Re: A Proposal...

[nparker@cie-2.uoregon.edu (Neil Parker)]

In article <4jtult$j27@atlantis.atlantis.actrix.gen.nz>
dempson@atlantis.actrix.gen.nz (David Empson) writes:
>In article <4jiv24$kdd@urvile.msus.edu>,
>Bill Scheffler <schefflr@news.msus.edu> wrote:
>> Font Sizes beyond 255 points would be nice for the newer printers.
>Can't be done with any existing applications - the Font Manager and
>Quickdraw only use a byte for the point size, limiting you to 255.
>
>It would be possible for a specially written printer driver to use a
>larger point size font internally and send it directly to the printer,
>if such a font was available (I doubt that Pointless can generate one,
>because it will have the same 255 point size limit).  The font file
>format is probably also limited to 255 points.

No, the font file format doesn't limit fonts to 255 points--the point size
field is two bytes wide.

But if you try to make a font that large, you'll run into other
difficulties.  The most obvious problem is the offset/width table...each
character has a "width" entry in the offset/width table which tells how far
the text cursor should be advanced after the character is drawn.  The width
must fit in a single byte, and the value $FF is reserved, which means no
character can be wider than 254 pixels.  In practice, the limit is even
less than that, since style modifications such as italics or boldface, and
extra spacing inserted with the Quickdraw SetCharExra and SetSpaceExtra
calls, all add to the effective width of the character, and it's the *total*
width after modifications that has to be less than 255 pixels.

So if you designed a 255-point font that really was 255 pixels high, you'd
have to make sure all the characters were tall and skinny.

               - Neil Parker
-- 
Neil Parker, nparker@{cie-2,cie}.uoregon.edu, http://cie-2.uoregon.edu/~nparker

                     "Bad move, Neil!"  -- The Tick