pic.1 (8482B)
1 .TH PIC 1 2 .de PS \" start picture 3 . \" $1 is height, $2 is width, both in inches 4 .if \\$1>0 .sp .35 5 .ie \\$1>0 .nr $1 \\$1 6 .el .nr $1 0 7 .in (\\n(.lu-\\$2)/2u 8 .ne \\$1 9 .. 10 .de PE \" end of picture 11 .in 12 .if \\n($1>0 .sp .65 13 .. 14 .SH NAME 15 pic, tpic, svgpic \- troff and tex preprocessors for drawing pictures 16 .SH SYNOPSIS 17 .B pic 18 [ 19 .I files 20 ] 21 .PP 22 .B tpic 23 [ 24 .I files 25 ] 26 .PP 27 .B svgpic 28 [ 29 .I files 30 ] 31 .SH DESCRIPTION 32 .I Pic 33 is a 34 .MR troff (1) 35 preprocessor for drawing figures on a typesetter. 36 .I Pic 37 code is contained between 38 .B .PS 39 and 40 .B .PE 41 lines: 42 .IP 43 .EX 44 \&.PS \f2optional-width\fP \f2optional-height\fP 45 \f2element-list\fP 46 \&.PE 47 .EE 48 .LP 49 or in a file mentioned in a 50 .B .PS 51 line: 52 .IP 53 .BI .PS " " < file 54 .LP 55 If 56 .IR optional-width 57 is present, the picture is made that many inches wide, 58 regardless of any dimensions used internally. 59 The height is scaled in the same proportion unless 60 .IR optional-height 61 is present. 62 If 63 .B .PF 64 is used instead of 65 .BR .PE , 66 the typesetting position after printing is restored to what it was 67 upon entry. 68 .PP 69 An 70 .IR element-list 71 is a list of elements: 72 .EX 73 \f2primitive attribute-list\fP 74 \f2placename\fP : \f2element\fP 75 \f2placename\fP : \f2position\fP 76 \f2var\fP = \f2expr\fP 77 \f2direction\fP 78 { \f2element-list\fP } 79 [ \f2element-list\fP ] 80 for \f2var\fP = \f2expr\fP to \f2expr\fP by \f2expr\fP do { \f2anything\fP } 81 if \f2expr\fP then { \f2anything\fP } else { \f2anything\fP } 82 copy \f2file,\fP copy thru \f2macro,\fP copy \f2file\fP thru \fPmacro\fP 83 sh { \f2commandline\fP } 84 print \f2expr\fP 85 reset \f2optional var-list\fP 86 \f2troff-command\fP 87 .EE 88 .PP 89 Elements are separated by newlines or semicolons; 90 a long element may be continued by ending the line with a backslash. 91 Comments are introduced by a 92 .BI # 93 and terminated by a newline. 94 Variable names begin with a lower case letter; 95 place names begin with upper case. 96 Place and variable names retain their values 97 from one picture to the next. 98 .PP 99 After each primitive 100 the current position moves in the current direction 101 .RB ( up , down , 102 .BR left , right 103 (default)) by the size of the primitive. 104 The current position and direction are saved upon entry 105 to a 106 .BR { ... } 107 block and restored upon exit. 108 Elements within a block enclosed in 109 .BR [ ... ] 110 are treated as a unit; 111 the dimensions are determined by the extreme points 112 of the contained objects. 113 Names, variables, and direction of motion within a block are local to that block. 114 .PP 115 .IR Troff-command 116 is any line that begins with a period. 117 Such a line is assumed to make sense in the context where it appears; 118 generally, this means only size and font changes. 119 .PP 120 The 121 .I primitive 122 objects are: 123 .br 124 .EX 125 box circle ellipse arc line arrow spline move \f2text-list\fP 126 .EE 127 .L arrow 128 is a synonym for 129 .LR "line ->" . 130 .PP 131 An 132 .IR attribute-list 133 is a sequence of zero or more attributes; 134 each attribute consists of a keyword, perhaps followed by a value. 135 .EX 136 .ta .5i 2.5i 137 h(eigh)t \f2expr\fP wid(th) \f2expr\fP 138 rad(ius) \f2expr\fP diam(eter) \f2expr\fP 139 up \f2opt-expr\fP down \f2opt-expr\fP 140 right \f2opt-expr\fP left \f2opt-expr\fP 141 from \f2position\fP to \f2position\fP 142 at \f2position\fP with \f2corner\fP 143 by \f2expr, expr\fP then 144 dotted \f2opt-expr\fP dashed \f2opt-expr\fP 145 chop \f2opt-expr\fP -> <- <-> 146 invis same 147 fill \f2opt-expr\fP 148 \f2text-list\fP \f2expr\fP 149 .EE 150 Missing attributes and values are filled in from defaults. 151 Not all attributes make sense for all primitives; 152 irrelevant ones are silently ignored. 153 The attribute 154 .L at 155 causes the geometrical center to be put at the specified place; 156 .L with 157 causes the position on the object to be put at the specified place. 158 For lines, splines and arcs, 159 .L height 160 and 161 .L width 162 refer to arrowhead size. 163 A bare 164 .I expr 165 implies motion in the current direction. 166 .PP 167 Text is normally an attribute of some primitive; 168 by default it is placed at the geometrical center of the object. 169 Stand-alone text is also permitted. 170 A text list 171 is a list of text items: 172 .EX 173 \f2 text-item\fP: 174 "..." \f2positioning ...\fP 175 sprintf("\f2format\fP", \f2expr\fP, \f2...\fP) \f2positioning ...\fP 176 \f2 positioning\fP: 177 center ljust rjust above below 178 .EE 179 If there are multiple text items for some primitive, 180 they are arranged vertically and centered except as qualified. 181 Positioning requests apply to each item independently. 182 Text items may contain 183 .I troff 184 commands for size and font changes, local motions, etc., 185 but make sure that these are balanced 186 so that the entering state is restored before exiting. 187 .PP 188 A position is ultimately an 189 .I x,y 190 coordinate pair, but it may be specified in other ways. 191 .EX 192 \f2 position\fP: 193 \f2expr, expr\fP 194 \f2place\fP ± \f2expr, expr\fP 195 \f2place\fP ± ( \f2expr, expr\fP ) 196 ( \f2position\fP,\f2 position\fP ) \f2x\fP\fR from one, \f2y\fP\fR the other\fP 197 \f2expr\fP [\fLof the way\fP] between \f2position\fP and \f2position\fP 198 \f2expr\fP < \f2position\fP , \f2position\fP > 199 ( \f2position\fP ) 200 .EE 201 .PP 202 .EX 203 \f2 place\fP: 204 \f2placename\fP \f2optional-corner\fP 205 \f2corner\fP of \f2placename\fP 206 \f2nth\fP \f2primitive\fP \f2optional-corner\fP 207 \f2corner\fP of \f2nth\fP \f2primitive\fP 208 Here 209 .EE 210 An 211 .IR optional-corner 212 is one of the eight compass points 213 or the center or the start or end of a primitive. 214 .EX 215 \f2 optional-corner\fP: 216 .n .e .w .s .ne .se .nw .sw .c .start .end 217 \f2 corner\fP: 218 top bot left right start end 219 .EE 220 Each object in a picture has an ordinal number; 221 .IR nth 222 refers to this. 223 .EX 224 \f2 nth\fP: 225 \f2n\fPth\f2, n\fPth last 226 .EE 227 .PP 228 The built-in variables and their default values are: 229 .EX 230 .ta .5i 2.5i 231 boxwid 0.75 boxht 0.5 232 circlerad 0.25 arcrad 0.25 233 ellipsewid 0.75 ellipseht 0.5 234 linewid 0.5 lineht 0.5 235 movewid 0.5 moveht 0.5 236 textwid 0 textht 0 237 arrowwid 0.05 arrowht 0.1 238 dashwid 0.1 arrowhead 2 239 scale 1 240 .EE 241 These may be changed at any time, 242 and the new values remain in force from picture to picture until changed again 243 or reset by a 244 .L reset 245 statement. 246 Variables changed within 247 .B [ 248 and 249 .B ] 250 revert to their previous value upon exit from the block. 251 Dimensions are divided by 252 .B scale 253 during output. 254 .PP 255 Expressions in 256 .I pic 257 are evaluated in floating point. 258 All numbers representing dimensions are taken to be in inches. 259 .EX 260 \f2 expr\fP: 261 \f2expr\fP \f2op\fP \f2expr\fP 262 - \f2expr\fP 263 ! \f2expr\fP 264 ( \f2expr\fP ) 265 variable 266 number 267 \f2place\fP .x \f2place\fP .y \f2place\fP .ht \f2place\fP .wid \f2place\fP .rad 268 sin(\f2expr\fP) cos(\f2expr\fP) atan2(\f2expr,expr\fP) log(\f2expr\fP) exp(\f2expr\fP) 269 sqrt(\f2expr\fP) max(\f2expr,expr\fP) min(\f2expr,expr\fP) int(\f2expr\fP) rand() 270 \f2 op\fP: 271 + - * / % < <= > >= == != && || 272 .EE 273 .PP 274 The 275 .B define 276 and 277 .B undef 278 statements are not part of the grammar. 279 .EX 280 define \f2name\fP { \f2replacement text\fP } 281 undef \f2name\fP 282 .EE 283 Occurrences of 284 .BR $1 , 285 .BR $2 , 286 etc., 287 in the replacement text 288 will be replaced by the corresponding arguments if 289 .I name 290 is invoked as 291 .EX 292 \f2name\fP(\f2arg1\fP, \f2arg2\fP, ...) 293 .EE 294 Non-existent arguments are replaced by null strings. 295 Replacement text 296 may contain newlines. 297 The 298 .B undef 299 statement removes the definition of a macro. 300 .PP 301 .I Tpic 302 is a 303 .MR tex (1) 304 preprocessor that accepts 305 .IR pic 306 language. 307 It produces Tex commands that define a box called 308 .BR \egraph , 309 which contains the picture. 310 The box may be output this way: 311 .IP 312 .L 313 \ecenterline{\ebox\egraph} 314 .PP 315 .I Svgpic 316 accepts 317 .IR pic 318 language and produces a Scalable Vector Graphics (SVG) image 319 suitable for use in HTML documents. 320 .SH EXAMPLES 321 .EX 322 arrow "input" above; box "process"; arrow "output" above 323 move 324 A: ellipse 325 circle rad .1 with .w at A.e 326 circle rad .05 at 0.5 <A.c, A.ne> 327 circle rad .065 at 0.5 <A.c, A.ne> 328 spline from last circle.nw left .25 then left .05 down .05 329 arc from A.c to A.se rad 0.5 330 for i = 1 to 10 do { line from A.s+.025*i,.01*i down i/50 } 331 .EE 332 .PP 333 .PS 334 arrow "input" above; box "process"; arrow "output" above 335 move 336 A: ellipse 337 circle rad .1 with .w at A.e 338 circle rad .05 at 0.5 <A.c, A.ne> 339 circle rad .065 at 0.5 <A.c, A.ne> 340 spline from last circle.nw left .25 then left .05 down .05 341 arc from A.c to A.se rad 0.5 342 for i = 1 to 10 do { line from A.s+.025*i,.01*i down i/50 } 343 .PE 344 .SH SOURCE 345 .B \*9/src/cmd/pic 346 .SH "SEE ALSO" 347 .IR grap (1), 348 .MR doctype (1) , 349 .MR troff (1) 350 .br 351 B. W. Kernighan, 352 ``PIC\(ema Graphics Language for Typesetting'', 353 .I 354 Unix Research System Programmer's Manual, 355 Tenth Edition, Volume 2 356 .SH BUGS 357 .I Svgpic 358 is only lightly tested. 359 It should handle troff commands in text output.