NAME
grn - groff preprocessor for gremlin files
SYNOPSIS
ggrrnn [ -CCvv ] [ -TTdev ] [ -MMdir ] [ -FFdir ] [ file... ]
It is possible to have whitespace between a command line option and its parameter.DESCRIPTION
grn is a preprocessor for including gremlin pictures in groff input.
grn writes to standard output, processing only input lines between two
that start with ..GGSS and ..GGEE.. Those lines must contain grn commands
(see below). These commands request a gremlin file, and the picture in that file is converted and placed in the troff input stream. The ..GGSSrequest may be followed by a C, L, or R to center, left, or right jus-
tify the whole gremlin picture (default justification is center). If no file is mentioned, the standard input is read. At the end of the picture, the position on the page is the bottom of the gremlin picture.If the grn entry is ended with ..GGFF instead of ..GGEE, the position is left
at the top of the picture.Please note that currently only the -me macro package has support for
..GGSS, ..GGEE, and ..GGFF.The following command-line options are understood:
-TTdev Prepare output for printer dev. The default device is ppss. See
ggrrooffff(1) for acceptable devices.-MMdir Prepend dir to the default search path for gremlin files. The
default path is (in that order) the current directory, the homedirectory, //uussrr//lliibb//ggrrooffff//ssiittee-ttmmaacc, //uussrr//sshhaarree//ggrrooffff//ssiittee-ttmmaacc,
and //uussrr//sshhaarree//ggrrooffff//11..1199..11//ttmmaacc.-FFdir Search dir for subdirectories ddeevvname (name is the name of the
device) for the DDEESSCC file before the default font directories//uussrr//sshhaarree//ggrrooffff//ssiittee-ffoonntt, //uussrr//sshhaarree//ggrrooffff//11..1199..11//ffoonntt, and
//uussrr//lliibb//ffoonntt.-CC Recognize ..GGSS and ..GGEE (resp. ..GGFF) even when followed by a char-
acter other than space or newline.-vv Print the version number.
GGRRNN CCOOMMMMAANNDDSSEach input line between ..GGSS and ..GGEE may have one grn command. Commands
consist of one or two strings separated by white space, the first string being the command and the second its operand. Commands may be upper or lower case and abbreviated down to one character. Commands that affect a picture's environment (those listed before ddeeffaauulltt, see below) are only in effect for the current picture: The environment is reinitialized to the defaults at the start of the next picture. The commands are as follows: 11 N 22 N 33 N 44 N Set gremlin's text size number 1 (2, 3, or 4) to N points. The default is 12 (resp. 16, 24, and 36). rroommaann f iittaalliiccss f bboolldd f ssppeecciiaall f Set the roman (italics, bold, or special) font to troff's font f (either a name or number). The default is R (resp. I, B, and S). ll f ssttiippppllee f Set the stipple font to troff's stipple font f (name or number). The command ssttiippppllee may be abbreviated down as far as `st' (to avoid confusion with ssppeecciiaall). There is no default for stipples (unless one is set by the default command), and it is invalid to include a gremlin picture with polygons without specifying a stipple font. xx N ssccaallee N Magnify the picture (in addition to any default magnification) by N, a floating point number larger than zero. The command ssccaallee may be abbreviated down to `sc'. nnaarrrrooww N mmeeddiiuumm N tthhiicckk N Set the thickness of gremlin's narrow (resp. medium and thick) lines to N times 0.15pt (this value can be changed at compiletime). The default is 1.0 (resp. 3.0 and 5.0), which corre-
sponds to 0.15pt (resp. 0.45pt and 0.75pt). A thickness value of zero selects the smallest available line thickness. Negativevalues cause the line thickness to be proportional to the cur-
rent point size. ppooiinnttssccaalleeScale text to match the picture. Gremlin text is usually printed in the point size specified with the commands 11, 22, 33, or 44 regardless of any scaling factors in the picture. Setting ppooiinnttssccaallee will cause the point sizes to scale with the picture (within troff's limitations, of course). An operand of anything but off will turn text scaling on. ddeeffaauulltt Reset the picture environment defaults to the settings in the current picture. This is meant to be used as a global parameter setting mechanism at the beginning of the troff input file, but can be used at any time to reset the default settings. wwiiddtthh N Forces the picture to be N inches wide. This overrides any scaling factors present in the same picture. `wwiiddtthh 0' is ignored. hheeiigghhtt N Forces picture to be N inches high, overriding other scaling factors. If both `width' and `height' are specified the tighter constraint will determine the scale of the picture. HHeeiigghhtt and wwiiddtthh commands are not saved with a ddeeffaauulltt command. They will, however, affect point size scaling if that option is set. ffiillee name Get picture from gremlin file name located the current directory (or in the library directory; see the -MM option above). If two
ffiillee commands are given, the second one overrides the first. If name doesn't exist, an error message is reported and processing continues from the ..GGEE line. NNOOTTEESS AABBOOUUTT GGRROOFFFFSince grn is a preprocessor, it doesn't know about current indents,
point sizes, margins, number registers, etc. Consequently, no troff input can be placed between the ..GGSS and ..GGEE requests. However, gremlin text is now processed by troff, so anything legal in a single line of troff input is legal in a line of gremlin text (barring `.' directives at the beginning of a line). Thus, it is possible to have equationswithin a gremlin figure by including in the gremlin file eqn expres-
sions enclosed by previously defined delimiters (e.g. $$).
When using grn along with other preprocessors, it is best to run tbl
before grn, pic, and/or ideal to avoid overworking tbl. Eqn should
always be run last. A picture is considered an entity, but that doesn't stop troff from trying to break it up if it falls off the end of a page. Placing thepicture between `keeps' in -me macros will ensure proper placement.
grn uses troff's number registers gg11 through gg99 and sets registers gg11
and gg22 to the width and height of the gremlin figure (in device units) before entering the ..GGSS request (this is for those who want to rewrite these macros). GGRREEMMLLIINN FFIILLEE FFOORRMMAATT There exist two distinct gremlin file formats, the original format from the AED graphic terminal version, and the SUN or X11 version. Anextension to the SUN/X11 version allowing reference points with nega-
tive coordinates is nnoott compatible with the AED version. As long as a gremlin file does not contain negative coordinates, either format willbe read correctly by either version of gremlin or grn. The other dif-
ference to the SUN/X11 format is the use of names for picture objects (e.g., POLYGON, CURVE) instead of numbers. Files representing the same picture are shown in Table 1 in each format. sungremlinfile gremlinfile 0 240.00 128.00 0 240.00 128.00 CENTCENT 2 240.00 128.00 240.00 128.00 185.00 120.00 185.00 120.00 240.00 120.00 240.00 120.00 296.00 120.00 296.00 120.00* -1.00 -1.00
2 3 2 3 10 A Triangle 10 A Triangle POLYGON 6 224.00 416.00 224.00 416.00 96.00 160.00 96.00 160.00 384.00 160.00 384.00 160.00* -1.00 -1.00
5 1 5 1 0 0-1 -1
Table 1. File examples +o The first line of each gremlin file contains either the string ggrreemmlliinnffiillee (AED version) or ssuunnggrreemmlliinnffiillee (SUN/X11) +o The second line of the file contains an orientation, and xx and yyvalues for a positioning point, separated by spaces. The orien-
tation, either 00 or 11, is ignored by the SUN/X11 version. 00 means that gremlin will display things in horizontal format (drawing area wider than it is tall, with menu across top). 11means that gremlin will display things in vertical format (draw-
ing area taller than it is wide, with menu on left side). xx and yy are floating point values giving a positioning point to be used when this file is read into another file. The stuff on this line really isn't all that important; a value of ``1 0.00 0.00'' is suggested.+o The rest of the file consists of zero or more element specifica-
tions. After the last element specification is a line contain-
ing the string ``-1''.
+o Lines longer than 127 characters are chopped to this limit. EELLEEMMEENNTT SSPPEECCIIFFIICCAATTIIOONNSS +o The first line of each element contains a single decimal number giving the type of the element (AED version) or its ASCII name (SUN/X11 version). See Table 2.gremlin File Format - Object Type Specification
AED Number SUN/X11 Name Description0 BOTLEFT bottom-left-justified text
1 BOTRIGHT bottom-right-justified text
2 CENTCENT center-justified text
3 VECTOR vector 4 ARC arc 5 CURVE curve 6 POLYGON polygon7 BSPLINE b-spline
8 BEZIER B'ezier10 TOPLEFT top-left-justified text
11 TOPCENT top-center-justified text
12 TOPRIGHT top-right-justified text
13 CENTLEFT left-center-justified text
14 CENTRIGHT right-center-justified text
15 BOTCENT bottom-center-justified text
Table 2. Type Specifications in gremlin Files +o After the object type comes a variable number of lines, eachspecifying a point used to display the element. Each line con-
tains an x-coordinate and a y-coordinate in floating point for-
mat, separated by spaces. The list of points is terminated by aline containing the string ``-1.0 -1.0'' (AED version) or a sin-
gle asterisk, ``*'' (SUN/X11 version). +o After the points comes a line containing two decimal values, giving the brush and size for the element. The brush determines the style in which things are drawn. For vectors, arcs, and curves there are six legal brush values:1 - thin dotted lines
2 - thin dot-dashed lines
3 - thick solid lines
4 - thin dashed lines
5 - thin solid lines
6 - medium solid lines
For polygons, one more value, 0, is legal. It specifies a poly-
gon with an invisible border. For text, the brush selects a font as follows:1 - roman (R font in groff)
2 - italics (I font in groff)
3 - bold (B font in groff)
4 - special (S font in groff)
If you're using grn to run your pictures through groff, the font
is really just a starting font: The text string can contain for-
matting sequences like ``\fI'' or ``\d'' which may change the font (as well as do many other things). For text, the size field is a decimal value between 1 and 4. It selects the size of the font in which the text will be drawn. For polygons, thissize field is interpreted as a stipple number to fill the poly-
gon with. The number is used to index into a stipple font at print time. +o The last line of each element contains a decimal number and a string of characters, separated by a single space. The number is a count of the number of characters in the string. This information is only used for text elements, and contains the text string. There can be spaces inside the text. For arcs, curves, and vectors, this line of the element contains the string ``0''. NNOOTTEESS OONN CCOOOORRDDIINNAATTEESS gremlin was designed for AEDs, and its coordinates reflect the AEDcoordinate space. For vertical pictures, x-values range 116 to 511,
and y-values from 0 to 483. For horizontal pictures, x-values range
from 0 to 511 and y-values range from 0 to 367. Although you needn't
absolutely stick to this range, you'll get best results if you at least stay in this vicinity. Also, point lists are terminated by a point of(-1, -1), so you shouldn't ever use negative coordinates. gremlin
writes out coordinates using format ``%f1.2''; it's probably a good
idea to use the same format if you want to modify the grn code.
NNOOTTEESS OONN SSUUNN//XX1111 CCOOOORRDDIINNAATTEESS There is no longer a restriction on the range of coordinates used to create objects in the SUN/X11 version of gremlin. However, files with negative coordinates wwiillll cause problems if displayed on the AED. FILES //uussrr//sshhaarree//ggrrooffff//11..1199..11//ffoonntt//ddeevvname//DDEESSCC Device description file for device name.SEE ALSO
ggrreemmlliinn(1), ggrrooffff(1), ppiicc(1), iiddeeaall(1) HISTORYDavid Slattengren and Barry Roitblat wrote the original Berkeley grn.
Daniel Senderowicz and Werner Lemberg modified it for groff. Groff Version 1.19.1 18 July 2003 GRN(1)