Question

我正在尝试使用Math::Geometry::Planar中的GpcClip()函数来查找两个多边形的交集。我使用Math::Geometry::Planar->new();构建了两个多边形，但在GpcClip()中使用它时出现以下错误：

在gpc_polygon_clip的参数2中输入错误。预计_p_gpc_polygon位于c：/strawberry/perl/site/lib/math/geometry/planar.pm第2028行

如何将Math::Geometry::Planar->new()返回的对象转换为GPC多边形？

Answer 1

根据documentation，您可以使用convert2gpc方法：

<强> $ polygon-＆GT; convert2gpc;

将多边形/轮廓转换为gpc结构并返回生成的gpc结构

示例：

use strict;
use warnings 'all';

use Math::Geometry::Planar;

my $outer = Math::Geometry::Planar->new;
my $inner = Math::Geometry::Planar->new;
$outer->points([[0, 0], [0, 3], [3, 3], [3, 0]]);
$inner->points([[1, 1], [1, 2], [2, 2], [2, 1]]);

my $diff = GpcClip('DIFFERENCE', $outer->convert2gpc, $inner->convert2gpc);

Answer 2

use strict;
use warnings 'all';
use Data::Dumper;
use Math::Geometry::Planar;

my $outer = Math::Geometry::Planar->new;
my $inner = Math::Geometry::Planar->new;
$outer->points([[0, 0], [0, 3], [3, 3], [3, 0],[0,0]]);
$inner->points([[2, 0], [2, 2], [4, 2], [4, 0],[2,0]]);

my $diff = GpcClip('INTERSECTION', $outer->convert2gpc, $inner->convert2gpc);
#first polygon rep the outer poly, the rest of them are holes
my @pgons = Gpc2Polygons($diff);  

#since here we don't have holes, only the first one is a valid polygon 
print Dumper($pgons[0]->polygons->[0]);

#convert the points into Planar Polygon
my $result = Math::Geometry::Planar->new;
$result->points($pgons[0]->polygons->[0]);

print Dumper($result);

感谢@ThisSuitlsBlackNot提供的帮助。顺便说一句，你是否有任何想法在多边形内找到一个随机点，这个多边形没有洞。再次感谢

如何创建GPC多边形以与Math :: Geometry :: Planar :: GpcClip一起使用？

2 个答案: