+/* values for redraw_mask */
+#define REDRAW_ALL (1 << 0)
+#define REDRAW_FIELD (1 << 1)
+#define REDRAW_TILES (1 << 2)
+#define REDRAW_DOOR_1 (1 << 3)
+#define REDRAW_VIDEO_1 (1 << 4)
+#define REDRAW_VIDEO_2 (1 << 5)
+#define REDRAW_VIDEO_3 (1 << 6)
+#define REDRAW_MICROLEVEL (1 << 7)
+#define REDRAW_FROM_BACKBUFFER (1 << 8)
+#define REDRAW_DOOR_2 (REDRAW_VIDEO_1 | \
+ REDRAW_VIDEO_2 | \
+ REDRAW_VIDEO_3)
+#define REDRAW_DOOR_3 (1 << 9)
+#define REDRAW_DOORS (REDRAW_DOOR_1 | \
+ REDRAW_DOOR_2 | \
+ REDRAW_DOOR_3)
+#define REDRAW_MAIN (REDRAW_FIELD | \
+ REDRAW_TILES | \
+ REDRAW_MICROLEVEL)
+#define REDRAW_FPS (1 << 10)
+#define REDRAWTILES_THRESHOLD (SCR_FIELDX * SCR_FIELDY / 2)
+
+