+Dec, 1984:
+
+reset varlist
+ resets built-in variables in list to default values.
+ empty list resets everything.
+
+sprintf("format", exprlist)
+ returns a text string suitable for use anywhere "..."
+ can be used.
+
+sh X anything X
+ passes "anything" to a shell for execution after
+ replacing any defined terms in it.
+
+Nov, 1984:
+
+line expr and move expr are treated as line/move by expr
+in current direction.
+
+The -D option has been rendered obsolete -- all output is
+produced with \D commands. The -T option is also
+meaningless -- the output is independent of typesetter.
+
+A new variable "arrowhead" controls printing of arrowheads,
+by defining the number of lines printed in a little fan.
+Default is 2; values around 7 give a filled-in head;
+other values are basically worthless. Arrowheads on arcs
+are now tilted somewhat in an attempt to improve their
+appearance.
+
+"undef foo" removes the definition of foo.
+
+July 1984:
+
+The functions log, exp (both base 10), sqrt, sin, cos, atan2(,),
+max, min (2 arguments only), int, and rand (which returns a
+float random on [0,1)) are now available, stolen directly
+from grap.
+
+Added copy, for and if from grap:
+ copy "file"
+ copy "file" thru X macro body X
+ copy thru X macro X [until "str"]
+ for var = expr to expr [by expr] do X anything X
+ if expr then X anything [else X anything X]
+
+In a copy, any .PS or .PE is discarded [sic], so copied files
+can be nested without editing. .PS <file still works
+but its use is discouraged.
+
+In an if, you can also test "string1" == "string2" or
+"string1" != "string2"
+
+The text primitive is now more systematic:
+"..." ".." "." makes an invisible object with
+properties much like a box. Height and width
+are settable: explicit ht and wid modifiers
+affect a specific instance; variables textht
+and textwid affect all subsequent occurrences.
+"textht" is the height of one line, so the height
+of n strings is n*textht.
+
+Added code from Eric Grosse to correctly compute bounding
+box for arcs. Also defined corners for arcs as same as
+corresponding circle, an idea due to Tom Cargill.
+
+Limits on text strings, attributes and objects grow until
+memory limit reached.
+
+Permits E format on input numbers.
+
+Output produced in inches, not units, so somewhat more
+typesetter-independent. The environment variable TYPESETTER
+is examined.
+
+Saves and restores fill state around .PS/.PE.
+
+.PS wid ht
+can be used to set width and height separately for picture;
+default ht is to scale in same proportion as width (as before).
+
+
+Dec 10/81:
+
+The "scale = ..." construction has been reinstated:
+if
+ scale = 100
+or some such appears in a picture, all numbers in that
+and subsequent pictures will be scaled by 1/100.
+Default scale is 1.0.
+
+Oct 8/81:
+
+I have finally installed sensible floating-point
+numbers in pic. This means that the trailing "i",
+as in 1.25i, is no longer necessary: all numbers
+are taken to be in inches.
+Furthermore, expressions may now use numbers like
+1.25 instead of circumlocutions like 5/4.
+It is now best to enter dimensions and positions simply
+in terms of inches, as in "box at 1,2" instead of in terms
+of internal units (which used to be "box at 200,400").
+Internal units are no longer used.
+
+I will be glad to assist with conversion if necessary;
+opic will remain around for a while too.
+
+New May, 1981:
+
+0. Diagnostics:
+ Error reporting is better; error location is marked
+ with a ^ at the point in the input where the error was detected;
+ line numbers are more accurate when define's are used.
+
+1. Shorthand for points
+ ( place1 , place2 ) now refers to the point ( place1.x, place2.y ),
+ as it does in i.
+
+2. Blocks
+ Any sequence of pic statements may be enclosed in [...] to form
+ a block, which can be positioned rather like an ordinary box.
+ Typical constructions look like
+ box ...
+ [ box; circle; arrow; whatever ] with .ne at last box.sw
+ move to top of 2nd last []
+ "last"-type constructs treat blocks as a unit and don't look
+ inside for objects. Blocks have the same compass corners as
+ boxes (determined by the bounding box); in addition it is
+ possible to position them by placing either an absolute
+ coordinate (like 0,0) or an internal label (like A) at some
+ external point. Thus:
+ [ ...; A: ...; ... ] with .A at ...
+ You can use "last []" just like "last box".
+ Blocks join with other things like boxes do (i.e., at the
+ center of the appropriate side). It's not clear that this
+ is the right thing to do, so it may change.
+
+ Names of variables and places within a block are local
+ to that block, and thus do not affect variables and places
+ of the same name outside. You can get at the internal
+ place names with constructs like
+ last [].A
+ or
+ B.A
+ where B is a name attached to a block like so:
+ B : [ ... ; A: ...; ]
+
+ When combined with define statements, blocks provide
+ a reasonable simulation of a procedure mechanism.
+
+ Blocks nest, but the code is shaky; let me know if
+ something suspicious happens.
+ It is currently possible to look only one level deep
+ with constructs like B.A, although A may be
+ further qualified (i.e., B.A.sw or "top of B.A" are legal).
+
+3. Flyback
+ If .PF is used instead of .PE, the position after printing is
+ restored to where it was before the picture started.
+ ("F" is for "flyback".)
+
+4. "Between" positions
+ It is now possible to specify a position somewhere between two
+ other positions either by the phrase
+ expr of the way between position1 and position2
+ or by the notation
+ expr <position1, position2>
+ where expr is some number like 0.3333 and the positions are anything
+ like corners, labels, etc. The result is a new position which is
+ "expr" of the way along a line from position1 to position2. Naturally
+ expr can be bigger than 1 or negative. "of the way" is optional.
+
+
+These are changes since the TM was issued in June, 1980:
+
+.PS <file
+ causes input to come from "file".
+ the .PS evaporates, so "file" has to
+ have balanced .PS/.PE pairs.
+
+splines are here. To get smooth curves,
+ "spline" followed by a set of up, down, from, to, etc.
+ causes a B-spline to be drawn using the specified
+ points to guide it. the word "then" can be stuck
+ in to separate unrelated groups of relative motions.
+ Arrows can go on either end.
+ E.g., spline from 10,20 up 30 right 40 then left 50 then \
+ down 20 to 100,200 to 300,350 ->
+
+Lines have been generalized somewhat, so you can use the same
+ construct as for splines, to specify a path rather than
+ just a single segment.
+
+
projects / unix-history / commitdiff