Bug 56074

Summary:

WebKit r80210 reports 16-bit depth precision on machines that support 24 bit depth

Product:

WebKit

Reporter:

sheets

Component:

WebGL

Assignee:

Nobody <webkit-unassigned>

Status:

RESOLVED CONFIGURATION CHANGED

Severity:

Normal

CC:

bfulgham, cmarrin, kbr, kkinnunen, zmo

Priority:

Version:

528+ (Nightly build)

Hardware:

Mac (Intel)

OS:

OS X 10.6

Attachments:

Description	Flags
Side-by-side compare of WebKit nightly, Chrome 11 Dev, and FF4 on a late 2010 iMac	none
Depth buffer precision test file	none

Description sheets 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 Chris Marrin 2011-03-10 12:15:37 PST

What OS are you running?

Comment 2 sheets 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 Chris Marrin 2011-03-10 14:08:44 PST

Would you mind attaching a quick test case that shows the reported depth?

Comment 4 sheets 2011-03-11 20:54:18 PST

Created attachment 85566 [details]
Side-by-side compare of WebKit nightly, Chrome 11 Dev, and FF4 on a late 2010 iMac

Comment 5 sheets 2011-03-11 20:56:05 PST

Created attachment 85567 [details]
Depth buffer precision test file

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