glFlush
NAME
glFlush - force execution of GL commands in finite time
C SPECIFICATION
void glFlush(void)
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 complete.
ERRORS
GL_INVALID_OPERATION is generated if glFlush is executed
between the execution of glBegin and the
corresponding execution of glEnd.
SEE ALSO
glFinish