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<p>Hi Robert<br>
</p>
<div class="moz-cite-prefix">On 21.08.2017 17:08, Robert Osfield
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAFN7Y+Xf5BiZ53vpPmBhkfhdJU1CSVrCDfOEoNYAHVEGswg9PQ@mail.gmail.com">
<div dir="ltr">Hi Sandro,<br>
<div class="gmail_extra"><br>
<div class="gmail_quote">On 21 August 2017 at 15:21, Sandro
Mani <span dir="ltr"><<a
href="mailto:manisandro@gmail.com" target="_blank"
moz-do-not-send="true">manisandro@gmail.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left:1px solid
rgb(204,204,204);padding-left:1ex">
<div bgcolor="#FFFFFF">OpenGL renderer string: Mesa DRI
Intel(R) HD Graphics 530 (Skylake GT2) <br>
OpenGL core profile version string: 4.5 (Core Profile)
Mesa 17.2.0-rc4<br>
OpenGL core profile shading language version string:
4.50 </div>
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<div><br>
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<div>Is there a reason why the driver isn't just directly
supporting the GL features that osgEarth is using? Is the
Intel/Mesa driver limiting features in some way?<br>
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</blockquote>
Someone please correct me if I'm using the wrong terminology, but as
far as I understand mesa (possibly restricted to the intel mesa
drivers, but possibly also others such as ati and nouveau) only
exposes GL3.2+ functionality through the corresponding core profile.
Compatibility profile is only implemented up to GL3.0 on my system:<br>
<br>
Vendor: Intel Open Source Technology Center (0x8086)<br>
Device: Mesa DRI Intel(R) HD Graphics 530 (Skylake GT2)
(0x191b)<br>
Version: 17.2.0<br>
Accelerated: yes<br>
Video memory: 3072MB<br>
Unified memory: yes<br>
Preferred profile: core (0x1)<br>
Max core profile version: 4.5<br>
Max compat profile version: 3.0<br>
Max GLES1 profile version: 1.1<br>
Max GLES[23] profile version: 3.2<br>
<br>
<br>
<blockquote type="cite"
cite="mid:CAFN7Y+Xf5BiZ53vpPmBhkfhdJU1CSVrCDfOEoNYAHVEGswg9PQ@mail.gmail.com">
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<div class="gmail_extra">
<div class="gmail_quote">
<div><br>
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<div>Have you tried on an NVIdia or AMD system?<br>
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</blockquote>
No, but if I'm not mistaken they have a full(?) compatibility
profile.<br>
<blockquote type="cite"
cite="mid:CAFN7Y+Xf5BiZ53vpPmBhkfhdJU1CSVrCDfOEoNYAHVEGswg9PQ@mail.gmail.com">
<div dir="ltr">
<div class="gmail_extra">
<div class="gmail_quote">
<div><br>
</div>
<div>FYI, I'm using NVidia under Kubunty 16.04 as my main
build system and routinely mix latest GL features with
just creating a normal graphics context, <br>
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<br>
<blockquote class="gmail_quote" style="margin:0px 0px 0px
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<div bgcolor="#FFFFFF"><span class="gmail-">
<blockquote type="cite">
<div dir="ltr">
<div class="gmail_extra"><br>
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<div class="gmail_extra">Are the osgEarth team
aware of the issues you've had?<br>
<br>
</div>
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</blockquote>
</span> I once asked before investigating [1] but no-one
reacted, I suppose they are mostly using Windows. Now I
have a better understanding of the underlying issues
(and indeed of what was missing in OSG itself), but
before reporting issues to the osgEarth team I'd like to
understand what the correct approach should be (if
indeed they are doing something wrong).<br>
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<div><br>
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<div>My guess is that they probably haven't used Linix+Intel
with the drivers that you are using so haven't come across
the issue. Real-time graphics under Linux has tended to
mostly done with NVidia as Intel and AMD have had
sub-standard GL drivers for looooong time.<br>
<br>
</div>
<div>I suspect it's not really a case of the osgEarth team
doing something wrong, but the Linux+Intel drivers adding
a new constraint for keeping things working sweetly.</div>
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</blockquote>
I don't think it's adding a constraint, rather than the mesa
developers focusing first on adding support for extensions required
to expose the newest possible version in the core profile, and then
working on the compatibility profile as time allows.<br>
<blockquote type="cite"
cite="mid:CAFN7Y+Xf5BiZ53vpPmBhkfhdJU1CSVrCDfOEoNYAHVEGswg9PQ@mail.gmail.com">
<div dir="ltr">
<div class="gmail_extra">
<div class="gmail_quote">
<div><br>
<div>I'm starting to wonder if you aren't hitting upon the
same issues that Apple OSG users have had with Apple's
decision to only support OpenGL 3+ features on a
graphics context without compatibility. While it seems
a uncontroversial decision at first glance it's ended up
being a real pain for OpenGL users needing to maintain
long lived applications that happen to rely upon both
newer features when available as well as old fixed
function pipeline features. The Apple approach is fine
for clean room application written recently such as new
games but crap for the many companies that develop
software that has a useful life that's over a decade
long.<br>
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</blockquote>
It is likely that the issues are of similar nature yes. But since,
with the changes from the PR + the proposed DisplaySettings change,
I'm able to run osgEarth fine on this system, I'd say the situation
is not that bad here, it's just a matter of clarifying how the
profile version should be set.<br>
<br>
Sandro<br>
<br>
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