Path.Area: respect zero start point when generating path

src/Mod/Path/App/AppPathPy.cpp

@@ -362,7 +362,7 @@ private:
         try {
             gp_Pnt pend;
             std::unique_ptr<Toolpath> path(new Toolpath);
-            Area::toPath(*path,shapes,&pstart, &pend,
+            Area::toPath(*path,shapes,start?&pstart:0, &pend,
                     PARAM_PY_FIELDS(PARAM_FARG,AREA_PARAMS_PATH));
             if(!PyObject_IsTrue(return_end))
                 return Py::asObject(new PathPy(path.release()));
@@ -415,7 +415,7 @@ private:
         
         try {
             bool need_arc_plane = arc_plane==Area::ArcPlaneAuto;
-            std::list<TopoDS_Shape> wires = Area::sortWires(shapes,&pstart,
+            std::list<TopoDS_Shape> wires = Area::sortWires(shapes,start!=0,&pstart,
                     &pend, 0, &arc_plane, PARAM_PY_FIELDS(PARAM_FARG,AREA_PARAMS_SORT));
             PyObject *list = PyList_New(0);
             for(auto &wire : wires)

src/Mod/Path/App/Area.cpp

@@ -2721,7 +2721,8 @@ typedef Standard_Real (gp_Pnt::*AxisGetter)() const;
 typedef void (gp_Pnt::*AxisSetter)(Standard_Real);
 
 std::list<TopoDS_Shape> Area::sortWires(const std::list<TopoDS_Shape> &shapes,
-    gp_Pnt *_pstart, gp_Pnt *_pend, double *stepdown_hint, short *_parc_plane,
+    bool has_start, gp_Pnt *_pstart, gp_Pnt *_pend, 
+    double *stepdown_hint, short *_parc_plane,
     PARAM_ARGS(PARAM_FARG,AREA_PARAMS_SORT))
 {
     std::list<TopoDS_Shape> wires;
@@ -2814,9 +2815,7 @@ std::list<TopoDS_Shape> Area::sortWires(const std::list<TopoDS_Shape> &shapes,
     gp_Pnt pstart,pend;
     if(_pstart)
         pstart = *_pstart;
-    bool use_bound = fabs(pstart.X())<Precision::Confusion() &&
-                     fabs(pstart.Y())<Precision::Confusion() &&
-                     fabs(pstart.Z())<Precision::Confusion();
+    bool use_bound = !has_start || _pstart==NULL;
 
     if(use_bound || sort_mode == SortMode2D5 || sort_mode == SortModeGreedy) {
         //Second stage, group shape by its plane, and find overall boundary
@@ -3079,7 +3078,7 @@ void Area::toPath(Toolpath &path, const std::list<TopoDS_Shape> &shapes,
     if(_pstart) pstart = *_pstart;
 
     double stepdown_hint = 1.0;
-    wires = sortWires(shapes,&pstart,pend,&stepdown_hint,
+    wires = sortWires(shapes,_pstart!=0,&pstart,pend,&stepdown_hint,
             PARAM_REF(PARAM_FARG,AREA_PARAMS_ARC_PLANE),
             PARAM_FIELDS(PARAM_FARG,AREA_PARAMS_SORT));
 

src/Mod/Path/App/Area.h

@@ -340,7 +340,10 @@ public:
      * minimize traval distance
      *
      * \arg \c shapes: input list of shapes.
-     * \arg \c pstart: optional start point
+     * \arg \c has_start: if false or pstart is 0, then a start point will be
+     * auto selected.
+     * \arg \c pstart: optional start point. If has_start is false, then the
+     * auto selected start point will be returned with this point if not NULL.
      * \arg \c pend: optional output containing the ending point of the returned
      * \arg \c stepdown_hint: optional output of a hint of step down as the max
      * distance between two sections.
@@ -352,7 +355,7 @@ public:
      * \return sorted wires
      */
     static std::list<TopoDS_Shape> sortWires(const std::list<TopoDS_Shape> &shapes,
-            gp_Pnt *pstart=NULL, gp_Pnt *pend=NULL, double *stepdown_hint=NULL,
+            bool has_start=false, gp_Pnt *pstart=NULL, gp_Pnt *pend=NULL, double *stepdown_hint=NULL,
             short *arc_plane = NULL, PARAM_ARGS_DEF(PARAM_FARG,AREA_PARAMS_SORT));
 
     /** Convert a list of wires to gcode

src/Mod/Path/App/FeaturePathShape.cpp

@@ -56,6 +56,7 @@ FeatureShape::FeatureShape()
 {
     ADD_PROPERTY(Sources,(0));
     ADD_PROPERTY_TYPE(StartPoint,(Base::Vector3d()),"Path",App::Prop_None,"Feed start position");
+    ADD_PROPERTY_TYPE(UseStartPoint,(false),"Path",App::Prop_None,"Enable feed start position");
     PARAM_PROP_ADD("Path",AREA_PARAMS_PATH);
     PARAM_PROP_SET_ENUM(Enums,AREA_PARAMS_PATH);
 }
@@ -86,7 +87,7 @@ App::DocumentObjectExecReturn *FeatureShape::execute(void)
         shapes.push_back(shape);
     }
 
-    Area::toPath(path,shapes,&pstart,NULL,PARAM_PROP_ARGS(AREA_PARAMS_PATH));
+    Area::toPath(path,shapes,UseStartPoint.getValue()?&pstart:0,0,PARAM_PROP_ARGS(AREA_PARAMS_PATH));
 
     Path.setValue(path);
     return App::DocumentObject::StdReturn;

src/Mod/Path/App/FeaturePathShape.h

@@ -53,6 +53,7 @@ public:
     // Part::PropertyPartShape Shape;
     App::PropertyLinkList Sources;
     App::PropertyVector StartPoint;
+    App::PropertyBool UseStartPoint;
     PARAM_PROP_DECLARE(AREA_PARAMS_PATH)
 
     //@{