vo_opengl, osd: allow osc.lua to react faster on resizes

Glitches when resizing are still possible, but are reduced. Other VOs
could support this too, but don't need to do so.

(Totally avoiding glitches would be much more effort, and probably not
worth the trouble. How about you just watch the video the player is
playing, instead of spending your time resizing the window.)

2 files changed, 30 insertions, 6 deletions

diff --git a/sub/osd.c b/sub/osd.c
index e37b6cf106..bbc6d9a1e1 100644
--- a/sub/osd.c
+++ b/sub/osd.c
@@ -212,6 +212,33 @@ void osd_set_external2(struct osd_state *osd, struct sub_bitmaps *imgs)
     pthread_mutex_unlock(&osd->lock);
 }
 
+static void check_obj_resize(struct osd_state *osd, struct mp_osd_res res,
+                             struct osd_object *obj)
+{
+    if (!osd_res_equals(res, obj->vo_res)) {
+        obj->vo_res = res;
+        obj->force_redraw = true;
+        mp_client_broadcast_event(mp_client_api_get_core(osd->global->client_api),
+                                  MP_EVENT_WIN_RESIZE, NULL);
+    }
+}
+
+// Optional. Can be called for faster reaction of OSD-generating scripts like
+// osc.lua. This can achieve that the resize happens first, so that the OSD is
+// generated at the correct resolution the first time the resized frame is
+// rendered. Since the OSD doesn't (and can't) wait for the script, this
+// increases the time in which the script can react, and also gets rid of the
+// unavoidable redraw delay (though it will still be racy).
+// Unnecessary for anything else.
+void osd_resize(struct osd_state *osd, struct mp_osd_res res)
+{
+    pthread_mutex_lock(&osd->lock);
+    int types[] = {OSDTYPE_OSD, OSDTYPE_EXTERNAL, OSDTYPE_EXTERNAL2, -1};
+    for (int n = 0; types[n] >= 0; n++)
+        check_obj_resize(osd, res, osd->objs[types[n]]);
+    pthread_mutex_unlock(&osd->lock);
+}
+
 static void render_object(struct osd_state *osd, struct osd_object *obj,
                           struct mp_osd_res res, double video_pts,
                           const bool sub_formats[SUBBITMAP_COUNT],
@@ -226,12 +253,7 @@ static void render_object(struct osd_state *osd, struct osd_object *obj,
 
     *out_imgs = (struct sub_bitmaps) {0};
 
-    if (!osd_res_equals(res, obj->vo_res)) {
-        obj->vo_res = res;
-        obj->force_redraw = true;
-        mp_client_broadcast_event(mp_client_api_get_core(osd->global->client_api),
-                                  MP_EVENT_WIN_RESIZE, NULL);
-    }
+    check_obj_resize(osd, res, obj);
 
     if (obj->type == OSDTYPE_SUB || obj->type == OSDTYPE_SUB2) {
         if (obj->sub) {
diff --git a/sub/osd.h b/sub/osd.h
index 494b534d5e..0c9dbc3e90 100644
--- a/sub/osd.h
+++ b/sub/osd.h
@@ -176,6 +176,8 @@ void osd_draw_on_image_p(struct osd_state *osd, struct mp_osd_res res,
                          double video_pts, int draw_flags,
                          struct mp_image_pool *pool, struct mp_image *dest);
 
+void osd_resize(struct osd_state *osd, struct mp_osd_res res);
+
 struct mp_image_params;
 struct mp_osd_res osd_res_from_image_params(const struct mp_image_params *p);