.ig Copyright (C) 1989-2000, 2001, 2002, 2003 Free Software Foundation, Inc. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions, except that this permission notice may be included in translations approved by the Free Software Foundation instead of in the original English. .. . . .\" Like TP, but if specified indent is more than half .\" the current line-length - indent, use the default indent. .de Tp .ie \\n(.$=0:((0\\$1)*2u>(\\n(.lu-\\n(.iu)) .TP .el .TP "\\$1" .. . .ie t \{\ . ds tx T\h'-.1667m'\v'.224m'E\v'-.224m'\h'-.125m'X . ds lx L\h'-0.36m'\v'-0.22v'\s-2A\s0\h'-0.15m'\v'0.22v'\*(tx .\} .el \{\ . ds tx TeX . ds lx LaTeX .\} . .ie \n(.g .ds ic \/ .el .ds ic \^ . .\" The BSD man macros can't handle " in arguments to font change macros, .\" so use \(ts instead of ". .tr \(ts" . . .TH PIC 1 "27 April 2003" "Groff Version 1.19" . . .SH NAME . pic \- compile pictures for troff or TeX . . .SH SYNOPSIS . .B pic [ .B \-nvCSU ] [ .I filename \&.\|.\|.\& ] .br .B pic .B \-t [ .B \-cvzCSU ] [ .I filename \&.\|.\|.\& ] . . .SH DESCRIPTION . This manual page describes the GNU version of .BR pic , which is part of the groff document formatting system. .B pic compiles descriptions of pictures embedded within .B troff or \*(tx input files into commands that are understood by \*(tx or .BR troff . Each picture starts with a line beginning with .B .PS and ends with a line beginning with .BR .PE . Anything outside of .B .PS and .B .PE is passed through without change. .LP It is the user's responsibility to provide appropriate definitions of the .B PS and .B PE macros. When the macro package being used does not supply such definitions (for example, old versions of \-ms), appropriate definitions can be obtained with .BR \-mpic : These will center each picture. . . .SH OPTIONS . Options that do not take arguments may be grouped behind a single .BR \- . The special option .B \-\^\- can be used to mark the end of the options. A filename of .B \- refers to the standard input. . .TP .B \-C Recognize .B .PS and .B .PE even when followed by a character other than space or newline. . .TP .B \-S Safer mode; do not execute .B sh commands. This can be useful when operating on untrustworthy input. (enabled by default) . .TP .B \-U Unsafe mode; revert the default option .BR \-S . . .TP .B \-n Don't use the groff extensions to the troff drawing commands. You should use this if you are using a postprocessor that doesn't support these extensions. The extensions are described in .BR groff_out (5). The .B \-n option also causes .B pic not to use zero-length lines to draw dots in troff mode. . .TP .B \-t \*(tx mode. . .TP .B \-c Be more compatible with .BR tpic . Implies .BR \-t . Lines beginning with .B \e are not passed through transparently. Lines beginning with .B . are passed through with the initial .B . changed to .BR \e . A line beginning with .B .ps is given special treatment: it takes an optional integer argument specifying the line thickness (pen size) in milliinches; a missing argument restores the previous line thickness; the default line thickness is 8 milliinches. The line thickness thus specified takes effect only when a non-negative line thickness has not been specified by use of the .B thickness attribute or by setting the .B linethick variable. . .TP .B \-v Print the version number. . .TP .B \-z In \*(tx mode draw dots using zero-length lines. . .LP The following options supported by other versions of .B pic are ignored: . .TP .B \-D Draw all lines using the \eD escape sequence. .B pic always does this. . .TP .BI \-T \ dev Generate output for the .B troff device .IR dev . This is unnecessary because the .B troff output generated by .B pic is device-independent. . . .SH USAGE . This section describes only the differences between GNU .B pic and the original version of .BR pic . Many of these differences also apply to newer versions of Unix .BR pic . A complete documentation is available in the file .LP .RS .B /usr/pkg/share/doc/groff/1.19/pic.ms .RE . .SS \*(tx mode . \*(tx mode is enabled by the .B \-t option. In \*(tx mode, .B pic will define a vbox called .B \egraph for each picture. Use the .B figname command to change the name of the vbox. You must yourself print that vbox using, for example, the command .RS .LP .B \ecenterline{\ebox\egraph} .RE .LP Actually, since the vbox has a height of zero (it is defined with \evtop) this will produce slightly more vertical space above the picture than below it; .RS .LP .B \ecenterline{\eraise 1em\ebox\egraph} .RE .LP would avoid this. .LP To make the vbox having a positive height and a depth of zero (as used e.g.\& by \*(lx's .BR \%graphics.sty ), define the following macro in your document: .RS .LP .B \edef\egpicbox#1{% .br .B " \evbox{\eunvbox\ecsname #1\eendcsname\ekern 0pt}}" .RE .LP Now you can simply say .B \egpicbox{graph} instead of \ebox\egraph. .LP You must use a \*(tx driver that supports the .B tpic specials, version 2. .LP Lines beginning with .B \e are passed through transparently; a .B % is added to the end of the line to avoid unwanted spaces. You can safely use this feature to change fonts or to change the value of .BR \ebaselineskip . Anything else may well produce undesirable results; use at your own risk. Lines beginning with a period are not given any special treatment. . .SS Commands . .TP \fBfor\fR \fIvariable\fR \fB=\fR \fIexpr1\fR \fBto\fR \fIexpr2\fR \ [\fBby\fR [\fB*\fR]\fIexpr3\fR] \fBdo\fR \fIX\fR \fIbody\fR \fIX\fR Set .I variable to .IR expr1 . While the value of .I variable is less than or equal to .IR expr2 , do .I body and increment .I variable by .IR expr3 ; if .B by is not given, increment .I variable by 1. If .I expr3 is prefixed by .B * then .I variable will instead be multiplied by .IR expr3 . .I X can be any character not occurring in .IR body . . .TP \fBif\fR \fIexpr\fR \fBthen\fR \fIX\fR \fIif-true\fR \fIX\fR \ [\fBelse\fR \fIY\fR \fIif-false\fR \fIY\fR] Evaluate .IR expr ; if it is non-zero then do .IR if-true , otherwise do .IR if-false . .I X can be any character not occurring in .IR if-true . .I Y can be any character not occurring in .IR if-false . . .TP \fBprint\fR \fIarg\fR\|.\|.\|. Concatenate the arguments and print as a line on stderr. Each .I arg must be an expression, a position, or text. This is useful for debugging. . .TP \fBcommand\fR \fIarg\fR\|.\|.\|. Concatenate the arguments and pass them through as a line to troff or \*(tx. Each .I arg must be an expression, a position, or text. This has a similar effect to a line beginning with .B .\& or .BR \e , but allows the values of variables to be passed through. . .TP \fBsh\fR \fIX\fR \fIcommand\fR \fIX\fR Pass .I command to a shell. .I X can be any character not occurring in .IR command . . .TP \fBcopy\fR \fB"\fIfilename\fB"\fR Include .I filename at this point in the file. . .TP \fBcopy\fR [\fB"\fIfilename\fB"\fR] \fBthru\fR \fIX\fR \fIbody\fR \fIX\fR \ [\fBuntil\fR \fB"\fIword\*(ic\fB"\fR] .ns .TP \fBcopy\fR [\fB"\fIfilename\fB"\fR] \fBthru\fR \fImacro\fR \ [\fBuntil\fR \fB"\fIword\*(ic\fB"\fR] This construct does .I body once for each line of .IR filename ; the line is split into blank-delimited words, and occurrences of .BI $ i in .IR body , for .I i between 1 and 9, are replaced by the .IR i -th word of the line. If .I filename is not given, lines are taken from the current input up to .BR .PE . If an .B until clause is specified, lines will be read only until a line the first word of which is .IR word ; that line will then be discarded. .I X can be any character not occurring in .IR body . For example, .RS .IP .ft B .nf \&.PS copy thru % circle at ($1,$2) % until "END" 1 2 3 4 5 6 END box \&.PE .ft .fi .RE .IP is equivalent to .RS .IP .ft B .nf \&.PS circle at (1,2) circle at (3,4) circle at (5,6) box \&.PE .ft .fi .RE .IP The commands to be performed for each line can also be taken from a macro defined earlier by giving the name of the macro as the argument to .BR thru . . .LP .B reset .br .ns .TP \fBreset\fI variable1\fR[\fB,\fR]\fI variable2 .\^.\^. Reset pre-defined variables .IR variable1 , .I variable2 \&.\^.\^. to their default values. If no arguments are given, reset all pre-defined variables to their default values. Note that assigning a value to .B scale also causes all pre-defined variables that control dimensions to be reset to their default values times the new value of scale. . .TP \fBplot\fR \fIexpr\fR [\fB"\fItext\*(ic\fB"\fR] This is a text object which is constructed by using .I text as a format string for sprintf with an argument of .IR expr . If .I text is omitted a format string of .B "\(ts%g\(ts" is used. Attributes can be specified in the same way as for a normal text object. Be very careful that you specify an appropriate format string; .B pic does only very limited checking of the string. This is deprecated in favour of .BR sprintf . . .TP .IB variable\ := \ expr This is similar to .B = except .I variable must already be defined, and .I expr will be assigned to .I variable without creating a variable local to the current block. (By contrast, .B = defines the variable in the current block if it is not already defined there, and then changes the value in the current block only.) For example, the following: .RS .IP .ft B .nf \&.PS x = 3 y = 3 [ x := 5 y = 5 ] print x " " y \&.PE .ft .fi .RE .IP prints .BR 5\ 3 . . .LP Arguments of the form .IP .I X anything X .LP are also allowed to be of the form .IP .BI {\ anything\ } .LP In this case .I anything can contain balanced occurrences of .B { and .BR } . Strings may contain .I X or imbalanced occurrences of .B { and .BR } . . .SS Expressions . The syntax for expressions has been significantly extended: . .LP .IB x\ ^\ y (exponentiation) .br .BI sin( x ) .br .BI cos( x ) .br .BI atan2( y , \ x ) .br .BI log( x ) (base 10) .br .BI exp( x ) (base 10, ie .ie t 10\v'-.4m'\fIx\*(ic\fR\v'.4m') .el 10^\fIx\fR) .br .BI sqrt( x ) .br .BI int( x ) .br .B rand() (return a random number between 0 and 1) .br .BI rand( x ) (return a random number between 1 and .IR x ; deprecated) .br .BI srand( x ) (set the random number seed) .br .BI max( e1 , \ e2 ) .br .BI min( e1 , \ e2 ) .br .BI ! e .br \fIe1\fB && \fIe2\fR .br \fIe1\fB || \fIe2\fR .br \fIe1\fB == \fIe2\fR .br \fIe1\fB != \fIe2\fR .br \fIe1\fB >= \fIe2\fR .br \fIe1\fB > \fIe2\fR .br \fIe1\fB <= \fIe2\fR .br \fIe1\fB < \fIe2\fR .br \fB"\fIstr1\*(ic\fB" == "\fIstr2\*(ic\fB"\fR .br \fB"\fIstr1\*(ic\fB" != "\fIstr2\*(ic\fB"\fR .br . .LP String comparison expressions must be parenthesised in some contexts to avoid ambiguity. . .SS Other Changes . A bare expression, .IR expr , is acceptable as an attribute; it is equivalent to .IR dir\ expr , where .I dir is the current direction. For example .IP .B line 2i .LP means draw a line 2\ inches long in the current direction. The `i' (or `I') character is ignored; to use another measurement unit, set the .I scale variable to an appropriate value. . .LP The maximum width and height of the picture are taken from the variables .B maxpswid and .BR maxpsht . Initially these have values 8.5 and 11. . .LP Scientific notation is allowed for numbers. For example .RS .B x = 5e\-2 .RE . .LP Text attributes can be compounded. For example, .RS .B "foo" above ljust .RE is legal. . .LP There is no limit to the depth to which blocks can be examined. For example, .RS .B [A: [B: [C: box ]]] with .A.B.C.sw at 1,2 .br .B circle at last [\^].A.B.C .RE is acceptable. . .LP Arcs now have compass points determined by the circle of which the arc is a part. . .LP Circles and arcs can be dotted or dashed. In \*(tx mode splines can be dotted or dashed. . .LP Boxes can have rounded corners. The .B rad attribute specifies the radius of the quarter-circles at each corner. If no .B rad or .B diam attribute is given, a radius of .B boxrad is used. Initially, .B boxrad has a value of\ 0. A box with rounded corners can be dotted or dashed. . .LP The .B .PS line can have a second argument specifying a maximum height for the picture. If the width of zero is specified the width will be ignored in computing the scaling factor for the picture. Note that GNU .B pic will always scale a picture by the same amount vertically as well as horizontally. This is different from the .SM DWB 2.0 .B pic which may scale a picture by a different amount vertically than horizontally if a height is specified. . .LP Each text object has an invisible box associated with it. The compass points of a text object are determined by this box. The implicit motion associated with the object is also determined by this box. The dimensions of this box are taken from the width and height attributes; if the width attribute is not supplied then the width will be taken to be .BR textwid ; if the height attribute is not supplied then the height will be taken to be the number of text strings associated with the object times .BR textht . Initially .B textwid and .B textht have a value of 0. . .LP In (almost all) places where a quoted text string can be used, an expression of the form .IP .BI sprintf(\(ts format \(ts,\ arg ,\fR.\|.\|.\fB) .LP can also be used; this will produce the arguments formatted according to .IR format , which should be a string as described in .BR printf (3) appropriate for the number of arguments supplied. . .LP The thickness of the lines used to draw objects is controlled by the .B linethick variable. This gives the thickness of lines in points. A negative value means use the default thickness: in \*(tx output mode, this means use a thickness of 8 milliinches; in \*(tx output mode with the .B -c option, this means use the line thickness specified by .B .ps lines; in troff output mode, this means use a thickness proportional to the pointsize. A zero value means draw the thinnest possible line supported by the output device. Initially it has a value of -1. There is also a .BR thick [ ness ] attribute. For example, .RS .LP .B circle thickness 1.5 .RE .LP would draw a circle using a line with a thickness of 1.5 points. The thickness of lines is not affected by the value of the .B scale variable, nor by the width or height given in the .B .PS line. . .LP Boxes (including boxes with rounded corners), circles and ellipses can be filled by giving them an attribute of .BR fill [ ed ]. This takes an optional argument of an expression with a value between 0 and 1; 0 will fill it with white, 1 with black, values in between with a proportionally gray shade. A value greater than 1 can also be used: this means fill with the shade of gray that is currently being used for text and lines. Normally this will be black, but output devices may provide a mechanism for changing this. Without an argument, then the value of the variable .B fillval will be used. Initially this has a value of 0.5. The invisible attribute does not affect the filling of objects. Any text associated with a filled object will be added after the object has been filled, so that the text will not be obscured by the filling. . .LP Three additional modifiers are available to specify colored objects: .BR outline [ d ] sets the color of the outline, .B shaded the fill color, and .BR colo [ u ] r [ ed ] sets both. All three keywords expect a suffix specifying the color, for example .RS .LP .B circle shaded """green""" outline """black""" .RE .LP Currently, color support isn't available in \*(tx mode. Predefined color names for .B groff are in the device macro files, for example .BR ps.tmac ; additional colors can be defined with the .B .defcolor request (see the manual page of .BR troff (1) for more details). .LP To change the name of the vbox in \*(tx mode, set the pseudo-variable .B figname (which is actually a specially parsed command) within a picture. Example: .RS .LP .B .PS .br .B figname = foobar; .br .B ... .br .B .PE .RE .LP The picture is then available in the box .BR \efoobar . .LP .B pic assumes that at the beginning of a picture both glyph and fill color are set to the default value. . .LP Arrow heads will be drawn as solid triangles if the variable .B arrowhead is non-zero and either \*(tx mode is enabled or the .B \-n option has not been given. Initially .B arrowhead has a value of\ 1. Note that solid arrow heads are always filled with the current outline color. . .LP The troff output of .B pic is device-independent. The .B \-T option is therefore redundant. All numbers are taken to be in inches; numbers are never interpreted to be in troff machine units. . .LP Objects can have an .B aligned attribute. This will only work if the postprocessor is .BR grops . Any text associated with an object having the .B aligned attribute will be rotated about the center of the object so that it is aligned in the direction from the start point to the end point of the object. Note that this attribute will have no effect for objects whose start and end points are coincident. . .LP In places where .IB n th is allowed .BI ` expr 'th is also allowed. Note that .B 'th is a single token: no space is allowed between the .B ' and the .BR th . For example, .IP .ft B .nf for i = 1 to 4 do { line from `i'th box.nw to `i+1'th box.se } .ft .fi . . .SH CONVERSION . To obtain a stand-alone picture from a .B pic file, enclose your .B pic code with .B .PS and .B .PE requests; .B roff configuration commands may be added at the beginning of the file, but no .B roff text. . .LP It is necessary to feed this file into .B groff without adding any page information, so you must check which .B .PS and .B .PE requests are actually called. For example, the mm macro package adds a page number, which is very annoying. At the moment, calling standard .B groff without any macro package works. Alternatively, you can define your own requests, e.g. to do nothing: .LP .RS .nf .ft B \&.de PS \&.. \&.de PE \&.. .ft .fi .RE . .LP .B groff itself does not provide direct conversion into other graphics file formats. But there are lots of possibilities if you first transform your picture into PostScript\*R format using the .B groff option .BR -Tps . Since this .IR ps -file lacks BoundingBox information it is not very useful by itself, but it may be fed into other conversion programs, usually named .BI ps2 other or .BI psto other or the like. Moreover, the PostScript interpreter .B ghostscript .RB ( gs ) has built-in graphics conversion devices that are called with the option .LP .RS .BI "gs -sDEVICE=" .RE .LP Call .RS .B gs --help .RE .LP for a list of the available devices. . .LP As the Encapsulated PostScript File Format .B EPS is getting more and more important, and the conversion wasn't regarded trivial in the past you might be interested to know that there is a conversion tool named .B ps2eps which does the right job. It is much better than the tool .B ps2epsi packaged with .BR gs . .LP For bitmapped graphic formats, you should use .BR pstopnm ; the resulting (intermediate) .B PNM file can be then converted to virtually any graphics format using the tools of the .B netpbm package . . . .SH FILES . .Tp \w'\fB/usr/pkg/share/groff/1.19/tmac/pic.tmac'u+3n .B /usr/pkg/share/groff/1.19/tmac/pic.tmac Example definitions of the .B PS and .B PE macros. . . .SH "SEE ALSO" . .BR troff (1), .BR groff_out (5), .BR tex (1), .BR gs (1), .BR ps2eps (1), .BR pstopnm (1), .BR ps2epsi (1), .BR pnm (5) .LP Tpic: Pic for \*(tx .LP Brian W. Kernighan, PIC \(em A Graphics Language for Typesetting (User Manual). AT&T Bell Laboratories, Computing Science Technical Report No.\ 116 (revised May, 1991). .LP .B ps2eps is available from CTAN mirrors, e.g. .br .LP W. Richard Stevens - Turning PIC Into HTML .br .LP W. Richard Stevens - Examples of picMacros .br . . .SH BUGS . Input characters that are invalid for .B groff (ie those with .SM ASCII code 0, or 013 octal, or between 015 and 037 octal, or between 0200 and 0237 octal) are rejected even in \*(tx mode. .LP The interpretation of .B fillval is incompatible with the pic in 10th edition Unix, which interprets 0 as black and 1 as white. .LP PostScript\*R is a registered trademark of Adobe Systems Incorporation. . .\" Local Variables: .\" mode: nroff .\" End: