Bug 86816 - rendering artifacts with WebGL zombies
Summary: rendering artifacts with WebGL zombies
Alias: None
Product: Mesa
Classification: Unclassified
Component: Drivers/DRI/i965 (show other bugs)
Version: git
Hardware: Other All
: medium normal
Assignee: Intel 3D Bugs Mailing List
QA Contact: Intel 3D Bugs Mailing List
Depends on:
Reported: 2014-11-28 10:21 UTC by Tapani Pälli
Modified: 2017-08-05 12:16 UTC (History)
3 users (show)

See Also:
i915 platform:
i915 features:

screencapture (163.59 KB, image/jpeg)
2014-11-28 10:23 UTC, Tapani Pälli
sandybridge screenshot (175.13 KB, image/jpeg)
2015-01-16 12:02 UTC, Tapani Pälli
screenshot with Mesa 13.1.0-devel (git-8015746) (162.52 KB, image/jpeg)
2016-11-04 06:00 UTC, Tapani Pälli
attachment-13021-0.html (34 bytes, text/html)
2016-11-04 06:28 UTC, Matt Turner

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Description Tapani Pälli 2014-11-28 10:21:45 UTC
There's strange pattern and blue flickering dots within rendered image. Also a strange pink triangle at bottom:


To be honest, I did not try yet with other drivers so filing for Intel for now.
Comment 1 Tapani Pälli 2014-11-28 10:23:50 UTC
Created attachment 110160 [details]
Comment 2 Christoph Haag 2014-11-28 13:03:28 UTC
With intel it looks the same for me, with radeonsi there is no blue flickering: https://www.youtube.com/watch?v=KwV7KFndRoM
Comment 3 Kenneth Graunke 2014-11-30 03:32:59 UTC
Looks like a i965 fs backend optimization bug.  Running with INTEL_DEBUG=no16 removes the blue flickering for me, and disabling i965/fs optimizations fixes other misrendering.

Still has the weird pink triangle though.
Comment 4 Tapani Pälli 2015-01-16 12:02:59 UTC
Created attachment 112337 [details]
sandybridge screenshot

on SNB this is more visible, similar pattern though
Comment 5 Tapani Pälli 2015-05-21 11:52:25 UTC
With NIR this is *completely* broken, INTEL_DEBUG=no16 again fixes the situation.
Comment 6 Matt Turner 2016-11-03 21:59:57 UTC
Seems fixed. Tested on HSW.
Comment 7 Tapani Pälli 2016-11-04 06:00:04 UTC
Created attachment 127747 [details]
screenshot with Mesa 13.1.0-devel (git-8015746)

for me it still looks like in the attached screenshot, there's noise and the weird triangle on bottom
Comment 8 Matt Turner 2016-11-04 06:28:07 UTC
Created attachment 127748 [details]

On what hardware?
Comment 9 Tapani Pälli 2016-11-04 06:30:19 UTC
(In reply to Matt Turner from comment #8)
> Created attachment 127748 [details]
> attachment-13021-0.html
> On what hardware?

this is on Mesa DRI Intel(R) Haswell Desktop  (0x412)
Comment 10 Eero Tamminen 2016-11-04 10:32:19 UTC
I tried it on SKL GT2.  With Mesa 11.2 there are small white triangles at bottom left corner.  With Mesa git from few minutes ago, there's a large noisy triangle, and few smaller ones on top of each other (smaller triangles have larger noisy "pixels").  Same both with Firefox & Chromium.

I wasn't able to get working apitrace trace from Firefox, but I got one from Chromium.

When replaying the trace, Apitrace outputs several times following:
* message: api issue 4: FBO incomplete: Unsupported HW texture/renderbuffer format attached: MESA_FORMAT_RGB_FLOAT32
* message: api issue 5: FBO incomplete: driver marked FBO as incomplete [-1]
* warning: 0:1(12): warning: extension `GL_ARB_gpu_shader5' unsupported in vertex shader
Comment 11 Eero Tamminen 2016-11-04 11:26:21 UTC
(In reply to Eero Tamminen from comment #10)
> * warning: 0:1(12): warning: extension `GL_ARB_gpu_shader5' unsupported in
> vertex shader

This warning is both for vertex & fragment shaders.

This extension is GL 4.0 one, the GLES one is GL_OES_gpu_shader5, and that's only in GLES 3.2 (at least according to Mesa features.txt).  Neither is mentioned in WebGL extensions list:
Comment 12 Cipri Tom 2016-11-26 13:43:22 UTC

On Firefox 50 only, I am seeing this "GL_ARB_gpu_shader5" warning in an app that I am developing with THREEjs. However, I grep-ed for "*shader5*" and it's not used anywhere in the code (neither mine nor THREEjs). So where could this be coming from?

For reference, the `zombies` rendering shows like this: http://i.imgur.com/fdhPve9.png (along with its errors)

If relevant, I'm on Ubuntu 14.04.3 with :
OpenGL core profile version string: 3.1 (Core Profile) Mesa 10.1.3
OpenGL core profile shading language version string: 1.40
OpenGL version string: 3.0 Mesa 10.1.3
OpenGL shading language version string: 1.30

I have a Sandy Bridge i7-2670QM
Comment 13 Jakub Szuppe 2017-04-10 12:10:12 UTC
We are working on this issue at StreamComputing.
Comment 14 Jakub Szuppe 2017-06-08 08:04:04 UTC
Variable add is uninitialized before operation add += color = org = texture2D( map, uv ); (line 266 in webgl_zombies.html). Initializing add or changing that line to add = color = org = texture2D( map, uv ); fixes the problem.

(Setting glsl_zero_init=true before starting browser also fixes the problem.)

Kind regards,
Stream HPC Team
Comment 15 Tapani Pälli 2017-08-05 12:16:20 UTC
per comment #14 I'm resolving this as NOTOURBUG, thanks Jakub!

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