bug#54040: 29.0.50; Text becomes blurry on PGTK/Wayland

[Thomas Jost]

Le 18 février 2022 à 15:38 +08, Po Lu a écrit :
> The reason `cairo_surface_create_similar' doesn't work is that Emacs
> recently gained a feature that allows frames to have a transparent
> background with opaque text, and surfaces created that way don't work to
> preserve the alpha channel when copying bits, so going back to that is
> not a solution.

That makes sense, thanks a lot for the explanation :)

> Does this patch help?
>
> diff --git a/src/pgtkterm.c b/src/pgtkterm.c
> index 65408801cf..54b65ac54e 100644
> --- a/src/pgtkterm.c
> +++ b/src/pgtkterm.c
> @@ -2927,6 +2927,7 @@ pgtk_copy_bits (struct frame *f, cairo_rectangle_t 
> *src_rect,
>    cairo_t *cr;
>    GdkWindow *window;
>    cairo_surface_t *surface;  /* temporary surface */
> +  int scale;
>  
>    window = gtk_widget_get_window (FRAME_GTK_WIDGET (f));
>  
> @@ -2936,6 +2937,9 @@ pgtk_copy_bits (struct frame *f, cairo_rectangle_t 
> *src_rect,
>                                      FRAME_CR_SURFACE_DESIRED_HEIGHT
>                                      (f));
>  
> +  scale = gtk_widget_get_scale_factor (FRAME_GTK_WIDGET (f));
> +  cairo_surface_set_device_scale (surface, scale, scale);
> +
>    cr = cairo_create (surface);
>    cairo_set_source_surface (cr, FRAME_CR_SURFACE (f), -src_rect->x,
>                           -src_rect->y);

Yes, that seems to solve it for me!

-- 
Thomas