Synchronizing with Hardware v-sync

[PjotrvA]

Hi,

I' am programming a monitor testing programm. I need to switch images during a v-sync. I would like to use DirectX if possible, but I need to make sure I display only 1 image between v-syncs.
Anyone have some suggestions.

Does anyone know if the D3DPRESENT parameter will force this behavior in DirectX 9.0?

thnx Pjotr

 

[timmay3141]

Yeah, set the PresentationInterval to D3DPRESENT_INTERVAL_DEFAULT and it will copy vsync.

 

[PjotrvA]

Hi,

It seems to work, at least for slower refresh rates. If I use it at 75 Hz. Some v-syncs are missed and the screen does not refresh for 2 v-syncs. Since we want to measure the decay of the screenfosfors, we need to make sure our application only displays a picture (or a white screen) for one v-sync. The next image should be an other image (or a blank (black) screen.)

Does anyone know how this is achieved?
The nicest solution would be to display two alternating images. When I try to do it, I lose one backbuffer. Resulting in one image (the last loaded) and a grey screen alternating.

thnx Pjotr

 

[PjotrvA]

Hi,

I've resolved some timer issues. Put the PresentationInterval on D3DPRESENT_INTERVAL_ONE and it's 'working'.

On high frequenties, you can sometimes see a small hickup on the display, suggesting a incorrect image (the wrong one) on the screen.

hope someone can use this info....

gr. Pjotr