OUGEEF ( ed_fn, parms, curve, cutype, start, st_t, end, end_t, sense, ifail )
=============================================================================

  Output geometry of edge or fin

    Can be called from the GO.

Receives:
  KI_tag_topology          *ed_fn          --- edge or fin being queried
  KI_cod_logical           *parms          --- request for parameters

Returns:
  KI_tag_curve             *curve          --- tag of curve
  KI_cod_tycu              *cutype         --- type of curve
  KI_vec_position           start          --- start position
  KI_dbl                   *st_t           --- parameter of 'start'
  KI_vec_position           end            --- end position
  KI_dbl                   *end_t          --- parameter of 'end'
  KI_cod_logical           *sense          --- true if 'curve' is in same
                                           --- direction as 'ed_fn'
  KI_cod_error             *ifail          --- failure code

Specific errors:
  KI_missing_geom           Insufficient geometry to represent 'ed_fn'
  KI_wrong_entity           wrong entity

Description:

  This function receives an item of topology, 'ed_fn', which may be an edge
  or a fin, and returns geometry representing it. The geometry comprises
  the tag of a curve, the curve type, position vectors on the curve
  corresponding to the end points of the item, and optionally the curve
  parameters of these position vectors. Together these represent a bounded
  portion of curve corresponding to 'ed_fn'.

  The position vectors 'start' and 'end' are returned such that movement
  from 'start' to 'end' along the curve is in the same direction as the curve.
  If 'sense' is returned as KI_false, then the curve direction is in the
  opposite direction to 'ed_fn', though this can only occur for fins and
  laminar edges on sheet bodies.

  Note that 'curve' is attached to the model and should not be modified
  or deleted without due care.

  If 'parms' is set to KI_true, the curve parameters corresponding to 'start'
  and 'end', ( 'st_t' and 'end_t' respectively ) will be calculated. 'st_t'
  will always be smaller than 'end_t', the period of parametrisation being
  added to 'end_t' if necessary. If 'parms' is set to KI_false, the parameters
  will be arbitrarily returned as zero.

  If 'ed_fn' has no curve attached, an attempt will be made to return
  equivalent geometry that lies in the same surface. Thus if 'ed_fn' is an
  edge, fin geometry may be returned, and vice versa. However if 'ed_fn'
  is a fin, the geometry of the other fin will not be returned.

  If 'ed_fn' is a ring, 'start' and 'end' will both be returned as the
  position vector corresponding to the lowest value in the parameter range
  for the curve. 'st_t' will be this lowest parameter value, and 'end_t' this
  value plus the period of parameterisation.

  Where no geometry representing 'ed_fn' can be found, this will give rise to
  ifail KI_missing_geom.