Allow passing a tuple to buff in SurroundingRectangle to specify buffer in x and y direction independently (#4390)

* Give SurroundingRectangle 2D buffer

* add test for SurroundingRectangle buff parameter

---------

Co-authored-by: Benjamin Hackl <devel@benjamin-hackl.at>

Author: nubDotDev

manim/mobject/geometry/shape_matchers.py

@@ -53,7 +53,7 @@ def __init__(
         self,
         *mobjects: Mobject,
         color: ParsableManimColor = YELLOW,
-        buff: float = SMALL_BUFF,
+        buff: float | tuple[float, float] = SMALL_BUFF,
         corner_radius: float = 0.0,
         **kwargs: Any,
     ) -> None:
@@ -64,11 +64,17 @@ def __init__(
                 "Expected all inputs for parameter mobjects to be a Mobjects"
             )
 
+        if isinstance(buff, tuple):
+            buff_x = buff[0]
+            buff_y = buff[1]
+        else:
+            buff_x = buff_y = buff
+
         group = Group(*mobjects)
         super().__init__(
             color=color,
-            width=group.width + 2 * buff,
-            height=group.height + 2 * buff,
+            width=group.width + 2 * buff_x,
+            height=group.height + 2 * buff_y,
             corner_radius=corner_radius,
             **kwargs,
         )
@@ -108,7 +114,7 @@ def __init__(
         stroke_width: float = 0,
         stroke_opacity: float = 0,
         fill_opacity: float = 0.75,
-        buff: float = 0,
+        buff: float | tuple[float, float] = 0,
         **kwargs: Any,
     ) -> None:
         if color is None:

tests/module/mobject/geometry/test_unit_geometry.py

@@ -116,6 +116,17 @@ def test_SurroundingRectangle():
     assert sr.get_fill_opacity() == 0.42
 
 
+def test_SurroundingRectangle_buff():
+    sq = Square()
+    rect1 = SurroundingRectangle(sq, buff=1)
+    assert rect1.width == sq.width + 2
+    assert rect1.height == sq.height + 2
+
+    rect2 = SurroundingRectangle(sq, buff=(1, 2))
+    assert rect2.width == sq.width + 2
+    assert rect2.height == sq.height + 4
+
+
 def test_BackgroundRectangle(manim_caplog):
     circle = Circle()
     square = Square()