NAME
Math::Polygon::Tree - fast check if point is inside polygon
VERSION
version 0.05
SYNOPSIS
use Math::Polygon::Tree;
my $poly = [ [0,0], [0,2], [2,2], ... ];
my $bound = Math::Polygon::Tree->new( $poly );
if ( $bound->contains( [1,1] ) ) { ... }DESCRIPTION
Math::Polygon::Tree creates a B-tree of polygon parts for fast check if object is inside this polygon. This method is effective if polygon has hundreds or more segments.
METHODS
new
Takes [at least one] contour and creates a tree structure. All polygons are outer, inners in not implemented.
Contour is an arrayref of points:
my $poly1 = [ [0,0], [0,2], [2,2], ... ];
...
my $bound = Math::Polygon::Tree->new( $poly1, $poly2, ... );or a .poly file
my $bound = Math::Polygon::Tree->new( 'boundary.poly' );contains
if ( $bound->contains( [1,1] ) ) { ... }Checks if point is inside bound polygon.
Returns 1 if point is inside polygon, -1 if it lays on polygon boundary (dirty), or 0 otherwise.
contains_points
Checks if points are inside bound polygon.
Returns 1 if all points are inside polygon, 0 if all outside, or undef.
if ( $bound->contains_points( [1,1], [2,2] ... ) ) { ...contains_bbox_rough
Checks if box is inside bound polygon.
Returns 1 if box is inside polygon, 0 if box is outside polygon or undef if it 'doubts'.
my ($xmin, $ymin, $xmax, $ymax) = ( 1, 1, 2, 2 );
if ( $bound->contains_bbox_rough( $xmin, $ymin, $xmax, $ymax ) ) { ... }contains_polygon_rough
Checks if polygon is inside bound polygon.
Returns 1 if inside, 0 if outside or undef if 'doubts'.
if ( $bound->contains_polygon_rough( [ [1,1], [1,2], [2,2], ... ] ) ) { ... }bbox
Returns polygon's bounding box.
my ( $xmin, $ymin, $xmax, $ymax ) = $bound->bbox();FUNCTIONS
polygon_bbox
Function that returns polygon's bbox.
my ( $xmin, $ymin, $xmax, $ymax ) = polygon_bbox( [1,1], [1,2], [2,2], ... );polygon_centroid
Function that returns polygon's weightened center.
my ( $x, $y ) = polygon_centroid( [1,1], [1,2], [2,2], ... );polygon_contains_point
Function that tests if polygon contains point (modified one from Math::Polygon::Calc).
Returns -1 if point lays on polygon's boundary
AUTHOR
liosha <liosha@cpan.org>
COPYRIGHT AND LICENSE
This software is copyright (c) 2013 by liosha.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.