[Webkit-unassigned] [Bug 79553] New: WebGL apparently breaks position:relative elements

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=79553

           Summary: WebGL apparently breaks position:relative elements
           Product: WebKit
           Version: 528+ (Nightly build)
          Platform: All
               URL: http://www.snappymaria.com/webgl/toolbar-test/
        OS/Version: All
            Status: UNCONFIRMED
          Severity: Normal
          Priority: P2
         Component: WebGL
        AssignedTo: webkit-unassigned at lists.webkit.org
        ReportedBy: glslsurf at blinken.com


Created an attachment (id=128840)
 --> (https://bugs.webkit.org/attachment.cgi?id=128840&action=review)
Screenshot of bug, showing a half-hover effect

When WebGL is initialized, it interferes with the rendering of position:relative HTML elements.  For example:

http://www.snappymaria.com/webgl/toolbar-test/

In the above example, a toolbar with a series of buttons has been given a simple CSS :hover effect, so the button backgrounds are supposed to turn bright yellow when the mouse hovers over them.  But these buttons are also offset with position:relative, and this breaks the hover effect, causing the buttons not to render yellow correctly.  The amount of pixels that don't update appears to be equivalent to the size of the relative offset.

I've reproduced this in Chrome stable on both Windows and Macintosh, and also Safari/WebKit nightly on Macintosh after enabling WebGL.

A screenshot is attached of the half-hover effect produced by this bug, where half the button turns yellow and half does not.  The correct behavior can be seen when WebGL is disabled (and in Firefox with or without WebGL enabled), where the whole button turns solid yellow on hover.

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