>Psychtoolbox>PsychGLImageProcessing

rval = kPsychSkipSwapForFlipOnce

Return a flag that you can pass as part of the flipFlags for a call to
Screen(‘Hookfunction’, windowPtr, ‘SetOneshotFlipFlags’, flipFlags);

This flag will disable the actual visual stimulus presentation to
the onscreen window via OpenGL double-buffer swap during execution
of the next Screen(‘Flip’) operation, ergo also any timestamping and
wait for swap completion. It will go through all the moves, post-
processing the stimulus, computing the final image, and most post-flip
operations, but the results of this work will not be shown as a visual
update to the onscreen window.