Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages


home | help
GRN(1)			    General Commands Manual			GRN(1)

       grn - groff preprocessor	for gremlin files

       grn [ -Cv ] [ -Tdev ] [ -Mdir ] [ -Fdir ] [ file... ]

       It is possible to have whitespace between a command line	option and its

       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 .GS and .GE.  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  .GS
       request	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 .GF instead of .GE, the position is left
       at the top of the picture.

       Please note that	currently only the -me macro package has  support  for
       .GS, .GE, and .GF.

       The following command-line options are understood:

       -Tdev  Prepare  output for printer dev.	The default device is ps.  See
	      groff(1) for acceptable devices.

       -Mdir  Prepend dir to the default search	path for gremlin  files.   The
	      default  path is (in that	order) the current directory, the home
	      directory,      /usr/share/tmac,	    /usr/share/tmac,	   and

       -Fdir  Search  dir  for subdirectories devname (name is the name	of the
	      device) for the DESC file	before the  default  font  directories
	      /usr/share/groff_font,	     /usr/share/groff_font,	   and

       -C     Recognize	.GS and	.GE (resp.  .GF) even when followed by a char-
	      acter other than space or	newline.

       -v     Print the	version	number.

       Each input line between .GS and .GE 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  de-
       fault, see below) are only in effect for	the current picture: The envi-
       ronment is reinitialized	to the defaults	at the start of	the next  pic-
       ture.  The commands are as follows:

       1 N
       2 N
       3 N
       4 N    Set  gremlin's text size number 1	(2, 3, or 4) to	N points.  The
	      default is 12 (resp. 16, 24, and 36).

       roman f
       italics f
       bold f
       special 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

       l f
       stipple f
	      Set the stipple font to troff's stipple font f (name or number).
	      The  command  stipple may	be abbreviated down as far as `st' (to
	      avoid confusion with special).  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.

       x N
       scale N
	      Magnify  the  picture (in	addition to any	default	magnification)
	      by N, a floating point number larger  than  zero.	  The  command
	      scale may	be abbreviated down to `sc'.

       narrow N
       medium N
       thick N
	      Set  the	thickness of gremlin's narrow (resp. medium and	thick)
	      lines to N times 0.15pt (this value can be  changed  at  compile
	      time).   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.  Negative
	      values cause the line thickness to be proportional to  the  cur-
	      rent point size.

       pointscale _off/on_
	      Scale  text  to  match  the  picture.   Gremlin  text is usually
	      printed  in  the	point  size  specified	 with	the   commands
	      1, 2, 3, or 4  regardless	of any scaling factors in the picture.
	      Setting pointscale 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.

	      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.

       width N
	      Forces  the  picture  to	be  N inches wide.  This overrides any
	      scaling factors present in the same picture.  `width 0'  is  ig-

       height 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.  Height and
	      width commands are not saved with	a default command.  They will,
	      however, affect point size scaling if that option	is set.

       file name
	      Get picture from gremlin file name located the current directory
	      (or in the library directory; see	the -M option above).  If  two
	      file commands are	given, the second one overrides	the first.  If
	      name doesn't exist, an error message is reported and  processing
	      continues	from the .GE line.

       Since  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 .GS and .GE 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  equations
       within  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 al-
       ways 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 the
       picture between `keeps' in -me macros will ensure proper	placement.

       grn uses	troff's	number registers g1 through g9 and sets	 registers  g1
       and  g2 to the width and	height of the gremlin figure (in device	units)
       before entering the .GS request (this is	for those who want to  rewrite
       these macros).

       There exist two distinct	gremlin	file formats, the original format from
       the AED graphic terminal	version, and the SUN or	X11 version.   An  ex-
       tension	to the SUN/X11 version allowing	reference points with negative
       coordinates is not compatible with the AED version.  As long as a grem-
       lin  file  does not contain negative coordinates, either	format will be
       read correctly by either	version	of gremlin or grn.  The	other  differ-
       ence  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
	      gremlinfile (AED version)	or sungremlinfile (SUN/X11)

       o      The second line of the file contains an orientation, and x and y
	      values for a positioning point, separated	by spaces.  The	orien-
	      tation, either 0 or 1, is	ignored	by  the	 SUN/X11  version.   0
	      means  that  gremlin  will  display  things in horizontal	format
	      (drawing area wider than it is tall, with	menu across  top).   1
	      means that gremlin will display things in	vertical format	(draw-
	      ing area taller than it is wide, with menu on left side).	 x and
	      y	 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.

       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	      Description
		       0       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	      polygon
		       7       BSPLINE	      b-spline
		       8       BEZIER	      Bezier
		      10       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,  each
	      specifying  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 a
	      line 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, this
	      size 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  in-
	      formation	 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''.

       gremlin	was designed for AEDs, and its coordinates reflect the AED co-
       ordinate	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	 abso-
       lutely  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.

       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 will cause problems	if displayed on	the AED.

	      Device description file for device name.

       gremlin(1), groff(1), pic(1), ideal(1)

       David Slattengren and Barry Roitblat wrote the original Berkeley	grn.

       Daniel Senderowicz and Werner Lemberg modified it for groff.

Groff Version 1.19		11 October 2002				GRN(1)


Want to link to this manual page? Use this URL:

home | help