Fix point interpolation (#1344)

* Extend formats tests with different track types

* Add unordered list comparison

* Skip empty list comparison

* fix

* fix

* Reproduce problem

* Fix point interpolation for single point

* undo rest api refactor

Author: zhiltsov-max

cvat/apps/engine/data_manager.py

@@ -293,7 +293,10 @@ def _modify_unmached_object(obj, end_frame):
 
     @staticmethod
     def normalize_shape(shape):
-        points = np.asarray(shape["points"]).reshape(-1, 2)
+        points = list(shape["points"])
+        if len(points) == 2:
+            points.extend(points) # duplicate points for single point case
+        points = np.asarray(points).reshape(-1, 2)
         broken_line = geometry.LineString(points)
         points = []
         for off in range(0, 100, 1):

cvat/apps/engine/tests/test_data_manager.py

@@ -0,0 +1,39 @@
+# Copyright (C) 2020 Intel Corporation
+#
+# SPDX-License-Identifier: MIT
+
+from cvat.apps.engine.data_manager import TrackManager
+
+from unittest import TestCase
+
+
+class TrackManagerTest(TestCase):
+    def test_single_point_interpolation(self):
+        track = {
+            "frame": 0,
+            "label_id": 0,
+            "group": None,
+            "attributes": [],
+            "shapes": [
+                {
+                    "frame": 0,
+                    "points": [1.0, 2.0],
+                    "type": "points",
+                    "occluded": False,
+                    "outside": False,
+                    "attributes": []
+                },
+                {
+                    "frame": 2,
+                    "attributes": [],
+                    "points": [3.0, 4.0, 5.0, 6.0],
+                    "type": "points",
+                    "occluded": False,
+                    "outside": True
+                },
+            ]
+        }
+
+        interpolated = TrackManager.get_interpolated_shapes(track, 0, 2)
+
+        self.assertEqual(len(interpolated), 3)