Spring RTS Engine

Don't know if anyone ever noticed that but when starting a game you can't move your starting unit directly north, it just sits there. I noticed this a long time ago and just felt to bring it up.

To reproduce just run the comtest on any map with any mod. Then select your starting unit and give a move order north of it. The comm in BA441 would just walk on the spot for instance. No idea if aircraft is affected but ground units are.

Basically this is the result of degenerate vector math. The vector describing the direction to the destination waypoint is (0, 0, -1), which gets converted to a single heading value in the range [0, 32767] (zero in this case). The commander's initial heading value however is also zero. That means the heading difference is zero whereas it should be 16348 (aka. 180 degrees), which causes your boy to get stuck in place and never actually reach the waypoint.

Everybody do the moonwalk now!