Customizable overlap ratio (it defaults to 0.15 now)

lib/Slic3r/Polyline/Closed.pm

@@ -4,6 +4,7 @@ use Moo;
 extends 'Slic3r::Polyline';
 
 use Math::Clipper qw(JT_MITER);
+use Slic3r::Geometry qw(scale);
 
 sub lines {
     my $self = shift;
@@ -31,7 +32,7 @@ sub is_printable {
     # if no offset is possible, then polyline is not printable
     my $p = $self->p;
     @$p = reverse @$p if !Math::Clipper::is_counter_clockwise($p);
-    my $offsets = Math::Clipper::offset([$p], -($Slic3r::flow_width / 2 / $Slic3r::resolution), $Slic3r::resolution * 100000, JT_MITER, 2);
+    my $offsets = Math::Clipper::offset([$p], -(scale $Slic3r::flow_spacing / 2), $Slic3r::resolution * 100000, JT_MITER, 2);
     return @$offsets ? 1 : 0;
 }