Hi Andre', Please clarify how this function is actually intended to be used. I assume it would be used by an application to make rendering decisions (no-draw/draw and what to draw) based upon previously obtained results (the delta since the last call), but want to make sure so that the need is properly met.
Thanks, Timothy >-----Original Message----- >From: directfb-dev-boun...@directfb.org >[mailto:directfb-dev-boun...@directfb.org] On Behalf Of Andre DRASZIK >Sent: Friday, January 29, 2010 1:32 PM >To: 'directfb-dev@directfb.org' >Subject: Re: [directfb-dev] screen related patches > >Hi Timothy, > >It starts counting at system startup/boot and just keeps going. >That's how linux' struct fb_vblank describes it, so I don't >think it makes sense to have different semantics in DirectFB >for this - other systems/screen drivers implementing it should >do exactly the same I think. > >And yes, it will wrap around at some point - but you'll have >this with any counter - 32bits is still a long time for vsyncs... > >Also, I think maybe the counter should be changed to u32? >Again, that's how the kernel defines it for the fbdev system, >instead of unsigned long. I noticed only now :-( > > >Cheers, >Andre' > >On Fri, 2010-01-29 at 09:29 -0800, Strelchun, Timothy wrote: >> Hi Andre', >> >> What's your definition for current vertical sync count? >> >> I assume it starts incrementing when the current output >display mode was configured by the display drivers or DFB. >Thus it is reset to zero each time the current output display >mode is reconfigured by the display drivers or DFB. I also >assume it will simply wrap on overflow (only way to determine >is tracking the previous value). >> >> This is important to understand for other system drivers >that will require different implementations of >IDirectFBScreen::GetVSyncCount. >> >> Thanks, >> Timothy >> >> -- >> >> Timothy Strelchun >> CE Software Engineering >> Digital Home Group >> Intel Corporation >> >> The views expressed above are my own and not those of Intel >> >> >-----Original Message----- >> >From: directfb-dev-boun...@directfb.org >> >[mailto:directfb-dev-boun...@directfb.org] On Behalf Of >Andre DRASZIK >> >Sent: Friday, January 29, 2010 4:01 AM >> >To: directfb-dev >> >Subject: [directfb-dev] screen related patches >> > >> >Hi, >> > >> >attached are two patches - >> > >> >1) fixes incorrect patching of the frequency for NTSC/PAL-60 >> >standards (they are defined as 59.94Hz not 60Hz, this is simply >> >wrong) >> > >> >2) I would like to have an API to retrieve the current >VSync count - >> >attached is an implementation for the fbdev system. >> > >> > >> >Cheers, >> >Andre' _______________________________________________ directfb-dev mailing list directfb-dev@directfb.org http://mail.directfb.org/cgi-bin/mailman/listinfo/directfb-dev
