jjc@jclark.UUCP (James Clark) (09/07/89)
A number of people have suggested that groff should produce ditroff compatible output. Initially I wasn't very keen on this since it involved a lot of extra work, but I want groff to be used and people seem to want ditroff output format, so I have decided to support it. I now have two separate versions of groff: one that supports TeX dvi and PostScript formats and one that supports ditroff output format. Unfortunately the differences between the two are rather extensive. For example, the dvi version takes the TeX approach to rounding -- it leaves it up to the driver to round motions to multiples of the output device's resolution -- whereas the ditroff version takes the troff approach and does the rounding to device resolution itself. This difference manifests itself throughout the program. Maintaining two separate versions is a lot of additional work; so my current inclination is to ditch the dvi version and go with the ditroff version. I don't think the technical arguments are conclusive in favour of either output format. But those whose needs are best met by dvi output format already have the option of using TeX. I think groff should serve those who prefer the ditroff approach to device independent output. The dvi version had some input incompatibilities with ditroff caused by the different approach to rounding; I have been able to eliminate these in the ditroff version. It was also not possible to support some ditroff features (\S and \H) when producing dvi output. My main problem with ditroff compatibility is the font metric format. The binary ditroff font format is rather inflexible and lacks important information; in particular, there's no pairwise kerning information. I can't live with that. So I have made groff read the ascii ditroff font format, but with a few (completely optional) extensions. For example, to make groff do pairwise kerning you just add a section like this (immediately before or after the charset section): kernpairs A V -12 A W -8 This provides ditroff compatibility without crippling groff's capabilities. James Clark jjc@jclark.uucp uunet!mcvax!ukc!jclark!jjc
wnp@attctc.Dallas.TX.US (Wolf Paul) (09/09/89)
In article <JJC.89Sep7135705@jclark.UUCP> jjc@jclark.UUCP (James Clark) writes: >I now have two separate versions of groff: one that supports TeX dvi >and PostScript formats and one that supports ditroff output format. > ... >My main problem with ditroff compatibility is the font metric format. >The binary ditroff font format is rather inflexible and lacks >important information; in particular, there's no pairwise kerning >information. I can't live with that. So I have made groff read the >ascii ditroff font format, but with a few (completely optional) >extensions. ... Fantastic! And where, pray, can one obtain groff? Even a beta version would be great to fiddle with :-). Wolf -- Wolf N. Paul * 3387 Sam Rayburn Run * Carrollton TX 75007 * (214) 306-9101 UUCP: {texbell, attctc, dalsqnt}!dcs!wnp DOMAIN: wnp@attctc.dallas.tx.us or wnp%dcs@texbell.swbt.com NOTICE: As of July 3, 1989, "killer" has become "attctc".