tidyups

engine/fill.go

@@ -15,7 +15,7 @@ var _ interface {
 } = &Fill{}
 
 func init() {
-	gob.Register(Fill{})
+	gob.Register(&Fill{})
 	gob.Register(color.Gray{})
 	gob.Register(color.RGBA{})
 }

engine/sceneref.go

@@ -16,7 +16,7 @@ var _ interface {
 } = &SceneRef{}
 
 func init() {
-	gob.Register(SceneRef{})
+	gob.Register(&SceneRef{})
 }
 
 // SceneRef loads a gzipped, gob-encoded Scene from the asset FS.

main.go

@@ -112,6 +112,7 @@ func writeLevel1() {
 		},
 		Components: []interface{}{
 			&engine.Fill{
+				ID:     "bg_fill",
 				Color:  color.Gray{100},
 				ZOrder: 0,
 			},