attribute controls whether points on the boundary of a Region
are considered to be inside or
outside the region. If the attribute value is non-zero (the default), points on the boundary
are considered to be inside the region (that is, the Region is
). However, if the
attribute value is zero, points on the bounary are considered to be outside the region.
All Regions have this attribute.
value of the Closed attribute is ignored by PointList regions. If the PointList region has
not been negated, then it is always assumed to be closed. If the PointList region has been
negated, then it is always assumed to be open. This is required since points have zero volume
and therefore consist entirely of boundary.
The default Closed value for a
CmpRegion is the Closed value of its first component Region.
The default Closed value for
an Stc is the Closed value of its encapsulated Region.
The Moc class ignored this
attribute, and the behaviour for boundary points is undefined (i.e. they may be inside or
outside the Region, depending on the position being tested and the nature of the Moc).