googlefonts · anthrotype · Feb 23, 2023 · Feb 23, 2023
diff --git a/src/picosvg/geometric_types.py b/src/picosvg/geometric_types.py
@@ -151,6 +151,19 @@ def _overlap(start1, end1, start2, end2):
             return Rect(x1, y1, x2 - x1, y2 - y1)
         return None
 
+    @property
+    def x_max(self) -> float:
+        return self.x + self.w
+
+    @property
+    def y_max(self) -> float:
+        return self.y + self.h
+
+    def union(self, other: "Rect") -> "Rect":
+        x, y = min(self.x, other.x), min(self.y, other.y)
+        x_max, y_max = max(self.x_max, other.x_max), max(self.y_max, other.y_max)
+        return Rect(x=x, y=y, w=x_max - x, h=y_max - y)
+
     def normalized_diagonal(self):
         # used for computing percentages of lengths relative to the SVG viewport:
         # https://www.w3.org/TR/SVG2/coords.html#Units

diff --git a/src/picosvg/svg.py b/src/picosvg/svg.py
@@ -403,6 +403,15 @@ def shapes(self):
         """
         return tuple(shape for (_, shapes) in self._elements() for shape in shapes)
 
+    def bounding_box(self) -> Optional[Rect]:
+        """Returns the bounding box of this SVG."""
+        shapes = self.shapes()
+        if not shapes:
+            return None
+        return reduce(
+            lambda a, b: a.union(b), (shape.bounding_box() for shape in shapes)
+        )
+
     def absolute(self, inplace=False):
         """Converts all basic shapes to their equivalent path."""
         if not inplace:

diff --git a/tests/bounding.svg b/tests/bounding.svg
diff --git a/tests/svg_test.py b/tests/svg_test.py
@@ -15,6 +15,7 @@
 import dataclasses
 from textwrap import dedent
 from lxml import etree
+import math
 import os
 import pytest
 from picosvg.svg import SVG, SVGPath
@@ -682,3 +683,12 @@ def test_allow_text():
     ):
         text_svg.topicosvg()
     assert "text" in text_svg.topicosvg(allow_text=True).tostring()
+
+
+def test_bounding_box():
+    bounding_svg = load_test_svg("bounding.svg")
+    bounds = bounding_svg.bounding_box()
+    assert math.isclose(bounds.x, 14.22469, abs_tol=1e-5)
+    assert math.isclose(bounds.y, 48.57185, abs_tol=1e-5)
+    assert math.isclose(bounds.w, 95.6410
991E
9, abs_tol=1e-5)
+    assert math.isclose(bounds.h, 62.20909, abs_tol=1e-5)
diff --git a/tests/svg_types_test.py b/tests/svg_types_test.py
@@ -514,3 +514,15 @@ def test_remove_empty_subpaths(path: str, expected_result: str):
     print(f"A: {actual}")
     print(f"E: {expected_result}")
     assert actual == expected_result
+
+
+def test_rect():
+    r = Rect(10, 20, 40, 50)
+    assert r.x_max == 50
+    assert r.y_max == 70
+    r2 = Rect(5, 20, 40, 55)
+    union = r.union(r2)
+    assert union.x == 5
+    assert union.y == 20
+    assert union.w == 45
+    assert union.h == 55