Date: Wed, 28 May 1997 08:03:19 -0700 From: Amancio Hasty <hasty@rah.star-gate.com> To: Luigi Rizzo <luigi@labinfo.iet.unipi.it> Cc: luigi@iet.unipi.it, multimedia@FreeBSD.ORG Subject: Re: bt848 status, comments and diffs Message-ID: <199705281503.IAA24013@rah.star-gate.com> In-Reply-To: Your message of "Wed, 28 May 1997 13:24:46 %2B0200." <199705281124.NAA17044@labinfo.iet.unipi.it>
next in thread | previous in thread | raw e-mail | index | archive | help
Hi Luigi, I am going to work on your mods is just that I am on my regular work schedule. As for your clipping idea , the existing clipping algorithm was designed for ease of programmability specially with respect to X. I decided to leave the smarts to the driver rather than to the programmer. As it is today no one is using the clipping code even though is pretty easy to use. The good thing about the existing scenario is that no one is using the clipping code;hence, we can provide both methods . Last but not least lets shoot for a checking by Monday . Not that interested in having various versions of the Bt848 driver floating around. I was planning to checking the existing code at my ftp site by this Friday however given that your mods are useful and not that hard to implement is best to attempt to test them now . Regards, Amancio >From The Desk Of Luigi Rizzo : > Yet another version of brooktree848.c with the cleanups I was > mentioning in my previous postings. The code is available at > > http://www.iet.unipi.it/~luigi/brooktree848.c > > I have tested it and it seems to work in both packed and planar mode, > with single frame capture. It works with the old and the new > grabber-meteor.cc > > Try it if you can, and send feedback. > > I have left the rgb_ code untouched, since amancio is probably working > on that. In passing, I noticed that the clipping features of the Bt848 > are quite powerful. A better way to exploit them would be, probably, to > let the application program pass the clipping shape in raster format, > rather than pass it as a set of rectangles. This would allow complex > figures (e.g. clipping into circles, ovals etc. which are not possible > now, and do not require time-consuming computations from the kernel like > sorting rectangles etc. > > Basically, I would describe a clipping shape as a sequence of lines > > BEGIN (skip n1 write n2) * > > (one per row in the output) and let the driver just translate this into > Bt848 instructions. The above description can be as small as 32 bit/row. > > Cheers > Luigi > -----------------------------+-------------------------------------- > Luigi Rizzo | Dip. di Ingegneria dell'Informazione > email: luigi@iet.unipi.it | Universita' di Pisa > tel: +39-50-568533 | via Diotisalvi 2, 56126 PISA (Italy) > fax: +39-50-568522 | http://www.iet.unipi.it/~luigi/ > _____________________________|______________________________________
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199705281503.IAA24013>