Indication of which end
of the string should be
extended to bounding
object 1. The other end
of the string will be
extended to bounding
object 2. This should be
set to one of the
following values:

UF_CURVE_TRIM_EXTEND_START
UF_CURVE_TRIM_EXTEND_END

Indication of which portion
of the string should be
trimmed away, this should
be set to one of the
following values:

UF_CURVE_TRIM_OUTSIDE
UF_CURVE_TRIM_INSIDE

The bounding definition for
boundary 1.

The bounding definition for
boundary 2.

Indication of whether the
bounding strings should be
trimmed or not.

Vector defining viewing
direction in which to
measure minimum distance.
If vector is defined with a
datum axis, the feature
will be associated to the
datum axis. If vector is
defined using plane of
curves option, curves do
not need to be supplied in
vector structure, the
bounding object strings and
string being trimmed will
determine plane. If
(void )0 then minimum
distance will be measured 3
dimensionally.