title: Exact software synchronisation on vsync pulse
body: <p>I'm trying to switch images on each incoming vsync pulse. In hardware the vsync pulse of my vga-signal can be easily used by using a trigger for each edge event of the incoming pulse ( VHDL). </p>
  
  <p>Now my question: Is it possible to trigger and swap images on this vsync signal in <strong>software</strong>, preferabele in a windows environment? So each screen refresh iteration would swap to another image. Any language, program is welcome. This triggering has to be as accurate as possible.. ( &lt; 1 ms)</p>
  
  <p>thanks!</p>