--- /dev/null
+.lf 1 tkspline.3tk
+.lf 1 man.macros
+'\" The definitions below are for supplemental macros used in Tcl/Tk
+'\" manual entries.
+'\"
+'\" .AP type name in/out ?indent?
+'\" Start paragraph describing an argument to a library procedure.
+'\" type is type of argument (int, etc.), in/out is either "in", "out",
+'\" or "in/out" to describe whether procedure reads or modifies arg,
+'\" and indent is equivalent to second arg of .IP (shouldn't ever be
+'\" needed; use .AS below instead)
+'\"
+'\" .AS ?type? ?name?
+'\" Give maximum sizes of arguments for setting tab stops. Type and
+'\" name are examples of largest possible arguments that will be passed
+'\" to .AP later. If args are omitted, default tab stops are used.
+'\"
+'\" .BS
+'\" Start box enclosure. From here until next .BE, everything will be
+'\" enclosed in one large box.
+'\"
+'\" .BE
+'\" End of box enclosure.
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+'\" .CS
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+'\" .CE
+'\" End code excerpt.
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+'\" Begin an indented unfilled display.
+'\"
+'\" .DE
+'\" End of indented unfilled display.
+'\"
+'\" .SO
+'\" Start of list of standard options for a Tk widget. The
+'\" options follow on successive lines, in four columns separated
+'\" by tabs.
+'\"
+'\" .SE
+'\" End of list of standard options for a Tk widget.
+'\"
+'\" .OP cmdName dbName dbClass
+'\" Start of description of a specific option. cmdName gives the
+'\" option's name as specified in the class command, dbName gives
+'\" the option's name in the option database, and dbClass gives
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+'\"
+'\" .UL arg1 arg2
+'\" Print arg1 underlined, then print arg2 normally.
+'\"
+'\" SCCS: @(#) man.macros 1.8 96/02/15 20:02:24
+'\"
+'\" # Set up traps and other miscellaneous stuff for Tcl/Tk man pages.
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+.nr ^l \n(.l
+.ad b
+'\" # Start an argument description
+.de AP
+.ie !"\\$4"" .TP \\$4
+.el \{\
+. ie !"\\$2"" .TP \\n()Cu
+. el .TP 15
+.\}
+.ie !"\\$3"" \{\
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+\&\\$1 \\fI\\$2\\fP (\\$3)
+.\".b
+.\}
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+.\}
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+.\}
+.\}
+..
+'\" # define tabbing values for .AP
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+.nr )C \\n()Bu+\\w'(in/out)'u+2n
+..
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+.\" box if the box started on an earlier page.
+.ie !\\n(^b\-1 \{\
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+.\}
+.el \}\
+\h'\-1.5n'\L'|\\n(^yu\-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v\-\\n(^yu'\l'|0u\-1.5n\(ul'
+.\}
+.\}
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+..
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+'\" # ^Y = starting y location
+'\" # ^v = 1 (for troff; for nroff this doesn't matter)
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+.\" Draw three-sided box if this is the box's first page,
+.\" draw two sides but no top otherwise.
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+.el \h'\-1.5n'\L'|\\n(^yu\-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v\-\\n(^yu'\h'|0u'\c
+.\}
+.if \\n(^v \{\
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+..
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+.nf
+.sp
+..
+'\" # DE \- end display
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+.RE
+.sp
+..
+'\" # SO \- start of list of standard options
+.de SO
+.SH "STANDARD OPTIONS"
+.LP
+.nf
+.ta 4c 8c 12c
+.ft B
+..
+'\" # SE \- end of list of standard options
+.de SE
+.fi
+.ft R
+.LP
+See the \\fBoptions\\fR manual entry for details on the standard options.
+..
+'\" # OP \- start of full description for a single option
+.de OP
+.LP
+.nf
+.ta 4c
+Command\-Line Name: \\fB\\$1\\fR
+Database Name: \\fB\\$2\\fR
+Database Class: \\fB\\$3\\fR
+.fi
+.IP
+..
+'\" # CS \- begin code excerpt
+.de CS
+.RS
+.nf
+.ta .25i .5i .75i 1i
+..
+'\" # CE \- end code excerpt
+.de CE
+.fi
+.RE
+..
+.de UL
+\\$1\l'|0\(ul'\\$2
+..
+.lf 2 tkspline.n
+.TH tkspline n 8.0 Tk "Tk Spline \- An additional smoothing method for canvas items "
+.BS
+'\" Note: do not modify the .SH NAME line immediately below!
+.SH NAME
+\fBspline\fR, \- additional smoothing method for canvas items.
+.SH SYNOPSIS
+.nf
+ package require Tkspline
+ ...
+ .c create line ... \-smooth spline ...
+ .c create polygon ... \-smooth spline ...
+.fo
+.BE
+.SH INTRODUCTION
+.PP
+The new option value: \fB\-smooth spline\fR provides an additional smoothing method to
+\fBline\fR and \fBpolygon\fR canvas items.
+
+.PP
+Spline smoothing will revert to the builtin smoothing method unless the number
+of points is 3n+1, where n is the number of spline segments.
+(Normally in polygons this means 3n points because the last point of the spline
+is understood to be the same as the first in order to close the polygon).
+
+.PP
+In \fBline\fR and \fBpolygon\fR items, the curves generated with the standard
+\fB\-smooth true\fR option have the following properties:
+.TP 3
+-
+the curve is always tangential to a straight line between consecutive points.
+.TP 3
+-
+the curve is only guaranteed to intersect the first and last points of \fBline\fRs.
+.TP 3
+-
+the curve is not guaranteed to intersect any points of \fBpolygon\fRs.
+
+.PP
+With \fB\-smooth spline\fR (and the right number of coordinates)
+the curves generated have the following different properties:
+.TP 3
+-
+the curve is guaranteed to intersect the first point, and every third point after that.
+.TP 3
+-
+each segment of the curve shares endpoints with the adjacent segments,
+but is otherwise independant of them.
+.TP 3
+-
+the curve is guaranteed to be tangential to a line between n and n+1 at
+point n, and also to a line between n+2 and n+3 at point n+3.
+.TP 3
+-
+the curve is not guaranteed to be smooth at the junctions between
+segments unless the shared point and the points either side of it are
+on a straight line.
+
+.PP
+These alternative properties are useful to some path planning algorithms.
+
+.SH CREDITS
+The underlying Bezier code is in John Ousterhout's original
+canvas widget, this extension just provides an alternate interface
+to it. The hooks into the canvas are provided by Jan Nijtmans in
+his "dash" patch.
+
+.SH KEYWORDS
+spline, line, polygon, bezier, canvas, widget
+
+.SH AUTHOR
+John Ellson, ellson@graphviz.org
projects / graphviz / commitdiff