731 lines
15 KiB
Groff
731 lines
15 KiB
Groff
.\" $Id: pic.1,v 1.3 1993/08/02 17:44:48 mycroft Exp $ -*- nroff -*-
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.\" Like TP, but if specified indent is more than half
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.\" the current line-length - indent, use the default indent.
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.de Tp
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.ie \\n(.$=0:((0\\$1)*2u>(\\n(.lu-\\n(.iu)) .TP
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.el .TP "\\$1"
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..
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.ie t .ds tx T\h'-.1667m'\v'.224m'E\v'-.224m'\h'-.125m'X
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.el .ds tx TeX
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.ie \n(.g .ds ic \/
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.el .ds ic \^
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.\" The BSD man macros can't handle " in arguments to font change macros,
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.\" so use \(ts instead of ".
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.tr \(ts"
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.TH PIC 1 "9 August 1992" "Groff Version 1.08"
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|
.SH NAME
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pic \- compile pictures for troff or TeX
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|
.SH SYNOPSIS
|
|
.B pic
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|
[
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|
.B \-nvC
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|
]
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|
[
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|
.I filename
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|
\&.\|.\|.
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]
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|
.br
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|
.B pic
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|
.B \-t
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|
[
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|
.B \-cvzC
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|
]
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|
[
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|
.I filename
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|
\&.\|.\|.
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|
]
|
|
.SH DESCRIPTION
|
|
.LP
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|
This manual page descibes the GNU version of
|
|
.BR pic ,
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|
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
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|
.BR troff .
|
|
Each picture starts with a line beginning with
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|
.B .PS
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|
and ends with a line beginning with
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|
.BR .PE .
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|
Anything outside of
|
|
.B .PS
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|
and
|
|
.B .PE
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|
is passed through without change.
|
|
.LP
|
|
It is the user's responsibility to provide appropriate definitions of the
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|
.B PS
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|
and
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|
.B PE
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|
macros.
|
|
When the macro package being used does not supply such definitions
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|
(for example, old versions of \-ms),
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|
appropriate definitions can be obtained with
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|
.BR \-mpic :
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|
these will center each picture.
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|
.SH OPTIONS
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|
.LP
|
|
Options that do not take arguments may be grouped behind a single
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|
.BR \- .
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|
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
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|
and
|
|
.B .PE
|
|
even when followed by a character other than space or newline.
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|
.TP
|
|
.B \-n
|
|
Don't use the groff extensions to the troff drawing commands.
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|
You should use this if you are using a postprocessor that doesn't support
|
|
these extensions.
|
|
The extensions are described in
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|
.BR groff_out (5).
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|
The
|
|
.B \-n
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|
option also causes pic
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|
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 pic and the original
|
|
version of pic.
|
|
Many of these differences also apply to newer versions of Unix pic.
|
|
.SS \*(tx mode
|
|
.LP
|
|
\*(tx mode is enabled by the
|
|
.B \-t
|
|
option.
|
|
In \*(tx mode, pic will define a vbox called
|
|
.B \egraph
|
|
for each picture.
|
|
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 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
|
|
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\fB,\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;
|
|
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 the value of
|
|
.I variable
|
|
will be changed only in the innermost block in which it is defined.
|
|
(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.)
|
|
.LP
|
|
Arguments of the form
|
|
.IP
|
|
.IR 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 10\v'-.4m'\fIx\*(ic\fR\v'.4m')
|
|
.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 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
|
|
.LP
|
|
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.
|
|
.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 pic will always scale a picture by the same amount
|
|
vertically as horizontally.
|
|
This is different from the
|
|
.SM DWB
|
|
2.0 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 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,
|
|
using only the
|
|
.BR e ,
|
|
.BR f ,
|
|
.B g
|
|
or
|
|
.B %
|
|
format characters.
|
|
.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 then 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
|
|
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 \-x
|
|
option has been given.
|
|
Initially
|
|
.B arrowhead
|
|
has a value of 1.
|
|
.LP
|
|
The troff output of 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 when 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
|
|
.B
|
|
.nf
|
|
for i = 1 to 4 do {
|
|
line from `i'th box.nw to `i+1'th box.se
|
|
}
|
|
.fi
|
|
.SH FILES
|
|
.Tp \w'\fB/usr/share/tmac/tmac.pic'u+3n
|
|
.B
|
|
/usr/share/tmac/tmac.pic
|
|
Example definitions of the
|
|
.B PS
|
|
and
|
|
.B PE
|
|
macros.
|
|
.SH "SEE ALSO"
|
|
.BR troff (1),
|
|
.BR groff_out (5),
|
|
.BR tex (1)
|
|
.br
|
|
Tpic: Pic for \*(tx
|
|
.br
|
|
AT&T Bell Laboratories, Computing Science Technical Report No.\ 116,
|
|
PIC \(em A Graphics Language for Typesetting.
|
|
(This can be obtained by sending a mail message to netlib@research.att.com
|
|
with a body of `send\ 116\ from\ research/cstr'.)
|
|
.SH BUGS
|
|
.LP
|
|
Input characters that are illegal for
|
|
.B groff
|
|
(ie those with
|
|
.SM ASCII
|
|
code 0 or between 013 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.
|