PARAMETERS
       token  Specifies a marker value to be placed in the feedback buffer fol‐
              lowing a GL_PASS_THROUGH_TOKEN.

DESCRIPTION
       Feedback is  a  GL  render  mode.   The  mode  is  selected  by  calling
       glRenderMode with GL_FEEDBACK.  When the GL is in feedback mode, no pix‐
       els are produced by rasterization.  Instead,  information  about  primi‐
       tives that would have been rasterized is fed back to the application us‐
       ing the GL.  See the glFeedbackBuffer reference page for  a  description
       of the feedback buffer and the values in it.

       glPassThrough  inserts a user-defined marker in the feedback buffer when
       it is executed in feedback mode.  token is returned  as  if  it  were  a
       primitive;  it  is  indicated  with  its  own  unique identifying value:
       GL_PASS_THROUGH_TOKEN.  The order of glPassThrough commands with respect
       to the specification of graphics primitives is maintained.

NOTES
       glPassThrough is ignored if the GL is not in feedback mode.

ERRORS
       GL_INVALID_OPERATION  is  generated if glPassThrough is executed between
       the execution of glBegin and the corresponding execution of glEnd.

ASSOCIATED GETS
       glGet with argument GL_RENDER_MODE

SEE ALSO
       glFeedbackBuffer, glRenderMode

                                                              GLPASSTHROUGH(3G)