Trigo math with ints.

Using integers for trigo math may seem unusual,
but the goal is just to get deterministic results.

The angles are not in degrees in the interval (0 .. 360),
but in tenth of degrees in the interval (0 .. 3600).

The coordinates are not in the interval (0.0 .. 1.0),
but in the interval (0 .. 1000).

This library is released under a restrictionless Zlib license,
see the file "LICENSE.txt" for details.