From fea0e02fc1a97d761196b7e34bc0c293413c4f67 Mon Sep 17 00:00:00 2001
From: ChrisLuck <c_j_l@web.de>
Date: Fri, 6 Jan 2017 16:03:11 +0100
Subject: [PATCH] support stepdown greater than total depth, 2nd try

---
 src/Mod/Path/PathScripts/PathUtils.py         | 65 +++++++++++++------
 src/Mod/Path/PathTests/TestPathDepthParams.py | 24 ++++++-
 2 files changed, 68 insertions(+), 21 deletions(-)

diff --git a/src/Mod/Path/PathScripts/PathUtils.py b/src/Mod/Path/PathScripts/PathUtils.py
index 2f6763b4d..4e75ef089 100644
--- a/src/Mod/Path/PathScripts/PathUtils.py
+++ b/src/Mod/Path/PathScripts/PathUtils.py
@@ -35,6 +35,7 @@ from DraftGeomUtils import geomType
 import PathScripts
 from PathScripts import PathJob
 # import itertools
+import numpy
 
 def cleanedges(splines, precision):
     '''cleanedges([splines],precision). Convert BSpline curves, Beziers, to arcs that can be used for cnc paths.
@@ -840,27 +841,53 @@ class depth_params:
         '''returns a list of depths to be used in order from first to last.
         equalstep=True: all steps down before the finish pass will be equalized.'''
 
-        depths = []
         if self.user_depths is not None:
-            depths = self.user_depths
-        else:
-            total_depth = self.start_depth - self.final_depth
-            if total_depth <= 0:
-                return depths
-            layers_required = int((total_depth - self.z_finish_step) / self.step_down)
-            partial_steplayer = (total_depth - self.z_finish_step) % self.step_down
-            if equalstep is True and partial_steplayer > 0:
-                layerstep = float((total_depth - self.z_finish_step) / (layers_required + 1))
+            return self.user_depths
+
+        total_depth = self.start_depth - self.final_depth
+
+        if total_depth < 0:
+            return []
+
+        depths = [self.final_depth]
+
+        # apply finish step if necessary
+        if self.z_finish_step > 0:
+            if self.z_finish_step < total_depth:
+                depths.append(self.z_finish_step + self.final_depth)
             else:
-                layerstep = self.step_down
+                return depths
 
-            for step in range(layers_required):
-                d = self.start_depth - ((step +1) * layerstep)
-                depths.append(d)
-
-            if self.z_finish_step != 0 and depths[-1] != self.final_depth + self.z_finish_step:
-                depths.append(self.final_depth + self.z_finish_step)
-            if depths[-1] != self.final_depth:
-                depths.append(self.final_depth)
+        if equalstep:
+            depths += self.__equal_steps(self.start_depth, depths[-1], self.step_down)[1:]
+        else:
+            depths += self.__fixed_steps(self.start_depth, depths[-1], self.step_down)[1:]
 
+        depths.reverse()
         return depths
+
+    def __equal_steps(self, start, stop, max_size):
+        '''returns a list of depths beginning with the bottom (included), ending
+        with the top (not included).
+        all steps are of equal size, which is as big as possible but not bigger
+        than max_size.'''
+
+        steps_needed = math.ceil((start - stop) / max_size)
+        depths = numpy.linspace(stop, start, steps_needed, endpoint=False)
+
+        return depths.tolist()
+
+    def __fixed_steps(self, start, stop, size):
+        '''returns a list of depths beginning with the bottom (included), ending
+        with the top (not included).
+        all steps are of size 'size' except the one at the bottom wich can be
+        smaller.'''
+
+        fullsteps = int((start - stop) / size)
+        last_step = start - (fullsteps * size)
+        depths = numpy.linspace(last_step, start, fullsteps, endpoint=False)
+
+        if last_step == stop:
+            return depths.tolist()
+        else:
+            return [stop] + depths.tolist()
diff --git a/src/Mod/Path/PathTests/TestPathDepthParams.py b/src/Mod/Path/PathTests/TestPathDepthParams.py
index 244bb700e..57e51a5d0 100644
--- a/src/Mod/Path/PathTests/TestPathDepthParams.py
+++ b/src/Mod/Path/PathTests/TestPathDepthParams.py
@@ -73,7 +73,7 @@ class depthTestCases(unittest.TestCase):
         final_depth = 10
         user_depths =  None
 
-        expected =[]
+        expected =[10]
 
         d = PU.depth_params(clearance_height, rapid_safety_space, start_depth, step_down, z_finish_step, final_depth, user_depths)
         r = d.get_depths()
@@ -109,7 +109,7 @@ class depthTestCases(unittest.TestCase):
         self.assertListEqual (r, expected)
 
     def test40(self):
-        '''Finish depth passed in.'''
+        '''z_finish_step passed in.'''
         clearance_height= 10
         rapid_safety_space = 5
 
@@ -161,3 +161,23 @@ class depthTestCases(unittest.TestCase):
         r = d.get_depths(equalstep=True)
         self.assertListEqual (r, expected)
 
+    def test70(self):
+        '''stepping down with stepdown greater than total depth'''
+        clearance_height= 10
+        rapid_safety_space = 5
+
+        start_depth = 10
+        step_down = 20
+        z_finish_step = 1
+        final_depth = 0
+        user_depths =  None
+
+        expected =[1.0, 0]
+
+        d = PU.depth_params(clearance_height, rapid_safety_space, start_depth, step_down, z_finish_step, final_depth, user_depths)
+        r = d.get_depths(equalstep=True)
+        self.assertListEqual (r, expected)
+
+        d = PU.depth_params(clearance_height, rapid_safety_space, start_depth, step_down, z_finish_step, final_depth, user_depths)
+        r = d.get_depths()
+        self.assertListEqual (r, expected)