shaped-texture: Move unobscured_region processing here

We want to remove a bunch of auxilliary duties from the MetaWindowActor
and MetaSurfaceActor, including some details of how culling is done.
Move the unobscured region culling code to the MetaShapedTexture, which
helps the actor become "more independent".

https://bugzilla.gnome.org/show_bug.cgi?id=720631

src/compositor/meta-shaped-texture-private.h

@@ -32,5 +32,8 @@
 ClutterActor *meta_shaped_texture_new (void);
 void meta_shaped_texture_set_texture (MetaShapedTexture *stex,
                                       CoglTexture       *texture);
+gboolean meta_shaped_texture_get_unobscured_bounds (MetaShapedTexture     *stex,
+                                                    cairo_rectangle_int_t *unobscured_bounds);
+gboolean meta_shaped_texture_is_obscured (MetaShapedTexture *self);
 
 #endif

src/compositor/meta-shaped-texture.c

@@ -72,10 +72,15 @@ struct _MetaShapedTexturePrivate
   CoglTexture *texture;
   CoglTexture *mask_texture;
 
-  cairo_region_t *clip_region;
-  cairo_region_t *opaque_region;
   cairo_region_t *input_shape_region;
 
+  /* The region containing only fully opaque pixels */
+  cairo_region_t *opaque_region;
+
+  /* MetaCullable regions, see that documentation for more details */
+  cairo_region_t *clip_region;
+  cairo_region_t *unobscured_region;
+
   guint tex_width, tex_height;
 
   guint create_mipmaps : 1;
@@ -112,6 +117,21 @@ meta_shaped_texture_init (MetaShapedTexture *self)
   priv->create_mipmaps = TRUE;
 }
 
+static void
+set_unobscured_region (MetaShapedTexture *self,
+                       cairo_region_t    *unobscured_region)
+{
+  MetaShapedTexturePrivate *priv = self->priv;
+
+  g_clear_pointer (&priv->unobscured_region, (GDestroyNotify) cairo_region_destroy);
+  if (unobscured_region)
+    {
+      cairo_rectangle_int_t bounds = { 0, 0, priv->tex_width, priv->tex_height };
+      priv->unobscured_region = cairo_region_copy (unobscured_region);
+      cairo_region_intersect_rectangle (priv->unobscured_region, &bounds);
+    }
+}
+
 static void
 set_clip_region (MetaShapedTexture *self,
                  cairo_region_t    *clip_region)
@@ -137,6 +157,7 @@ meta_shaped_texture_dispose (GObject *object)
   g_clear_pointer (&priv->opaque_region, cairo_region_destroy);
 
   meta_shaped_texture_set_mask_texture (self, NULL);
+  set_unobscured_region (self, NULL);
   set_clip_region (self, NULL);
 
   G_OBJECT_CLASS (meta_shaped_texture_parent_class)->dispose (object);
@@ -497,10 +518,37 @@ meta_shaped_texture_get_preferred_height (ClutterActor *self,
 }
 
 static gboolean
-meta_shaped_texture_get_paint_volume (ClutterActor *self,
+meta_shaped_texture_get_paint_volume (ClutterActor *actor,
                                       ClutterPaintVolume *volume)
 {
-  return clutter_paint_volume_set_from_allocation (volume, self);
+  MetaShapedTexture *self = META_SHAPED_TEXTURE (actor);
+  cairo_rectangle_int_t unobscured_bounds;
+
+  if (!clutter_paint_volume_set_from_allocation (volume, actor))
+    return FALSE;
+
+  if (meta_shaped_texture_get_unobscured_bounds (self, &unobscured_bounds))
+    {
+      ClutterVertex origin;
+      cairo_rectangle_int_t bounds;
+
+      /* I hate ClutterPaintVolume so much... */
+      clutter_paint_volume_get_origin (volume, &origin);
+      bounds.x = origin.x;
+      bounds.y = origin.y;
+      bounds.width = clutter_paint_volume_get_width (volume);
+      bounds.height = clutter_paint_volume_get_height (volume);
+
+      gdk_rectangle_intersect (&bounds, &unobscured_bounds, &bounds);
+
+      origin.x = bounds.x;
+      origin.y = bounds.y;
+      clutter_paint_volume_set_origin (volume, &origin);
+      clutter_paint_volume_set_width (volume, bounds.width);
+      clutter_paint_volume_set_height (volume, bounds.height);
+    }
+
+  return TRUE;
 }
 
 void
@@ -546,6 +594,40 @@ meta_shaped_texture_set_mask_texture (MetaShapedTexture *stex,
   clutter_actor_queue_redraw (CLUTTER_ACTOR (stex));
 }
 
+static cairo_region_t *
+effective_unobscured_region (MetaShapedTexture *self)
+{
+  MetaShapedTexturePrivate *priv = self->priv;
+
+  return clutter_actor_has_mapped_clones (CLUTTER_ACTOR (self)) ? NULL : priv->unobscured_region;
+}
+
+gboolean
+meta_shaped_texture_get_unobscured_bounds (MetaShapedTexture     *self,
+                                           cairo_rectangle_int_t *unobscured_bounds)
+{
+  cairo_region_t *unobscured_region = effective_unobscured_region (self);
+
+  if (unobscured_region)
+    {
+      cairo_region_get_extents (unobscured_region, unobscured_bounds);
+      return TRUE;
+    }
+  else
+    return FALSE;
+}
+
+gboolean
+meta_shaped_texture_is_obscured (MetaShapedTexture *self)
+{
+  MetaShapedTexturePrivate *priv = self->priv;
+  cairo_region_t *unobscured_region = effective_unobscured_region (self);
+
+  if (unobscured_region)
+    return cairo_region_is_empty (unobscured_region);
+  else
+    return FALSE;
+}
 
 /**
  * meta_shaped_texture_update_area:
@@ -554,14 +636,9 @@ meta_shaped_texture_set_mask_texture (MetaShapedTexture *stex,
  * @y: the y coordinate of the damaged area
  * @width: the width of the damaged area
  * @height: the height of the damaged area
- * @unobscured_region: The unobscured region of the window or %NULL if
- * there is no valid one (like when the actor is transformed or
- * has a mapped clone)
  *
  * Repairs the damaged area indicated by @x, @y, @width and @height
- * and queues a redraw for the intersection @visibible_region and
- * the damage area. If @visibible_region is %NULL a redraw will always
- * get queued.
+ * and potentially queues a redraw.
  *
  * Return value: Whether a redraw have been queued or not
  */
@@ -570,10 +647,10 @@ meta_shaped_texture_update_area (MetaShapedTexture *stex,
 				 int                x,
 				 int                y,
 				 int                width,
-				 int                height,
-				 cairo_region_t    *unobscured_region)
+				 int                height)
 {
   MetaShapedTexturePrivate *priv;
+  cairo_region_t *unobscured_region;
   const cairo_rectangle_int_t clip = { x, y, width, height };
 
   priv = stex->priv;
@@ -583,6 +660,7 @@ meta_shaped_texture_update_area (MetaShapedTexture *stex,
 
   meta_texture_tower_update_area (priv->paint_tower, x, y, width, height);
 
+  unobscured_region = effective_unobscured_region (stex);
   if (unobscured_region)
     {
       cairo_region_t *intersection;
@@ -851,6 +929,7 @@ meta_shaped_texture_cull_out (MetaCullable   *cullable,
   MetaShapedTexture *self = META_SHAPED_TEXTURE (cullable);
   MetaShapedTexturePrivate *priv = self->priv;
 
+  set_unobscured_region (self, unobscured_region);
   set_clip_region (self, clip_region);
 
   if (clutter_actor_get_paint_opacity (CLUTTER_ACTOR (self)) == 0xff)

src/compositor/meta-window-actor.c

@@ -74,9 +74,6 @@ struct _MetaWindowActorPrivate
   /* The region we should clip to when painting the shadow */
   cairo_region_t   *shadow_clip;
 
-  /* The region that is visible, used to optimize out redraws */
-  cairo_region_t   *unobscured_region;
-
   guint              send_frame_messages_timer;
   gint64             frame_drawn_time;
 
@@ -395,7 +392,6 @@ meta_window_actor_dispose (GObject *object)
       priv->send_frame_messages_timer = 0;
     }
 
-  g_clear_pointer (&priv->unobscured_region, cairo_region_destroy);
   g_clear_pointer (&priv->shape_region, cairo_region_destroy);
   g_clear_pointer (&priv->shadow_clip, cairo_region_destroy);
 
@@ -663,7 +659,7 @@ meta_window_actor_get_paint_volume (ClutterActor       *actor,
 {
   MetaWindowActor *self = META_WINDOW_ACTOR (actor);
   MetaWindowActorPrivate *priv = self->priv;
-  cairo_rectangle_int_t bounds;
+  cairo_rectangle_int_t unobscured_bounds, bounds;
   gboolean appears_focused = meta_window_appears_focused (priv->window);
   ClutterVertex origin;
 
@@ -688,12 +684,8 @@ meta_window_actor_get_paint_volume (ClutterActor       *actor,
       gdk_rectangle_union (&bounds, &shadow_bounds, &bounds);
     }
 
-  if (priv->unobscured_region && !clutter_actor_has_mapped_clones (actor))
-    {
-      cairo_rectangle_int_t unobscured_bounds;
-      cairo_region_get_extents (priv->unobscured_region, &unobscured_bounds);
+  if (meta_shaped_texture_get_unobscured_bounds (META_SHAPED_TEXTURE (priv->actor), &unobscured_bounds))
     gdk_rectangle_intersect (&bounds, &unobscured_bounds, &bounds);
-    }
 
   origin.x = bounds.x;
   origin.y = bounds.y;
@@ -905,9 +897,7 @@ meta_window_actor_damage_all (MetaWindowActor *self)
   redraw_queued = meta_shaped_texture_update_area (META_SHAPED_TEXTURE (priv->actor),
                                                    0, 0,
                                                    cogl_texture_get_width (texture),
-                                                   cogl_texture_get_height (texture),
-                                                   clutter_actor_has_mapped_clones (priv->actor) ?
-                                                   NULL : priv->unobscured_region);
+                                                   cogl_texture_get_height (texture));
   priv->repaint_scheduled = priv->repaint_scheduled || redraw_queued;
   priv->needs_damage_all = FALSE;
 }
@@ -962,17 +952,7 @@ meta_window_actor_queue_frame_drawn (MetaWindowActor *self,
 
   if (!priv->repaint_scheduled)
     {
-      gboolean is_obscured = FALSE;
-
-      /* Find out whether the window is completly obscured */
-      if (priv->unobscured_region)
-        {
-          cairo_region_t *unobscured_window_region;
-          unobscured_window_region = cairo_region_copy (priv->shape_region);
-          cairo_region_intersect (unobscured_window_region, priv->unobscured_region);
-          is_obscured = cairo_region_is_empty (unobscured_window_region);
-          cairo_region_destroy (unobscured_window_region);
-        }
+      gboolean is_obscured = meta_shaped_texture_is_obscured (META_SHAPED_TEXTURE (priv->actor));
 
       /* A frame was marked by the client without actually doing any
        * damage or any unobscured, or while we had the window frozen
@@ -1641,30 +1621,6 @@ see_region (cairo_region_t *region,
 }
 #endif
 
-/**
- * meta_window_actor_set_unobscured_region:
- * @self: a #MetaWindowActor
- * @unobscured_region: the region of the screen that isn't completely
- *  obscured.
- *
- * Provides a hint as to what areas of the window need to queue
- * redraws when damaged. Regions not in @unobscured_region are completely obscured.
- */
-static void
-meta_window_actor_set_unobscured_region (MetaWindowActor *self,
-                                         cairo_region_t  *unobscured_region)
-{
-  MetaWindowActorPrivate *priv = self->priv;
-
-  if (priv->unobscured_region)
-    cairo_region_destroy (priv->unobscured_region);
-
-  if (unobscured_region)
-    priv->unobscured_region = cairo_region_copy (unobscured_region);
-  else
-    priv->unobscured_region = NULL;
-}
-
 /**
  * meta_window_actor_set_clip_region_beneath:
  * @self: a #MetaWindowActor
@@ -1715,7 +1671,6 @@ meta_window_actor_cull_out (MetaCullable   *cullable,
   if (priv->unredirected)
     return;
 
-  meta_window_actor_set_unobscured_region (self, unobscured_region);
   meta_cullable_cull_out_children (cullable, unobscured_region, clip_region);
   meta_window_actor_set_clip_region_beneath (self, clip_region);
 }
@@ -1947,9 +1902,7 @@ meta_window_actor_process_damage (MetaWindowActor    *self,
                                                    event->area.x,
                                                    event->area.y,
                                                    event->area.width,
-                                                   event->area.height,
-                                                   clutter_actor_has_mapped_clones (priv->actor) ?
-                                                   NULL : priv->unobscured_region);
+                                                   event->area.height);
   priv->repaint_scheduled = priv->repaint_scheduled || redraw_queued;
 }
 

src/meta/meta-shaped-texture.h

@@ -69,8 +69,7 @@ gboolean meta_shaped_texture_update_area (MetaShapedTexture *stex,
                                           int                x,
                                           int                y,
                                           int                width,
-                                          int                height,
-                                          cairo_region_t    *unobscured_region);
+                                          int                height);
 
 CoglTexture * meta_shaped_texture_get_texture (MetaShapedTexture *stex);