Merge pull request #680 from danieledapo/dev

fix location_at, position_at and tangent_at with PositionMode.LENGTH for Wire
gumyr · Aug 30, 2024 · 55a6e8b · 55a6e8b
2 parents e9539dc + dfb1cee
commit 55a6e8b
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Showing 2 changed files with 63 additions and 3 deletions.
diff --git a/src/build123d/topology.py b/src/build123d/topology.py
@@ -444,7 +444,7 @@ def tangent_at(
             if position_mode == PositionMode.PARAMETER:
                 parameter = self.param_at(position)
             else:
-                parameter = position
+                parameter = self.param_at(position / self.length)
         else:
             try:
                 pnt = Vector(position)
@@ -682,7 +682,7 @@ def position_at(
         if position_mode == PositionMode.PARAMETER:
             param = self.param_at(distance)
         else:
-            param = distance
+            param = self.param_at(distance / self.length)
 
         return Vector(curve.Value(param))
 
@@ -733,7 +733,7 @@ def location_at(
         if position_mode == PositionMode.PARAMETER:
             param = self.param_at(distance)
         else:
-            param = distance
+            param = self.param_at(distance / self.length)
 
         law: GeomFill_TrihedronLaw
         if frame_method == FrameMethod.FRENET:

diff --git a/tests/test_direct_api.py b/tests/test_direct_api.py
@@ -1989,6 +1989,52 @@ def test_position_at(self):
         )
         self.assertTrue(all([0.0 < v < 1.0 for v in point]))
 
+        wire = Wire([Edge.make_line((0, 0, 0), (10, 0, 0))])
+        self.assertVectorAlmostEquals(wire.position_at(0.3), (3, 0, 0), 5)
+        self.assertVectorAlmostEquals(
+            wire.position_at(3, position_mode=PositionMode.LENGTH), (3, 0, 0), 5
+        )
+        self.assertVectorAlmostEquals(wire.edge().position_at(0.3), (3, 0, 0), 5)
+        self.assertVectorAlmostEquals(
+            wire.edge().position_at(3, position_mode=PositionMode.LENGTH), (3, 0, 0), 5
+        )
+
+        circle_wire = Wire(
+            [
+                Edge.make_circle(1, start_angle=0, end_angle=180),
+                Edge.make_circle(1, start_angle=180, end_angle=360),
+            ]
+        )
+        p1 = circle_wire.position_at(math.pi, position_mode=PositionMode.LENGTH)
+        p2 = circle_wire.position_at(math.pi / circle_wire.length)
+        self.assertVectorAlmostEquals(p1, (-1, 0, 0), 14)
+        self.assertVectorAlmostEquals(p2, (-1, 0, 0), 14)
+        self.assertVectorAlmostEquals(p1, p2, 14)
+
+        circle_edge = Edge.make_circle(1)
+        p3 = circle_edge.position_at(math.pi, position_mode=PositionMode.LENGTH)
+        p4 = circle_edge.position_at(math.pi / circle_edge.length)
+        self.assertVectorAlmostEquals(p3, (-1, 0, 0), 14)
+        self.assertVectorAlmostEquals(p4, (-1, 0, 0), 14)
+        self.assertVectorAlmostEquals(p3, p4, 14)
+
+        circle = Wire(
+            [
+                Edge.make_circle(2, start_angle=0, end_angle=180),
+                Edge.make_circle(2, start_angle=180, end_angle=360),
+            ]
+        )
+        self.assertVectorAlmostEquals(
+            circle.position_at(0.5),
+            (-2, 0, 0),
+            5,
+        )
+        self.assertVectorAlmostEquals(
+            circle.position_at(2 * math.pi, position_mode=PositionMode.LENGTH),
+            (-2, 0, 0),
+            5,
+        )
+
     def test_positions(self):
         e = Edge.make_line((0, 0, 0), (1, 1, 1))
         distances = [i / 4 for i in range(3)]
@@ -2009,6 +2055,14 @@ def test_tangent_at(self):
         )
         self.assertTrue(all([0.0 <= v <= 1.0 for v in tangent]))
 
+        self.assertVectorAlmostEquals(
+            Edge.make_circle(1, start_angle=0, end_angle=180).tangent_at(
+                math.pi / 2, position_mode=PositionMode.LENGTH
+            ),
+            (-1, 0, 0),
+            5,
+        )
+
     def test_tangent_at_point(self):
         circle = Wire(
             [
@@ -2078,6 +2132,12 @@ def test_location_at(self):
         self.assertVectorAlmostEquals(loc.position, (0, 1, 0), 5)
         self.assertVectorAlmostEquals(loc.orientation, (0, -90, -90), 5)
 
+        loc = Edge.make_circle(1).location_at(
+            math.pi / 2, position_mode=PositionMode.LENGTH
+        )
+        self.assertVectorAlmostEquals(loc.position, (0, 1, 0), 5)
+        self.assertVectorAlmostEquals(loc.orientation, (0, -90, -90), 5)
+
     def test_locations(self):
         locs = Edge.make_circle(1).locations([i / 4 for i in range(4)])
         self.assertVectorAlmostEquals(locs[0].position, (1, 0, 0), 5)