From: Keith W. <ke...@tu...> - 2007-08-02 16:57:24
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Michel D=E4nzer wrote: > On Thu, 2007-08-02 at 17:44 +0200, Jerome Glisse wrote: >> Btw i think that some GPU can wait on vblank using cmd ie you >> don't need to ask the card to emit irq you just insert a cmd in >> stream which stall further cmd execution until vblank happen, >> this might be good for power consumption.=20 >=20 > It's generally a bad idea because it prevents the GPU from doing > anything else that could be done before vertical blank. This is true on cards with a single command stream - if you had=20 per-context ringbuffers and a hardware scheduler, it might be better. Unfortunately, you still end up forcing the cliprects not to change,=20 unless you also have some hardware mechanism for that, which I think is=20 pretty rare nowdays. Hmm. Maybe you could use the frontbuffer alpha bits as a window id.=20 You'd still need to either lock the window position, or find some way of = telling the hardware about window position changes, or... something else.= =2E. Anyway, it gets complicated... Keith |