[Qgis-developer] Future of the Globe plugin in QGIS 3 with Qt5

[Sandro Mani]

Hi

I've had a look recently at adding osgEarth 2.8 support (and produced a 
tentative patch [1]), however the rendering is completely broken. I've 
not had time to investigate yet, but it looks like osgEarth2.8 puts a 
hard minimum requirement on GLSL 3.30, i.e. debug log output:

FRAGMENT glCompileShader "main(fragment)" FAILED
FRAGMENT Shader "main(fragment)" infolog:
0:1(10): error: the compatibility profile is not supported
0:1(10): error: GLSL 3.30 is not supported. Supported versions are: 
1.10, 1.20, 1.30, 1.00 ES, and 3.00 ES

This makes me uncomfortable: I'm pretty sure many users running somewhat 
older distros or older hardware will hit this. So upgrading to osgEarth 
2.8 just for the sake of upgrading and braking the globe for many user 
is in my view not the best of plans.

Technically nothing speaks against building osgEarth2.7 against Qt5 (for 
clarity: osgEarth 2.7 supports Qt5 alread) and keeping that version 
packaged for the forseable future.

Alternatively, distros wanting to upgrade could keep osgEarth 2.7 
packaged as osgEarth27 and renaming library names (i.e. libosgEarthXXX 
-> libosgEarth27XXX) and the header dirs. Up to this point it would be 
fairly easy, the problem comes with osgPlugins - I'm not sure if it is 
possible to install multiple versions simultaneously in 
/usr/lib64/osgPlugins-3.4.0/ or similar.

Happy to hear other suggestions.

Best
Sandro

[1] https://smani.fedorapeople.org/osgEarth28.patch


On 28.09.2016 13:40, Sebastiaan Couwenberg wrote:
> As discussed in #15536 [0], osgEarth 2.8 has been released and requires
> OpenSceneGraph 3.4. The Debian packages for OSG 3.4 have switched to Qt5
> as has the Debian packaging for osgEarth 2.8.
>
> Unfortunately the Globe plugin only supports osgEarth 2.7 in QGIS 2.16
> (which both still use Qt4). And I've not been able to get an answer from
> Pirmin about the plans for the Globe plugin in QGIS 3 which will use Qt5.
>
> Currently most packages that depend on OpenSceneGraph in Debian use the
> OpenSceneGraph 3.2 packages, and those will remain available in the next
> Debian stable release (stretch). The OpenSceneGraph maintainers have now
> also move the OpenSceneGraph 3.4 packages to unstable to have it
> available alongside the 3.2 packages in stretch. [1]
>
> Because the QGIS 2.14 LTR packages in Debian lack support for osgEarth
> 2.7 in the Globe plugin, there is no need to keep the osgEarth package
> at version 2.7, it's only used by the upstream QGIS 2.16 packages.
>
> I'm considering moving the osgEarth 2.8 packages from experimental to
> unstable for inclusion in stretch, hoping that support for it will be
> added as part of the move to Qt5 in QGIS 3. Although based on my
> questions in the Redmine issue not being answered and prior experience
> with time needed to get support for osgEarth 2.7 in QGIS, I'm not seeing
> a bright future for the Globe plugin in QGIS 3 with Qt5 expecting it to
> be disabled for a long time until support for osgEarth 2.8 or later is
> added.
>
> If there is sufficient demand to keep osgEarth 2.7 in stretch for the
> sake of upstream users of the QGIS 2.x packages, I'm willing to keep the
> osgEarth 2.8 packages in experimental until stretch is released.
> Otherwise I'll move the osgEarth 2.8 packages to unstable for inclusion
> in stretch, breaking the Globe plugin in the upstream QGIS 2.16 packages.
>
> Please share your thoughts about the future of the Globe plugin in QGIS
> 3 with Qt5.
>
> [0] https://hub.qgis.org/issues/15536
> [1] https://lists.debian.org/debian-gis/2016/09/msg00022.html
>
> Kind Regards,
>
> Bas
>