public static extern SUCurveRef SUArcCurveToCurve(SUArcCurveRef arccurve);
public static extern SU_RESULT SUArcCurveCreate(ref SUArcCurveRef arccurve, ref SUPoint3D center, ref SUPoint3D start_point, ref SUPoint3D end_point, ref SUVector3D normal, long num_edges);
public static extern SU_RESULT SUArcCurveGetIsFullCircle(SUArcCurveRef arccurve, ref bool is_full);
public static extern SUEntityRef SUArcCurveToEntity(SUArcCurveRef arccurve);
public static extern SU_RESULT SUArcCurveGetNormal(SUArcCurveRef arccurve, out SUVector3D normal);
public static extern SU_RESULT SUArcCurveGetEndAngle(SUArcCurveRef arccurve, out double angle);
public static extern SU_RESULT SUArcCurveGetCenter(SUArcCurveRef arccurve, out SUPoint3D point);
public static extern SU_RESULT SUArcCurveGetYAxis(SUArcCurveRef arccurve, out SUVector3D axis);
public static extern SU_RESULT SUArcCurveGetEndPoint(SUArcCurveRef arccurve, ref SUPoint3D point);
public static extern SU_RESULT SUArcCurveGetRadius(SUArcCurveRef arccurve, ref double radius);
public static extern SU_RESULT SUArcCurveRelease(ref SUArcCurveRef arccurve);