add format_svg_path, deprecate format_svg (#33)

Author: snoyer

ocpsvg/hlr.py

@@ -24,7 +24,7 @@
 from OCP.TopoDS import TopoDS, TopoDS_Edge, TopoDS_Shape
 
 from .ocp import bounding_box, topoDS_iterator
-from .svg import edge_to_svg_path, format_svg
+from .svg import edge_to_svg_path, float_formatter, format_svg_path
 
 HlrEdgeTypeName = Literal["undefined", "isoline", "sewn", "smooth", "sharp", "outline"]
 
@@ -170,7 +170,7 @@ def to_svg(
         css_style: Optional[CssStyle] = None,
         background: Optional[bool] = None,
         tolerance: float = 1e-6,
-        float_format: str = "g",
+        decimals: Optional[int] = None,
     ) -> ET.ElementTree:
         (x0, y0, x1, y1), scale, (W, H) = _viewbox_and_scale(
             self.bounds(),
@@ -180,8 +180,7 @@ def to_svg(
         )
         ty = -(y1 + y0) / scale
 
-        def fmt(v: float):
-            return v.__format__(float_format)
+        fmt = float_formatter(decimals)
 
         svg = ET.Element("svg", xmlns="http://www.w3.org/2000/svg")
         svg.attrib["viewBox"] = f"{fmt(x0)} {fmt(y0)} {fmt(x1-x0)} {fmt(y1-y0)}"
@@ -224,9 +223,9 @@ def fmt(v: float):
 
             attrs = {
                 "id": f"e{i}",
-                "d": format_svg(
+                "d": format_svg_path(
                     edge_to_svg_path(edge.projected_edge, tolerance=tolerance),
-                    float_format=float_format,
+                    decimals=decimals,
                 ),
                 "class": " ".join(classnames),
             }

ocpsvg/svg.py

@@ -1,5 +1,6 @@
 import logging
 import pathlib
+import warnings
 from itertools import chain
 from math import degrees, pi
 from typing import (
@@ -58,7 +59,7 @@
     "edge_to_svg_path",
     "curve_to_svg_path",
     "SvgPathCommand",
-    "format_svg",
+    "format_svg_path",
 ]
 
 
@@ -78,7 +79,29 @@
 ]
 
 
+class float_formatter:
+    """float formatter with given precision and no trailing zeroes."""
+
+    def __init__(self, decimals: Optional[int] = None):
+        self.format_spec = f".{decimals or 12}f"
+
+    def __call__(self, v: float):
+        return v.__format__(self.format_spec).rstrip("0").rstrip(".")
+
+
+def format_svg_path(
+    path: Iterable[SvgPathCommand], *, decimals: Optional[int] = None
+) -> str:
+    ff = float_formatter(decimals)
+    return " ".join(f"{cmd[0]}{','.join(map(ff, cmd[1:]))}" for cmd in path)
+
+
 def format_svg(path: Iterable[SvgPathCommand], float_format: str = "f") -> str:
+    warnings.warn(
+        "`format_svg` is deprecated, use `format_svg_path` instead.",
+        FutureWarning,
+        stacklevel=2,
+    )
     return " ".join(
         f"{cmd[0]}{','.join(arg.__format__(float_format) for arg in cmd[1:])}"
         for cmd in path
@@ -808,7 +831,7 @@ def _path_from_SvgPathLike(path: SvgPathLike) -> svgelements.Path:
         return path
 
     if not isinstance(path, str):
-        path = format_svg(path)
+        path = format_svg_path(path)
 
     try:
         return svgelements.Path(str(path))

tests/test_svg.py

@@ -31,14 +31,15 @@
 from ocpsvg.svg import (
     ColorAndLabel,
     SvgPathCommand,
-    _SegmentInPath,
+    _SegmentInPath,  # type: ignore private usage
     bezier_to_svg_path,
     edge_to_svg_path,
     edges_from_svg_path,
     face_to_svg_path,
     faces_from_svg_path,
     find_shapes_svg_in_document,
     format_svg,
+    format_svg_path,
     import_svg_document,
     polyline_to_svg_path,
     svg_element_to_path,
@@ -52,7 +53,7 @@
 
 class SvgPath(list[SvgPathCommand]):
     def __str__(self) -> str:
-        return format_svg(self)
+        return format_svg_path(self)
 
 
 def wire_from_curves(*curves: Geom_Curve):
@@ -821,7 +822,7 @@ def test_fix_closing_lines_doc():
     for e, _ in find_shapes_svg_in_document(StringIO(svg_src)):
         path = svg_element_to_path(e)
         assert path
-        for segment in path:
+        for segment in path:  # type: ignore
             assert not isinstance(segment, svgelements.Line)
 
 
@@ -985,3 +986,18 @@ def split_floats(text: str):
             yield end
 
     return list(split_floats(str(path)))
+
+
+def test_format_svg_path():
+    assert format_svg_path([("M", 1, 2), ("L", 3.45, 6.78)]) == "M1,2 L3.45,6.78"
+
+
+def test_format_svg_path_number_format():
+    path: list[SvgPathCommand] = [("M", 1.0, 2.0), ("L", 3e-8, 4.56789123456789)]
+    assert format_svg_path(path, decimals=2) == "M1,2 L0,4.57"
+    assert format_svg_path(path, decimals=8) == "M1,2 L0.00000003,4.56789123"
+
+
+def test_format_svg_deprecated():
+    with pytest.warns(FutureWarning):
+        format_svg([("M", 1, 2), ("L", 3.45, 6.78)])