To be able to do so requires the developing dynamic outline fonts, in which points in the outline have variables in their x- and y-coordinates. Heretofore, the outline of all characters in all fonts have only constants for their x- and y-coordinates. Indeed, the type 1 mechanism that is utilized by nearly all commercial fonts assumes only constants. Additionally, it must be possible to slant characters on demand. Here again, heretofore, all fonts do not allow the angle of the baseline of characters to be changed on the fly.
Besides working out the details of these dynamisms and implementing them into specific Persian fonts, it is necessary to work out the interface between such fonts and formatters, so that formatters can provide commands or style sheet entries requesting stretched and slanted characters and will issue the proper commands to the printer to use the facilities in the associated fonts.
The research is thus focused on adding the ability to typeset Persian with stretchable and slantable fonts in the tri-directional troff. Another way to look at this work is that it is finally making fuller utilization of the computer that is in modern laser printers to do things with the printer-resident font software that cannot be done completely by the computer that does the formatting.
Berry, D.M. ``Stretching Letter and Slanted-Baseline Formatting for Arabic, Hebrew, and Persian with ditroff and Dynamic POSTSCRIPT Fonts,'' Technical Report, Faculty of Computer Science, Technion, Haifa, Israel, 1998 PDF ps.Z
Berry, D.M. ``Stretching Letter and Slanted-Baseline Formatting for Arabic, Hebrew, and Persian with ditroff and Dynamic POSTSCRIPT Fonts,'' Software--Practice & Experience, 29:15, 1417-1457 1999 PDF ps.Z