From cd7cf1b712f9f43af3eeb141e041768c8d6a410c Mon Sep 17 00:00:00 2001
From: Oleg Belov <obelov@audiology.ru>
Date: Fri, 7 Jan 2022 21:12:37 +0300
Subject: [PATCH]  Path: Fix simulator bug workaround while milling curves with
 small radius. Path Simulator produces out of trace artifacts while milling
 curves with small radius. In VolSim.cpp the branch for curve radius smaller
 then tool radius is not implemented yet. In this condition the simulator
 produces artifacts of higher radius while milling path using G2 or G3. There
 is an implementation of G2 and G3 in python level.

---
 src/Mod/Path/PathScripts/PathSimulatorGui.py | 27 ++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/src/Mod/Path/PathScripts/PathSimulatorGui.py b/src/Mod/Path/PathScripts/PathSimulatorGui.py
index 28b478c627..116e230357 100644
--- a/src/Mod/Path/PathScripts/PathSimulatorGui.py
+++ b/src/Mod/Path/PathScripts/PathSimulatorGui.py
@@ -165,7 +165,8 @@ class PathSimulation:
             maxlen = self.stock.BoundBox.XLength
             if maxlen < self.stock.BoundBox.YLength:
                 maxlen = self.stock.BoundBox.YLength
-            self.voxSim.BeginSimulation(self.stock, 0.01 * self.accuracy * maxlen)
+            self.resolution = 0.01 * self.accuracy * maxlen
+            self.voxSim.BeginSimulation(self.stock, self.resolution)
             (
                 self.cutMaterial.Mesh,
                 self.cutMaterialIn.Mesh,
@@ -343,7 +344,29 @@ class PathSimulation:
         # for cmd in job.Path.Commands:
         if cmd.Name in ["G0", "G1", "G2", "G3"]:
             self.firstDrill = True
-            self.curpos = self.voxSim.ApplyCommand(self.curpos, cmd)
+            if cmd.Name in ['G2', 'G3'] and (cmd.k or 0) == 0:
+                cx = self.curpos.Base.x + (cmd.i or 0)
+                cy = self.curpos.Base.y + (cmd.j or 0)
+                a0 = math.atan2( self.curpos.Base.y - cy, self.curpos.Base.x - cx )
+                a1 = math.atan2( cmd.y - cy, cmd.x - cx )
+                da = a1 - a0
+                if cmd.Name == 'G3':
+                    da = da % (2 * math.pi)
+                else:
+                    da = -((-da) % (2 * math.pi))
+                r  = math.sqrt( (cmd.i or 0) ** 2 + (cmd.j or 0) ** 2 )
+                n  = math.ceil( math.sqrt( r / self.resolution * da * da ) )
+                da = da / n
+                dz = (cmd.z - self.curpos.Base.z) / n
+                cmd.Name = 'G1'
+                for i in range( n ):
+                    a0 += da
+                    cmd.x = cx + r * math.cos( a0 )
+                    cmd.y = cy + r * math.sin( a0 )
+                    cmd.z = self.curpos.Base.z + dz
+                    self.curpos = self.voxSim.ApplyCommand(self.curpos, cmd)
+            else:
+                self.curpos = self.voxSim.ApplyCommand(self.curpos, cmd)
             if not self.disableAnim:
                 self.cutTool.Placement = self.curpos
                 (