Possible values
LEGACY_MOVEMENT_MODE: Old BYOND behavior regarding pixel movement and turf contents (see below)TILE_MOVEMENT_MODE: All atoms are locked to the tile gridPIXEL_MOVEMENT_MODE: All movable atoms can use pixel movement unless otherwise specified (see below), but legacy behavior for turf contents is ignored
Default value
LEGACY_MOVEMENT_MODE
Controls how movement works on the map.
TILE_MOVEMENT_MODE allows you to easily discard any and all pixel movement, so if step_x or step_y coordinates or unexpected atom bounds were loaded from a savefile, for instance, they would be eliminated. If you use any other movement mode, you can give an atom the TILE_MOVER flag and it will behave as if it were in this mode, while other atoms are free to do their own thing.
LEGACY_MOVEMENT_MODE exists to distinguish between old and new movement behavior. In older versions of BYOND before pixel movement, turfs took their contents into consideration by default in Enter() and Exit(). This doesn’t really make sense for newer games, so in any other movement mode the turf behavior will ignore its contents. mob.Cross() is also affected, since it would return 0 by default in legacy mode when both mobs were dense; now by default it checks mob.group.