Ifc2DCompositeCurve

Definition from IAI: An Ifc2DCompositeCurve is an IfcCompositeCurve that is defined within the coordinate space of an IfcPlane. Therefore the dimensionality of the Ifc2DCompositeCurve has to be 2.

> NOTE OF DEPRECATION: After the enhancement of the profile definition capacities in IFC Release 2.x this entity is not needed anymore for the definition of boundaries on a plane. Therefore this entity is marked as deprecated - that means it will not be supported in future versions of IFC.

> NOTE: This entity has been introduced to get a more straight forward definition of surface boundaries than by its counterpart in STEP: composite_curve_on_surface and boundary_curve. Since the only basis elementary surface in IFC is the plane surface, a two dimensional composite curve provides enough capability to define the boundary.

> HISTORY: New class in IFC Release 1.5

EXPRESS specification:

ENTITY Ifc2DCompositeCurve
SUBTYPE OF ( | IfcCompositeCurve);
WHERE
WR1 | : | SELF\IfcCompositeCurve.ClosedCurve;
WR2 | : | SELF\IfcCurve.Dim = 2;
END_ENTITY;

Formal Propositions:

WR1 | : | The composite curve shall be closed.
WR2 | : | The dimensionality of the composite curve shall be 2

Inheritance graph

ENTITY Ifc2DCompositeCurve;
ENTITY IfcRepresentationItem;
INVERSE
LayerAssignments | : | SET OF IfcPresentationLayerAssignment FOR AssignedItems;
StyledByItem | : | SET [0:1] OF IfcStyledItem FOR Item;
ENTITY IfcGeometricRepresentationItem;
ENTITY IfcCurve;
DERIVE
Dim | : | IfcDimensionCount := IfcCurveDim(SELF);
ENTITY IfcBoundedCurve;
ENTITY IfcCompositeCurve;
Segments | : | LIST [1:?] OF IfcCompositeCurveSegment;
SelfIntersect | : | LOGICAL;
DERIVE
NSegments | : | INTEGER := SIZEOF(Segments);
ClosedCurve | : | LOGICAL := Segments[NSegments].Transition <> Discontinuous;
ENTITY Ifc2DCompositeCurve;
END_ENTITY;