I have been writing Mac and Vax programs that output files
in Adobe Illustrator 88 format. In doing so I have required a program
to take MacDraw patterns and convert them into AI88 Patterns.
The way I do this is to take the hexadecimal representation of a pattern
and type it into a small Mac Program I have written (Think C 4.0) row by row, two
hex characters at a time. The resulting patterns look pretty nice, especially the bit type patterns like the Ice Cream Cone, Checkers, Molecules, Indian Jewelry, etc. The only patterns that didn't look so nice were the diagonal patterns which exhibited Moire patterns no matter what the magnification. So to get around that I created straight line patterns that I then rotated plus or minus 45 degrees and they look great.
Why would anyone want to creat AI88 patterns from MacDraw patterns?
First off for my programs I needed patterns and wanted postscript output. AI88 patterns are completely transformable, they can be resized, rotated, offset, skewed to your heart's content or your eye's tolerance for unaesthetic patterns. Thus they can be used in perspective, blowouts, etc. Because they are raw postscript, they seem to print out faster though I have no scientific way to profile this. The disadvantage is that with these patterns it takes a long time to preview, normal artwork mode is fine. It's best just to print out documents containing these patterns, printing can often be faster than displaying. The preceding does not apply if you have a monster machine. Sorry a MacPlus is not a monster machine
In this package I have included the following,
1. An Adobe Illustrator 88 (AI88) document containing the converted standard
MacDraw patterns.
2. A MacDraw document containing the same MacDraw patterns.
3. An AI88 document containing further Illustrator patterns that may be useful,
primarily from marine geology but they are most likely of more general use.
4. A Think C program in the standard console environment
and source code, (Warning: The hex decomposition routines
are quick and dirty and will make any computer scientist lose his lunch,
but they work ). The patterns document must be opened from within AI88, it
will not be a double clickable document.
An important aside came up from writing the source code. I found that when
opening up AI88 documents the postscript libraries were automatically
added. Therefore you can considerably reduce the size of the AI88 documents
your code produces if you use a header without the libraries. The size
reduction is from 12K of text to 12 lines of text. The subroutine header.c
demonstrates the minimum header required for the AI88 program to recognize
