Path: chuka.playstation.co.uk!scea!peter_alau@playstation.sony.com From: Gerrit Goossen Newsgroups: scee.yaroze.programming.3d_graphics Subject: Re: GsLinkObject4 Confusion - Moving on to GsSortObject4 Date: Tue, 25 Aug 1998 06:23:29 -0400 Organization: SCEA News Server Lines: 40 Message-ID: <35E2909F.3394@funnytown.com> NNTP-Posting-Host: 38.165.241.13 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 3.01-C-MACOS8 (Macintosh; I; PPC) >Gerrit Goossen wrote: >> >> While attempting to write some code to read primitives from an already >> linked TMD model (for the purpose of using its polys for collision >> detection) I discovered that GsLinkObject4 is tinkering with the first >> primitive in the object: Specifically it writes over the first >> primitive's ilen and olen with "0x0400". > >It's not just the first primitive that changes. It adjusts the Ilen/Olen every time >the primitive code changes. The number that it writes is a 16 bit value that >describes the number of primitives of the current type to follow. Okay, I can deal with that :) >So it looks like you've got 0x400 (=1024) polygons of a certain type in >consecutive order. Subsequent primitives of the same type are not adjusted. Actually that was little-endian (I read it out of the MW Debugger). If I had 1024 polygons now *that* would be interesting, but alas I only have four polygons in that object. (But I tell you, they are 4 *really* *really* interesting polygons! ;) I guess now my question is: Can anyone tell me exactly what operations GsSortObject4() performs? Some of the bits that the documentation doesn't really clear up for me include: - Is perspective conversion performed on all the verticies in a TMD object? (Regardless of whether they are used in primitives or not?) Or does it perform the same conversion on the verticies multiple times if they are used in multiple primitives? - Is there anyway to *prevent* GsSortObject4() from performing perspective conversion? (And just perform sorting?) Thanks again for any help! I'd really prefer to beat GsSortObject4 into submission as opposed to re-writing the beast :) - Gerrit