Some considerations

[Marcelo E. Magallon]

On Mon, Jan 05, 2004 at 04:57:02PM +0100, Martijn Sipkema wrote:

 > For OpenGL rendering the flush command could be used for this; one
 > shouldn't call flush in the middle of drawing though I suspect some
 > applications may... For X11 drawing the flush isn't sent over the
 > wire, is it?

 from glFlush(3x):

   Different GL implementations buffer commands in several different loca-
   tions, 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.

-- 
Marcelo