Bug 56074

Summary: WebKit r80210 reports 16-bit depth precision on machines that support 24 bit depth
Product: WebKit Reporter: sheets
Component: WebGLAssignee: Nobody <webkit-unassigned>
Status: RESOLVED CONFIGURATION CHANGED    
Severity: Normal CC: bfulgham, cmarrin, kbr, kkinnunen, zmo
Priority: P2    
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

sheets
Reported 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
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 		no flags
Details
Depth buffer precision test file (1.03 KB, text/html)
2011-03-11 20:56 PST, sheets 		no flags
Details
View All Add attachment proposed patch, testcase, etc.
Chris Marrin
Comment 1 2011-03-10 12:15:37 PST
What OS are you running?
sheets
Comment 2 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
Chris Marrin
Comment 3 2011-03-10 14:08:44 PST
Would you mind attaching a quick test case that shows the reported depth?
sheets
Comment 4 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
sheets
Comment 5 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
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