The router began as a port of FreeRouting and has grown its own engine
(negotiated congestion, tree nets, exact checks, axis escapes), and
'freeroute' was one letter from the project it no longer follows. The
package, module and command are now rpmroute; the freeroute command stays
as an alias, and the RPMROUTE / RPMROUTE_ORACLE_JAVA variables fall back
to the old FREEROUTE names. Version 2026.10.07. Routing is unchanged: a
PCBench board routes to a byte-identical session either way.
Ports Direction/IntDirection (equivalence classes of vectors, gcd-
normalized, exact angular compare) and Line. Line.side_of uses an exact
integer determinant; Line.intersection returns an IntPoint when the
crossing is integral and a RationalPoint otherwise, with the orthogonal
and 45-degree fast paths from the source preserved. Parallel lines yield
a point at infinity (z=0). BigIntDirection is folded into IntDirection
since unbounded int always fits.
Tests cover integral and rational intersections, parallel-line infinity,
exactness beyond double precision (verified via exact collinearity of the
result), and direction normalization/ordering.