- force execution of GL commands in finite time



C SPECIFICATION


DESCRIPTION

       Different  GL  implementations  buffer commands in several
       different locations, including  network  buffers  and  the
       graphics accelerator itself.  glFlush empties all of these
       buffers, causing all issued commands  to  be  executed  as
       quickly  as  they  are  accepted  by  the actual rendering
       engine.  Though this execution may not be completed in any
       particular time period, it does complete in finite time.

       Because  any  GL program might be executed over a network,
       or on an accelerator that buffers commands,  all  programs
       should  call  glFlush whenever they count on having all of
       their previously issued commands completed.  For  example,
       call glFlush before waiting for user input that depends on
       the generated image.


NOTES

       glFlush can return at any time.  It does  not  wait  until
       the execution of all previously issued GL commands is com-
       plete.


ERRORS

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


SEE ALSO

       glFinish



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