RosettaCodeData/Task/Ray-casting-algorithm/Perl/ray-casting-algorithm-2.pl

40 lines
1.2 KiB
Perl

# the following are utilities to use the same Fortran data...
sub point
{
[shift, shift];
}
sub create_polygon
{
my ($pts, $sides) = @_;
my @poly;
for(my $i = 0; $i < $#$sides; $i += 2) {
push @poly, [ $pts->[$sides->[$i]-1], $pts->[$sides->[$i+1]-1] ];
}
\@poly;
}
my @pts = ( point(0,0), point(10,0), point(10,10), point(0,10),
point(2.5,2.5), point(7.5,2.5), point(7.5,7.5), point(2.5,7.5),
point(0,5), point(10,5),
point(3,0), point(7,0), point(7,10), point(3,10) );
my %pgs = (
squared => create_polygon(\@pts, [ 1,2, 2,3, 3,4, 4,1 ] ),
squaredhole => create_polygon(\@pts, [ 1,2, 2,3, 3,4, 4,1, 5,6, 6,7, 7,8, 8,5 ] ),
strange => create_polygon(\@pts, [ 1,5, 5,4, 4,8, 8,7, 7,3, 3,2, 2,5 ] ),
exagon => create_polygon(\@pts, [ 11,12, 12,10, 10,13, 13,14, 14,9, 9,11 ]) ,
);
my @p = ( point(5,5), point(5, 8), point(-10, 5), point(0,5), point(10,5), &
point(8,5), point(10,10) );
foreach my $pol ( sort keys %pgs ) {
no strict 'refs';
print "$pol\n";
my $rp = $pgs{$pol};
foreach my $tp ( @p ) {
print "\t($tp->[0],$tp->[1]) " .
( point_in_polygon($tp, $rp) ? "INSIDE" : "OUTSIDE" ) . "\n";
}
}