Path: chuka.playstation.co.uk!scea!greg_labrec@interactive.sony.com
From: jamin1@psu.edu (Jamin Frederick)
Newsgroups: scea.yaroze.beginners
Subject: Re: Ordering Tables
Date: Thu, 29 May 1997 19:13:30 GMT
Organization: SCEA Net Yaroze News
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	I've been programming some 2d stuff for like a week and
a half now and I still haven't figured out how big the PACKETs
need to be.  You need enough space for each basic thing you stick
in the OT.  It hasn't been real clear to me yet, though, exactly how
the OT, packets, and tags are structurally organized.
	You need two OTs, two tag arrays and two PACKET arrays.
since the playstation does two things at once: displaying and drawing.
So while its drawing with one OT, tag array, and PACKET, it's
displaying the other set.  The programmer doesn't really have to worry
about this, though.  Its always done the same way.  You stick things
like lines, sprites, and boxes into the "currently active"  OT, sort
them, and draw them, just make sure you do the sorting/drawing in the
right order, per the demos.  The switch to the opposite set is done
at every screen refresh, when the opposite buffer is now "active".
Actually, the loop present in all the demos is only going around once
per screen refresh, since one of the commands, VSync(0), pauses
execution until the screen is ready to be refreshed.


Jamin Frederick
jamin1@psu.edu

On 16 May 1997 23:08:08 GMT, "Nelson Santos" <nelson@total.net> wrote:

>To whoever can help:
>
>I am a little unclear as to the meaning of an Ordering Table (OT).
>According to the User Guide, an ordering table is used "for controlling
>the proper display of polygons".  Polygons means 3D, however I've seen
>OT's used in 2D graphics programming as well as a simple "Hello World"
>program.  What gives?
>
>Here is MY analysis:  An ordering table is actually a place where you
>insert a list of instructions on where to place sprites on the screen.
>It basically holds all of the locations of each object on the screen.
>When the list is complete, you call GsDrawOT() to place everything on
>the screen that is defined in the table.
>
>Is this correct?  If not, please clarify for me as it seems to be an
>essential step for placing any kind of graphics on the screen.
>
>Also, how do packets fit into all this?
>
>Thank you very much in advance!
>
>Nelson.
>
>