Show Mon field effect

include/global.fieldmap.h

@@ -4,6 +4,13 @@
 #define OBJECT_EVENTS_COUNT 16
 
 #define METATILE_COLLISION_MASK 0x0C00
+#define METATILE_ID_MASK 0x03FF
+#define METATILE_ID_UNDEFINED 0x03FF
+#define METATILE_ELEVATION_SHIFT 12
+#define METATILE_COLLISION_SHIFT 10
+#define METATILE_ELEVATION_MASK 0xF000
+
+#define METATILE_ID(tileset, name) (METATILE_##tileset##_##name)
 
 enum
 {
@@ -17,8 +24,6 @@ enum
 
 typedef void (*TilesetCB)(void);
 
-#define METATILE_ID(tileset, name) (METATILE_##tileset##_##name)
-
 struct Tileset
 {
     /*0x00*/ bool8 isCompressed;

include/overworld.h

@@ -84,6 +84,7 @@ void sub_8084E80(s8, s8, s8, s8, s8);
 void sub_8084EBC(s16, s16);
 void sub_80555E0(void);
 void copy_saved_warp3_bank_and_enter_x_to_warp1(void);
+u8 IsMapTypeOutdoors(u8 mapType);
 
 void player_avatar_init_params_reset(void);