From 1b29d265a8506ffeb0f0d01199ffa962c29d51d0 Mon Sep 17 00:00:00 2001
From: Georges Basile Stavracas Neto <georges.stavracas@gmail.com>
Date: Thu, 22 Oct 2020 19:34:51 -0300
Subject: [PATCH] clutter/stage: Remove cached pick mode

The cached pick mode never actually cached anything, since it is
always, unconditionally reset when painting. Furthermore, next
commits will cull out actors during pick, which makes the pick
stack uncacheable.

Remove the cached pick mode.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1520>
---
 clutter/clutter/clutter-stage.c | 52 +++++----------------------------
 1 file changed, 7 insertions(+), 45 deletions(-)

diff --git a/clutter/clutter/clutter-stage.c b/clutter/clutter/clutter-stage.c
index 430233534..3d2edf95e 100644
--- a/clutter/clutter/clutter-stage.c
+++ b/clutter/clutter/clutter-stage.c
@@ -124,9 +124,6 @@ struct _ClutterStagePrivate
   GTimer *fps_timer;
   gint32 timer_n_frames;
 
-  ClutterPickStack *pick_stack;
-  ClutterPickMode cached_pick_mode;
-
   ClutterStageState current_state;
 
   int update_freeze_count;
@@ -228,15 +225,6 @@ clutter_stage_get_preferred_height (ClutterActor *self,
     *natural_height_p = geom.height;
 }
 
-static void
-_clutter_stage_clear_pick_stack (ClutterStage *stage)
-{
-  ClutterStagePrivate *priv = stage->priv;
-
-  g_clear_pointer (&priv->pick_stack, clutter_pick_stack_unref);
-  priv->cached_pick_mode = CLUTTER_PICK_NONE;
-}
-
 static void
 clutter_stage_add_redraw_clip (ClutterStage          *stage,
                                cairo_rectangle_int_t *clip)
@@ -457,19 +445,12 @@ clutter_stage_do_paint_view (ClutterStage         *stage,
                              ClutterStageView     *view,
                              const cairo_region_t *redraw_clip)
 {
-  ClutterStagePrivate *priv = stage->priv;
   ClutterPaintContext *paint_context;
   cairo_rectangle_int_t clip_rect;
   g_autoptr (GArray) clip_frusta = NULL;
   graphene_frustum_t clip_frustum;
   int n_rectangles;
 
-  /* Any mode of painting/picking invalidates the pick cache, unless we're
-   * in the middle of building it. So we reset the cached flag but don't
-   * completely clear the pick stack.
-   */
-  priv->cached_pick_mode = CLUTTER_PICK_NONE;
-
   n_rectangles = redraw_clip ? cairo_region_num_rectangles (redraw_clip) : 0;
   if (redraw_clip && n_rectangles < MAX_FRUSTA)
     {
@@ -632,7 +613,6 @@ clutter_stage_hide (ClutterActor *self)
   ClutterStagePrivate *priv = CLUTTER_STAGE (self)->priv;
 
   g_assert (priv->impl != NULL);
-  _clutter_stage_clear_pick_stack (CLUTTER_STAGE (self));
   _clutter_stage_window_hide (priv->impl);
 
   CLUTTER_ACTOR_CLASS (clutter_stage_parent_class)->hide (self);
@@ -1100,31 +1080,23 @@ _clutter_stage_do_pick_on_view (ClutterStage     *stage,
                                 ClutterPickMode   mode,
                                 ClutterStageView *view)
 {
-  ClutterStagePrivate *priv = stage->priv;
+  g_autoptr (ClutterPickStack) pick_stack = NULL;
+  ClutterPickContext *pick_context;
   graphene_point3d_t p;
   graphene_ray_t ray;
   ClutterActor *actor;
 
   COGL_TRACE_BEGIN_SCOPED (ClutterStagePickView, "Pick (view)");
 
-  if (!priv->pick_stack || mode != priv->cached_pick_mode)
-    {
-      ClutterPickContext *pick_context;
+  pick_context = clutter_pick_context_new_for_view (view, mode);
 
-      _clutter_stage_clear_pick_stack (stage);
-
-      pick_context = clutter_pick_context_new_for_view (view, mode);
-
-      clutter_actor_pick (CLUTTER_ACTOR (stage), pick_context);
-      priv->pick_stack = clutter_pick_context_steal_stack (pick_context);
-      priv->cached_pick_mode = mode;
-
-      clutter_pick_context_destroy (pick_context);
-    }
+  clutter_actor_pick (CLUTTER_ACTOR (stage), pick_context);
+  pick_stack = clutter_pick_context_steal_stack (pick_context);
+  clutter_pick_context_destroy (pick_context);
 
   setup_ray_for_coordinates (stage, x, y, &p, &ray);
 
-  actor = clutter_pick_stack_search_actor (priv->pick_stack, &p, &ray);
+  actor = clutter_pick_stack_search_actor (pick_stack, &p, &ray);
   return actor ? actor : CLUTTER_ACTOR (stage);
 }
 
@@ -1334,8 +1306,6 @@ clutter_stage_finalize (GObject *object)
 
   g_array_free (priv->paint_volume_stack, TRUE);
 
-  _clutter_stage_clear_pick_stack (stage);
-
   if (priv->fps_timer != NULL)
     g_timer_destroy (priv->fps_timer);
 
@@ -1653,8 +1623,6 @@ clutter_stage_init (ClutterStage *self)
 
   priv->paint_volume_stack =
     g_array_new (FALSE, FALSE, sizeof (ClutterPaintVolume));
-
-  priv->cached_pick_mode = CLUTTER_PICK_NONE;
 }
 
 static void
@@ -2727,12 +2695,6 @@ clutter_stage_queue_actor_redraw (ClutterStage             *stage,
   CLUTTER_NOTE (CLIPPING, "stage_queue_actor_redraw (actor=%s, clip=%p): ",
                 _clutter_actor_get_debug_name (actor), clip);
 
-  /* Queuing a redraw or clip change invalidates the pick cache, unless we're
-   * in the middle of building it. So we reset the cached flag but don't
-   * completely clear the pick stack...
-   */
-  priv->cached_pick_mode = CLUTTER_PICK_NONE;
-
   if (!priv->pending_finish_queue_redraws)
     {
       GList *l;