You are not logged in.

#1 2017-06-27 11:06:15

zenorogue
Member
Registered: 2017-06-27
Posts: 3

bad quality of OpenGL on Intel graphics

Hello,

I am using ArchLinux on a MacBook Air computer. I have discovered that apparently OpenGL does not work as good as it could, for example line smoothing does not seem to work (try the line-smooth demo from mesa-demos -- nothing changes when I disable line-smoothing with 's'). These work perfectly on the other OS (OSX) so this appears to be a problem with the drivers or my installation. Is there any way to fix this?

lspci | grep VGA returns:

00:02.0 VGA compatible controller: Intel Corporation Haswell-ULT Integrated Graphics Controller (rev 09)

glxinfo -B returns:

name of display: :0
display: :0  screen: 0
direct rendering: Yes
Extended renderer info (GLX_MESA_query_renderer):
    Vendor: Intel Open Source Technology Center (0x8086)
    Device: Mesa DRI Intel(R) Haswell Mobile  (0xa26)
    Version: 17.1.3
    Accelerated: yes
    Video memory: 1536MB
    Unified memory: yes
    Preferred profile: core (0x1)
    Max core profile version: 4.5
    Max compat profile version: 3.0
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 3.1
OpenGL vendor string: Intel Open Source Technology Center
OpenGL renderer string: Mesa DRI Intel(R) Haswell Mobile 
OpenGL core profile version string: 4.5 (Core Profile) Mesa 17.1.3
OpenGL core profile shading language version string: 4.50
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile

OpenGL version string: 3.0 Mesa 17.1.3
OpenGL shading language version string: 1.30
OpenGL context flags: (none)

OpenGL ES profile version string: OpenGL ES 3.1 Mesa 17.1.3
OpenGL ES profile shading language version string: OpenGL ES GLSL ES 3.10

Offline

#2 2017-06-27 11:18:39

Trilby
Inspector Parrot
Registered: 2011-11-29
Posts: 29,449
Website

Re: bad quality of OpenGL on Intel graphics

Is this a hybrid graphics system?  i.e., does the following give any output:

lspci | grep 3D

If this is an intel-only system, are you using the intel DDX (xf86-video-intel)?  If so, it's known to be problematic on a wide range of hardware and is often best removed (the modesetting driver in the kernel will take over and perform better in many cases).


"UNIX is simple and coherent..." - Dennis Ritchie, "GNU's Not UNIX" -  Richard Stallman

Offline

#3 2017-06-27 11:36:49

zenorogue
Member
Registered: 2017-06-27
Posts: 3

Re: bad quality of OpenGL on Intel graphics

lspci | grep 3D produces no output. I have uninstalled xf86-video-intel, no changes.

Offline

#4 2017-06-27 12:28:07

Lone_Wolf
Member
From: Netherlands, Europe
Registered: 2005-10-04
Posts: 11,868

Re: bad quality of OpenGL on Intel graphics

linesmooth appears to be trying to use Anti-Aliasing, which is not well supported on linux.

driconf allows to set some AA related options, are they active ?


Disliking systemd intensely, but not satisfied with alternatives so focusing on taming systemd.


(A works at time B)  && (time C > time B ) ≠  (A works at time C)

Offline

#5 2017-06-27 21:36:06

R00KIE
Forum Fellow
From: Between a computer and a chair
Registered: 2008-09-14
Posts: 4,734

Re: bad quality of OpenGL on Intel graphics

I have tested with the igpu (intel) and dgpu (amd) in my laptop and I can see what you mean. However what I think is going on is that the default anti-aliasing method may be different or do something different than what you were expecting.

For the amd card with the default values a difference can be seen very clearly, for the intel card if you increase the width of the lines you will also see that there is also a difference, just not as strong as with the amd card.


R00KIE
Tm90aGluZyB0byBzZWUgaGVyZSwgbW92ZSBhbG9uZy4K

Offline

#6 2017-06-29 09:42:29

zenorogue
Member
Registered: 2017-06-27
Posts: 3

Re: bad quality of OpenGL on Intel graphics

Indeed, the effect is visible when the line width is increased. I do not see any AA related options in driconf... I guess I will have to live with the bad narrow lines then. Thanks for the help!

(This was actually one of two problems that led me to thinking that something is wrong with the drivers -- another one was glFramebufferTexture not working, but it was enough to use glFramebufferTexture2D instead to fix this.)

Offline

Board footer

Powered by FluxBB