[Webkit-unassigned] [Bug 82251] [chromium] Layers should should know their visibility outside their content bounds

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=82251





--- Comment #12 from Eric Penner <epenner at chromium.org>  2012-03-27 16:04:56 PST ---
(In reply to comment #10)

> I would need to be convinced that this could be a replacement for visibleRect.  It seems to me that we'd need to add a bunch of intersect(contentBounds()) calls elsewhere.

Well we still have the clipped visible rect already if it suffices for those cases. But otherwise we can just store both if we are repeating the calculation a lot... Each usage would need to pick the appropriate rect.

> I'm not sure that you really want the viewport.  What if a surface masks to bounds and something is animating inside of that? That's why I was thinking clip rect and not viewport.

Yeah, I thought of that right after my comment. Although primary concern still being that the target surface is at least clipped to the viewport (if not clipped further).

> > Simplified idea: visibility(Tile T) = distance outside target surface * visibility(closest tile in target surface)
> 
> That's along the lines of what I was thinking too.  If you project the target surface's clip rect into a FloatQuad in content space, you can make a prioritization function based on distance from tile rect to that projected clip rect, with the assumption that tiles that are closer to the clip rect will be visible first.  You might additionally be able to add in animation velocity as a second check and do a separating axes test to make sure that the tile rect will ever intersect the clip rect.

This was my thinking as well.

-- 
Configure bugmail: https://bugs.webkit.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.