[mutter/wip/carlosg/honor-pick-vmethod] clutter: Honor pick vmethod rectangle during region caching

[Carlos Garnacho <carlosg src gnome org>]

commit 92413a4ca37648648915a0eb4c37ee6a33aa354b
Author: Carlos Garnacho <carlosg gnome org>
Date:   Fri Feb 11 14:40:21 2022 +0100

    clutter: Honor pick vmethod rectangle during region caching
    
    We retrieve the picked actor's allocation for figuring out the pick
    cache clear area, but don't take into account that the pick vmethod
    might have returned a different area for it.
    
    Make sure to honor that rectangle, as that is what is accounted as
    the input region.
    
    Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/2135

 clutter/clutter/clutter-pick-stack.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)
---
diff --git a/clutter/clutter/clutter-pick-stack.c b/clutter/clutter/clutter-pick-stack.c
index c7d8a71b63..db5c8d385d 100644
--- a/clutter/clutter/clutter-pick-stack.c
+++ b/clutter/clutter/clutter-pick-stack.c
@@ -453,8 +453,8 @@ get_verts_rectangle (graphene_point3d_t     verts[4],
 
 static void
 calculate_clear_area (ClutterPickStack  *pick_stack,
+                      PickRecord        *pick_rec,
                       int                elem,
-                      ClutterActor      *actor,
                       cairo_region_t   **clear_area)
 {
   cairo_region_t *area = NULL;
@@ -462,7 +462,7 @@ calculate_clear_area (ClutterPickStack  *pick_stack,
   cairo_rectangle_int_t rect;
   int i;
 
-  clutter_actor_get_abs_allocation_vertices (actor,
+  clutter_actor_get_abs_allocation_vertices (pick_rec->actor,
                                              (graphene_point3d_t *) &verts);
   if (!get_verts_rectangle (verts, &rect))
     {
@@ -471,6 +471,13 @@ calculate_clear_area (ClutterPickStack  *pick_stack,
       return;
     }
 
+  rect.x += ceil (pick_rec->base.rect.x1);
+  rect.y += ceil (pick_rec->base.rect.y1);
+  rect.width =
+    MIN (rect.width, floor (pick_rec->base.rect.x2 - pick_rec->base.rect.x1));
+  rect.height =
+    MIN (rect.height, floor (pick_rec->base.rect.y2 - pick_rec->base.rect.y1));
+
   area = cairo_region_create_rectangle (&rect);
 
   for (i = elem + 1; i < pick_stack->vertices_stack->len; i++)
@@ -521,7 +528,7 @@ clutter_pick_stack_search_actor (ClutterPickStack          *pick_stack,
           ray_intersects_record (pick_stack, rec, point, ray))
         {
           if (clear_area)
-            calculate_clear_area (pick_stack, i, rec->actor, clear_area);
+            calculate_clear_area (pick_stack, rec, i, clear_area);
           return rec->actor;
         }
     }