Support edge-inclusive intersections in mapToVisibleRectInAncestorSpace

third_party/WebKit/Source/platform/geometry/LayoutRect.cpp

 /*
  * Copyright (c) 2012, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 62 matching lines @@
     // Return a clean empty rectangle for non-intersecting cases.
     if (newLocation.x() >= newMaxPoint.x() || newLocation.y() >= newMaxPoint.y()) {
         newLocation = LayoutPoint();
         newMaxPoint = LayoutPoint();
     }
 
     m_location = newLocation;
     m_size = newMaxPoint - newLocation;
 }
 
+bool LayoutRect::inclusiveIntersect(const LayoutRect& other)
+{
+    LayoutPoint newLocation(std::max(x(), other.x()), std::max(y(), other.y()));
+    LayoutPoint newMaxPoint(std::min(maxX(), other.maxX()), std::min(maxY(), other.maxY()));
+
+    if (newLocation.x() > newMaxPoint.x() || newLocation.y() > newMaxPoint.y()) {
+        *this = LayoutRect();
+        return false;
+    }
+
+    m_location = newLocation;
+    m_size = newMaxPoint - newLocation;
+    return true;
+}
+
 void LayoutRect::unite(const LayoutRect& other)
 {
     // Handle empty special cases first.
     if (other.isEmpty())
         return;
     if (isEmpty()) {
         *this = other;
         return;
     }
 
@@ skipping 82 matching lines @@
 }
 
 LayoutRect enclosingLayoutRect(const FloatRect& rect)
 {
     LayoutPoint location = flooredLayoutPoint(rect.minXMinYCorner());
     LayoutPoint maxPoint = ceiledLayoutPoint(rect.maxXMaxYCorner());
     return LayoutRect(location, maxPoint - location);
 }
 
 } // namespace blink