+ /* !!! THIS DOES NOT WORK !!! REPLACED BITMAPS MAY HAVE SAME ADDRESS !!! */
+#if 0
+ static Bitmap *main_bitmap_tile = NULL;
+ static Bitmap *door_bitmap_tile = NULL;
+
+ if (mask == REDRAW_FIELD)
+ {
+ if (background_bitmap_tile == main_bitmap_tile)
+ return; /* main background tile has not changed */
+
+ main_bitmap_tile = background_bitmap_tile;
+ }
+ else if (mask == REDRAW_DOOR_1)
+ {
+ if (background_bitmap_tile == door_bitmap_tile)
+ return; /* main background tile has not changed */
+
+ door_bitmap_tile = background_bitmap_tile;
+ }
+ else /* should not happen */
+ return;
+#endif
+