[texhax] TeX -> PostScript, but in a resolution-independent manner

Randolph J. Herber herber at dcdrjh.fnal.gov
Wed Jun 4 20:17:03 CEST 2003

The following header lines retained to effect attribution:
|Date: Thu, 05 Jun 2003 00:23:15 +0100
|From: Robin Fairbairns <Robin.Fairbairns at cl.cam.ac.uk>
|Subject: Re: [texhax] TeX -> PostScript, but in a resolution-independent manner
|To: "Randolph J. Herber" <herber at fnal.gov>
|Cc: texhax <texhax at tug.org>

|> 	I opine that the proper statement is that scalable or outline
|> 	fonts, when actually displayed or printered become bitmap fonts.

|in context (discussing what you send to the printer or display driver)
|this is a pointless remark.  the output that is produced is indeed a
|bitmap, but the font attributes are something else entirely.  (you
|typically can't retrieve the rasterised bits destined for the output
|medium for re-use -- and re-use is what fonts are about.)

	1) The start of this discusssion was the poor appearance of
	   bitmapped fonts, when printed or displayed.  Therefore,
	   I opine (regardless of your opinion), that my point is
	   in fact pertinent, as you admit with ``output that is
	   produced is indeed a bitmap.''

	2) The bitmaps are in fact recoverable using appropriate
	   PostScript language interpreters.  That is how ghostscript
	   is used frequently: to gnerate bitmaps for dotmatrix or
	   HPCL printers.

	3) (Scalable) PostScript fonts, whether, Type 1, Type 3,
	   Type 42, Multiple-Master, et al., are a very close
	   equivalent to Metafont in both purpose and function.
	   Before display they are converted to bitmaps in the
	   PostScript interperters.

	4) Printing is a form of bitmap recovery.

|> 	One of the parameters that can be given to dvips is the
|> 	resolution of printer or display device so that dvips can
|> 	use the correct font set or trigger the proper font
|> 	generation.  As most printers work at 300 dpi, 600 dpi,
|> 	1200 dpi, 1270 dpi (50dpmm), 1440 dpi or 2540 dpi (100
|> 	dpmm), it is common to find pre-generated font sets at
|> 	those resolutions.  [rest omitted]

|_really_?  i've never seen a pk font set at anything higher than
|600dpi, and i wouldn't want to.  i typically print to a 1200dpi
|printer, and *never* use bitmaps on it.  i know there are fonts
|available only in metafont form, but i'm fortunate in not needing

	I have generated and used 1200dpi fonts and have
	encountered the other resolutions (as least, the 1440
	dpi resolution and have heard from others using Linotype
	class film generators of 2540 dpi pre-generated fonts).

	I forget which of the acceptable-to-dvips bitmap font
	format I used, but to resultant fonts where acceptable
	to me and to the people for whom I work.  It perhaps
	was not pk but one of the more compressed formats.

|bitmap fonts were ok for the footling resolutions that knuth was
|dealing with in the 1970s, but we're miles away from that world, now:
|and who cares? -- xdvi rasterising type 1 fonts is adequately fast,
|even for my impatient eyes, and the rasterisers in printers are
|written by people whose only speciality it is.

	rasterizing ==> bitmap generation.  Which is my point.

Randolph J. Herber, herber at fnal.gov, +1 630 840 2966, CD/CDFTF PK-149F,
Mail Stop 318, Fermilab, Kirk & Pine Rds., PO Box 500, Batavia, IL 60510-0500,
USA.  (Speaking for myself and not for US, US DOE, FNAL nor URA.)  (Product,
trade, or service marks herein belong to their respective owners.)

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