[MX: <X>,<Y>,<W>,<H> ]
[MX: <X1>,<Y1>,<W1>,<H1>,<X2>,<Y2>,<W2>,<H2>, … ]

Mirror eXchange

The rectangular field at the position <X>, <Y> of the size <W>, <H> is mirrored and then exchanged with the (identically sized) corresponding area that appears at the mirrored area.

For example:  A streetcar can travel in two directions.  When it is supposed to travel in the opposite direction, it is useful to use this command to mirror the part of the image on the end which shows the driver, so that he is facing the correct direction regardless of travel direction.

If the two areas not accurately at the mirrored position, use the [MX1: ] modifier instead, which allows you to specify the position of both areas.