Promising approach to medial axis pruning

xs/src/Line.cpp

@@ -1,6 +1,7 @@
 #include "Line.hpp"
 #include "Polyline.hpp"
 #include <algorithm>
+#include <cmath>
 #include <sstream>
 
 namespace Slic3r {
@@ -85,6 +86,21 @@ Line::distance_to(const Point* point) const
     return point->distance_to(this);
 }
 
+double
+Line::atan2_() const
+{
+    return atan2(this->b.y - this->a.y, this->b.x - this->a.x);
+}
+
+double
+Line::direction() const
+{
+    double atan2 = this->atan2_();
+    return (atan2 == PI) ? 0
+        : (atan2 < 0) ? (atan2 + PI)
+        : atan2;
+}
+
 #ifdef SLIC3RXS
 void
 Line::from_SV(SV* line_sv)