How about this idea ... If you have a user who has opened a window and it is tearing in generally the same sort of place, although the hz rate is synchronized to the desktop, and you generally can't do anything about it, you COULD allow the user to press some keys which would move the tear `up or down` the display, given that it is usually confined to a given region.
The achieve this, what you need to do is use software timing to do your flip, ie time it with millisecs based on the hertz rate and use Flip 0, and adjust the amount of milliseconds that you offset it (ie wait a bit) so that the tear moves. By inserting a wait for a little while when the user presses the key, and still calling Flip 0 at a given framerate, you should be able to move the tear up and down the display.
It's at least an option for those who might be interested in using it. It would be kind of like tuning a tv to prevent picture roll.
Also if you have access to a correct vwait or beam position, you could use this to synchronize your software flip.
The achieve this, what you need to do is use software timing to do your flip, ie time it with millisecs based on the hertz rate and use Flip 0, and adjust the amount of milliseconds that you offset it (ie wait a bit) so that the tear moves. By inserting a wait for a little while when the user presses the key, and still calling Flip 0 at a given framerate, you should be able to move the tear up and down the display.
It's at least an option for those who might be interested in using it. It would be kind of like tuning a tv to prevent picture roll.
Also if you have access to a correct vwait or beam position, you could use this to synchronize your software flip.