NetNews Usenet Archive 1992 #31/NN_1992_31.iso/spool/comp/lang/postscri/6108

Text File | 1992-12-28 | 1.6 KB | 34 lines

Newsgroups: comp.lang.postscript
Path: sparky!uunet!cs.utexas.edu!qt.cs.utexas.edu!yale.edu!spool.mu.edu!umn.edu!femto!cahoon
From: [e-mail] (Forrest Clinton Cahoon)
Subject: problem manipulating binary data in postscript
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Sender: [e-mail] (Usenet News Administration)
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Organization: University of Minnesota, Minneapolis, CSci dept.
Date: Mon, 28 Dec 1992 17:12:57 GMT
Lines: 22

I'm trying to write some postscript which will color a hexagonal grid,
reading the color data from the end of my ps file.  I'm reading one
byte for each hexagon, then doing some bit-twiddling to get values to call
setrgbcolor with before filling the hexagon.

I've got a version using "read" which works, but since "read" treats my
newline characters as valid binary data, it's not entirely
satisfactory.

What I want to use is "readhexstring", but since what this reads in is
treated as a string rather than an integer, I'm having trouble.  I
need to convert my one-byte string into an integer having the same
binary representation.  I don't want "cvi", because this parses a
string which represents an integer to us humans, and puts that value
on the stack -- cvi would read (1) and put the integer value 1 on the
stack, but what I need would take (1) and put the integer value 49 --
the ASCII value of the character 1 -- on the stack.

--
|  Forrest Cahoon      | [e-mail] |------------------------------|
|  850 21st Ave SE     |-------------------| Only unbalanced people       |
|  Mpls MN  55414-2514 |                   |        can tip the scales... |