Added the mask sprite layer

This layer is below the normal sprite layer. Sprites on it are only rendered within the area of a zone that is defined per-map.

1 files changed, 3 insertions, 1 deletions

@@ -11,8 +11,10 @@
 #include "step_type.h"
 
 enum class SpriteLayer {
+  Mask,
   Normal,
-  Above
+  Above,
+  NUM_SPRITE_LAYERS // do not use
 };
 
 struct SpriteFrame {