From c3293f00be889affcee5fb166b6fc8a3848459ce Mon Sep 17 00:00:00 2001
From: "Zheng, Lei" <realthunder.dev@gmail.com>
Date: Tue, 31 Jan 2017 19:08:39 +0800
Subject: [PATCH] libarea: make ChangeStartToNearest path breaking optinoal

---
 src/Mod/Path/libarea/Area.cpp | 39 +++++++++++++++++++++++++----------
 src/Mod/Path/libarea/Area.h   |  2 +-
 2 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/src/Mod/Path/libarea/Area.cpp b/src/Mod/Path/libarea/Area.cpp
index c39bde2e49..a4e5bf29d9 100644
--- a/src/Mod/Path/libarea/Area.cpp
+++ b/src/Mod/Path/libarea/Area.cpp
@@ -73,8 +73,8 @@ Point CArea::NearestPoint(const Point& p)const
 	return best_point;
 }
 
-void CArea::ChangeStartToNearest(const Point *point, double min_dist) {
-
+void CArea::ChangeStartToNearest(const Point *point, double min_dist) 
+{
 	for(std::list<CCurve>::iterator It=m_curves.begin(),ItNext=It; 
             It != m_curves.end(); It=ItNext) 
     {
@@ -99,8 +99,22 @@ void CArea::ChangeStartToNearest(const Point *point, double min_dist) {
         for(; It != m_curves.end(); ++It)
         {
             const CCurve& curve = *It;
-            Point near_point = curve.NearestPoint(p);
-            double dist = near_point.dist(p);
+            Point near_point;
+            double dist;
+            if(min_dist>Point::tolerance && !curve.IsClosed()) {
+                double d1 = curve.m_vertices.front().m_p.dist(p);
+                double d2 = curve.m_vertices.back().m_p.dist(p);
+                if(d1<d2) {
+                    dist = d1;
+                    near_point = curve.m_vertices.front().m_p;
+                }else{
+                    dist = d2;
+                    near_point = curve.m_vertices.back().m_p;
+                }
+            }else{
+                near_point = curve.NearestPoint(p);
+                dist = near_point.dist(p);
+            }
             if(dist < best_dist)
             {
                 best_dist = dist;
@@ -110,13 +124,16 @@ void CArea::ChangeStartToNearest(const Point *point, double min_dist) {
         }
         if(ItBest->IsClosed()) {
             ItBest->ChangeStart(best_point);
-        }else if(ItBest->m_vertices.back().m_p.dist(best_point)<=min_dist) {
-            ItBest->Reverse();
-        }else if(ItBest->m_vertices.front().m_p.dist(best_point)>min_dist) {
-            ItBest->Break(best_point);
-            m_curves.push_back(*ItBest);
-            m_curves.back().ChangeEnd(best_point);
-            ItBest->ChangeStart(best_point);
+        }else{
+            double dfront = ItBest->m_vertices.front().m_p.dist(best_point);
+            double dback = ItBest->m_vertices.back().m_p.dist(best_point);
+            if(min_dist>Point::tolerance && dfront>min_dist && dback>min_dist) {
+                ItBest->Break(best_point);
+                m_curves.push_back(*ItBest);
+                m_curves.back().ChangeEnd(best_point);
+                ItBest->ChangeStart(best_point);
+            }else if(dfront>dback)
+                ItBest->Reverse();
         }
         curves.splice(curves.end(),m_curves,ItBest);
         p = curves.back().m_vertices.back().m_p;
diff --git a/src/Mod/Path/libarea/Area.h b/src/Mod/Path/libarea/Area.h
index ca9a641527..88e8fca5cf 100644
--- a/src/Mod/Path/libarea/Area.h
+++ b/src/Mod/Path/libarea/Area.h
@@ -85,7 +85,7 @@ public:
 	void CurveIntersections(const CCurve& curve, std::list<Point> &pts)const; 
 	void InsideCurves(const CCurve& curve, std::list<CCurve> &curves_inside)const;
 
-    void ChangeStartToNearest(const Point *point=NULL, double min_dist=1.0);
+    void ChangeStartToNearest(const Point *pstart=NULL, double min_dist=1.0);
 
     //Avoid outside direct accessing static member variable because of Windows DLL issue
 #define CAREA_PARAM_DECLARE(_type,_name) \