Re: [PATCH v2 15/18] ui/sdl: try to instantiate the matching opengl renderer

[Marc-André Lureau]

Hi

On Fri, Mar 10, 2023 at 2:03 PM Daniel P. Berrangé <berrange@redhat.com> wrote:
>
> On Tue, Mar 07, 2023 at 03:56:34PM +0400, marcandre.lureau@redhat.com wrote:
> > From: Marc-André Lureau <marcandre.lureau@redhat.com>
> >
> > User can still bypass the QEMU choice with SDL_RENDER_DRIVER environment
> > variable. (for some reason, specifying a driver disables batching and
> > breaks rendering, so enable it explicitly)
>
> What problem is this change actually fixing ?  Can you explain here.

Simply that -display sdl,gl=es didn't actually use OpenGL ES without this.

Using OpenGL ES allows to use ANGLE, which works generally better than
Windows/OEM OpenGL.

>
> >
> > Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> > ---
> >  ui/sdl2.c | 11 +++++++++++
> >  1 file changed, 11 insertions(+)
> >
> > diff --git a/ui/sdl2.c b/ui/sdl2.c
> > index 592eca3e1c..e83ea53628 100644
> > --- a/ui/sdl2.c
> > +++ b/ui/sdl2.c
> > @@ -99,7 +99,18 @@ void sdl2_window_create(struct sdl2_console *scon)
> >                                           surface_width(scon->surface),
> >                                           surface_height(scon->surface),
> >                                           flags);
> > +    if (scon->opengl) {
> > +        const char *driver = "opengl";
> > +
> > +        if (scon->opts->gl == DISPLAYGL_MODE_ES) {
> > +            driver = "opengles2";
> > +        }
> > +
> > +        SDL_SetHint(SDL_HINT_RENDER_DRIVER, driver);
> > +        SDL_SetHint(SDL_HINT_RENDER_BATCHING, "1");
> > +    }
> >      scon->real_renderer = SDL_CreateRenderer(scon->real_window, -1, 0);
> > +
> >      if (scon->opengl) {
> >          scon->winctx = SDL_GL_CreateContext(scon->real_window);
> >      }
> > --
> > 2.39.2
> >
>
> With regards,
> Daniel
> --
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>
>


-- 
Marc-André Lureau