Museum

     passthrough(3G)                                   passthrough(3G)



     NAME

          passthrough - passes a single token through the Geometry

          Pipeline


     SPECIFICATION

          C         passthrough(token)

                    short token;




          FORTRAN   subroutine passth(token)

                    integer*4 token


     DESCRIPTION

          passthrough 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 passthrough between every pair of

          points that is being transformed and clipped by the Geometry

          Engines. If a point is clipped out, two passthrough tokens

          appear in a row in the output buffer.  It is dangerous to

          use passthrough when not in feedback mode; it can send a

          random routine to the raster subsystem.


     SEE ALSO

          Programming Guide, Section 10.2, Feeback Mode


     NOTE

          This routine is available only in feedback mode.


























     Page 1                                          (printed 8/20/87)