From 3dbea6c396e226759a359f9daf2df5abd5992b42 Mon Sep 17 00:00:00 2001
From: Nikolay Khabarov <2xl@mail.ru>
Date: Sun, 21 May 2017 15:13:23 +0300
Subject: [PATCH] add ijk to gcode parser

---
 cnc/enums.py        | 18 ++++++++++++++++++
 cnc/gcode.py        | 24 ++++++++++++++++++++++++
 tests/test_gcode.py | 36 ++++++++++++++++++++++++++++++++++++
 3 files changed, 78 insertions(+)
 create mode 100644 cnc/enums.py

diff --git a/cnc/enums.py b/cnc/enums.py
new file mode 100644
index 0000000..040ccee
--- /dev/null
+++ b/cnc/enums.py
@@ -0,0 +1,18 @@
+from enum import Enum
+
+""" This module describes system wide enums.
+"""
+
+class Plane(Enum):
+    """ Enum for choosing plane for circular interpolation.
+    """
+    PLANE_XY = 1
+    PLANE_ZX = 2
+    PLANE_YZ = 3
+
+
+class RotationDirection(Enum):
+    """ Enum for choosing rotation direction.
+    """
+    CW = 1
+    CCW = 2
diff --git a/cnc/gcode.py b/cnc/gcode.py
index 08e0591..81d7616 100644
--- a/cnc/gcode.py
+++ b/cnc/gcode.py
@@ -1,6 +1,8 @@
 import re
+import math
 
 from cnc.coordinates import Coordinates
+from cnc.enums import Plane
 
 gpattern = re.compile('([A-Z])([-+]?[0-9.]+)')
 cleanpattern = re.compile('\s+|\(.*?\)|;.*') # white spaces and comments start with ';' and in '()'
@@ -50,6 +52,26 @@ class GCode(object):
         """
         return 'X' in self.params or 'Y' in self.params or 'Z' in self.params
 
+    def radius(self, plane, default, multiply):
+        """ Get radius for circular interpolation(I, J, K or R).
+        :param plane: If R is present, specify which axises should be used.
+        :param default: Default values, if any of coords is not specified.
+        :param multiply: If value exist, multiply it by this value.
+        :return: Coord object.
+        """
+        i = self.get('I', default.x, multiply)
+        j = self.get('J', default.y, multiply)
+        k = self.get('K', default.z, multiply)
+        if 'R' in self.params:
+            r1 = self.get('R', None, multiply) / math.sqrt(2.0)
+            if plane == Plane.PLANE_XY:
+                i = j = r1
+            elif plane == Plane.PLANE_ZX:
+                k = i = r1
+            elif plane == Plane.PLANE_YZ:
+                j = k = r1
+        return Coordinates(i, j, k)
+
     def command(self):
         """ Get value from gcode line.
         :return: String with command or None if no command specified.
@@ -82,4 +104,6 @@ class GCode(object):
             raise GCodeException('duplicated gcode entries')
         if 'G' in params and 'M' in params:
             raise GCodeException('g and m command found')
+        if 'R' in params and ('I' in params or 'J' in params or 'K' in params):
+            raise GCodeException('r and component radius found')
         return GCode(params)
diff --git a/tests/test_gcode.py b/tests/test_gcode.py
index 538b818..cf44aca 100644
--- a/tests/test_gcode.py
+++ b/tests/test_gcode.py
@@ -1,6 +1,8 @@
 import unittest
+import math
 
 from cnc.coordinates import *
+from cnc.enums import *
 from cnc.gcode import *
 
 
@@ -65,6 +67,40 @@ class TestGCode(unittest.TestCase):
         gc = GCode.parse_line("Z1")
         self.assertTrue(gc.has_coordinates())
 
+    def test_radius(self):
+        gc = GCode.parse_line("G2I1J2K3")
+        self.assertEqual(gc.radius(None, self.default, 1).x, 1)
+        self.assertEqual(gc.radius(None, self.default, 1).y, 2)
+        self.assertEqual(gc.radius(None, self.default, 1).z, 3)
+        gc = GCode.parse_line("G3")
+        self.assertEqual(gc.radius(None, self.default, 1).x, self.default.x)
+        self.assertEqual(gc.radius(None, self.default, 1).y, self.default.y)
+        self.assertEqual(gc.radius(None, self.default, 1).z, self.default.z)
+        self.assertRaises(GCodeException, GCode.parse_line, "R1I2")
+        self.assertRaises(GCodeException, GCode.parse_line, "R1J2")
+        self.assertRaises(GCodeException, GCode.parse_line, "R1K2")
+        gc = GCode.parse_line("G3R9")
+        self.assertAlmostEqual(gc.radius(Plane.PLANE_XY, self.default, 1).x,
+                               math.sqrt(40.5), 9)
+        self.assertAlmostEqual(gc.radius(Plane.PLANE_XY, self.default, 1).y,
+                               math.sqrt(40.5), 9)
+        self.assertEqual(gc.radius(Plane.PLANE_XY, self.default, 1).z,
+                         self.default.z)
+        gc = GCode.parse_line("G3R10")
+        self.assertAlmostEqual(gc.radius(Plane.PLANE_ZX, self.default, 1).x,
+                               math.sqrt(50), 9)
+        self.assertEqual(gc.radius(Plane.PLANE_ZX, self.default, 1).y,
+                         self.default.y)
+        self.assertAlmostEqual(gc.radius(Plane.PLANE_ZX, self.default, 1).z,
+                               math.sqrt(50), 9)
+        gc = GCode.parse_line("G3R11")
+        self.assertEqual(gc.radius(Plane.PLANE_YZ, self.default, 1).x,
+                         self.default.x)
+        self.assertAlmostEqual(gc.radius(Plane.PLANE_YZ, self.default, 1).y,
+                               math.sqrt(60.5), 9)
+        self.assertAlmostEqual(gc.radius(Plane.PLANE_YZ, self.default, 1).z,
+                               math.sqrt(60.5), 9)
+
     def test_multiply(self):
         # getting coordinates could modify value be specified multiplier.
         gc = GCode.parse_line("X2 Y-3 Z4")