Some initial work for 3D slice rendering

xs/src/libslic3r/Line.cpp

@@ -133,6 +133,12 @@ Line::vector() const
     return Vector(this->b.x - this->a.x, this->b.y - this->a.y);
 }
 
+Vector
+Line::normal() const
+{
+    return Vector((this->b.y - this->a.y), -(this->b.x - this->a.x));
+}
+
 #ifdef SLIC3RXS
 
 REGISTER_CLASS(Line, "Line");

xs/src/libslic3r/Line.hpp

@@ -34,6 +34,7 @@ class Line
     double orientation() const;
     double direction() const;
     Vector vector() const;
+    Vector normal() const;
     
     #ifdef SLIC3RXS
     void from_SV(SV* line_sv);

xs/xsp/Line.xsp

@@ -32,6 +32,7 @@
     Clone<Point> point_at(double distance);
     Polyline* as_polyline()
         %code{% RETVAL = new Polyline(*THIS); %};
+    Clone<Point> normal();
 %{
 
 Line*