Removed dependency on Math::Clipper

xs/src/ClipperUtils.hpp

@@ -6,6 +6,11 @@
 #include "ExPolygon.hpp"
 #include "Polygon.hpp"
 
+// import these wherever we're included
+using ClipperLib::jtMiter;
+using ClipperLib::jtRound;
+using ClipperLib::jtSquare;
+
 namespace Slic3r {
 
 #define CLIPPER_OFFSET_SCALE 100000.0

xs/src/Polygon.cpp

@@ -72,6 +72,12 @@ Polygon::is_counter_clockwise() const
     return orientation;
 }
 
+bool
+Polygon::is_clockwise() const
+{
+    return !this->is_counter_clockwise();
+}
+
 bool
 Polygon::make_counter_clockwise()
 {

xs/src/Polygon.hpp

@@ -18,6 +18,7 @@ class Polygon : public MultiPoint {
     Polyline* split_at_first_point();
     double area() const;
     bool is_counter_clockwise() const;
+    bool is_clockwise() const;
     bool make_counter_clockwise();
     bool make_clockwise();
     bool is_valid() const;

xs/xsp/Clipper.xsp

@@ -10,6 +10,16 @@
 
 %{
 
+IV
+_constant()
+  ALIAS:
+    JT_MITER        = jtMiter
+    JT_ROUND        = jtRound
+    JT_SQUARE       = jtSquare
+  CODE:
+    RETVAL = ix;
+  OUTPUT: RETVAL
+
 Polygons
 offset(polygons, delta, scale = CLIPPER_OFFSET_SCALE, joinType = ClipperLib::jtMiter, miterLimit = 3)
     Polygons                polygons

xs/xsp/Polygon.xsp

@@ -25,6 +25,7 @@
         %code{% const char* CLASS = "Slic3r::Polyline"; RETVAL = THIS->split_at_first_point(); %};
     double area();
     bool is_counter_clockwise();
+    bool is_clockwise();
     bool make_counter_clockwise();
     bool make_clockwise();
     bool is_valid();