[webkit-dev] nodeAtPoint is very confusing

[Eric Seidel]

Dave, Simon, and other rendering gurus:

bool RenderObject::nodeAtPoint(const HitTestRequest&, HitTestResult&
result, int _x, int _y, int tx, int ty, HitTestAction hitTestAction)

_x, _y, tx, ty are very confusing.

As far as I can tell, _x, _y are relative to the root layer (which can
change during hit-testing!) and tx, ty are more of the HTML "offset to
your parent" optimization which painting uses.

Can you explain what the best way to convert from _x, _y to local
coordinates?  And what I should rename _x, _y, and tx, ty to in a
forthcoming "make hit testing readable to normal humans" cleanup
patch?

Thanks again.

-eric