fix datashader Point behavior

Author: Sonja Stockhaus

src/spatialdata_plot/pl/render.py

@@ -186,19 +186,23 @@ def _render_shapes(
     if method == "datashader":
         _geometry = shapes["geometry"]
         is_point = _geometry.type == "Point"
+        filtered_shapes_element = sdata_filt.shapes[element]
 
         # Handle circles encoded as points with radius
         if is_point.any():
+            filtered_shapes_element = sd.deepcopy(filtered_shapes_element)
             scale = shapes[is_point]["radius"] * render_params.scale
-            sdata_filt.shapes[element].loc[is_point, "geometry"] = _geometry[is_point].buffer(scale.to_numpy())
+            filtered_shapes_element.loc[is_point, "geometry"] = _geometry[is_point].buffer(scale.to_numpy())
 
         # apply transformations to the individual points
-        element_trans = get_transformation(sdata_filt.shapes[element], to_coordinate_system=coordinate_system)
+        element_trans = get_transformation(filtered_shapes_element, to_coordinate_system=coordinate_system)
         tm = _get_transformation_matrix_for_datashader(element_trans)
-        transformed_element = shapes.transform(lambda x: (np.hstack([x, np.ones((x.shape[0], 1))]) @ tm)[:, :2])
+        transformed_element = filtered_shapes_element.transform(
+            lambda x: (np.hstack([x, np.ones((x.shape[0], 1))]) @ tm)[:, :2]
+        )
         transformed_element = ShapesModel.parse(
             gpd.GeoDataFrame(
-                data=sdata_filt.shapes[element].drop("geometry", axis=1),
+                data=filtered_shapes_element.drop("geometry", axis=1),
                 geometry=transformed_element,
             )
         )