wayland: drop buffer scale for cursor as well

Could have been done in e32554cd57, but I
skipped it there. However, using viewporter is actually a win here.
There's been a longstanding issue in upstream wayland* exactly related
to this. I even forgot about cd7a7a1de8
which was made for this exactly problem and explains the random
spawn_cursor calls. Anyways, just not using buffer scale and instead
scaling the cursor surface via viewporter works just fine and completely
sidesteps this problem. This means we can drop the random looking
spawn_cursor calls and some additional checks.

*: https://gitlab.freedesktop.org/wayland/wayland/-/issues/194

video/out/wayland_common.c

@@ -870,7 +870,6 @@ static void output_handle_done(void *data, struct wl_output *wl_output)
      * geometry and scaling should be recalculated. */
     if (wl->current_output && wl->current_output->output == wl_output) {
         set_surface_scaling(wl);
-        spawn_cursor(wl);
         set_geometry(wl, false);
         prepare_resize(wl, 0, 0);
     }
@@ -934,7 +933,6 @@ static void surface_handle_enter(void *data, struct wl_surface *wl_surface,
 
     if (wl->scaling != wl->current_output->scale) {
         set_surface_scaling(wl);
-        spawn_cursor(wl);
         force_resize = true;
     }
 
@@ -1656,6 +1654,7 @@ static bool create_input(struct vo_wayland_state *wl)
 static int create_viewports(struct vo_wayland_state *wl)
 {
     wl->viewport = wp_viewporter_get_viewport(wl->viewporter, wl->surface);
+    wl->cursor_viewport = wp_viewporter_get_viewport(wl->viewporter, wl->cursor_surface);
     wl->osd_viewport = wp_viewporter_get_viewport(wl->viewporter, wl->osd_surface);
     wl->video_viewport = wp_viewporter_get_viewport(wl->viewporter, wl->video_surface);
 
@@ -1968,7 +1967,8 @@ static int set_cursor_visibility(struct vo_wayland_seat *s, bool on)
             int scale = MPMAX(wl->scaling, 1);
             wl_pointer_set_cursor(s->pointer, s->pointer_serial, wl->cursor_surface,
                                   img->hotspot_x / scale, img->hotspot_y / scale);
-            wl_surface_set_buffer_scale(wl->cursor_surface, scale);
+            wp_viewport_set_destination(wl->cursor_viewport, lround(img->width / scale),
+                                        img->height / scale);
             wl_surface_attach(wl->cursor_surface, buffer, 0, 0);
             wl_surface_damage_buffer(wl->cursor_surface, 0, 0, img->width, img->height);
         }
@@ -2085,12 +2085,11 @@ static void set_window_bounds(struct vo_wayland_state *wl)
 
 static int spawn_cursor(struct vo_wayland_state *wl)
 {
-    if (wl->cursor_shape_manager)
+    if (wl->allocated_cursor_scale == wl->scaling) {
         return 0;
-    if (wl->allocated_cursor_scale == wl->scaling)
+    } else if (wl->cursor_theme) {
-        return 0;
-    else if (wl->cursor_theme)
         wl_cursor_theme_destroy(wl->cursor_theme);
+    }
 
     const char *xcursor_theme = getenv("XCURSOR_THEME");
     const char *size_str = getenv("XCURSOR_SIZE");
@@ -2669,6 +2668,9 @@ void vo_wayland_uninit(struct vo *vo)
     if (wl->viewport)
         wp_viewport_destroy(wl->viewport);
 
+    if (wl->cursor_viewport)
+        wp_viewport_destroy(wl->cursor_viewport);
+
     if (wl->osd_viewport)
         wp_viewport_destroy(wl->osd_viewport);
 

video/out/wayland_common.h

@@ -133,6 +133,7 @@ struct vo_wayland_state {
     /* viewporter */
     struct wp_viewporter *viewporter;
     struct wp_viewport   *viewport;
+    struct wp_viewport   *cursor_viewport;
     struct wp_viewport   *osd_viewport;
     struct wp_viewport   *video_viewport;