The argument -Pxxx loads parameters and character definitions for typesetter xxx, which at the moment is typically one of psc (PostScript), ip (imagen), va (varian), vp (versatec) or ter (terminal or printer).
-Fyyy causes font information to be loaded from directory yyy instead of the default /sprite/lib/ditroff/devxxx.
The most significant new facility is the ability to draw simple graphical objects --- diagonal lines, circles, ellipses, arcs, splines, and filled polygons --- in TROFF .
The new graphical commands are
\D'l dh dv'
draw line from current position by dh, dv
\D'c d'
draw circle of diameter d with left side at current position
\D'e d1 d2'
draw ellipse of diameters d1 d2
\D'a dh1 dv1 dh2 dv2'
draw arc counter-clockwise from current position to dh1+dh2
dv1+dv2, with center at dh1 dv1 from current position
\D'~ dh1 dv1 dh2 dv2 ...'
draw B-spline from current position by dh1 dv1
then by dh2, dv2, then by dh3, dv3, then ...
\D'g dh1 dv1 dh2 dv2 ...'
same as \D'~ dh1 ...' except the gremlin spline
algorithm is used.
\D'p n dh1 dv1 dh2 dv2 ...'
draw polygon using stipple n from current stipple font
starting at current position by dh1 dv1 then by dh2, dv2,
then by dh3, dv3, then ...
\D'P n dh1 dv1 dh2 dv2 ...'
same as \D'p n dh1 ...' except no border is printed.
\D't d'
set line thickness to d (set to 3 units at startup).
The default units are ems, so d must be given in u
units if a number of pixels is needed.
\D's d'
set line style to d (set to -1 at startup). The value is
taken as a coordinate mask on the individual bits of the line.
The default units are ems, so d must be given in u units.
The position after a graphical object has been drawn is at its ``end'', where for circles and ellipses, the end is at the right side. As with other commands, default units are ems horizontally and line spaces vertically.
Realistically, these commands are not intended for direct use, but for preprocessors like PIC, IDEAL, and GRN.
.sy commandline executes the command, then returns. Output is not captured anyplace.
.cf file copies file into the TROFF output file at this point, uninterpreted. Havoc ensues unless the motions in the file restore current horizontal and vertical position. This command hasn't been used much, and is probably a bad idea anyway.
.pi program (pipe the output into program) now works in TROFF as well as NROFF, since it makes somewhat more sense to allow it.
.st stipple_font loads stipple_font as the current font used to fill polygons, with each polygon command selecting one pattern number from the font. The available stipple fonts are listed in the "font" manual page.
The number register $$ contains the process id of the TROFF process.
The string .T contains the name of the current typesetter (e.g., psc, va, vp, ip).
The .ft command causes the named font to be loaded on font position 0 (which is in all other ways inaccessible) if the font exists and is not currently mounted by default or by a .fp command. The font must be still or again in position 0 when the line is printed.
Transparent mode (\!) has been fixed so that transparent output actually appears in the output; thus special commands can be passed through to postprocessors by witchcraft like
.if "\*(.T"psc" \!x ...
(If this makes no sense to you, you shouldn't be using it anyway.)
The .fz and .li commands are no more. The -p, -g and +n command line arguments have also been eliminated, as has the hp number register.