Bug 36892

Summary: oglc pxstore-gettex fails if texture-float enabled (luminance-related spec question)
Product: Mesa Reporter: fangxun <xunx.fang>
Component: Drivers/DRI/i965Assignee: Intel 3D Bugs Mailing List <intel-3d-bugs>
Status: CLOSED WONTFIX QA Contact:
Severity: minor    
Priority: low CC: eric
Version: git   
Hardware: All   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:
Attachments: pxstore-gettex output file

Description fangxun 2011-05-06 01:00:45 UTC 
Created attachment 46388 [details]
pxstore-gettex output file

System Environment:
--------------------------
Arch:           x86_64
Platform:     Sandybridge  
Libdrm:         (master)2.4.25
Mesa:           (master)fc30910c65e7ab078b900c29d2066e45d3edd8c2
Xf86_video_intel:(master)2.15.0-6-g67e5a74e997f199327f9115c7ba867df3c49da8d
Xserver:(master)xorg-server-1.10.0-257-g918a9c99cf2ebc73acb34b95f597904b93c690d9
Kernel: (drm-intel-next)daab1470018f025e0b1c8731dfb825ff421ffd9b


Bug detailed description:
-------------------------
With enable texture-float on Mesa, oglc case pxstore-gettex, pxtrans-gettex and pxconv-gettex failed on sandybridge and Ironlake.
Bisect shows 87478cd6e3e6349abc2688b390f8845d1e21af3d is the first bad commit commit 87478cd6e3e6349abc2688b390f8845d1e21af3d 
Author:     Eric Anholt <eric@anholt.net>
AuthorDate: Fri Apr 15 11:00:00 2011 -0700
Commit:     Eric Anholt <eric@anholt.net>
CommitDate: Wed Apr 20 10:35:42 2011 -0700

    intel: Add support for ARB_texture_float.

    For 1 and 2-channel formats the hardware only supports rendering to R
    and RG.  To do I and L render targets we just call them R and
    everything works out.  For A, we would need to rewrite the CC to do
    the alpha channel's blending on color instead, and send the fragment
    alpha down the red channel.  For LA, there doesn't seem to be any
    hope, because we can't do independent color/alpha blending while
    treating the LA surface as RG.


Reproduced steps:
------------------
1. start X
2. oglconform -z -s -suite all -v 2 -D 33 -test pxstore-gettex
Comment 1 Ian Romanick 2011-05-20 00:30:07 UTC 
Was Mesa built with or without --enable-texture-float?
Comment 2 fangxun 2011-05-20 00:33:31 UTC 
Mesa built with --enable-texture-float
Comment 3 Eric Anholt 2011-06-19 11:19:50 UTC 
Not a regression, just a new failure in new functionality.  oglconform is so awful.

Patch sent to mailing list.
Comment 4 Gordon Jin 2012-05-11 00:00:35 UTC 
(In reply to comment #3)
> Not a regression, just a new failure in new functionality.  oglconform is so
> awful.
> Patch sent to mailing list.

Eric, any update?
Comment 5 Eric Anholt 2012-09-25 15:22:07 UTC 
We're not convinced that oglconform's interpretation of the spec makes sense.

http://comments.gmane.org/gmane.comp.video.mesa3d.devel/27334
Comment 6 Gordon Jin 2015-06-16 02:40:57 UTC 
closing as won't fix.

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