xanthian@zorch.SF-Bay.ORG (Kent Paul Dolan) (06/10/90)
[Steve's long WYSIWYG printing article omitted; read it for context] I did the text layout package for a commercial product. The way to make both screen and printer text output nice is to use fonts scaled for the screen to draw the screen, and fonts scaled for the printer to do the printing, and to _rerun_ your text layout routine at the changed resolution, with the fonts appropriate for that resolution, when you go from screen to printer, so that the intercharacter and interword spacing doesn't suffer from pixel roundoff errors, rather than attempt to go from the pixels laid out for the scrren to pixels on the printer. In general, this requires outline fonts be available that can be scaled and pixel tweaked for the various resolutions of, say, 12 point courier, that are to be printed various places. This also requires that the printing application (desktop pub software, say) be able to ask the printer driver what its resolution is. Several difficulties exist besides the general ones of creating the software at all. First, font technology today (except METAFONT, and partially Postscript) is proprietary and expensive and arcane. Next, different printing technologies require adjustments for peculiarities of the printing process (particularly "write white" laser printers, which tend to lose single pixel wide lines). Third, good font technology is slow. Fourth, good font technology is both memory and disk storage intensive. An ideal goal would be to have TeX and METAFONT universally available, preferably with METAFONT on a special purpose processor for sufficient speed, and to put the character/font caching technology of Postscript et alia into TeX, so that the incredibly messy job of maintaining libraries of pre-rasterized METAFONT font-at-resolution files could be eliminated by doing all "outline" to pixel conversions on demand, rather than before the fact. If the speed and font library maintenance problems of METAFONT were overcome, I don't think there is a technology that can touch it with TeX for printing quality, and TeX is "resolution independent" in the sense that it does output from the same input file at about the best quality each display device can support. Kent, the man from xanth. <xanthian@Zorch.SF-Bay.ORG> <xanthian@well.sf.ca.us>