-/* If we start including very thin buildings, numerical accuracy errors can
- arise. Therefore, we ignore all buildings that are less than epsilon wide. */
-#define EPS 1e-5
+ From 2007 through 2012, buildings of width less than EPS were discarded,
+ citing numerical accuracy concerns. We remember that floating point
+ comparisons of nearly-equal values can be affected by rounding error.
+ Also, some target machines use the x87 floating point unit, which provides
+ extended precision for intermediate results held in registers. On this type
+ of hardware comparisons such as
+ double c = 1.0/3.0; boolean compare = (c == 1.0/3.0)
+ could go either way because the 1.0/3.0 is allowed to be kept
+ higher precision than the variable 'c'.
+ Alert to these considerations, we now accept buildings of zero-width.
+*/