+#define IS_BD_BITER(e) ((e) == EL_BD_BITER || \
+ (e) == EL_BD_BITER_RIGHT || \
+ (e) == EL_BD_BITER_UP || \
+ (e) == EL_BD_BITER_LEFT || \
+ (e) == EL_BD_BITER_DOWN)
+
+#define IS_BD_EXPANDABLE_WALL(e) ((e) == EL_BD_EXPANDABLE_WALL_HORIZONTAL || \
+ (e) == EL_BD_EXPANDABLE_WALL_VERTICAL || \
+ (e) == EL_BD_EXPANDABLE_WALL_ANY || \
+ (e) == EL_BD_EXPANDABLE_STEELWALL_HORIZONTAL ||\
+ (e) == EL_BD_EXPANDABLE_STEELWALL_VERTICAL || \
+ (e) == EL_BD_EXPANDABLE_STEELWALL_ANY)
+
+#define IS_BD_CONVEYOR_BELT(e) ((e) == EL_BD_CONVEYOR_LEFT || \
+ (e) == EL_BD_CONVEYOR_LEFT_ACTIVE || \
+ (e) == EL_BD_CONVEYOR_RIGHT || \
+ (e) == EL_BD_CONVEYOR_RIGHT_ACTIVE)
+
+#define IS_BD_CONVEYOR_BELT_SWITCH(e) ((e) == EL_BD_CONVEYOR_SWITCH || \
+ (e) == EL_BD_CONVEYOR_SWITCH_ACTIVE || \
+ (e) == EL_BD_CONVEYOR_DIR_SWITCH_LEFT || \
+ (e) == EL_BD_CONVEYOR_DIR_SWITCH_RIGHT)
+