Fix the input region not working properly

The input region was set on the shaped texture, but the shaped texture
was never picked properly, as it was never set to be reactive. Move the
pick implementation and reactivity to the MetaSurfaceActor, and update
the code everywhere else to expect a MetaSurfaceActor.

src/compositor/meta-surface-actor.c

@@ -22,8 +22,12 @@
 
 struct _MetaSurfaceActorPrivate
 {
+  MetaWaylandSurface *surface;
+
   MetaShapedTexture *texture;
   MetaWaylandBuffer *buffer;
+
+  cairo_region_t *input_region;
 };
 
 static void cullable_iface_init (MetaCullableInterface *iface);
@@ -39,9 +43,77 @@ meta_surface_actor_get_unobscured_bounds (MetaSurfaceActor      *self,
   return meta_shaped_texture_get_unobscured_bounds (priv->texture, unobscured_bounds);
 }
 
+static void
+meta_surface_actor_pick (ClutterActor       *actor,
+                         const ClutterColor *color)
+{
+  MetaSurfaceActor *self = META_SURFACE_ACTOR (actor);
+  MetaSurfaceActorPrivate *priv = self->priv;
+
+  if (!clutter_actor_should_pick_paint (actor))
+    return;
+
+  /* If there is no region then use the regular pick */
+  if (priv->input_region == NULL)
+    CLUTTER_ACTOR_CLASS (meta_surface_actor_parent_class)->pick (actor, color);
+  else
+    {
+      int n_rects;
+      float *rectangles;
+      int i;
+      CoglPipeline *pipeline;
+      CoglContext *ctx;
+      CoglFramebuffer *fb;
+      CoglColor cogl_color;
+
+      n_rects = cairo_region_num_rectangles (priv->input_region);
+      rectangles = g_alloca (sizeof (float) * 4 * n_rects);
+
+      for (i = 0; i < n_rects; i++)
+        {
+          cairo_rectangle_int_t rect;
+          int pos = i * 4;
+
+          cairo_region_get_rectangle (priv->input_region, i, &rect);
+
+          rectangles[pos + 0] = rect.x;
+          rectangles[pos + 1] = rect.y;
+          rectangles[pos + 2] = rect.x + rect.width;
+          rectangles[pos + 3] = rect.y + rect.height;
+        }
+
+      ctx = clutter_backend_get_cogl_context (clutter_get_default_backend ());
+      fb = cogl_get_draw_framebuffer ();
+
+      cogl_color_init_from_4ub (&cogl_color, color->red, color->green, color->blue, color->alpha);
+
+      pipeline = cogl_pipeline_new (ctx);
+      cogl_pipeline_set_color (pipeline, &cogl_color);
+      cogl_framebuffer_draw_rectangles (fb, pipeline, rectangles, n_rects);
+      cogl_object_unref (pipeline);
+    }
+}
+
+static void
+meta_surface_actor_dispose (GObject *object)
+{
+  MetaSurfaceActor *self = META_SURFACE_ACTOR (object);
+  MetaSurfaceActorPrivate *priv = self->priv;
+
+  g_clear_pointer (&priv->input_region, cairo_region_destroy);
+
+  G_OBJECT_CLASS (meta_surface_actor_parent_class)->dispose (object);
+}
+
 static void
 meta_surface_actor_class_init (MetaSurfaceActorClass *klass)
 {
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+  ClutterActorClass *actor_class = CLUTTER_ACTOR_CLASS (klass);
+
+  object_class->dispose = meta_surface_actor_dispose;
+  actor_class->pick = meta_surface_actor_pick;
+
   g_type_class_add_private (klass, sizeof (MetaSurfaceActorPrivate));
 }
 
@@ -172,7 +244,14 @@ meta_surface_actor_set_input_region (MetaSurfaceActor *self,
                                      cairo_region_t   *region)
 {
   MetaSurfaceActorPrivate *priv = self->priv;
-  meta_shaped_texture_set_input_shape_region (priv->texture, region);
+
+  if (priv->input_region)
+    cairo_region_destroy (priv->input_region);
+
+  if (region)
+    priv->input_region = cairo_region_reference (region);
+  else
+    priv->input_region = NULL;
 }
 
 void
@@ -183,8 +262,20 @@ meta_surface_actor_set_opaque_region (MetaSurfaceActor *self,
   meta_shaped_texture_set_opaque_region (priv->texture, region);
 }
 
-MetaSurfaceActor *
-meta_surface_actor_new (void)
+MetaWaylandSurface *
+meta_surface_actor_get_surface (MetaSurfaceActor *self)
 {
-  return g_object_new (META_TYPE_SURFACE_ACTOR, NULL);
+  MetaSurfaceActorPrivate *priv = self->priv;
+  return priv->surface;
+}
+
+MetaSurfaceActor *
+meta_surface_actor_new (MetaWaylandSurface *surface)
+{
+  MetaSurfaceActor *self = g_object_new (META_TYPE_SURFACE_ACTOR, NULL);
+  MetaSurfaceActorPrivate *priv = self->priv;
+
+  priv->surface = surface;
+
+  return self;
 }