
 LayoutRect LayoutObject::localVisualRect() const {
   NOTREACHED();
   return LayoutRect();
 }
 
 bool LayoutObject::mapToVisualRectInAncestorSpace(
     const LayoutBoxModelObject* ancestor,
     LayoutRect& rect,
     VisualRectFlags visualRectFlags) const {
+  TransformState transformState(TransformState::ApplyTransformDirection,
+                                FloatQuad(FloatRect(rect)));
+  bool retval = mapToVisualRectInAncestorSpaceInternal(ancestor, transformState,
+                                                       visualRectFlags);
+  transformState.flatten();
+  rect = LayoutRect(transformState.lastPlanarQuad().boundingBox());
+  return retval;
+}
+
+bool LayoutObject::mapToVisualRectInAncestorSpaceInternal(
+    const LayoutBoxModelObject* ancestor,
+    TransformState& transformState,
+    VisualRectFlags visualRectFlags) const {
   // For any layout object that doesn't override this method (the main example
   // is LayoutText), the rect is assumed to be in the parent's coordinate space,
   // except for container flip.
 
   if (ancestor == this)
     return true;
 
   if (LayoutObject* parent = this->parent()) {
     if (parent->isBox()) {
       LayoutBox* parentBox = toLayoutBox(parent);
 
       // Never flip for SVG as it handles writing modes itself.
-      if (!isSVG())
+      if (!isSVG()) {
+        transformState.flatten();
+        LayoutRect rect(transformState.lastPlanarQuad().boundingBox());
         parentBox->flipForWritingMode(rect);
+        transformState.setQuad(FloatQuad(FloatRect(rect)));
+      }
+
+      bool preserve3D = (parent->style()->preserves3D() && !parent->isText()) ||

[Xianzhu, 2017/03/03 01:24:42]

Ditto about !parent->isText().

[chrishtr, 2017/03/03 02:45:11]

I copied this conditional from:

https://cs.chromium.org/chromium/src/third_party/WebKit/Source/core/layout/La...

This is meant to cover inlines. Added here:

https://codereview.chromium.org/1516003003

+                        (style()->preserves3D() && !isText());
+
+      TransformState::TransformAccumulation accumulation =
+          preserve3D ? TransformState::AccumulateTransform
+                     : TransformState::FlattenTransform;
 
       if (parent != ancestor &&
-          !parentBox->mapScrollingContentsRectToBoxSpace(rect, visualRectFlags))
+          !parentBox->mapScrollingContentsRectToBoxSpace(
+              transformState, accumulation, visualRectFlags))
         return false;
     }
-    return parent->mapToVisualRectInAncestorSpace(ancestor, rect,
-                                                  visualRectFlags);
+    return parent->mapToVisualRectInAncestorSpaceInternal(
+        ancestor, transformState, visualRectFlags);
   }
   return true;
 }
 
 void LayoutObject::dirtyLinesFromChangedChild(LayoutObject*, MarkingBehavior) {}
 
 #ifndef NDEBUG
 
 void LayoutObject::showTreeForThis() const {
   if (node())
@@ skipping 951 matching lines @@
 }
 
 FloatQuad LayoutObject::localToAncestorQuadInternal(
     const FloatQuad& localQuad,
     const LayoutBoxModelObject* ancestor,
     MapCoordinatesFlags mode) const {
   // Track the point at the center of the quad's bounding box. As
   // mapLocalToAncestor() calls offsetFromContainer(), it will use that point
   // as the reference point to decide which column's transform to apply in
   // multiple-column blocks.
+  // TODO(chrishtr): the second argument to this constructor is unnecessary,
+  // since we never call lastPlanarPoint().
   TransformState transformState(TransformState::ApplyTransformDirection,
                                 localQuad.boundingBox().center(), localQuad);
   mapLocalToAncestor(ancestor, transformState, mode | ApplyContainerFlip);
   transformState.flatten();
 
   return transformState.lastPlanarQuad();
 }
 
 FloatPoint LayoutObject::localToAncestorPoint(
     const FloatPoint& localPoint,
@@ skipping 1247 matching lines @@
     const blink::LayoutObject* root = object1;
     while (root->parent())
       root = root->parent();
     root->showLayoutTreeAndMark(object1, "*", object2, "-", 0);
   } else {
     WTFLogAlways("%s", "Cannot showLayoutTree. Root is (nil)");
   }
 }
 
 #endif