From 90194ee581ada784835d9c1d869d00d7cc741579 Mon Sep 17 00:00:00 2001
From: Alessandro Ranellucci <aar@cpan.org>
Date: Fri, 17 Jan 2014 14:49:51 +0100
Subject: [PATCH] Fix overflow in Point::ccw() affecting convex hull
 generation. Includes regression test

---
 lib/Slic3r/GUI/Plater.pm | 1 -
 xs/src/Point.cpp         | 2 +-
 xs/t/03_point.t          | 9 ++++++++-
 xs/xsp/Point.xsp         | 2 ++
 4 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/lib/Slic3r/GUI/Plater.pm b/lib/Slic3r/GUI/Plater.pm
index b55bb81fd..8fd9ed5bb 100644
--- a/lib/Slic3r/GUI/Plater.pm
+++ b/lib/Slic3r/GUI/Plater.pm
@@ -1057,7 +1057,6 @@ sub repaint {
     if (@{$parent->{objects}} && $parent->{config}->skirts) {
         my @points = map @{$_->contour}, map @$_, map @{$_->instance_thumbnails}, @{$parent->{objects}};
         if (@points >= 3) {
-            my @o = @{Slic3r::Geometry::Clipper::simplify_polygons([convex_hull(\@points)])};
             my ($convex_hull) = @{offset([convex_hull(\@points)], scale($parent->{config}->skirt_distance), 1, JT_ROUND, scale(0.1))};
             $dc->SetPen($parent->{skirt_pen});
             $dc->SetBrush($parent->{transparent_brush});
diff --git a/xs/src/Point.cpp b/xs/src/Point.cpp
index ff63eae58..9b95c6fb8 100644
--- a/xs/src/Point.cpp
+++ b/xs/src/Point.cpp
@@ -125,7 +125,7 @@ Point::distance_to(const Line &line) const
 double
 Point::ccw(const Point &p1, const Point &p2) const
 {
-    return (p2.x - p1.x)*(this->y - p1.y) - (p2.y - p1.y)*(this->x - p1.x);
+    return (double)(p2.x - p1.x)*(double)(this->y - p1.y) - (double)(p2.y - p1.y)*(double)(this->x - p1.x);
 }
 
 double
diff --git a/xs/t/03_point.t b/xs/t/03_point.t
index 39a2313ec..e1c88977f 100644
--- a/xs/t/03_point.t
+++ b/xs/t/03_point.t
@@ -4,7 +4,7 @@ use strict;
 use warnings;
 
 use Slic3r::XS;
-use Test::More tests => 9;
+use Test::More tests => 10;
 
 my $point = Slic3r::Point->new(10, 15);
 is_deeply [ @$point ], [10, 15], 'point roundtrip';
@@ -39,4 +39,11 @@ ok !$point->coincides_with($point2), 'coincides_with';
     is $point->distance_to_line($line), 16671685, 'distance_to_line() does not overflow';
 }
 
+{
+    my $p0 = Slic3r::Point->new(76975850,89989996);
+    my $p1 = Slic3r::Point->new(76989990,109989991);
+    my $p2 = Slic3r::Point->new(76989987,89989994);
+    ok $p0->ccw($p1, $p2) < 0, 'ccw() does not overflow';
+}
+
 __END__
diff --git a/xs/xsp/Point.xsp b/xs/xsp/Point.xsp
index 8afcf1838..79439d099 100644
--- a/xs/xsp/Point.xsp
+++ b/xs/xsp/Point.xsp
@@ -25,6 +25,8 @@
         %code{% const char* CLASS = "Slic3r::Point"; RETVAL = new Point(*(THIS->nearest_point(points))); %};
     double distance_to(Point* point);
     %name{distance_to_line} double distance_to(Line* line);
+    double ccw(Point* p1, Point* p2)
+        %code{% RETVAL = THIS->ccw(*p1, *p2); %};
 
 %{