Bugfix: Douglas-Peucker used perpendicular distance instead of shortest distance, thus clipping more than it should. #2474

2 files changed, 34 insertions, 3 deletions

diff --git a/xs/t/03_point.t b/xs/t/03_point.t
index 0ec9df552..d983fafc9 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 => 15;
+use Test::More tests => 22;
 
 my $point = Slic3r::Point->new(10, 15);
 is_deeply [ @$point ], [10, 15], 'point roundtrip';
@@ -31,12 +31,27 @@ ok !$point->coincides_with($point2), 'coincides_with';
 }
 
 {
+    my $line = Slic3r::Line->new([0,0], [100,0]);
+    is +Slic3r::Point->new(0,0)->distance_to_line($line),    0, 'distance_to_line()';
+    is +Slic3r::Point->new(100,0)->distance_to_line($line),  0, 'distance_to_line()';
+    is +Slic3r::Point->new(50,0)->distance_to_line($line),   0, 'distance_to_line()';
+    is +Slic3r::Point->new(150,0)->distance_to_line($line), 50, 'distance_to_line()';
+    is +Slic3r::Point->new(0,50)->distance_to_line($line),  50, 'distance_to_line()';
+    is +Slic3r::Point->new(50,50)->distance_to_line($line), 50, 'distance_to_line()';
+}
+
+{
+    my $line = Slic3r::Line->new([50,50], [125,-25]);
+    is +Slic3r::Point->new(100,0)->distance_to_line($line),  0, 'distance_to_line()';
+}
+
+{
     my $line = Slic3r::Line->new(
         [18335846,18335845],
         [18335846,1664160],
     );
     $point = Slic3r::Point->new(1664161,18335848);
-    is $point->distance_to_line($line), 16671685, 'distance_to_line() does not overflow';
+    is $point->perp_distance_to_line($line), 16671685, 'perp_distance_to_line() does not overflow';
 }
 
 {
diff --git a/xs/t/09_polyline.t b/xs/t/09_polyline.t
index 5ce8d87cb..99077aad3 100644
--- a/xs/t/09_polyline.t
+++ b/xs/t/09_polyline.t
@@ -4,7 +4,7 @@ use strict;
 use warnings;
 
 use Slic3r::XS;
-use Test::More tests => 14;
+use Test::More tests => 16;
 
 my $points = [
     [100, 100],
@@ -36,6 +36,14 @@ is_deeply $polyline->pp, [ @$points, @$points ], 'append_polyline';
 
 {
     my $polyline = Slic3r::Polyline->new(
+        [0,0], [20,0], [50,0], [80,0], [100,0],
+    );
+    $polyline->simplify(2);
+    is_deeply $polyline->pp, [ [0,0], [100,0] ], 'Douglas-Peucker';
+}
+
+{
+    my $polyline = Slic3r::Polyline->new(
         [0,0], [50,50], [100,0], [125,-25], [150,50],
     );
     $polyline->simplify(25);
@@ -43,6 +51,14 @@ is_deeply $polyline->pp, [ @$points, @$points ], 'append_polyline';
 }
 
 {
+    my $polyline = Slic3r::Polyline->new(
+        [0,0], [100,0], [50,10],
+    );
+    $polyline->simplify(25);
+    is_deeply $polyline->pp, [ [0,0], [100,0], [50,10] ], 'Douglas-Peucker uses shortest distance instead of perpendicular distance';
+}
+
+{
     my $polyline = Slic3r::Polyline->new(@$points);
     is $polyline->length, 100*2, 'length';
     $polyline->extend_end(50);