Incomplete work for porting simplify() to XS

lib/Slic3r/ExtrusionPath.pm

@@ -10,9 +10,4 @@ our @EXPORT_OK = qw(EXTR_ROLE_PERIMETER EXTR_ROLE_EXTERNAL_PERIMETER
     EXTR_ROLE_INTERNALBRIDGE EXTR_ROLE_SKIRT EXTR_ROLE_SUPPORTMATERIAL EXTR_ROLE_GAPFILL);
 our %EXPORT_TAGS = (roles => \@EXPORT_OK);
 
-sub simplify {
-    my $self = shift;
-    $self->polyline($self->polyline->simplify(@_));
-}
-
 1;

lib/Slic3r/GCode/MotionPlanner.pm

@@ -38,7 +38,7 @@ sub BUILD {
     my $crossing_edges = $self->_crossing_edges;
     
     # simplify islands
-    @{$self->islands} = map $_->simplify($self->_inner_margin), @{$self->islands};
+    $_->simplify($self->_inner_margin) for @{$self->islands};
     
     # process individual islands
     for my $i (0 .. $#{$self->islands}) {        

lib/Slic3r/GUI/Plater.pm

@@ -1360,10 +1360,10 @@ sub make_thumbnail {
         # remove polygons with area <= 1mm
         my $area_threshold = Slic3r::Geometry::scale 1;
         $self->thumbnail->append(
-            map $_->simplify(0.5),
             grep $_->area >= $area_threshold,
             @{ $mesh->horizontal_projection },
         );
+        $self->thumbnail->simplify(0.5);
     } else {
         my $convex_hull = Slic3r::ExPolygon->new($self->convex_hull)->clone;
         $convex_hull->scale(1/&Slic3r::SCALING_FACTOR);

lib/Slic3r/Polygon.pm

@@ -32,13 +32,6 @@ sub grow {
     return $self->split_at_first_point->grow(@_);
 }
 
-# NOTE that this will turn the polygon to ccw regardless of its 
-# original orientation
-sub simplify {
-    my $self = shift;
-    return @{Slic3r::Geometry::Clipper::simplify_polygons([ $self->SUPER::simplify(@_) ])};
-}
-
 # this method subdivides the polygon segments to that no one of them
 # is longer than the length provided
 sub subdivide {

lib/Slic3r/Polyline.pm

@@ -27,14 +27,6 @@ sub remove_acute_vertices {
     polyline_remove_acute_vertices($self);
 }
 
-sub simplify {
-    my $self = shift;
-    my $tolerance = shift || 10;
-    
-    my $simplified = Boost::Geometry::Utils::linestring_simplify($self->pp, $tolerance);
-    return __PACKAGE__->new(@$simplified);
-}
-
 sub bounding_box {
     my $self = shift;
     return Slic3r::Geometry::BoundingBox->new_from_points($self);

lib/Slic3r/Print.pm

@@ -317,14 +317,8 @@ sub _simplify_slices {
     my ($distance) = @_;
     
     foreach my $layer (map @{$_->layers}, @{$self->objects}) {
-        my @new = map $_->simplify($distance), map $_->clone, @{$layer->slices};
-        $layer->slices->clear;
-        $layer->slices->append(@new);
-        foreach my $layerm (@{$layer->regions}) {
-            my @new = map $_->simplify($distance), map $_->clone, @{$layerm->slices};
-            $layerm->slices->clear;
-            $layerm->slices->append(@new);
-        }
+        $layer->slices->simplify($distance);
+        $_->slices->simplify($distance) for @{$layer->regions};
     }
 }
 

lib/Slic3r/Surface.pm

@@ -38,11 +38,6 @@ sub offset {
     return [ map $self->clone(expolygon => $_), @{$self->expolygon->offset_ex(@_)} ];
 }
 
-sub simplify {
-    my $self = shift;
-    return map $self->clone(expolygon => $_), $self->expolygon->simplify(@_);
-}
-
 sub p {
     my $self = shift;
     return @{$self->polygons};

t/clean_polylines.t

@@ -24,7 +24,7 @@ use Slic3r;
     my $polyline = Slic3r::Polyline->new(
         [0,0],[1,0],[2,0],[2,1],[2,2],[1,2],[0,2],[0,1],[0,0],
     );
-    $polyline = $polyline->simplify(1);
+    $polyline->simplify(1);
     is_deeply $polyline->pp, [ [0, 0], [2, 0], [2, 2], [0, 2], [0, 0] ], 'Douglas-Peucker';
 }
 
@@ -32,7 +32,7 @@ use Slic3r;
     my $polyline = Slic3r::Polyline->new(
         [0,0], [50,50], [100,0], [125,-25], [150,50],
     );
-    $polyline = $polyline->simplify(25);
+    $polyline->simplify(25);
     is_deeply $polyline->pp, [ [0, 0], [50, 50], [125, -25], [150, 50] ], 'Douglas-Peucker';
 }
 

xs/src/ExPolygon.cpp

@@ -82,6 +82,32 @@ ExPolygon::contains_point(const Point* point) const
     return true;
 }
 
+Polygons
+ExPolygon::simplify(double tolerance) const
+{
+    Polygons p;
+    this->contour.simplify(tolerance, p);
+    for (Polygons::const_iterator it = this->holes.begin(); it != this->holes.end(); ++it)
+        it->simplify(tolerance, p);
+    simplify_polygons(p, p);
+    return p;
+}
+
+ExPolygons
+ExPolygon::simplify(double tolerance) const
+{
+    Polygons p = this->simplify(tolerance);
+    return union_(p);
+}
+
+void
+ExPolygon::simplify(double tolerance, ExPolygons &expolygons) const
+{
+    ExPolygons ep = this->simplify(tolerance);
+    expolygons.reserve(expolygons.size() + ep.size());
+    expolygons.insert(expolygons.end(), ep.begin(), ep.end());
+}
+
 #ifdef SLIC3RXS
 SV*
 ExPolygon::to_AV() {

xs/src/ExPolygon.hpp

@@ -19,6 +19,9 @@ class ExPolygon
     bool is_valid() const;
     bool contains_line(const Line* line) const;
     bool contains_point(const Point* point) const;
+    Polygons simplify(double tolerance) const;
+    ExPolygons simplify(double tolerance) const;
+    void simplify(double tolerance, ExPolygons &expolygons) const;
     
     #ifdef SLIC3RXS
     void from_SV(SV* poly_sv);

xs/src/ExPolygonCollection.cpp

@@ -47,4 +47,14 @@ ExPolygonCollection::contains_point(const Point* point) const
     return false;
 }
 
+void
+ExPolygonCollection::simplify(double tolerance)
+{
+    ExPolygons t;
+    for (ExPolygons::const_iterator it = this->expolygons.begin(); it != this->expolygons.end(); ++it) {
+        it->simplify_and_append_to(tolerance, t);
+    }
+    this->expolygons = t;
+}
+
 }

xs/src/ExPolygonCollection.hpp

@@ -15,6 +15,7 @@ class ExPolygonCollection
     void translate(double x, double y);
     void rotate(double angle, Point* center);
     bool contains_point(const Point* point) const;
+    void simplify(double tolerance);
 };
 
 }

xs/src/ExtrusionEntity.cpp

@@ -78,6 +78,12 @@ ExtrusionPath::clip_end(double distance)
     this->polyline.clip_end(distance);
 }
 
+void
+ExtrusionPath::simplify(double tolerance)
+{
+    this->polyline.simplify(tolerance);
+}
+
 double
 ExtrusionPath::length() const
 {

xs/src/ExtrusionEntity.hpp

@@ -54,6 +54,7 @@ class ExtrusionPath : public ExtrusionEntity
     ExtrusionEntityCollection* intersect_expolygons(ExPolygonCollection* collection) const;
     ExtrusionEntityCollection* subtract_expolygons(ExPolygonCollection* collection) const;
     void clip_end(double distance);
+    void simplify(double tolerance);
     double length() const;
     private:
     ExtrusionEntityCollection* _inflate_collection(const Polylines &polylines) const;

xs/src/MultiPoint.cpp

@@ -55,6 +55,47 @@ MultiPoint::is_valid() const
     return this->points.size() >= 2;
 }
 
+void
+MultiPoint::simplify(double tolerance)
+{
+    this->points = MultiPoint::_douglas_peucker(this->points, tolerance);
+}
+
+Points
+MultiPoint::_douglas_peucker(Points &points, double tolerance)
+{
+    Points results;
+    double dmax = 0;
+    int index = 0;
+    Line full(points.front(), points.back());
+    for (Points::const_iterator it = points.begin() + 1; it != points.end(); ++it) {
+        double d = it->distance_to(full);
+        if (d > dmax) {
+            index = it - points.begin();
+            dmax = d;
+        }
+    }
+    if (dmax >= tolerance) {
+        Points dp0;
+        dp0.reserve(index + 1);
+        dp0.insert(dp0.end(), points.begin(), points.begin() + index + 1);
+        Points dp1 = MultiPoint::_douglas_peucker(dp0, tolerance);
+        results.reserve(results.size() + dp1.size() - 1);
+        results.insert(results.end(), dp1.begin(), dp1.end() - 1);
+        
+        dp0.clear();
+        dp0.reserve(points.size() - index + 1);
+        dp0.insert(dp0.end(), points.begin() + index, points.end());
+        dp1 = MultiPoint::_douglas_peucker(dp0, tolerance);
+        results.reserve(results.size() + dp1.size());
+        results.insert(results.end(), dp1.begin(), dp1.end());
+    } else {
+        results.push_back(points.front());
+        results.push_back(points.back());
+    }
+    return results;
+}
+
 #ifdef SLIC3RXS
 void
 MultiPoint::from_SV(SV* poly_sv)

xs/src/MultiPoint.hpp

@@ -21,6 +21,7 @@ class MultiPoint
     virtual Lines lines() const = 0;
     double length() const;
     bool is_valid() const;
+    void simplify(double tolerance);
     
     #ifdef SLIC3RXS
     void from_SV(SV* poly_sv);
@@ -28,6 +29,9 @@ class MultiPoint
     SV* to_AV();
     SV* to_SV_pureperl() const;
     #endif
+    
+    private:
+    static Points _douglas_peucker(Points &points, double tolerance);
 };
 
 }

xs/src/Point.cpp

@@ -76,12 +76,18 @@ Point::distance_to(const Point* point) const
 double
 Point::distance_to(const Line* line) const
 {
-    if (line->a.coincides_with(&line->b)) return this->distance_to(&line->a);
+    return this->distance_to(*line);
+}
+
+double
+Point::distance_to(const Line &line) const
+{
+    if (line.a.coincides_with(&line.b)) return this->distance_to(&line.a);
     
-    double n = (line->b.x - line->a.x) * (line->a.y - this->y)
-        - (line->a.x - this->x) * (line->b.y - line->a.y);
+    double n = (line.b.x - line.a.x) * (line.a.y - this->y)
+        - (line.a.x - this->x) * (line.b.y - line.a.y);
     
-    return abs(n) / line->length();
+    return abs(n) / line.length();
 }
 
 #ifdef SLIC3RXS

xs/src/Point.hpp

@@ -25,6 +25,7 @@ class Point
     Point* nearest_point(Points points) const;
     double distance_to(const Point* point) const;
     double distance_to(const Line* line) const;
+    double distance_to(const Line &line) const;
     
     #ifdef SLIC3RXS
     void from_SV(SV* point_sv);

xs/src/Polygon.cpp

@@ -125,6 +125,12 @@ Polygon::contains_point(const Point* point) const
     return result;
 }
 
+Polygons
+Polygon::simplify(double tolerance) const
+{
+    
+}
+
 #ifdef SLIC3RXS
 SV*
 Polygon::to_SV_ref() {

xs/src/Polygon.hpp

@@ -24,6 +24,8 @@ class Polygon : public MultiPoint {
     bool make_clockwise();
     bool is_valid() const;
     bool contains_point(const Point* point) const;
+    Polygons simplify(double tolerance) const;
+    void simplify(double tolerance, Polygons &polygons) const;
     
     #ifdef SLIC3RXS
     SV* to_SV_ref();

xs/xsp/ExPolygonCollection.xsp

@@ -17,6 +17,7 @@
     int count()
         %code{% RETVAL = THIS->expolygons.size(); %};
     bool contains_point(Point* point);
+    void simplify(double tolerance);
 %{
 
 ExPolygonCollection*

xs/xsp/ExtrusionPath.xsp

@@ -25,6 +25,7 @@
     ExtrusionEntityCollection* subtract_expolygons(ExPolygonCollection* collection)
         %code{% const char* CLASS = "Slic3r::ExtrusionPath::Collection"; RETVAL = THIS->subtract_expolygons(collection); %};
     void clip_end(double distance);
+    void simplify(double tolerance);
     double length();
     bool is_perimeter();
     bool is_fill();

xs/xsp/Polygon.xsp

@@ -34,6 +34,7 @@
     Point* first_point()
         %code{% const char* CLASS = "Slic3r::Point"; RETVAL = THIS->first_point(); %};
     bool contains_point(Point* point);
+    void simplify(double tolerance);
 %{
 
 Polygon*

xs/xsp/Polyline.xsp

@@ -29,6 +29,7 @@
     bool is_valid();
     void clip_end(double distance);
     void clip_start(double distance);
+    void simplify(double tolerance);
 %{
 
 Polyline*