feat: add test for contour data size

tests/test_rtstruct_builder.py

@@ -152,6 +152,20 @@ def test_no_approximation_iou(new_rtstruct: RTStruct):
     IOU_threshold = 0.95 # Expected accuracy
     run_mask_iou_test(new_rtstruct, mask, IOU_threshold, approximate_contours=False)
 
+def test_contour_data_sizes(new_rtstruct: RTStruct):
+    mask = get_empty_mask(new_rtstruct)
+    mask[50:100, 50:100, 0] = 1
+    mask[60:150, 40:120, 0] = 1
+
+    # Given we've added the same mask with and without contour approximation
+    new_rtstruct.add_roi(mask)
+    new_rtstruct.add_roi(mask, approximate_contours=False)
+
+    # Then using approximation leads to less data within the contour data
+    assert get_data_len_by_index(new_rtstruct, 0) < get_data_len_by_index(new_rtstruct, 1)
+
+def get_data_len_by_index(rt_struct: RTStruct, i: int):
+    return len(rt_struct.ds.ROIContourSequence[i].ContourSequence[0].ContourData)
 
 def run_mask_iou_test(rtstruct:RTStruct, mask, IOU_threshold, use_pin_hole=False, approximate_contours=True):
     # Save and load mask