ui/gtk: Add keep-aspect-ratio option

When aspect ratio of host window and that of guest display are not
aligned, we can either zoom the guest content to fill the whole host
window or add padding to respect aspect ratio of the guest. Add an
option keep-aspect-ratio to allow users to select their preferred
behavior in this case.

Suggested-by: BALATON Zoltan <balaton@eik.bme.hu>
Suggested-by: Kim, Dongwon <dongwon.kim@intel.com>
Signed-off-by: Weifeng Liu <weifeng.liu.z@gmail.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Tested-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20250601045245.36778-2-weifeng.liu.z@gmail.com>

1 files changed, 10 insertions, 2 deletions

diff --git a/ui/gtk.c b/ui/gtk.c
index 8c4a94c8f6..9104509ee1 100644
--- a/ui/gtk.c
+++ b/ui/gtk.c
@@ -828,8 +828,12 @@ void gd_update_scale(VirtualConsole *vc, int ww, int wh, int fbw, int fbh)
 
         sx = (double)ww / fbw;
         sy = (double)wh / fbh;
-
-        vc->gfx.scale_x = vc->gfx.scale_y = MIN(sx, sy);
+        if (vc->s->keep_aspect_ratio) {
+            vc->gfx.scale_x = vc->gfx.scale_y = MIN(sx, sy);
+        } else {
+            vc->gfx.scale_x = sx;
+            vc->gfx.scale_y = sy;
+        }
     }
 }
 /**
@@ -2328,6 +2332,10 @@ static GSList *gd_vc_gfx_init(GtkDisplayState *s, VirtualConsole *vc,
         s->free_scale = true;
     }
 
+    s->keep_aspect_ratio = true;
+    if (s->opts->u.gtk.has_keep_aspect_ratio)
+        s->keep_aspect_ratio = s->opts->u.gtk.keep_aspect_ratio;
+
     for (i = 0; i < INPUT_EVENT_SLOTS_MAX; i++) {
         struct touch_slot *slot = &touch_slots[i];
         slot->tracking_id = -1;