Best way to detect the end of a frame?

[earok]

I'm currently tracking VPOS and if it goes backwards (example, 300 to 10) I've made the assumption that we've started a new frame. Is there a better way to do this?

[idrougge]

VWait

[Daedalus]

Yes, VWait will suspend your program until the next frame begins, which is suitable for syncing for double buffering, animation and so on. If you need to catch *every* frame however, a type 5 interrupt is executed at the start of every frame, even if your main loop takes longer than a frame to execute.

[meynaf]

Just setup a vblank interrupt and set some flag somewhere.

[idrougge]

There is also VWaitPos that waits for a certain line.

[Cylon]

Also graphics' WaitTOF_ is available.

Well, wait-top-of-frame, not end.

[earok]

Thanks guys, appreciated

[Mrs Beanbag]

Originally Posted by meynaf

Just setup a vblank interrupt and set some flag somewhere.

or use the Copper to do it, it can write to INTREQ (bit 4 is reserved for Copper interrupts!)

[ReadOnlyCat]

Originally Posted by Mrs Beanbag

or use the Copper to do it, it can write to INTREQ (bit 4 is reserved for Copper interrupts!)

Indeed, and this gives you great flexibility in deciding when and why to trigger that interrupt. This could be either at the actual VBlank or immediately after the last onscreen word of data was fetched by the custom chips.