From 8e4aa3370deaab114a3cccad72e56001297b3c95 Mon Sep 17 00:00:00 2001
From: snoyer <noyer.stephane@gmail.com>
Date: Fri, 21 Feb 2025 20:28:06 +0400
Subject: [PATCH] add `align` parameter to `import_svg`

---
 pyproject.toml             |  2 +-
 src/build123d/importers.py | 19 ++++++++++++++++---
 tests/test_importers.py    | 36 ++++++++++++++++++++++++++++++++++--
 3 files changed, 51 insertions(+), 6 deletions(-)

diff --git a/pyproject.toml b/pyproject.toml
index 2a96c458..b5aa3330 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -43,7 +43,7 @@ dependencies = [
     "ezdxf >= 1.1.0, < 2",
     "ipython >= 8.0.0, < 9",
     "py-lib3mf >= 2.3.1",
-    "ocpsvg >= 0.4, < 0.5",
+    "ocpsvg >= 0.5, < 0.6",
     "trianglesolver",
 ]
 
diff --git a/src/build123d/importers.py b/src/build123d/importers.py
index 0fa4bb8f..73be5a7d 100644
--- a/src/build123d/importers.py
+++ b/src/build123d/importers.py
@@ -70,7 +70,8 @@
 from ocpsvg import ColorAndLabel, import_svg_document
 from svgpathtools import svg2paths
 
-from build123d.geometry import Color, Location
+from build123d.build_enums import Align
+from build123d.geometry import Color, Location, Vector, to_align_offset
 from build123d.topology import (
     Compound,
     Edge,
@@ -337,6 +338,7 @@ def import_svg(
     svg_file: str | Path | TextIO,
     *,
     flip_y: bool = True,
+    align: Align | tuple[Align, Align] | None = Align.MIN,
     ignore_visibility: bool = False,
     label_by: Literal["id", "class", "inkscape:label"] | str = "id",
     is_inkscape_label: bool | None = None,  # TODO remove for `1.0` release
@@ -346,6 +348,8 @@ def import_svg(
     Args:
         svg_file (Union[str, Path, TextIO]): svg file
         flip_y (bool, optional): flip objects to compensate for svg orientation. Defaults to True.
+        align (Align | tuple[Align, Align] | None, optional): alignment of the SVG's viewbox,
+            if None, the viewbox's origin will be at `(0,0,0)`. Defaults to Align.MIN.
         ignore_visibility (bool, optional): Defaults to False.
         label_by (str, optional): XML attribute to use for imported shapes' `label` property.
             Defaults to "id".
@@ -368,12 +372,18 @@ def import_svg(
     label_by = re.sub(
         r"^inkscape:(.+)", r"{http://www.inkscape.org/namespaces/inkscape}\1", label_by
     )
-    for face_or_wire, color_and_label in import_svg_document(
+    imported = import_svg_document(
         svg_file,
         flip_y=flip_y,
         ignore_visibility=ignore_visibility,
         metadata=ColorAndLabel.Label_by(label_by),
-    ):
+    )
+
+    doc_xy = Vector(imported.viewbox.x, imported.viewbox.y)
+    doc_wh = Vector(imported.viewbox.width, imported.viewbox.height)
+    offset = to_align_offset(doc_xy, doc_xy + doc_wh, align)
+
+    for face_or_wire, color_and_label in imported:
         if isinstance(face_or_wire, TopoDS_Wire):
             shape = Wire(face_or_wire)
         elif isinstance(face_or_wire, TopoDS_Face):
@@ -381,6 +391,9 @@ def import_svg(
         else:  # should not happen
             raise ValueError(f"unexpected shape type: {type(face_or_wire).__name__}")
 
+        if offset.X != 0 or offset.Y != 0:  # avoid copying if we don't need to
+            shape = shape.translate(offset)
+
         if shape.wrapped:
             shape.color = Color(*color_and_label.color_for(shape.wrapped))
         shape.label = color_and_label.label
diff --git a/tests/test_importers.py b/tests/test_importers.py
index 0fa7088d..f246ef31 100644
--- a/tests/test_importers.py
+++ b/tests/test_importers.py
@@ -16,10 +16,10 @@
     import_step,
     import_stl,
 )
-from build123d.geometry import Pos
+from build123d.geometry import Pos, Vector
 from build123d.exporters import ExportSVG
 from build123d.exporters3d import export_brep, export_step
-from build123d.build_enums import GeomType
+from build123d.build_enums import Align, GeomType
 
 
 class ImportSVG(unittest.TestCase):
@@ -116,6 +116,38 @@ def test_import_svg_colors(self):
         self.assertEqual(str(svg[1].color), str(Color(1, 0, 0, 1)))
         self.assertEqual(str(svg[2].color), str(Color(0, 0, 0, 1)))
 
+    def test_import_svg_origin(self):
+        svg_src = (
+            '<svg xmlns="http://www.w3.org/2000/svg" viewBox="1 1 6 8" width="6" height="8">'
+            '<circle r="1" cx="2" cy="3"/>'
+            "</svg>"
+        )
+
+        svg = import_svg(StringIO(svg_src), align=None, flip_y=False)
+        self.assertAlmostEqual(svg[0].bounding_box().center(), Vector(2.0, +3.0))
+
+        svg = import_svg(StringIO(svg_src), align=None, flip_y=True)
+        self.assertAlmostEqual(svg[0].bounding_box().center(), Vector(2.0, -3.0))
+
+    def test_import_svg_align(self):
+        svg_src = (
+            '<svg xmlns="http://www.w3.org/2000/svg" viewBox="1 1 6 8" width="6" height="8">'
+            '<rect x="1" y="1" width="6" height="8"/>'
+            "</svg>"
+        )
+
+        svg = import_svg(StringIO(svg_src), align=Align.MIN, flip_y=False)
+        self.assertAlmostEqual(svg[0].bounding_box().min, Vector(0.0, 0.0))
+
+        svg = import_svg(StringIO(svg_src), align=Align.MIN, flip_y=True)
+        self.assertAlmostEqual(svg[0].bounding_box().min, Vector(0, 0))
+
+        svg = import_svg(StringIO(svg_src), align=Align.MAX, flip_y=False)
+        self.assertAlmostEqual(svg[0].bounding_box().max, Vector(0.0, 0.0))
+
+        svg = import_svg(StringIO(svg_src), align=Align.MAX, flip_y=True)
+        self.assertAlmostEqual(svg[0].bounding_box().max, Vector(0, 0))
+
 
 class ImportBREP(unittest.TestCase):
     def test_bad_filename(self):