Re: [PATCH 2/2] winex11.drv: Make the GL context current even if no drawables were given.

[Alexandre Julliard]

Charles Davis <cdavis5x(a)gmail.com> writes:
> @@ -1833,26 +1833,29 @@ static BOOL glxdrv_wglMakeCurrent(HDC hdc, struct wgl_context *ctx)
>          return TRUE;
>      }
>
> -    if ((gl = get_gl_drawable( WindowFromDC( hdc ), hdc )))
> +    if (!hdc || (gl = get_gl_drawable( WindowFromDC( hdc ), hdc )))
>      {
> -        if (ctx->fmt != gl->format)
> +        if (gl && ctx->fmt != gl->format)
>          {
>              WARN( "mismatched pixel format hdc %p %p ctx %p %p\n", hdc, gl->format, ctx, ctx->fmt );
>              SetLastError( ERROR_INVALID_PIXEL_FORMAT );
>              goto done;
>          }
>
> -        TRACE("hdc %p drawable %lx fmt %p ctx %p %s\n", hdc, gl->drawable, gl->format, ctx->ctx,
> -              debugstr_fbconfig( gl->format->fbconfig ));
> +        if (gl)
> +            TRACE("hdc %p drawable %lx fmt %p ctx %p %s\n", hdc, gl->drawable, gl->format, ctx->ctx,
> +                  debugstr_fbconfig( gl->format->fbconfig ));
> +        else
> +            TRACE("ctx %p (no drawable)\n", ctx->ctx);
>
> -        ret = pglXMakeCurrent(gdi_display, gl->drawable, ctx->ctx);
> +        ret = pglXMakeCurrent(gdi_display, gl ? gl->drawable : None, ctx->ctx);
>          if (ret)
>          {
>              NtCurrentTeb()->glContext = ctx;
>              ctx->has_been_current = TRUE;
>              ctx->hdc = hdc;
> -            ctx->drawables[0] = gl->drawable;
> -            ctx->drawables[1] = gl->drawable;
> +            ctx->drawables[0] = gl ? gl->drawable : 0;
> +            ctx->drawables[1] = gl ? gl->drawable : 0;

You really want a separate code path instead of adding pointer checks
everywhere.

-- 
Alexandre Julliard
julliard(a)winehq.org

[PATCH 2/2] winex11.drv: Make the GL context current even if no drawables were given.

[Ken Thomases]

On Feb 23, 2016, at 3:07 AM, Alexandre Julliard <julliard(a)winehq.org> wrote:
> Charles Davis <cdavis5x(a)gmail.com> writes:
> > @@ -1833,26 +1833,29 @@ static BOOL glxdrv_wglMakeCurrent(HDC hdc, struct wgl_context *ctx)
> >         return TRUE;
> >     }
> >
> > -    if ((gl = get_gl_drawable( WindowFromDC( hdc ), hdc )))
> > +    if (!hdc || (gl = get_gl_drawable( WindowFromDC( hdc ), hdc )))
> >     {
> > -        if (ctx->fmt != gl->format)
> > +        if (gl && ctx->fmt != gl->format)
> >         {
> >             WARN( "mismatched pixel format hdc %p %p ctx %p %p\n", hdc, gl->format, ctx, ctx->fmt );
> >             SetLastError( ERROR_INVALID_PIXEL_FORMAT );
> >             goto done;
> >         }
> >
> > -        TRACE("hdc %p drawable %lx fmt %p ctx %p %s\n", hdc, gl->drawable, gl->format, ctx->ctx,
> > -              debugstr_fbconfig( gl->format->fbconfig ));
> > +        if (gl)
> > +            TRACE("hdc %p drawable %lx fmt %p ctx %p %s\n", hdc, gl->drawable, gl->format, ctx->ctx,
> > +                  debugstr_fbconfig( gl->format->fbconfig ));
> > +        else
> > +            TRACE("ctx %p (no drawable)\n", ctx->ctx);
> >
> > -        ret = pglXMakeCurrent(gdi_display, gl->drawable, ctx->ctx);
> > +        ret = pglXMakeCurrent(gdi_display, gl ? gl->drawable : None, ctx->ctx);
> >         if (ret)
> >         {
> >             NtCurrentTeb()->glContext = ctx;
> >             ctx->has_been_current = TRUE;
> >             ctx->hdc = hdc;
> > -            ctx->drawables[0] = gl->drawable;
> > -            ctx->drawables[1] = gl->drawable;
> > +            ctx->drawables[0] = gl ? gl->drawable : 0;
> > +            ctx->drawables[1] = gl ? gl->drawable : 0;
>
> You really want a separate code path instead of adding pointer checks
> everywhere.

Not to mention that if hdc is NULL, then gl is just uninitialized and all of those checks are invalid, as is the release_gl_drawable() call at the end of the function.

That said, some of the existing code path can be shared by creating a "drawable" variable (of type Drawable).

-Ken