Ported Polygon->area

lib/Slic3r/Polygon.pm

@@ -8,7 +8,6 @@ use parent 'Slic3r::Polyline';
 use Slic3r::Geometry qw(polygon_remove_parallel_continuous_edges
     polygon_remove_acute_vertices polygon_segment_having_point
     PI X1 X2 Y1 Y2 epsilon);
-use Slic3r::Geometry::Clipper qw(JT_MITER);
 
 sub wkt {
     my $self = shift;
@@ -34,11 +33,6 @@ sub encloses_point {
     return Boost::Geometry::Utils::point_covered_by_polygon($point->pp, [$self->pp]);
 }
 
-sub area {
-    my $self = shift;
-    return Slic3r::Geometry::Clipper::area($self->pp);
-}
-
 sub grow {
     my $self = shift;
     return $self->split_at_first_point->grow(@_);

xs/src/Polygon.cpp

@@ -54,6 +54,14 @@ Polygon::split_at_first_point()
     return this->split_at_index(0);
 }
 
+double
+Polygon::area()
+{
+    ClipperLib::Polygon p;
+    Slic3rPolygon_to_ClipperPolygon(*this, p);
+    return ClipperLib::Area(p);
+}
+
 bool
 Polygon::is_counter_clockwise()
 {

xs/src/Polygon.hpp

@@ -16,6 +16,7 @@ class Polygon : public MultiPoint {
     Polyline* split_at(const Point* point);
     Polyline* split_at_index(int index);
     Polyline* split_at_first_point();
+    double area();
     bool is_counter_clockwise();
     bool make_counter_clockwise();
     bool make_clockwise();

xs/t/06_polygon.t

@@ -4,7 +4,7 @@ use strict;
 use warnings;
 
 use Slic3r::XS;
-use Test::More tests => 11;
+use Test::More tests => 12;
 
 my $square = [  # ccw
     [100, 100],
@@ -30,6 +30,7 @@ is_deeply [ map $_->pp, @$lines ], [
 is_deeply $polygon->split_at_first_point->pp, [ @$square[0,1,2,3,0] ], 'split_at_first_point';
 is_deeply $polygon->split_at_index(2)->pp, [ @$square[2,3,0,1,2] ], 'split_at_index';
 is_deeply $polygon->split_at(Slic3r::Point->new(@{$square->[2]}))->pp, [ @$square[2,3,0,1,2] ], 'split_at';
+is $polygon->area, 100*100, 'area';
 
 ok $polygon->is_counter_clockwise, 'is_counter_clockwise';
 {

xs/xsp/Polygon.xsp

@@ -23,6 +23,7 @@
         %code{% const char* CLASS = "Slic3r::Polyline"; RETVAL = THIS->split_at_index(index); %};
     Polyline* split_at_first_point()
         %code{% const char* CLASS = "Slic3r::Polyline"; RETVAL = THIS->split_at_first_point(); %};
+    double area();
     bool is_counter_clockwise();
     bool make_counter_clockwise();
     bool make_clockwise();