Move comment about periodic boundary close to statement

yt/visualization/volume_rendering/off_axis_projection.py

@@ -444,19 +444,19 @@ def temp_weightfield(field, data):
         # We need the width of the plot window in projected coordinates,
         # i.e. we ignore the z-component
         wmax = width[:2].max()
-        # Recenter positions w.r.t. center of the plot window
         xyz = data_source.ds.arr(
             np.zeros((len(data_source[vol.field]), 3)), "code_length"
         )
 
-        # If we have periodic boundaries, we need to wrap the positions
         for idim, periodic in enumerate(data_source.ds.periodicity):
             axis = data_source.ds.coordinates.axis_order[idim]
+            # Recenter positions w.r.t. center of the plot window
             xyz[..., idim] = data_source["index", axis] - center[idim]
             if not periodic:
                 continue
+            # If we have periodic boundaries, we need to wrap the corresponding
+            # coordinates into [-w/2, +w/2]
             w = data_source.ds.domain_width[idim]
-            # Wrap into [-w/2, +w/2]
             xyz[..., idim] = (xyz[..., idim] + w / 2) % w - w / 2
 
         # Rescale to [-0.5, +0.5]