IfcNormalise

注：定义符合ISO/CD 10303-42:1992

此函数返回一个向量或方向，其分量被规格化为平方和为1.0。输出与输入参数的类型相同（方向或向量，单位相同）。如果输入参数未定义或长度为零，则输出向量未定义。

注：函数改编自ISO 10303-42中定义的标准化。

IFC1.5中的新函数

EXPRESS Specification

FUNCTION IfcNormalise
  (Arg : IfcVectorOrDirection)
    : IfcVectorOrDirection;
LOCAL
  Ndim : INTEGER;
  V    : IfcDirection
         := IfcRepresentationItem() || IfcGeometricRepresentationItem () || IfcDirection([1.,0.]);
  Vec  : IfcVector
         := IfcRepresentationItem() || IfcGeometricRepresentationItem () || IfcVector (
            IfcRepresentationItem() || IfcGeometricRepresentationItem () || IfcDirection([1.,0.]), 1.);
  Mag  : REAL;
  Result : IfcVectorOrDirection
         := V;
END_LOCAL;

  IF NOT EXISTS (Arg) THEN
    RETURN (?);
  ELSE
    IF 'IFCGEOMETRYRESOURCE.IFCVECTOR' IN TYPEOF(Arg) THEN
      BEGIN
        Ndim := ArgIfcVector.Dim;
V.DirectionRatios := ArgIfcVector.Orientation.DirectionRatios;
        Vec.Magnitude := ArgIfcVector.Magnitude;
Vec.Orientation := V;
        IF ArgIfcVector.Magnitude = 0.0 THEN
          RETURN(?);
        ELSE
          Vec.Magnitude := 1.0;
        END_IF;
      END;
    ELSE
      BEGIN
        Ndim := ArgIfcDirection.Dim;
        V.DirectionRatios := ArgIfcDirection.DirectionRatios;
      END;
    END_IF;

    Mag := 0.0;
      REPEAT i := 1 TO Ndim;
        Mag := Mag + V.DirectionRatios[i]*V.DirectionRatios[i];
      END_REPEAT;
    IF Mag > 0.0 THEN
      Mag := SQRT(Mag);
      REPEAT i := 1 TO Ndim;
        V.DirectionRatios[i] := V.DirectionRatios[i]/Mag;
      END_REPEAT;
      IF 'IFCGEOMETRYRESOURCE.IFCVECTOR' IN TYPEOF(arg) THEN
        Vec.Orientation := V;
        Result := Vec;
      ELSE
        Result := V;
      END_IF;
    ELSE
      RETURN(?);
    END_IF;
  END_IF;
  RETURN (Result);
END_FUNCTION;