1Math::Polygon::Clip(3)User Contributed Perl DocumentationMath::Polygon::Clip(3)
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NAME

6       Math::Polygon::Clip - frame a polygon in a square
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INHERITANCE

9        Math::Polygon::Clip
10          is a Exporter
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SYNOPSIS

13        my @poly  = ( [1,2], [2,4], [5,7], [1, 2] );
14        my @box   = ( $xmin, $ymin, $xmax, $ymax );
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16        my $boxed = polygon_clip \@box, @poly;
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DESCRIPTION

19       Cut-off all parts of the polygon which are outside the box
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FUNCTIONS

22       polygon_fill_clip1(\@box, @points)
23           Clipping a polygon into rectangles can be done in various ways.
24           With this algorithm (which I designed myself, but may not be new),
25           the parts of the polygon which are outside the @box are mapped on
26           the borders.  The polygon stays in one piece.
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28           Returned is one list of points, which is cleaned from double
29           points, spikes and superfluous intermediate points.
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31       polygon_fill_clip2(\@box, @points)
32           To be implemented.  The polygon falls apart in fragments, which are
33           not connected: paths which are followed in two directions are
34           removed.  This is required by some applications, like polygons used
35           in geographical context (country contours and such).
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37       polygon_fill_clip3( \@box, $out-$poly, [$in-$polys] )
38           To be implemented.  A surrounding polygon, with possible
39           inclussions.
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41       polygon_line_clip(\@box, @points)
42           Returned is a list of ARRAYS (possibly 0 long) containing line
43           pieces from the input polygon (or line).
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45           example:
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47            my @points = ( [1,2], [2,3], [2,0], [1,-1], [1,2] );
48            my @bbox   = ( 0, -2, 2, 2 );
49            my @l      = polygon_line_clip \@bbox, @points;
50            print scalar @l;      # 1, only one piece found
51            my @first = @{$l[0]}; # first is [2,0], [1,-1], [1,2]
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SEE ALSO

54       This module is part of Math-Polygon distribution version 1.10, built on
55       January 03, 2018. Website: http://perl.overmeer.net/CPAN/
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LICENSE

58       Copyrights 2004-2018 by [Mark Overmeer]. For other contributors see
59       ChangeLog.
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61       This program is free software; you can redistribute it and/or modify it
62       under the same terms as Perl itself.  See http://dev.perl.org/licenses/
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66perl v5.34.0                      2022-01-21            Math::Polygon::Clip(3)
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