Re: Flickering with Socket and Plug

[René Hansen <rene hansen-audio de>]

Hey Paul,

thanks for your remark. Since Steinberg released the technical preview 
of VST3 with Linux support, I try to port my synthesizer. The SDK 
contains a tiny host called EditorHost. It simply opens up the GUI 
editor of a plug-in. The host uses gtkmm (like my plug-in) and passes 
the socket_id resp. the window id to the plug-in.

Until I switched to Ubuntu 17.04 everything was running smooth already. 
Unfortunately it started flickering.

So, in case of Ardour the plug-in has to use gtkmm for building its GUI, 
right? Using another GUI framework is not possible.

OT: Any plans of having VST3 in Ardour for Linux?

René

On 26.09.2017 20:13, Paul Davis wrote:
> For whatever it's worth, I was working on a similar plugin situation 16 
> years ago.  I tried using plug+socket. Couldn't make it work. GTK+ 
> developers at the time told me to stop using it.
>
> We now get a Gtk::Widget* from a plugin and add that to our own Gtk::Window.
>
> On Tue, Sep 26, 2017 at 1:54 PM, René Hansen <rene hansen-audio de 
> <mailto:rene hansen-audio de>> wrote:
>
>     Hey Eric,
>
>         It looks like you are trying to paint a surface 100 times every
>         16ms.
>         Maybe not such a good thing to do.
>
>
>     Yes, I agree but that's on purpose in order to make the problem
>     *very* obvious ;) In one of my projects I draw round about 25
>     bitmaps (which partly overlap) onto the drawingarea. While some
>     mouse interaction takes place I need to redraw several times. This
>     results in flickering of all single bitmaps almost everytime I
>     redraw. It looks as if the drawingarea gets cleared before I finish
>     drawing my bitmaps.
>
>     > The plug and socket are separate programs. You would start your socket
>     > and add one or more plugs to it. Each plug is running as it's own
>     > process.
>
>     Yes, that's correct. But in the documentation of Gtk::Socket::add_id
>     it says:
>     "Adds an XEMBED client, such as a Gtk::Plug, to the Gtk::Socket.
>     The client may be in the same process or in a different process."
>
>     So I am of the assumption that both is possible. Either Socket and
>     Plug live in the same process or different processes. Is that correct?
>
>     Some details about my real world project (I hope it is not too
>     confusing). I have a host application (executable) which builds its
>     GUI with Gtk. Then I have a plug-in (shared object resp. .so file)
>     which also builds its GUI with Gtk. But the plug-ins GUI must be
>     shown by embedding it into the host application (like x11 is capable
>     of). So I pass the socket_id of the host to the plug-in so it can
>     connect by creating a plug. The plug-in lives inside the host
>     application's process. But it is also possible that the host creates
>     an extra process to let the plug-in run, but still, the GUI must be
>     shown inside the host application. Both scenarios are possible.
>
>     > There is some socket and plug test code at the following.
>     ...
>     > I just added a frame clock to the plug. If you are looking to animate a drawing in a plug that might be 
> of some help.
>
>     Thanks! I will have closer look and try to figure out how this works.
>
>     > If you are programming in C++, the gtkmm tutorial is very good.
>
>     Yes, I know this one, built it and let it run successfully. No
>     flickering. Afterwards I extended this example by having both socket
>     and plug in the same process. I added some idle call to the plug and
>     let it draw a bunch of bitmaps. It started flickering. Then I
>     removed all the gtkmm stuff in order to have plain Gtk code. And
>     this is the example I have put on my github ;)
>
>     Thanks for help. I will study your "plug2.c" example and see what I
>     will come up with.
>
>
>     René
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