Re: Upcoming Qt switch to OpenGL ES on arm64
On Thursday 22 November 2018 19:17:29 Lisandro Damián Nicanor Pérez Meyer
wrote:
> Hi! Please let me reply first to your last part:
> > Is there any possible way to support *BOTH* OpenGL / OpenGLES?
> > Mutually exclusive from an install POV, but give the end user the
> > choice which to install? Why should we have one Architecture forced
> > down a path different to another architecture?
>
> No, I'm afraid there is no way to do that. We did consider it many
> times, but is definitely too much work to hack on.
>
> So we need to force an architecture (actually, all of them!) to either
> one or the other.
>
> El jueves, 22 de noviembre de 2018 20:04:33 -03 Andy Simpkins escribió:
> > On 22/11/18 22:33, Lisandro Damián Nicanor Pérez Meyer wrote:
> > > El jueves, 22 de noviembre de 2018 15:37:29 -03 Dmitry Shachnev
escribió:
> > >> Hi all!
> > >>
> > >> The Qt framework can be built either with “desktop” OpenGL, or
> > >> with OpenGL
> > >> ES support. At the moment we are building it with OpenGL ES on
> > >> armel and armhf, and with desktop OpenGL on all other
> > >> architectures
> > >
> > > Maybe we missed to properly explain the main point of this change:
> > > currently most arm64 boards are using software rasterization
> > > because their video cards do not support Desktop OpenGL.
> >
> > I am not sure that is correct. I certainly don't agree...
> >
> > There is no special case here. If you have a video card in your
> > ARM64 PC then it is likely the same video card that you have for an
> > AMD64 PC - i.e. it is an off the shelf PCIe card.
> >
> > Now it is correct that there is a large number of ARM64 based SoC
> > solutions out there with an embedded GPU - these are aimed mainly at
> > the mobile market (but as the computational power in these SoCs
> > increases we are already seeing that is enough for a lot of peoples
> > 'PC' needs)
> >
> > I guess what I am trying to say here is the GPU architecture is NOT
> > tied to the CPU architecture.
>
> - GPU architecture is not tied to the arch: right.
> - Qt is tied to either Desktop or GLES: yes
>
> So we need to pick one. The question is then which one will benefit
> our users most.
>
> So far I personally know 0 people with an arm64 board with PCI slots,
> while I know many with arm64 boards with hardware GLES support.
>
> > If we switch to GLES then most amr64 boards
> >
> > > will be able to render using their video hardware, thus greatly
> > > improving speed to the point of being actually usable for some
> > > stuff.
> > >
> > > I imagine (but would *love* hard data) that any PCI video card
> > > added to an arm64 machine will probably also support GLES, so they
> > > will still have use.
> >
> > So <sarcasm>
> > any PCI video card added to s/amr64/AMD64 machine will probably also
> > support GLES, so they will still have use.
> > OK that is true - lets enact this across ALL architectures, but I
> > suspect that there may be a bit of pushback from the AMD64 heavy
> > graphic users...
> > </sarcasm>
>
> No need to use sarcasm. Yes, it's a matter of choice. No one noted yet
> that all archs except armel and armhf have Desktop support and not
> GLES. And this is because, so far and to the best of our knowledge,
> that has been the right thing to do.
>
> So: what's the best outcome for our *current* users? Again, pick only
> one.
And that is something you probably won't have the power to do, because
the huge majority of these things are being designed by engineers
looking for the most bang for the buck, and coming up thru the schools
all run by M$ or Apple. Linux is simply not even on their radar.
But, what you do do, makes or breaks their success in doing things that
only linux can do best. Windows has no possibility of a realtime kernel,
linux does, has several choices depending on just how realtime you want.
Windows hasn't figured out what this thing called SPI is yet that I've
heard about.
One LinuxCNC driver has SPI figured out, and you can find it in the
LinuxCNC srcs as rpspi.c, but the professor that wrote it, with me and
my pi 3b, driving a 70 yo Sheldon 11x36 Lathe as lab rats to test it,
also wrote it so it only runs on an r-pi-3b. Fixing it to build and run
on another platform with a different, probably broadcom gpio driver
headers would be a very welcome addition to the arm toolbox as a whole,
but is beyond my well aged wet ram's ability at my age.
Now, I'll go play Al Capp from the comic strip and shaddup.
--
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>
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