[SDL] Is it forbidden to run SDL apps from X11 on the Pi?

Andreas Falkenhahn andreas at falkenhahn.com
Fri Sep 16 07:37:07 PDT 2016

On 15.09.2016 at 22:57 Eric Wing wrote:

> On 9/15/16, Andreas Falkenhahn <andreas at falkenhahn.com> wrote:
>> On 15.09.2016 at 00:37 Eric Wing wrote:

>>>> Is there no way to make SDL apps cooperate nicely with X11? If there
>>>> isn't,
>>>> I think it should *really*
>>>> be mentioned in the README that running SDL apps from X11 can have
>>>> disastrous consequences because
>>>> mouse clicks are forwarded to the desktop without the user noticing
>>>> because
>>>> the whole display is
>>>> filled by the SDL app...

>>> As I mentioned earlier in the other thread, if this really is
>>> important for you

>> Hmm, isn't it important for you too? I mean, what do you tell your Blurrr
>> users? Something like: "Blurrr supports the Pi but it only works without
>> X11"? ... not too convincing ;)

>>> you should try the official experimental OpenGL
>>> driver for Pi.
>>> https://www.raspberrypi.org/blog/another-new-raspbian-release/

>> Well, I think it's clear that we'll get proper OpenGL support on the Pi
>> sooner or later but still, I'm wondering whether the existing RPI backend
>> can't be modified to prevent input being routed through to X11. If this
>> could be done without going to great pains, why not do it? But as I said,
>> I'm not the one to judge/assess the feasability because I have no idea
>> what's going on under the hood.

>>> Since nobody else has tried it yet and reported back, we'd all be
>>> interested in hearing the details of how it works.

>> To tell you the truth, I'm not very keen on trying out experimental
>> things on Linux because I still consider myself a Linux beginner and
>> I think chances are high that I'll end up with a messed up system
>> after those tests and the only way out is a reinstall...

> The simple answer is that what you want is not possible without the
> experimental driver. That's why they have been developing the driver
> and made a big deal about it, and why I keep pointing you to it.

> As for making games, X11 in the background is a big tradeoff due to
> the memory consumption. Most games run exclusively and do not benefit
> from X11. Trading off constrained resources on the Pi is not a
> decision to be taken lightly. 

Ok, but such information should really go into the README for the Pi.
Currently, it sounds like the Pi backend can be run on top of X11.
There is no word on that the backend was specifically designed to run
without X11. It's mentioned that it "works without X11" but this sounds
more like a feature, not like a constraint...

Best regards,
 Andreas Falkenhahn                            mailto:andreas at falkenhahn.com

More information about the SDL mailing list