bugGNU Octave - Bugs: bug #42580, contour shows interconnections...


bug #42580: contour shows interconnections (AMD and Intel GPU)

Submitted by:  Andreas Weber <andy1978>
Submitted on:  Wed 18 Jun 2014 04:30:10 PM UTC  
Category:  Plotting with OpenGL Severity:  3 - Normal
Priority:  5 - Normal Item Group:  Incorrect Result
Status:  Works For Me Assigned to:  None
Originator Name:  Open/Closed:  Open
Release:  dev Operating System:  GNU/Linux

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( Jump to the original submission)

Wed 23 Dec 2015 06:15:43 PM UTC, comment #6:

I also see this with Intel i915 on a Lenovo E540. I tried to debug this in Darmstadt during OctConf 2015 and as far as I remember it looked like the problem is inside the tesselation routines and not an Octave bug.

Andreas Weber <andy1978>
Project Member
Tue 22 Dec 2015 04:27:49 PM UTC, comment #5:

I see this on Ubuntu 15.10 octave dev.
doug@speedy:~$ glxinfo |grep OpenGL
OpenGL vendor string: X.Org
OpenGL renderer string: Gallium 0.4 on AMD RS780 (DRM 2.43.0, LLVM 3.6.2)
OpenGL core profile version string: 3.3 (Core Profile) Mesa 11.0.2
OpenGL core profile shading language version string: 3.30
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile
OpenGL core profile extensions:
OpenGL version string: 3.0 Mesa 11.0.2
OpenGL shading language version string: 1.30
OpenGL context flags: (none)
OpenGL extensions:
OpenGL ES profile version string: OpenGL ES 3.0 Mesa 11.0.2
OpenGL ES profile shading language version string: OpenGL ES GLSL ES 3.00
OpenGL ES profile extensions:

(file #35842)

Doug Stewart <dastew>
Thu 19 Jun 2014 03:35:28 PM UTC, comment #4:

There are several possibilities. One is that this is related to bug #39370 (duplicate points added to start/end of contour level). More likely, it is due to differences in the OpenGL version or in to the implementation by AMD.

I am running OpenGL 2.1 on Intel hardware and don't see the problem.

Rik <rik5>
Project Administrator
Thu 19 Jun 2014 09:27:28 AM UTC, comment #3:

Yes, the machine with AMD GPU (at work) shows this issue too. Just tried at home with nvidia GPU and the problem doesn't occur.

However, even with nvidia GPU there are strange effects when moving the plot window outside the screen. While moving the windows back to center, the part that was outside the screen gets disturbed. If I stop moving the window the plot is redrawn and looks normal again.

Stefan Mahr <dac922>
Thu 19 Jun 2014 06:19:46 AM UTC, comment #2:

I was able to reproduce this on 2 different machines (but both AMD GPU)

dac922 was also able to reproduce the problem on his system.

Andreas Weber <andy1978>
Project Member
Thu 19 Jun 2014 01:59:30 AM UTC, comment #1:

This works for me, i.e., no problematical lines across the contour. Maybe try running 'run-octave -f' to make sure you are running without any initialization files. Also, what version of OpenGL are you using?

Rik <rik5>
Project Administrator
Wed 18 Jun 2014 04:30:10 PM UTC, original submission:

hg id 5eca3080c7cd

and move mouse over plot window or move the window to trigger the fl_window:draw routine and thus opengl_renderer::draw_patch. I guess the error happens here but I haven't enough time yet to debug it further. This also happens with graphics_toolkit qt when you move the window (moving the cursor over the figure doesn't call the redraw routine in qt)

You will see additional secants drawn in the color of the current patch. (attached some screenshots)

Andreas Weber <andy1978>
Project Member


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Attach Files:

Attached Files
file #35842:  testAMD.png added by dastew (21KiB - image/png)
file #31576:  sec1.png added by andy1978 (17KiB - image/png)
file #31577:  sec3.png added by andy1978 (16KiB - image/png)
file #31578:  sec5.png added by andy1978 (16KiB - image/png)
file #31579:  sec6.png added by andy1978 (16KiB - image/png)


Depends on the following items: None found

Items that depend on this one: None found


Carbon-Copy List
  • -email is unavailable- added by dastew (Updated the item)
  • -email is unavailable- added by dac922 (Posted a comment)
  • -email is unavailable- added by rik5 (Posted a comment)
  • -email is unavailable- added by andy1978 (Submitted the item)

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    Follow 10 latest changes.

    Date Changed by Updated Field Previous Value => Replaced by
    2019-01-24 mtmiller Carbon-CopyRemoved 80942 => -
    2015-12-23 andy1978 Summarycontour shows interconnections (AMD GPU) => contour shows interconnections (AMD and Intel GPU)
    2015-12-22 dastew Attached File- => Added testAMD.png, #35842
    2015-12-22 mtmiller Item GroupNone => Incorrect Result
        Summarycontour shows interconnections => contour shows interconnections (AMD GPU)
    2014-06-19 rik5 StatusNone => Works For Me
    2014-06-18 andy1978 Attached File- => Added sec1.png, #31576
        Attached File- => Added sec3.png, #31577
        Attached File- => Added sec5.png, #31578
        Attached File- => Added sec6.png, #31579

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