Make it possible to shrink to align aspect ratio and update star shape

src/data_morph/bounds/bounding_box.py

@@ -133,14 +133,28 @@ def adjust_bounds(self, x: Number | None = None, y: Number | None = None) -> Non
         if y:
             self.y_bounds.adjust_bounds(y)
 
-    def align_aspect_ratio(self) -> None:
-        """Align the aspect ratio to 1:1."""
+    def align_aspect_ratio(self, shrink: bool = False) -> None:
+        """
+        Align the aspect ratio to 1:1.
+
+        Parameters
+        ----------
+        shrink : bool, default ``False``
+            Whether to shrink the larger bound (``True``), or
+            expand the smaller bound (``False``).
+        """
         x_range, y_range = self.range
         diff = x_range - y_range
         if diff < 0:
-            self.adjust_bounds(x=-diff)
+            if shrink:
+                self.adjust_bounds(y=diff)
+            else:
+                self.adjust_bounds(x=-diff)
         elif diff > 0:
-            self.adjust_bounds(y=diff)
+            if shrink:
+                self.adjust_bounds(x=-diff)
+            else:
+                self.adjust_bounds(y=diff)
 
     @property
     def aspect_ratio(self) -> Number:

src/data_morph/shapes/lines/star.py

@@ -26,17 +26,11 @@ class Star(LineCollection):
     """
 
     def __init__(self, dataset: Dataset) -> None:
-        bounds = dataset.data_bounds.clone()
-        bounds.align_aspect_ratio()
+        bounds = dataset.morph_bounds.clone()
+        bounds.align_aspect_ratio(shrink=True)
 
-        x_bounds = bounds.x_bounds
-        y_bounds = bounds.y_bounds
-
-        xmin, xmax = x_bounds
-        ymin, ymax = y_bounds
-
-        x_range = x_bounds.range
-        y_range = y_bounds.range
+        (xmin, xmax), (ymin, ymax) = bounds
+        x_range, y_range = bounds.range
 
         pts = [
             [xmin, ymin + y_range * 0.625],

tests/bounds/test_bounding_box.py

@@ -165,18 +165,19 @@ def test_adjust_bounds(self, x, y):
         assert new_range_y == initial_range_y + y
 
     @pytest.mark.parametrize(
-        ('x', 'y'),
+        ('x', 'y', 'shrink', 'expected_range'),
         [
-            ([10, 90], [500, 600]),
-            ([500, 600], [10, 90]),
-            ([10, 90], [10, 90]),
+            ([10, 90], [500, 600], False, 100),
+            ([500, 600], [10, 90], True, 80),
+            ([10, 90], [10, 90], False, 80),
         ],
     )
-    def test_align_aspect_ratio(self, x, y):
+    def test_align_aspect_ratio(self, x, y, shrink, expected_range):
         """Test that the align_aspect_ratio() method is working."""
         bbox = BoundingBox(x, y)
-        bbox.align_aspect_ratio()
+        bbox.align_aspect_ratio(shrink)
         assert pytest.approx(bbox.aspect_ratio) == 1
+        assert bbox.x_bounds.range == bbox.y_bounds.range == expected_range
 
     def test_clone(self):
         """Test that the clone() method is working."""

tests/shapes/lines/test_star.py

@@ -11,5 +11,18 @@ class TestStar(PolygonsLineModuleTestBase):
     """Test the Star class."""
 
     shape_name = 'star'
-    distance_test_cases = (((20, 50), 5.856516), ((30, 60), 3.709127))
+    distance_test_cases = (
+        ((8, 68), 0),
+        ((17, 68), 0),
+        ((20, 77), 0),
+        ((23, 68), 0),
+        ((32, 68), 0),
+        ((24.5, 62), 0),
+        ((27.5, 53), 0),
+        ((20, 59), 0),
+        ((12.5, 53), 0),
+        ((15.5, 62), 0),
+        ((20, 50), 7.027819284987274),
+        ((30, 60), 4.58530260724415),
+    )
     expected_line_count = 10