Fixing the infill order for concentric infill to outside-in.

Relies to:
Concentric Fill Start Point - New Feature Request #4948
Feature Request: Archimedean Chords - Option to define direction of travel (Inside-Out or Outside-In) #5214

1 files changed, 14 insertions, 26 deletions

diff --git a/src/libslic3r/ClipperUtils.cpp b/src/libslic3r/ClipperUtils.cpp
index 59872ad66..305ea134f 100644
--- a/src/libslic3r/ClipperUtils.cpp
+++ b/src/libslic3r/ClipperUtils.cpp
@@ -716,45 +716,33 @@ static void traverse_pt_noholes(const ClipperLib::PolyNodes &nodes, Polygons *ou
     });
 }
 
-static void traverse_pt_old(ClipperLib::PolyNodes &nodes, Polygons* retval)
+static void traverse_pt_outside_in(const ClipperLib::PolyNodes &nodes, Polygons *retval)
 {
-    /* use a nearest neighbor search to order these children
-       TODO: supply start_near to chained_path() too? */
-    
     // collect ordering points
     Points ordering_points;
     ordering_points.reserve(nodes.size());
-    for (ClipperLib::PolyNodes::const_iterator it = nodes.begin(); it != nodes.end(); ++it) {
-        Point p((*it)->Contour.front().X, (*it)->Contour.front().Y);
-        ordering_points.push_back(p);
-    }
-    
-    // perform the ordering
-    ClipperLib::PolyNodes ordered_nodes = chain_clipper_polynodes(ordering_points, nodes);
-    
-    // push results recursively
-    for (ClipperLib::PolyNodes::iterator it = ordered_nodes.begin(); it != ordered_nodes.end(); ++it) {
+    for (const ClipperLib::PolyNode *node : nodes)
+        ordering_points.emplace_back(node->Contour.front().X, node->Contour.front().Y);
+
+    // Perform the ordering, push results recursively.
+    //FIXME pass the last point to chain_clipper_polynodes?
+    for (const ClipperLib::PolyNode *node : chain_clipper_polynodes(ordering_points, nodes)) {
+        retval->emplace_back(ClipperPath_to_Slic3rPolygon(node->Contour));
+        if (node->IsHole()) 
+            // Orient a hole, which is clockwise oriented, to CCW.
+            retval->back().reverse();
         // traverse the next depth
-        traverse_pt_old((*it)->Childs, retval);
-        retval->push_back(ClipperPath_to_Slic3rPolygon((*it)->Contour));
-        if ((*it)->IsHole()) retval->back().reverse();  // ccw
+        traverse_pt_outside_in(node->Childs, retval);
     }
 }
 
-Polygons union_pt_chained(const Polygons &subject, bool safety_offset_)
+Polygons union_pt_chained_outside_in(const Polygons &subject, bool safety_offset_)
 {
     ClipperLib::PolyTree polytree = union_pt(subject, safety_offset_);
     
     Polygons retval;
-    traverse_pt_old(polytree.Childs, &retval);
+    traverse_pt_outside_in(polytree.Childs, &retval);
     return retval;
-    
-// TODO: This needs to be tested:
-//    ClipperLib::PolyTree polytree = union_pt(subject, safety_offset_);
-    
-//    Polygons retval;
-//    traverse_pt_noholes(polytree.Childs, &retval);
-//    return retval;
 }
 
 Polygons simplify_polygons(const Polygons &subject, bool preserve_collinear)