From: dstamp@watserv1.waterloo.edu (Dave Stampe-Psy+Eng)
Subject: Re: TECH: New 386 polyblit release
Date: Thu, 6 Feb 1992 02:32:30 GMT
Message-ID: <1992Feb6.023230.16457@watserv1.waterloo.edu>
Organization: University of Waterloo


psantangeli@alias.com (Peter Santangeli) writes:

>I'm sorry, but I have been holding my tongue on this one for too long.
>
>A. A blitter is in fact a piece of hard/software for moving rectangular
>   blocks of data around or on/off a frame bufffer. The common usage 
>   for such a thing is to move windows etc. around a screen (but much 
>   more interesting things can be done them).
>
>B. A piece of of hard/software that displays polygons in a frame buffer
>   IS NOT A BLITTER. It is a POLYGON SCAN CONVERTER. It is named such
>   because its purpose is to take the cartesian definition of a polygon
>   and convert it into spans of pixels for each of the scan lines
>   covered by the polygon. 

Picky, picky, picky.  A blitter is far more descriptive of
the way that REND386 does polys.  A poly scan converter is far more
complex than this: it usually handles concave polys as well.

Too much concern about terminology in a field is my cue to exit, stage left.
VR is interesting to me because it is a new, fluid field.  Physics and
math are not, because the librarians have taken over.  Luckily, there is
plenty of room for free creative spirits in VR yet.

>Those wanting to really make graphics sing should read "Graphics Gems"
>edited by Andrew S. Glassner, and "Graphics Gems II", edited by

The stuff in Graphics Gems is VERY slow.  It is based on frame buffers, 
powerful processors, and no need for real time.  For PCs, real-time graphics
requires much more "crude" but fast methods.  Forget about textures,
luminosity, etc if you want to do real VR on a PC (at least until some
hardware assist of better video interface comes along).

--------------------------------------------------------------------------
| My life is Hardware,                    |                              | 
| my destiny is Software,                 |         Dave Stampe          |
| my CPU is Wetware...                    |                              | 
| Anybody got a SDB I can borrow?         | dstamp@watserv1.uwaterloo.ca |
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