QDDone
QDDone Ensure that all drawing is done
#include <QDOff screen.h> Color QuickDraw
GrafPtr port; a pointer to a graphics port
returns TRUE = drawing operations have finished in the
designated graphics port.
You can use the QDDone function to ensure that all drawing is done and avoid
the possibility that new drawing operations might be overlaid by previously
issued but un executed operations. This function is especially useful if a
graphics accelerator is present and operating asynchronously.
port the designated graphics port
Returns: a Boolean value. The QDDone function returns TRUE if drawing
operations have finished in the designated graphics port, FALSE if any
remain to be executed. If you pass NIL as the port parameter, then
QDDone returns TRUE only if drawing operations have completed in
all ports. (If a port has a clock or other continuously operating
process, QDDone may never return TRUE.)