wayland: Make the surface actor set its own state

Since the surface actor knows more about how it draws itself, instead of
pushing texture state (buffer and scale), input region and opaque region
from MetaWaylandSurface after having transformed into what the surface
actor expects, make the surface actor set its own state given what state
the Wayland surface is in.

https://bugzilla.gnome.org/show_bug.cgi?id=744933

src/compositor/meta-surface-actor-wayland.c

@@ -31,6 +31,8 @@
 
 #include "wayland/meta-wayland-private.h"
 
+#include "compositor/region-utils.h"
+
 struct _MetaSurfaceActorWaylandPrivate
 {
   MetaWaylandSurface *surface;
@@ -126,12 +128,51 @@ meta_surface_actor_wayland_get_scale (MetaSurfaceActorWayland *actor)
 }
 
 void
-meta_surface_actor_wayland_scale_texture (MetaSurfaceActorWayland *actor)
+meta_surface_actor_wayland_sync_state (MetaSurfaceActorWayland *self)
 {
-  MetaShapedTexture *stex = meta_surface_actor_get_texture (META_SURFACE_ACTOR (actor));
-  double output_scale = meta_surface_actor_wayland_get_scale (actor);
+  MetaWaylandSurface *surface = meta_surface_actor_wayland_get_surface (self);
+  MetaShapedTexture *stex =
+    meta_surface_actor_get_texture (META_SURFACE_ACTOR (self));
+  double texture_scale;
 
-  clutter_actor_set_scale (CLUTTER_ACTOR (stex), output_scale, output_scale);
+  /* Given the surface's window type and what output the surface actor has the
+   * largest region, scale the actor with the determined scale. */
+  texture_scale = meta_surface_actor_wayland_get_scale (self);
+
+  /* Actor scale. */
+  clutter_actor_set_scale (CLUTTER_ACTOR (stex), texture_scale, texture_scale);
+
+  /* Input region */
+  if (surface->input_region)
+    {
+      cairo_region_t *scaled_input_region;
+      int region_scale;
+
+      /* The input region from the Wayland surface is in the Wayland surface
+       * coordinate space, while the surface actor input region is in the
+       * physical pixel coordinate space. */
+      region_scale = (int)(surface->scale * texture_scale);
+      scaled_input_region = meta_region_scale (surface->input_region,
+                                               region_scale);
+      meta_surface_actor_set_input_region (META_SURFACE_ACTOR (self),
+                                           scaled_input_region);
+      cairo_region_destroy (scaled_input_region);
+    }
+
+  /* Opaque region */
+  if (surface->opaque_region)
+    {
+      cairo_region_t *scaled_opaque_region;
+
+      /* The opaque region from the Wayland surface is in Wayland surface
+       * coordinate space, while the surface actor opaque region is in the
+       * same coordinate space as the unscaled buffer texture. */
+      scaled_opaque_region = meta_region_scale (surface->opaque_region,
+                                                surface->scale);
+      meta_surface_actor_set_opaque_region (META_SURFACE_ACTOR (self),
+                                            scaled_opaque_region);
+      cairo_region_destroy (scaled_opaque_region);
+    }
 }
 
 static MetaWindow *

src/compositor/meta-surface-actor-wayland.h

@@ -63,7 +63,8 @@ void meta_surface_actor_wayland_set_texture (MetaSurfaceActorWayland *self,
 
 double meta_surface_actor_wayland_get_scale (MetaSurfaceActorWayland *actor);
 
-void meta_surface_actor_wayland_scale_texture (MetaSurfaceActorWayland *actor);
+void meta_surface_actor_wayland_sync_state (MetaSurfaceActorWayland *self);
+
 G_END_DECLS
 
 #endif /* __META_SURFACE_ACTOR_WAYLAND_H__ */

src/compositor/region-utils.c

@@ -172,6 +172,35 @@ meta_region_iterator_next (MetaRegionIterator *iter)
     }
 }
 
+cairo_region_t *
+meta_region_scale (cairo_region_t *region, int scale)
+{
+  int n_rects, i;
+  cairo_rectangle_int_t *rects;
+  cairo_region_t *scaled_region;
+
+  if (scale == 1)
+    return cairo_region_copy (region);
+
+  n_rects = cairo_region_num_rectangles (region);
+
+  rects = g_malloc (sizeof(cairo_rectangle_int_t) * n_rects);
+  for (i = 0; i < n_rects; i++)
+    {
+      cairo_region_get_rectangle (region, i, &rects[i]);
+      rects[i].x *= scale;
+      rects[i].y *= scale;
+      rects[i].width *= scale;
+      rects[i].height *= scale;
+    }
+
+  scaled_region = cairo_region_create_rectangles (rects, n_rects);
+
+  g_free (rects);
+
+  return scaled_region;
+}
+
 static void
 add_expanded_rect (MetaRegionBuilder  *builder,
                    int                 x,

src/compositor/region-utils.h

@@ -92,6 +92,8 @@ void     meta_region_iterator_init      (MetaRegionIterator *iter,
 gboolean meta_region_iterator_at_end    (MetaRegionIterator *iter);
 void     meta_region_iterator_next      (MetaRegionIterator *iter);
 
+cairo_region_t *meta_region_scale (cairo_region_t *region, int scale);
+
 cairo_region_t *meta_make_border_region (cairo_region_t *region,
                                          int             x_amount,
                                          int             y_amount,

src/wayland/meta-wayland-surface.c

@@ -356,36 +356,6 @@ parent_surface_committed (gpointer data, gpointer user_data)
   subsurface_parent_surface_committed (data);
 }
 
-static cairo_region_t*
-scale_region (cairo_region_t *region, int scale)
-{
-  int n_rects, i;
-  cairo_rectangle_int_t *rects;
-  cairo_region_t *scaled_region;
-
-  if (scale == 1)
-    return region;
-
-  n_rects = cairo_region_num_rectangles (region);
-
-  rects = g_malloc (sizeof(cairo_rectangle_int_t) * n_rects);
-  for (i = 0; i < n_rects; i++)
-    {
-      cairo_region_get_rectangle (region, i, &rects[i]);
-      rects[i].x *= scale;
-      rects[i].y *= scale;
-      rects[i].width *= scale;
-      rects[i].height *= scale;
-    }
-
-  scaled_region = cairo_region_create_rectangles (rects, n_rects);
-
-  g_free (rects);
-  cairo_region_destroy (region);
-
-  return scaled_region;
-}
-
 static void
 commit_pending_state (MetaWaylandSurface      *surface,
                       MetaWaylandPendingState *pending)
@@ -426,18 +396,20 @@ commit_pending_state (MetaWaylandSurface      *surface,
 
   if (pending->opaque_region)
     {
-      pending->opaque_region = scale_region (pending->opaque_region, surface->scale);
-      meta_surface_actor_set_opaque_region (surface->surface_actor, pending->opaque_region);
-    }
-  if (pending->input_region)
-    {
-      pending->input_region = scale_region (pending->input_region,
-                                            meta_surface_actor_wayland_get_scale (META_SURFACE_ACTOR_WAYLAND (surface->surface_actor)));
-      meta_surface_actor_set_input_region (surface->surface_actor, pending->input_region);
+      if (surface->opaque_region)
+        cairo_region_destroy (surface->opaque_region);
+      surface->opaque_region = cairo_region_reference (pending->opaque_region);
     }
 
-  /* scale surface texture */
-  meta_surface_actor_wayland_scale_texture (META_SURFACE_ACTOR_WAYLAND (surface->surface_actor));
+  if (pending->input_region)
+    {
+      if (surface->input_region)
+        cairo_region_destroy (surface->input_region);
+      surface->input_region = cairo_region_reference (pending->input_region);
+    }
+
+  meta_surface_actor_wayland_sync_state (
+    META_SURFACE_ACTOR_WAYLAND (surface->surface_actor));
 
   /* wl_surface.frame */
   wl_list_insert_list (&compositor->frame_callbacks, &pending->frame_callback_list);
@@ -692,6 +664,11 @@ wl_surface_destructor (struct wl_resource *resource)
   surface_set_buffer (surface, NULL);
   pending_state_destroy (&surface->pending);
 
+  if (surface->opaque_region)
+    cairo_region_destroy (surface->opaque_region);
+  if (surface->input_region)
+    cairo_region_destroy (surface->input_region);
+
   g_object_unref (surface->surface_actor);
 
   if (surface->resource)

src/wayland/meta-wayland-surface.h

@@ -81,6 +81,8 @@ struct _MetaWaylandSurface
   MetaWindow *window;
   MetaWaylandBuffer *buffer;
   struct wl_listener buffer_destroy_listener;
+  cairo_region_t *input_region;
+  cairo_region_t *opaque_region;
   int scale;
   int32_t offset_x, offset_y;
   GList *subsurfaces;