🚀 go-pugleaf

In article <7941@tut.cis.ohio-state.edu> mills-cl@pike.cis.ohio-state.edu (christopher mills) writes:
>In article <2801@gryphon.CTS.COM> richard@gryphon.CTS.COM (Richard Sexton) writes:
>>Alright, I'm letting you guys in on one of my secrets.
>>I've been using this tip to acheive what looks for all the world
>>like 32 gray scales.
>	Not so big of a secret.  My first ray-tracing attempts were in black
>and white, 640 x 400, 16 shades of grey with a 2 x 2 dither patern, giving
>(as I recall) 61 shades of grey.  It looked pretty good...

Come on, guys! This stuff has been in the literature for over 6 years.   Take
a look at "Fundamentals of Interactive Computer Graphics" by J.D. Foley and 
Andrew Van Dam, published in 1981:

"Halftone approximation", on page 597-602 on bi-level displays [1 bit/pixel],
and "Reporoducing Color Hard Copy", p. 620, on generating 125 different colors
on 3 bit/pixel displays. This is how it is done on Tektronix 4105/4107 
terminals (see Color Plate  27).  I did it on the Amiga for our unreleased
Tek 4105 emulator, and it looked pretty good, except for the flicker. Nothing
new.  Just what everybody should now by now.

-- Marco