Make use of bounding_box for area freezing when available

pyresample/geometry.py

@@ -1317,7 +1317,10 @@ def _extract_lons_lats(lonslats):
         try:
             lons, lats = lonslats
         except (TypeError, ValueError):
-            lons, lats = lonslats.get_lonlats()
+            try:
+                lons, lats = lonslats.attrs["bounding_box"]
+            except (AttributeError, KeyError):
+                lons, lats = lonslats.get_lonlats()
         return lons, lats
 
     def _compute_new_x_corners_for_antimeridian(self, xarr, antimeridian_mode):

pyresample/test/test_geometry/test_area.py

@@ -30,6 +30,7 @@
 from pyresample.future.geometry.area import ignore_pyproj_proj_warnings
 from pyresample.future.geometry.base import get_array_hashable
 from pyresample.geometry import AreaDefinition as LegacyAreaDefinition
+from pyresample.geometry import DynamicAreaDefinition
 from pyresample.test.utils import assert_future_geometry
 
 
@@ -1754,3 +1755,11 @@ def test_non2d_shape_error(shape):
     """Test that non-2D shapes fail."""
     with pytest.raises(NotImplementedError):
         AreaDefinition("EPSG:4326", shape, (-1000.0, -1000.0, 1000.0, 1000.0))
+
+
+def test_dynamic_area_can_use_bounding_box_attribute():
+    """Test that area freezing can use bounding box info."""
+    area_def = DynamicAreaDefinition("test_area", "", "epsg:3035", resolution=500)
+    swath_def_to_freeze_on = SwathDefinition(None, None, attrs=dict(bounding_box=[[0, 20, 20, 0], [55, 55, 45, 45]]))
+    res_area = area_def.freeze(swath_def_to_freeze_on)
+    assert res_area.area_extent == (3533500, 2484500, 5108500, 3588500)