+/* values for custom move patterns (bits 0 - 3: basic move directions) */
+#define MV_BIT_TOWARDS_PLAYER 4
+#define MV_BIT_AWAY_FROM_PLAYER 5
+#define MV_BIT_ALONG_LEFT_SIDE 6
+#define MV_BIT_ALONG_RIGHT_SIDE 7
+#define MV_BIT_TURNING_LEFT 8
+#define MV_BIT_TURNING_RIGHT 9
+#define MV_BIT_WHEN_PUSHED 10
+#define MV_BIT_MAZE_RUNNER 11
+#define MV_BIT_MAZE_HUNTER 12
+#define MV_BIT_WHEN_DROPPED 13
+#define MV_BIT_TURNING_LEFT_RIGHT 14
+#define MV_BIT_TURNING_RIGHT_LEFT 15
+#define MV_BIT_TURNING_RANDOM 16
+
+/* values for custom move patterns */
+#define MV_HORIZONTAL (MV_LEFT | MV_RIGHT)
+#define MV_VERTICAL (MV_UP | MV_DOWN)
+#define MV_ALL_DIRECTIONS (MV_HORIZONTAL | MV_VERTICAL)
+#define MV_ANY_DIRECTION (MV_ALL_DIRECTIONS)
+#define MV_TOWARDS_PLAYER (1 << MV_BIT_TOWARDS_PLAYER)
+#define MV_AWAY_FROM_PLAYER (1 << MV_BIT_AWAY_FROM_PLAYER)
+#define MV_ALONG_LEFT_SIDE (1 << MV_BIT_ALONG_LEFT_SIDE)
+#define MV_ALONG_RIGHT_SIDE (1 << MV_BIT_ALONG_RIGHT_SIDE)
+#define MV_TURNING_LEFT (1 << MV_BIT_TURNING_LEFT)
+#define MV_TURNING_RIGHT (1 << MV_BIT_TURNING_RIGHT)
+#define MV_WHEN_PUSHED (1 << MV_BIT_WHEN_PUSHED)
+#define MV_MAZE_RUNNER (1 << MV_BIT_MAZE_RUNNER)
+#define MV_MAZE_HUNTER (1 << MV_BIT_MAZE_HUNTER)
+#define MV_MAZE_RUNNER_STYLE (MV_MAZE_RUNNER | MV_MAZE_HUNTER)
+#define MV_WHEN_DROPPED (1 << MV_BIT_WHEN_DROPPED)
+#define MV_TURNING_LEFT_RIGHT (1 << MV_BIT_TURNING_LEFT_RIGHT)
+#define MV_TURNING_RIGHT_LEFT (1 << MV_BIT_TURNING_RIGHT_LEFT)
+#define MV_TURNING_RANDOM (1 << MV_BIT_TURNING_RANDOM)
+
+/* values for initial move direction (bits 0 - 3: basic move directions) */
+#define MV_START_BIT_PREVIOUS 4
+
+/* values for initial move direction */
+#define MV_START_AUTOMATIC (MV_NO_MOVING)
+#define MV_START_LEFT (MV_LEFT)
+#define MV_START_RIGHT (MV_RIGHT)
+#define MV_START_UP (MV_UP)
+#define MV_START_DOWN (MV_DOWN)
+#define MV_START_RANDOM (MV_ALL_DIRECTIONS)
+#define MV_START_PREVIOUS (1 << MV_START_BIT_PREVIOUS)
+
+/* values for elements left behind by custom elements */
+#define LEAVE_TYPE_UNLIMITED 0
+#define LEAVE_TYPE_LIMITED 1
+
+/* values for slippery property for custom elements */
+#define SLIPPERY_ANY_RANDOM 0
+#define SLIPPERY_ANY_LEFT_RIGHT 1
+#define SLIPPERY_ANY_RIGHT_LEFT 2
+#define SLIPPERY_ONLY_LEFT 3
+#define SLIPPERY_ONLY_RIGHT 4