Path: chuka.playstation.co.uk!news From: James Russell Newsgroups: scee.yaroze.programming.3d_graphics Subject: Re: 2d sprites in a 3d world Date: Tue, 08 Dec 1998 13:44:39 +0000 Organization: Sony Computer Entertainment Europe Lines: 19 Message-ID: <366D2D47.1AB292C6@scee.sony.co.uk> References: <3659BEF7.663E@mdx.ac.uk> <3659D5B1.41EB5140@scee.sony.co.uk> <366959c3.522585@www.netyaroze-europe.com> <366B9EB5.B8FA3B6C@scee.sony.co.uk> <366c34f0.669519@www.netyaroze-europe.com> <366CF3F0.7429A66C@scee.sony.co.uk> NNTP-Posting-Host: mailgate.scee.sony.co.uk Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 4.5 [en] (Win95; I) X-Accept-Language: en James Russell wrote: > > By default (a default that you can't change, I might add), all the SZ's are multiplied by 1/16 > (1.3.12 fixed point format) before being added to make the 'average'. Why it's 1/16 and not 1/4 I'm > not sure. But that means that the answer will always be 14 bits maximum. Which is why you subtract > from 14. Hooray for everything. Adden-dumb: The reason why it's a 1/16 is to _make_sure_ that the maximum bit length is 14. The final value is shifted left by 2 when it's used to index the OT (because OT's are an array of u_longs which are 4 bytes in size). So it's an optimization thing. J -- == James_Russell@scee.sony.co.uk +44 (171) 447-1626 == Developer Support Engineer - Sony Computer Entertainment Europe As unaquainted as a blind man and his shadow.