IfcGetBasisSurface

IfcGetBasisSurface

函数定义

注：根据ISO/CD 10303-42:1992的定义

此函数用于将曲线的基础曲面作为一组曲面返回。对于不是曲面上曲线的曲线，将返回一个空集。

注：根据ISO 10303-42中定义的get_基准面调整的函数。

IFC1.5中增加的新功能

EXPRESS Specification

FUNCTION IfcGetBasisSurface
(C : IfcCurveOnSurface) : SET[0:2] OF IfcSurface;

  LOCAL
    Surfs : SET[0:2] OF IfcSurface;
    N : INTEGER;
  END_LOCAL;

  Surfs := [];
  IF 'IFCGEOMETRYRESOURCE.IFCPCURVE' IN TYPEOF (C) THEN
    Surfs := [C\IfcPCurve.BasisSurface];
  ELSE
    IF 'IFCGEOMETRYRESOURCE.IFCCOMPOSITECURVEONSURFACE' IN TYPEOF (C) THEN

    (* For an IfcCompositeCurveOnSurface the BasisSurface is the intersection
       of the BasisSurface of all the segments. *)

    N := SIZEOF(C\IfcCompositeCurve.Segments);
    Surfs := IfcGetBasisSurface(C\IfcCompositeCurve.Segments[1].ParentCurve);
    
      IF N > 1 THEN
        REPEAT i := 2 TO N;
          Surfs := Surfs * IfcGetBasisSurface(C\IfcCompositeCurve.Segments[1].ParentCurve);
        END_REPEAT;
      END_IF;
    END_IF;
  END_IF;
  RETURN(Surfs);
END_FUNCTION;

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