AFM files
28-Jan-90 15:21:55
Sb: #6514-AFM files
Fm: Tripp Narup 76340,134
To: Rick LePage/MacInTouch 76117,1765
The AFM files are more for reference than anything else. The Mac doesn't
actually *use* the AFM files since all the font metrics are contained
within the font itself. What AFM files are useful for is helping other
programs "load" font widths. For instance, Magnatype uses AFMS to load font
widths and kern information for its PostScript module. We have one client
who wrote their own publishing software and they too use AFMs to load font
widths and kerns. The AFM files are also of great use to PS programmers.
For instance, if you want to create a new accented character, you have to
refer to the AFMs to figure out precisely where to place the accent. In
short, yes, you're right, the info is all contained within the font, but
the AFMs are a handy ASCII version of the info which can be accessed a lot
easier than trying to pick the font apart. Ventura Publisher, BTW, uses an
abbreviated form of the AFM files to generate its width and kern tables.
The only programs that I know of that actually *use* AFM files are
PC-based.