backends: Add argument for best scale on MetaCursorSprite::prepare-at

Instead of letting implementations poke backend internals from various
places, give that information right away.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1403>

src/backends/meta-cursor-renderer.c

@@ -28,6 +28,8 @@
 
 #include <math.h>
 
+#include "backends/meta-backend-private.h"
+#include "backends/meta-logical-monitor.h"
 #include "backends/meta-stage-private.h"
 #include "clutter/clutter.h"
 #include "clutter/clutter-mutter.h"
@@ -332,6 +334,41 @@ meta_cursor_renderer_calculate_rect (MetaCursorRenderer *renderer,
   };
 }
 
+static float
+find_highest_logical_monitor_scale (MetaBackend      *backend,
+                                    MetaCursorSprite *cursor_sprite)
+{
+  MetaMonitorManager *monitor_manager =
+    meta_backend_get_monitor_manager (backend);
+  MetaCursorRenderer *cursor_renderer =
+    meta_backend_get_cursor_renderer (backend);
+  graphene_rect_t cursor_rect;
+  GList *logical_monitors;
+  GList *l;
+  float highest_scale = 0.0f;
+
+  cursor_rect = meta_cursor_renderer_calculate_rect (cursor_renderer,
+                                                     cursor_sprite);
+
+  logical_monitors =
+    meta_monitor_manager_get_logical_monitors (monitor_manager);
+  for (l = logical_monitors; l; l = l->next)
+    {
+      MetaLogicalMonitor *logical_monitor = l->data;
+      graphene_rect_t logical_monitor_rect =
+        meta_rectangle_to_graphene_rect (&logical_monitor->rect);
+
+      if (!graphene_rect_intersection (&cursor_rect,
+                                       &logical_monitor_rect,
+                                       NULL))
+        continue;
+
+      highest_scale = MAX (highest_scale, logical_monitor->scale);
+    }
+
+  return highest_scale;
+}
+
 static void
 meta_cursor_renderer_update_cursor (MetaCursorRenderer *renderer,
                                     MetaCursorSprite   *cursor_sprite)
@@ -340,9 +377,14 @@ meta_cursor_renderer_update_cursor (MetaCursorRenderer *renderer,
   gboolean handled_by_backend;
 
   if (cursor_sprite)
-    meta_cursor_sprite_prepare_at (cursor_sprite,
+    {
-                                   (int) priv->current_x,
+      float scale = find_highest_logical_monitor_scale (priv->backend,
-                                   (int) priv->current_y);
+                                                        cursor_sprite);
+      meta_cursor_sprite_prepare_at (cursor_sprite,
+                                     MAX (1, scale),
+                                     (int) priv->current_x,
+                                     (int) priv->current_y);
+    }
 
   handled_by_backend =
     META_CURSOR_RENDERER_GET_CLASS (renderer)->update_cursor (renderer,

src/backends/meta-cursor.c

@@ -179,11 +179,12 @@ meta_cursor_sprite_get_texture_transform (MetaCursorSprite *sprite)
 }
 
 void
-meta_cursor_sprite_prepare_at (MetaCursorSprite *sprite,
+meta_cursor_sprite_prepare_at (MetaCursorSprite   *sprite,
-                               int               x,
+                               float               best_scale,
-                               int               y)
+                               int                 x,
+                               int                 y)
 {
-  g_signal_emit (sprite, signals[PREPARE_AT], 0, x, y);
+  g_signal_emit (sprite, signals[PREPARE_AT], 0, best_scale, x, y);
 }
 
 void
@@ -226,7 +227,8 @@ meta_cursor_sprite_class_init (MetaCursorSpriteClass *klass)
                                       G_SIGNAL_RUN_LAST,
                                       0,
                                       NULL, NULL, NULL,
-                                      G_TYPE_NONE, 2,
+                                      G_TYPE_NONE, 3,
+                                      G_TYPE_FLOAT,
                                       G_TYPE_INT,
                                       G_TYPE_INT);
   signals[TEXTURE_CHANGED] = g_signal_new ("texture-changed",

src/backends/meta-cursor.h

@@ -43,6 +43,7 @@ struct _MetaCursorSpriteClass
 };
 
 void meta_cursor_sprite_prepare_at (MetaCursorSprite *sprite,
+                                    float             best_scale,
                                     int               x,
                                     int               y);
 

src/core/display.c

@@ -46,7 +46,6 @@
 #include "backends/meta-idle-monitor-dbus.h"
 #include "backends/meta-input-device-private.h"
 #include "backends/meta-input-settings-private.h"
-#include "backends/meta-logical-monitor.h"
 #include "backends/meta-stage-private.h"
 #include "backends/x11/meta-backend-x11.h"
 #include "backends/x11/meta-event-x11.h"
@@ -1629,43 +1628,9 @@ meta_cursor_for_grab_op (MetaGrabOp op)
   return META_CURSOR_DEFAULT;
 }
 
-static float
-find_highest_logical_monitor_scale (MetaBackend      *backend,
-                                    MetaCursorSprite *cursor_sprite)
-{
-  MetaMonitorManager *monitor_manager =
-    meta_backend_get_monitor_manager (backend);
-  MetaCursorRenderer *cursor_renderer =
-    meta_backend_get_cursor_renderer (backend);
-  graphene_rect_t cursor_rect;
-  GList *logical_monitors;
-  GList *l;
-  float highest_scale = 0.0;
-
-  cursor_rect = meta_cursor_renderer_calculate_rect (cursor_renderer,
-                                                     cursor_sprite);
-
-  logical_monitors =
-    meta_monitor_manager_get_logical_monitors (monitor_manager);
-  for (l = logical_monitors; l; l = l->next)
-    {
-      MetaLogicalMonitor *logical_monitor = l->data;
-      graphene_rect_t logical_monitor_rect =
-        meta_rectangle_to_graphene_rect (&logical_monitor->rect);
-
-      if (!graphene_rect_intersection (&cursor_rect,
-                                       &logical_monitor_rect,
-                                       NULL))
-        continue;
-
-      highest_scale = MAX (highest_scale, logical_monitor->scale);
-    }
-
-  return highest_scale;
-}
-
 static void
 root_cursor_prepare_at (MetaCursorSpriteXcursor *sprite_xcursor,
+                        float                    best_scale,
                         int                      x,
                         int                      y,
                         MetaDisplay             *display)
@@ -1675,14 +1640,11 @@ root_cursor_prepare_at (MetaCursorSpriteXcursor *sprite_xcursor,
 
   if (meta_is_stage_views_scaled ())
     {
-      float scale;
+      if (best_scale != 0.0f)
-
-      scale = find_highest_logical_monitor_scale (backend, cursor_sprite);
-      if (scale != 0.0)
         {
           float ceiled_scale;
 
-          ceiled_scale = ceilf (scale);
+          ceiled_scale = ceilf (best_scale);
           meta_cursor_sprite_xcursor_set_theme_scale (sprite_xcursor,
                                                       (int) ceiled_scale);
           meta_cursor_sprite_set_texture_scale (cursor_sprite,

src/wayland/meta-wayland-cursor-surface.c

@@ -81,6 +81,7 @@ update_cursor_sprite_texture (MetaWaylandCursorSurface *cursor_surface)
 
 static void
 cursor_sprite_prepare_at (MetaCursorSprite         *cursor_sprite,
+                          float                     best_scale,
                           int                       x,
                           int                       y,
                           MetaWaylandCursorSurface *cursor_surface)

src/wayland/meta-wayland-tablet-tool.c

@@ -395,6 +395,7 @@ tablet_tool_handle_cursor_surface_destroy (struct wl_listener *listener,
 
 static void
 tool_cursor_prepare_at (MetaCursorSpriteXcursor *sprite_xcursor,
+                        float                    best_scale,
                         int                      x,
                         int                      y,
                         MetaWaylandTabletTool   *tool)