passth(3G)

NAME
     passth - passes a single token through the Geometry Pipeline

FORTRAN 77 SPECIFICATION
     subroutine passth(token)
     integer*4 token

PARAMETERS
     token   expects an integer which is used to mark specific sections in
             input data so that when it is returned from the feedback buffer
             the data is easier to decipher.

DESCRIPTION
     passth passes a single 16-bit integer through the Geometry Pipeline. Use
     it in feedback mode to parse the returned information.

     For example, you can use passth between every pair of points that is
     being transformed and clipped by the Geometry Engines. If a point is
     clipped out, two passth tokens appear in a row in the output buffer.

NOTE
     This routine is available only in feedback mode; otherwise it is ignored.