[path] Sort helix drill jobs to improve efficiency

src/Mod/Path/PathScripts/PathHelix.py

@@ -297,6 +297,35 @@ class ObjectPathHelix(object):
     def __setstate__(self, state):
         return None
 
+    def sort_jobs(self, jobs):
+        """ sort holes by the nearest neighbor method """
+        from Queue import PriorityQueue
+
+        def sqdist(a, b):
+            """ square Euclidean distance """
+            return (a['xc'] - b['xc']) ** 2 + (a['yc'] - b['yc']) ** 2
+
+        def find_closest(job_list, job, dist):
+            q = PriorityQueue()
+
+            for j in job_list:
+                q.put((dist(j, job) + job['xc'], j))
+
+            prio, result = q.get()
+            return result
+
+        out = []
+        zero = {'xc': 0, 'yc': 0}
+
+        out.append(find_closest(jobs, zero, sqdist))
+
+        while jobs:
+            closest = find_closest(jobs, out[-1], sqdist)
+            out.append(closest)
+            jobs.remove(closest)
+
+        return out
+
     def execute(self, obj):
         from Part import Circle, Cylinder, Plane
         from math import sqrt
@@ -404,6 +433,8 @@ class ObjectPathHelix(object):
 
                     drill_jobs.extend(jobs)
 
+            drill_jobs = self.sort_jobs(drill_jobs)
+
             for job in drill_jobs:
                 output += helix_cut((job["xc"], job["yc"]), job["r_out"], job["r_in"], obj.DeltaR.Value,
                                     job["zmax"], job["zmin"], obj.StepDown.Value,