projectToPlane returns self and added tests

The projectToPlane method of Vector returns self to allow for a fluent interface. There is now full test converge of projectToPlane method. Bug fixed in projectToPlane when plane is passed instead of base and normal.

.vscode/settings.json

@@ -0,0 +1,6 @@
+{
+    "python.linting.flake8Enabled": false,
+    "python.linting.pylintEnabled": true,
+    "python.linting.enabled": true,
+    "python.pythonPath": "C:\\Users\\micha\\Anaconda3\\envs\\cq\\python.exe"
+}

cadquery/cq.py

@@ -376,9 +376,7 @@ class CQ(object):
 
         # update center to projected origin if desired
         if centerOption == 'ProjectedOrigin':
-            projected_center = Vector(0, 0, 0)
-            projected_center.projectToPlane(center, normal)
-            center = projected_center
+            center = Vector(0, 0, 0).projectToPlane(center, normal)
 
         # invert if requested
         if invert:

cadquery/occ_impl/geom.py

@@ -154,9 +154,12 @@ class Vector(object):
         if len(args) == 2:
             base = args[0]
             normal = args[1]
-        else:
+        elif len(args) == 1:
             base = args[0].origin
-            normal = args[1].zDir
+            normal = args[0].zDir
+        else:
+            raise TypeError("Expected 1 or 2 arguments consisting of 1 Plane object \
+or a base Vector and a normal Vector object.")
 
         result = self-normal*(((self-base).dot(normal))/normal.Length**2)
 
@@ -164,6 +167,8 @@ class Vector(object):
         self.y = result.y
         self.z = result.z
 
+        return self
+
     def __neg__(self):
         return self * -1
 

tests/TestCadObjects.py

@@ -151,6 +151,34 @@ class TestCadObjects(BaseTest):
         self.assertEqual(a, b)
         self.assertEqual(a, c)
 
+    def testVectorProject(self):
+        """
+        Test method to project vector to plane.
+        """
+        decimal_places = 9
+
+        normal = Vector(1, 2, 3)
+        base = Vector(5, 7, 9)
+        x_dir = Vector(1, 0, 0)
+
+        # test passing plane defined by base and normal
+        point = Vector(10, 11, 12).projectToPlane(base, normal)
+        self.assertTupleAlmostEquals(point.toTuple(), (59/7, 55/7, 51/7),
+                                     decimal_places)
+
+        point = Vector(10, 11, 12).projectToPlane(base, normal.normalized())
+        self.assertTupleAlmostEquals(point.toTuple(), (59/7, 55/7, 51/7),
+                                     decimal_places)
+
+        # test passing Plane object
+        point = Vector(10, 11, 12).projectToPlane(Plane(base, x_dir, normal))
+        self.assertTupleAlmostEquals(point.toTuple(), (59/7, 55/7, 51/7),
+                                     decimal_places)
+
+        # test wrong number of input arguments
+        with self.assertRaises(TypeError):
+            Vector(10,11.12).projectToPlane(1,1,1)
+
     def testMatrixCreationAndAccess(self):
         def matrix_vals(m):
             return [[m[r,c] for c in range(4)] for r in range(4)]