Hi All,
When using a canvas control, is there any way to get CVI to synchronise the update of the canvas with the pixel clock/counter of the video card?
If you look closley, you can see this glitch in the update, it appears that CVI is putting pixel values in the video RAM in a manner which is not timed WRT video sync.
The demo project attached demonstrates this glitch. If you maximise the panel, click on the 'toggle' control, then hold the spacebar down, you can quite clearly see the sync mismatch as a horizontal bar travelling up or down the screen.
This demo program is an exaggerated situation, but identifies the problem clearly.
Assuming this was a low level issue and not easily fixed, I was wondering if I could work around this by accesing the video clocks/counters & try to time a call to ProcessDrawEvents immediatley after the 'beam position' was 0,0, but I am unaware of where these counters might be located.
You would need access to these counters to program a light pen - Although I havent heard of a light pen in years..!
ta.
