Re: [PATCH] ui/sdl2: Support multiple OpenGL-enabled windows

[Akihiko Odaki <akihiko.odaki@gmail.com>]

On 2023/06/07 19:29, Marc-André Lureau wrote:
> Hi Antonio
> 
> On Wed, Jun 7, 2023 at 1:13 PM Antonio Caggiano 
> <quic_acaggian@quicinc.com <mailto:quic_acaggian@quicinc.com>> wrote:
> 
>     Multiple graphics devices can be defined with an associated OpenGL
>     enabled SDL console, hence make sure to not destroy their shaders and
>     windows.

I guess you meant multiple graphics devices can be associated to an 
OpenGL-enabled console and a switch event from a device destroys the 
shared state, but I don't see anything that associates multiple devices 
to a single console.

> 
>     Signed-off-by: Antonio Caggiano <quic_acaggian@quicinc.com
>     <mailto:quic_acaggian@quicinc.com>>
>     ---
>       ui/sdl2-gl.c | 2 +-
>       1 file changed, 1 insertion(+), 1 deletion(-)
> 
>     diff --git a/ui/sdl2-gl.c b/ui/sdl2-gl.c
>     index bbfa70eac3..795fb1afc9 100644
>     --- a/ui/sdl2-gl.c
>     +++ b/ui/sdl2-gl.c
>     @@ -89,7 +89,7 @@ void sdl2_gl_switch(DisplayChangeListener *dcl,
> 
>           scon->surface = new_surface;
> 
>     -    if (is_placeholder(new_surface) &&
>     qemu_console_get_index(dcl->con)) {
>     +    if (is_placeholder(new_surface) && !scon->opengl) {
>               qemu_gl_fini_shader(scon->gls);
>               scon->gls = NULL;
>               sdl2_window_destroy(scon);
> 
> 
> This was introduced in commit c821a58ee7003c2a0567dddaee33c2a5ae71c404 
> by Akihiko.
> 
> Why should the window visibility behaviour be different whether it uses 
> opengl or not ?
> 
> If you are fixing a GL/shader crash, maybe it needs to be done differently.
> 
> thanks
> 
It does not make sense to check scon->opengl here; it should be always 
true when this function is called.

The condition qemu_console_get_index(dcl->con) should not be removed 
either. This keeps the first console persistent and makes sure the user 
can always interact with QEMU with the GUI SDL2 provides.

Regards,
Akihiko Odaki