- place a marker in the feedback buffer



C SPECIFICATION


PARAMETERS

       _param1  Specifies  a  marker  value  to  be placed in the
                feedback        buffer        following         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  pixels are produced by rasterization.
       Instead, information about primitives that would have been
       rasterized  is  fed  back to the application using 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 feed-
       back buffer when it is executed in feedback mode.  _param1
       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 com-
       mands with respect to the specification of graphics primi-
       tives is maintained.


NOTES

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


ERRORS

       GL_INVALID_OPERATION is generated if glPassThrough is exe-
       cuted between the execution of glBegin and the correspond-
       ing execution of glEnd.


ASSOCIATED GETS

       glGet with argument GL_RENDER_MODE


SEE ALSO

       glFeedbackBuffer, glRenderMode



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