Math::Polygon::Clip - frame a polygon in a square
Math::Polygon::Clip is a Exporter
my @poly = ( [1,2], [2,4], [5,7], [1, 2] ); my @box = ( $xmin, $ymin, $xmax, $ymax ); my $boxed = polygon_clip \@box, @poly;
Cut-off all parts of the polygon which are outside the box
Clipping a polygon into rectangles can be done in various ways. With this algorithm (which I designed myself, but may not be new), the parts of the polygon which are outside the $box are mapped on the borders. The polygon stays in one piece.
Returned is one list of points, which is cleaned from double points, spikes and superfluous intermediate points.
To be implemented. The polygon falls apart in fragments, which are not connected: paths which are followed in two directions are removed. This is required by some applications, like polygons used in geographical context (country contours and such).
To be implemented. A surrounding polygon, with possible inclussions.
Returned is a list of ARRAYS (possibly 0 long) containing line pieces from the input polygon (or line).
example:
my @points = ( [1,2], [2,3], [2,0], [1,-1], [1,2] ); my @bbox = ( 0, -2, 2, 2 ); my @l = polygon_line_clip \@bbox, @points; print scalar @l; # 1, only one piece found my @first = @{$l[0]}; # first is [2,0], [1,-1], [1,2]
This module is part of Math-Polygon distribution version 1.06, built on July 16, 2017. Website: http://perl.overmeer.net/geo/
Copyrights 2004-2017 by [Mark Overmeer]. For other contributors see ChangeLog.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See http://dev.perl.org/licenses/
To install Math::Polygon, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Math::Polygon
CPAN shell
perl -MCPAN -e shell install Math::Polygon
For more information on module installation, please visit the detailed CPAN module installation guide.