Use structured NumPy points.dtype.itemsize as default point_step in create_cloud

Signed-off-by: xndcn <[email protected]>

Author: xndcn

sensor_msgs_py/sensor_msgs_py/point_cloud2.py

@@ -250,8 +250,10 @@ def create_cloud(
                    for each point, with the elements of each iterable being the
                    values of the fields for that point (in the same order as
                    the fields parameter)
-    :param point_step: Point step size in bytes. Calculated from the given fields by default.
-                       (Type: optional of integer)
+    :param point_step: Point step size in bytes. If not provided, it is calculated
+                       from the given fields, except when 'points' is a structured
+                       NumPy array, in which case points.dtype.itemsize is used.
+                       (Type: optional integer)
     :return: The point cloud as sensor_msgs.msg.PointCloud2
     """
     # Check if input is numpy array
@@ -266,7 +268,7 @@ def create_cloud(
                 points,
                 dtype=dtype_from_fields(fields, point_step))
         else:
-            assert points.dtype == dtype_from_fields(fields, point_step), \
+            assert points.dtype == dtype_from_fields(fields, point_step or points.dtype.itemsize), \
                 'PointFields and structured NumPy array dtype do not match for all fields! \
                     Check their field order, names and types.'
     else:

sensor_msgs_py/test/test_point_cloud2.py

@@ -296,10 +296,18 @@ def test_create_cloud(self):
     def test_create_cloud_itemsize(self):
 
         with self.assertRaises(AssertionError):
+            dtype_from_fields = point_cloud2.dtype_from_fields(fields)
             point_cloud2.create_cloud(
+                Header(frame_id='frame'),
+                fields,
+                points_end_padding,
+                dtype_from_fields.itemsize)
+
+        thispcd = point_cloud2.create_cloud(
                 Header(frame_id='frame'),
                 fields,
                 points_end_padding)
+        self.assertEqual(thispcd.point_step, itemsize_end_padding)
 
         thispcd = point_cloud2.create_cloud(
             Header(frame_id='frame'),