Fix bug in :class:.VMobjectFromSVGPath (#3677)

* Fixes #3676

* Update manim/mobject/svg/svg_mobject.py

Co-authored-by: adeshpande <[email protected]>

* Fixed problem and added test

---------

Co-authored-by: adeshpande <[email protected]>

Author: 2 people

manim/mobject/svg/svg_mobject.py

@@ -510,17 +510,15 @@ def handle_commands(self) -> None:
         all_points: list[np.ndarray] = []
         last_move = None
         curve_start = None
+        last_true_move = None
 
-        # These lambdas behave the same as similar functions in
-        # vectorized_mobject, except they add to a list of points instead
-        # of updating this Mobject's numpy array of points. This way,
-        # we don't observe O(n^2) behavior for complex paths due to
-        # numpy's need to re-allocate memory on every append.
-        def move_pen(pt):
-            nonlocal last_move, curve_start
+        def move_pen(pt, *, true_move: bool = False):
+            nonlocal last_move, curve_start, last_true_move
             last_move = pt
             if curve_start is None:
                 curve_start = last_move
+            if true_move:
+                last_true_move = last_move
 
         if self.n_points_per_curve == 4:
 
@@ -568,7 +566,7 @@ def add_line(start, end):
         for segment in self.path_obj:
             segment_class = segment.__class__
             if segment_class == se.Move:
-                move_pen(_convert_point_to_3d(*segment.end))
+                move_pen(_convert_point_to_3d(*segment.end), true_move=True)
             elif segment_class == se.Line:
                 add_line(last_move, _convert_point_to_3d(*segment.end))
             elif segment_class == se.QuadraticBezier:
@@ -588,8 +586,8 @@ def add_line(start, end):
                 # If the SVG path naturally ends at the beginning of the curve,
                 # we do *not* need to draw a closing line. To account for floating
                 # point precision, we use a small value to compare the two points.
-                if abs(np.linalg.norm(last_move - curve_start)) > 0.0001:
-                    add_line(last_move, curve_start)
+                if abs(np.linalg.norm(last_move - last_true_move)) > 0.0001:
+                    add_line(last_move, last_true_move)
                 curve_start = None
             else:
                 raise AssertionError(f"Not implemented: {segment_class}")

tests/module/mobject/svg/test_svg_mobject.py

@@ -134,3 +134,71 @@ def test_closed_path_does_not_have_extra_point():
         ),
         decimal=5,
     )
+
+
+def test_close_command_closes_last_move_not_the_starting_one():
+    # This A.svg is the output of a Text("A") in some systems
+    # It contains a path that moves from the outer boundary of the A
+    # to the boundary of the inner triangle, anc then closes the path
+    # which should close the inner triangle and not the outer boundary.
+    svg = SVGMobject(
+        get_svg_resource("A.svg"),
+    )
+    assert len(svg.points) == 0, svg.points
+    assert len(svg.submobjects) == 1, svg.submobjects
+    capital_A = svg.submobjects[0]
+
+    # The last point should not be the same as the first point
+    assert not all(capital_A.points[0] == capital_A.points[-1])
+    np.testing.assert_almost_equal(
+        capital_A.points,
+        np.array(
+            [
+                [-0.8380339075214888, -1.0, 1.2246467991473532e-16],
+                [-0.6132152047642527, -0.3333333333333336, 4.082155997157847e-17],
+                [-0.388396502007016, 0.3333333333333336, -4.082155997157847e-17],
+                [-0.16357779924977994, 1.0, -1.2246467991473532e-16],
+                [-0.16357779924977994, 1.0, -1.2246467991473532e-16],
+                [-0.05425733591657368, 1.0, -1.2246467991473532e-16],
+                [0.05506312741663405, 1.0, -1.2246467991473532e-16],
+                [0.16438359074984032, 1.0, -1.2246467991473532e-16],
+                [0.16438359074984032, 1.0, -1.2246467991473532e-16],
+                [0.3889336963403905, 0.3333333333333336, -4.082155997157847e-17],
+                [0.6134838019309422, -0.3333333333333336, 4.082155997157847e-17],
+                [0.8380339075214923, -1.0, 1.2246467991473532e-16],
+                [0.8380339075214923, -1.0, 1.2246467991473532e-16],
+                [0.744560897060354, -1.0, 1.2246467991473532e-16],
+                [0.6510878865992157, -1.0, 1.2246467991473532e-16],
+                [0.5576148761380774, -1.0, 1.2246467991473532e-16],
+                [0.5576148761380774, -1.0, 1.2246467991473532e-16],
+                [0.49717968849274957, -0.8138597980824822, 9.966907966764229e-17],
+                [0.4367445008474217, -0.6277195961649644, 7.687347942054928e-17],
+                [0.3763093132020939, -0.4415793942474466, 5.407787917345625e-17],
+                [0.3763093132020939, -0.4415793942474466, 5.407787917345625e-17],
+                [0.12167600863867864, -0.4415793942474466, 5.407787917345625e-17],
+                [-0.13295729592473662, -0.4415793942474466, 5.407787917345625e-17],
+                [-0.38759060048815186, -0.4415793942474466, 5.407787917345625e-17],
+                [-0.38759060048815186, -0.4415793942474466, 5.407787917345625e-17],
+                [-0.4480257881334797, -0.6277195961649644, 7.687347942054928e-17],
+                [-0.5084609757788076, -0.8138597980824822, 9.966907966764229e-17],
+                [-0.5688961634241354, -1.0, 1.2246467991473532e-16],
+                [-0.5688961634241354, -1.0, 1.2246467991473532e-16],
+                [-0.6586087447899202, -1.0, 1.2246467991473532e-16],
+                [-0.7483213261557048, -1.0, 1.2246467991473532e-16],
+                [-0.8380339075214888, -1.0, 1.2246467991473532e-16],
+                [0.3021757525699033, -0.21434317946653003, 2.6249468865275272e-17],
+                [0.1993017037512583, 0.09991949373745423, -1.2236608817799732e-17],
+                [0.09642765493261184, 0.4141821669414385, -5.072268650087473e-17],
+                [-0.006446393886033166, 0.7284448401454228, -8.920876418394973e-17],
+                [-0.006446393886033166, 0.7284448401454228, -8.920876418394973e-17],
+                [-0.10905185929034443, 0.4141821669414385, -5.072268650087473e-17],
+                [-0.2116573246946542, 0.09991949373745423, -1.2236608817799732e-17],
+                [-0.31426279009896546, -0.21434317946653003, 2.6249468865275272e-17],
+                [-0.31426279009896546, -0.21434317946653003, 2.6249468865275272e-17],
+                [-0.10878327587600921, -0.21434317946653003, 2.6249468865275272e-17],
+                [0.09669623834694704, -0.21434317946653003, 2.6249468865275272e-17],
+                [0.3021757525699033, -0.21434317946653003, 2.6249468865275272e-17],
+            ]
+        ),
+        decimal=5,
+    )