Bug 63469

Summary:	OSMesa Gallium llvmpipe VTK Test Failures
Product:	Mesa	Reporter:	Kevin Hobbs <hobbsk>
Component:	Drivers/Gallium/llvmpipe	Assignee:	mesa-dev
Status:	RESOLVED MOVED	QA Contact:
Severity:	normal
Priority:	medium
Version:	git
Hardware:	x86-64 (AMD64)
OS:	Linux (All)
Whiteboard:
i915 platform:		i915 features:

Description Kevin Hobbs 2013-04-12 12:50:48 UTC

Since OSMesa switched to Gallium and defaults to the llvmpipe driver VTK's test :

  vtkRenderingOpenGLCxx-TestTransformCoordinateUseDouble

has been failing.

This test has a page on VTK's dashboard :

  http://open.cdash.org/testSummary.php?project=11&name=vtkRenderingOpenGLCxx-TestTransformCoordinateUseDouble&date=2013-04-12

The take home message is that the test passes in my OSMesa-9.1.1 build which uses the Mesa Offscreen driver and fails on all of the builds that use the llvmpipe driver.

I played around with different drivers by setting GALLIUM_DRIVER to one llvmpipe or softpipe and used on screen and off screen builds of VTK. I set LIBGL_ALWAYS_SOFTWARE to get one of the software drivers or left it unset to use the nouveau driver on my on screen build. What I got was :

OSMesa-9.1.1 offscreen pass
OSMesa-git   softpipe  pass
OSMesa-git   llvmpipe  fail
  Mesa-9.1.1 softpipe  pass
  Mesa-9.1.1 nouveau   pass
  Mesa-9.1.1 llvmpipe  fail
  Mesa-git   softpipe  pass
  Mesa-git   nouveau   pass
  Mesa-git   llvmpipe  fail

which says that llvmpipe is the issue.

I did a bunch of apitraces and put them here :

http://crab-lab.zool.ohiou.edu/kevin/vtk_apitraces.tar.bz2

Comment 1 Brian Paul 2013-04-20 18:35:34 UTC

Thanks for the traces.  It appears that we've got the sub-pixel positioning of lines incorrect in llvmpipe.  Softpipe matches NVIDIA's driver but llvmpipe is off by a half pixel both in x and y.  I'm digging into it.

Comment 2 GitLab Migration User 2019-09-18 18:31:19 UTC

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