Bug 56074 - WebKit r80210 reports 16-bit depth precision on machines that support 24 bit depth
: WebKit r80210 reports 16-bit depth precision on machines that support 24 bit ...
Status: UNCONFIRMED
: WebKit
WebGL
: 528+ (Nightly build)
: Macintosh Intel Mac OS X 10.6
: P2 Normal
Assigned To:
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:
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  Show dependency treegraph
 
Reported: 2011-03-09 22:26 PST by
Modified: 2014-01-09 20:27 PST (History)


Attachments
Side-by-side compare of WebKit nightly, Chrome 11 Dev, and FF4 on a late 2010 iMac (299.03 KB, image/png)
2011-03-11 20:54 PST, sheets@ashimaarts.com
no flags Details
Depth buffer precision test file (1.03 KB, text/html)
2011-03-11 20:56 PST, sheets@ashimaarts.com
no flags Details


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Description From 2011-03-09 22:26:57 PST
Firefox 4 and Chrome 11 dev on this machine both report DEPTH_BITS of 24. WebKit reports DEPTH_BITS of 16. Technically this satisfies the spec but delivers a subpar user experience. I haven't been able to reproduce this behavior on an early 2009 Mac Pro, a late 2010 MacBook Air, or a late 2009 MBP. I've only seen this on this iMac (notably with ATI GPU).

Hardware Overview:

  Model Name:    iMac
  Model Identifier:    iMac11,3

ATI Radeon HD 5750:

  Chipset Model:    ATI Radeon HD 5750
  Type:    GPU
  Bus:    PCIe
  PCIe Lane Width:    x16
  VRAM (Total):    1024 MB
  Vendor:    ATI (0x1002)
  Device ID:    0x68a1
  Revision ID:    0x0000
  ROM Revision:    113-B9710C-238
  EFI Driver Version:    01.00.417
  Displays:
iMac:
  Resolution:    2560 x 1440
  Pixel Depth:    32-Bit Color (ARGB8888)
  Main Display:    Yes
  Mirror:    Off
  Online:    Yes
  Built-In:    Yes
  Connection Type:    DisplayPort
------- Comment #1 From 2011-03-10 12:15:37 PST -------
What OS are you running?
------- Comment #2 From 2011-03-10 13:21:31 PST -------
(In reply to comment #1)
> What OS are you running?

System Software Overview:

  System Version:    Mac OS X 10.6.6 (10J567)
  Kernel Version:    Darwin 10.6.0
------- Comment #3 From 2011-03-10 14:08:44 PST -------
Would you mind attaching a quick test case that shows the reported depth?
------- Comment #4 From 2011-03-11 20:54:18 PST -------
Created an attachment (id=85566) [details]
Side-by-side compare of WebKit nightly, Chrome 11 Dev, and FF4 on a late 2010 iMac
------- Comment #5 From 2011-03-11 20:56:05 PST -------
Created an attachment (id=85567) [details]
Depth buffer precision test file

Also available at https://github.com/ashima/webgl-diagnostic/blob/master/depth.html