[Spice-devel] [spice-gtk PATCH v2] spice-widget: init egl only after first gl_scanout

[Marc-André Lureau]

Hi

----- Original Message -----
> 
> ----- Original Message -----
> > When using GtkDrawingArea and EGL was not used, it was still initialized.
> > This produced warning messages on systems where EGL is not supported.
> 
> Not sure it's really a big problem since we require GL anyway.
> 
> Which system doesn't support egl?
> 
> For example when running the client in virtual machine.
> The point is, that we shouldn't initialize EGL, if we are not going to use
> it.

I thought gtk required gl anyway these days, doesn't it? it's quite minor imho, we could lower it to a debug message during init, and a critical if GL scanout is actually being used and EGL init failed.

> 
> > 
> > Move spice_egl_init from drawing_area_realize to gl_scanout.
> > Drawing_area_realize is no longer needed.
> > ---
> > Changes since v1:
> > - changed from recursive call to if check
> > - moved set_egl_enabled(display, true); after initialisation is finished
> > ---
> 
> Have you checked the behaviour on wayland?
> 
> Yes, it's working correctly in wayland.
> 
> 
> Because spice_egl_init() is already called in gl_area_realize in this case.
> 
> Well spice_egl_init() sets context_ready to true, so it should never be
> called twice.

Ok, I would keep it under the GDK_IS_X11_DISPLAY condition, not necessary to call it here when using gtkglarea.
 
> 
> Furthermore, there is no guarantee that the widget is realized when
> spice_display_widget_gl_scanout() is called, which would results in other
> warnings/criticals messages.
> 
> This could potentionally be a problem. Does spice_egl_realize_display()
> require the widget to be fully realized before the call?

Yes, on x11 at least, iirc, you must have a realized X window.

> Also wouldn't it be better, to move all of the EGL code to GtkGLArea, instead
> of GtkDrawArea even for X11?

It would, but unfortunately, gtkglarea doesn't use EGL on X11 (egl is needed to import the dmabuf). So we need this weird EGL on top of drawingarea code.