josip@ra.src.umd.edu (Josip Loncaric) (07/31/90)
I have had a bizarre problem with a font of special math symbols which came with my Textures program (from Blue Sky Research, currently v1.2). Certain characters in CMEX10 font at 50pt (prints as 12pt size on 300dpi devices) are not rendered on the screen or printed properly. I could not discover anything wrong with the font, or the Textures program which has served me well for over two years. In fact, the culprit seemed to be Mac's QuickDraw; and this is confirmed by the following explanation I got from Blue Sky Research: In article <15235@reed.UUCP> barry@reed.UUCP (Barry Smith) writes: >From a letter to Mr. Loncaric: > ........... > >The problem is, as far as we can determine, due to errors in >the Macintosh system software, specifically the QuickDraw >graphic display language. In certain cases, especially with >larger point sizes, fonts that contain characters that differ >from ``normal'' placement are drawn incorrectly or >incompletely. We have seen this problem with several fonts, at >a variety of sizes and on a wide selection of devices; >different versions of the system software will sometimes >display varying examples of the problem. > >Some examples from fonts CMEX10 and CIRCLE may help explain >the sort of characters that are involved with this problem. >In the font CMEX10, the \TeX\ math extension font, the >characters are entirely descent with no ascent (they hang >below the reference point on the type baseline), and in some of >the characters (e.g., the integral signs) the character image >is wider than the character advance width, or, in other words, >some characters may overhang the reference point of the >adjacent character. In the CIRCLE font used in \LaTeX, the >reference points and character widths of the circle sections >are placed so as to make alignment easy; this results in some >character images that are entirely to the left of their >reference points. Yet another type of problem can be caused >by characters that have a zero advance width, or ``no width'', >such as the slash used for negation of various math symbols. > >It is our belief that our fonts are well-formed, and that the >problems you (and we) are experiencing are entirely due to >errors in the Apple system software. We have made various >people at Apple aware of these problems on several occasions >in the past three years. I can only hope that these problems >will be corrected in a future release of the Apple software, >and offer any assistance you may desire should you wish to >pursue this problem with Apple yourself. > >If you have access to a PostScript laser printer, please be >aware that problems of this sort do not occur on PostScript >printers, in our experience. > >--- >Barry Smith, Blue Sky Research >barry@reed.edu What I'd like to know is the following: (1) How come Apple has not yet fixed this known problem? Will it ever be fixed? (2) Does anyone offer a QuickDraw substitute which eliminates this problem with character drawing? Sincerely, Josip Loncaric <josip@ra.src.umd.edu> -- Josip Loncaric / SRC / U. of Maryland, College Park, MD 20745