improve basic multi output support

diyac.h

@@ -18,7 +18,7 @@
 #include <wlr/types/wlr_foreign_toplevel_management_v1.h>
 
 #define LAYER_TREE_SZ 4
-/* For brevity's sake, struct members are annotated where they are used. */
+
 enum diyac_cursor_mode
 {
     DIYAC_CURSOR_PASSTHROUGH,
@@ -83,7 +83,7 @@ struct diyac_popup
     void *parent;
 };
 
-struct diyac_layer_scenes
+struct diyac_output_scenes
 {
     struct wlr_scene_tree *background;
     struct wlr_scene_tree *bottom;
@@ -161,8 +161,8 @@ struct diyac_output
     struct wlr_box usable_area;
 
     // layer output
-    struct diyac_layer_scenes scenes;
-    // alias to diyac_layer_scenes elements
+    struct diyac_output_scenes scenes;
+    // alias to diyac_output_scenes elements
     struct wlr_scene_tree *layer_tree[LAYER_TREE_SZ];
 };
 
@@ -207,7 +207,7 @@ struct diyac_view
     struct wl_listener request_maximize;
     struct wl_listener request_fullscreen;
 
-    struct wl_listener set_app_id; // only useful when using SSD
+    struct wl_listener set_app_id;
     struct wl_listener new_popup;
     struct wl_listener set_title;