.\" Automatically generated by Pod::Man 4.14 (Pod::Simple 3.42) .\" .\" Standard preamble: .\" ======================================================================== .de Sp \" Vertical space (when we can't use .PP) .if t .sp .5v .if n .sp .. .de Vb \" Begin verbatim text .ft CW .nf .ne \\$1 .. .de Ve \" End verbatim text .ft R .fi .. .\" Set up some character translations and predefined strings. \*(-- will .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left .\" double quote, and \*(R" will give a right double quote. \*(C+ will .\" give a nicer C++. Capital omega is used to do unbreakable dashes and .\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff, .\" nothing in troff, for use with C<>. .tr \(*W- .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' .ie n \{\ . ds -- \(*W- . ds PI pi . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch . ds L" "" . ds R" "" . ds C` "" . ds C' "" 'br\} .el\{\ . ds -- \|\(em\| . ds PI \(*p . ds L" `` . ds R" '' . ds C` . ds C' 'br\} .\" .\" Escape single quotes in literal strings from groff's Unicode transform. .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" .\" If the F register is >0, we'll generate index entries on stderr for .\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index .\" entries marked with X<> in POD. Of course, you'll have to process the .\" output yourself in some meaningful fashion. .\" .\" Avoid warning from groff about undefined register 'F'. .de IX .. .nr rF 0 .if \n(.g .if rF .nr rF 1 .if (\n(rF:(\n(.g==0)) \{\ . if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{\ . nr % 0 . nr F 2 . \} . \} .\} .rr rF .\" ======================================================================== .\" .IX Title "Bezier 3pm" .TH Bezier 3pm "2022-10-13" "perl v5.34.0" "User Contributed Perl Documentation" .\" For nroff, turn off justification. Always turn off hyphenation; it makes .\" way too many mistakes in technical documents. .if n .ad l .nh .SH "NAME" Math::Bezier \- solution of Bezier Curves .SH "SYNOPSIS" .IX Header "SYNOPSIS" .Vb 1 \& use Math::Bezier; \& \& # create curve passing list of (x, y) control points \& my $bezier = Math::Bezier\->new($x1, $y1, $x2, $y2, ..., $xn, $yn); \& \& # or pass reference to list of control points \& my $bezier = Math::Bezier\->new([ $x1, $y1, $x2, $y2, ..., $xn, $yn]); \& \& # determine (x, y) at point along curve, range 0 \-> 1 \& my ($x, $y) = $bezier\->point(0.5); \& \& # returns list ref in scalar context \& my $xy = $bezier\->point(0.5); \& \& # return list of 20 (x, y) points along curve \& my @curve = $bezier\->curve(20); \& \& # returns list ref in scalar context \& my $curve = $bezier\->curve(20); .Ve .SH "DESCRIPTION" .IX Header "DESCRIPTION" This module implements the algorithm for the solution of Bezier curves as presented by Robert D. Miller in Graphics Gems V, \*(L"Quick and Simple Bezier Curve Drawing\*(R". .PP A new Bezier curve is created using the \fBnew()\fR constructor, passing a list of (x, y) control points. .PP .Vb 1 \& use Math::Bezier; \& \& my @control = ( 0, 0, 10, 20, 30, \-20, 40, 0 ); \& my $bezier = Math::Bezier\->new(@control); .Ve .PP Alternately, a reference to a list of control points may be passed. .PP .Vb 1 \& my $bezier = Math::Bezier\->new(\e@control); .Ve .PP The point($theta) method can then be called on the object, passing a value in the range 0 to 1 which represents the distance along the curve. When called in list context, the method returns the x and y coordinates of that point on the Bezier curve. .PP .Vb 2 \& my ($x, $y) = $bezier\->point(0.5); \& print "x: $x y: $y\en .Ve .PP When called in scalar context, it returns a reference to a list containing the x and y coordinates. .PP .Vb 2 \& my $point = $bezier\->point(0.5); \& print "x: $point\->[0] y: $point\->[1]\en"; .Ve .PP The curve($n) method can be used to return a set of points sampled along the length of the curve (i.e. in the range 0 <= \f(CW$theta\fR <= 1). The parameter indicates the number of sample points required, defaulting to 20 if undefined. The method returns a list of ($x1, \&\f(CW$y1\fR, \f(CW$x2\fR, \f(CW$y2\fR, ..., \f(CW$xn\fR, \f(CW$yn\fR) points when called in list context, or a reference to such an array when called in scalar context. .PP .Vb 1 \& my @points = $bezier\->curve(10); \& \& while (@points) { \& my ($x, $y) = splice(@points, 0, 2); \& print "x: $x y: $y\en"; \& } \& \& my $points = $bezier\->curve(10); \& \& while (@$points) { \& my ($x, $y) = splice(@$points, 0, 2); \& print "x: $x y: $y\en"; \& } .Ve .SH "AUTHOR" .IX Header "AUTHOR" Andy Wardley .SH "SEE ALSO" .IX Header "SEE ALSO" Graphics Gems 5, edited by Alan W. Paeth, Academic Press, 1995, \&\s-1ISBN 0\-12\-543455\-3.\s0 Section \s-1IV.8,\s0 'Quick and Simple Bezier Curve Drawing' by Robert D. Miller, pages 206\-209.