fix TypeError when converting pathops.Path to svg

src/picosvg/svg_pathops.py

@@ -45,34 +45,18 @@
 }
 
 
-def _simple_skia_to_svg(svg_cmd, points) -> SVGCommandGen:
+def _skia_pts_to_svg(svg_cmd, points) -> SVGCommandGen:
     # pathops.Path gives us sequences of points, flatten 'em
     yield (svg_cmd, tuple(c for pt in points for c in pt))
 
 
-def _qcurveto_to_svg(points) -> SVGCommandGen:
-    for control_pt, end_pt in pathops.decompose_quadratic_segment(points):
-        yield ("Q", control_pt + end_pt)
-
-
-def _end_path(points) -> SVGCommandGen:
-    if points:
-        raise ValueError("endPath should have no points")
-    return  # pytype: disable=bad-return-type
-    yield
-
-
 _SKIA_CMD_TO_SVG_CMD = {
-    # simple conversions
-    "moveTo": functools.partial(_simple_skia_to_svg, "M"),
-    "lineTo": functools.partial(_simple_skia_to_svg, "L"),
-    "quadTo": functools.partial(_simple_skia_to_svg, "Q"),
-    "curveTo": functools.partial(_simple_skia_to_svg, "C"),
-    "closePath": functools.partial(_simple_skia_to_svg, "Z"),
-    # more interesting conversions
-    "qCurveTo": _qcurveto_to_svg,
-    # nop
-    "endPath": _end_path,
+    pathops.PathVerb.MOVE: functools.partial(_skia_pts_to_svg, "M"),
+    pathops.PathVerb.LINE: functools.partial(_skia_pts_to_svg, "L"),
+    pathops.PathVerb.QUAD: functools.partial(_skia_pts_to_svg, "Q"),
+    pathops.PathVerb.CUBIC: functools.partial(_skia_pts_to_svg, "C"),
+    pathops.PathVerb.CLOSE: functools.partial(_skia_pts_to_svg, "Z"),
+    # pathops.PathVerb.CONIC... convertConicsToQuads should have taken care of these
 }
 
 _SVG_FILL_RULE_TO_SKIA_FILL_TYPE = {
@@ -95,10 +79,10 @@ def skia_path(svg_cmds: SVGCommandSeq, fill_rule: str) -> pathops.Path:
 
 
 def svg_commands(skia_path: pathops.Path) -> SVGCommandGen:
-    for cmd, points in skia_path.segments:
-        if cmd not in _SKIA_CMD_TO_SVG_CMD:
-            raise ValueError(f'No mapping to svg for "{cmd} {points}"')
-        for svg_cmd, svg_args in _SKIA_CMD_TO_SVG_CMD[cmd](points):
+    for verb, points in skia_path:
+        if verb not in _SKIA_CMD_TO_SVG_CMD:
+            raise ValueError(f'No mapping to svg for "{verb} {points}"')
+        for svg_cmd, svg_args in _SKIA_CMD_TO_SVG_CMD[verb](points):
             yield (svg_cmd, svg_args)
 
 

tests/svg_pathops_test.py

@@ -15,6 +15,7 @@
 import pytest
 from picosvg import svg_pathops
 from picosvg.svg_types import SVGCircle, SVGPath, SVGRect
+from pathops import PathVerb
 
 
 def _round(pt, digits):
@@ -27,43 +28,74 @@ def _round(pt, digits):
         # path
         (
             SVGPath(d="M1,1 2,2 z"),
-            (("moveTo", ((1.0, 1.0),)), ("lineTo", ((2.0, 2.0),)), ("closePath", ())),
+            (
+                (PathVerb.MOVE, ((1.0, 1.0),)),
+                (PathVerb.LINE, ((2.0, 2.0),)),
+                (PathVerb.CLOSE, ()),
+            ),
             "M1,1 L2,2 Z",
         ),
         # rect
         (
             SVGRect(x=4, y=4, width=6, height=16),
             (
-                ("moveTo", ((4.0, 4.0),)),
-                ("lineTo", ((10.0, 4.0),)),
-                ("lineTo", ((10.0, 20.0),)),
-                ("lineTo", ((4.0, 20.0),)),
-                ("lineTo", ((4.0, 4.0),)),
-                ("closePath", ()),
+                (PathVerb.MOVE, ((4.0, 4.0),)),
+                (PathVerb.LINE, ((10.0, 4.0),)),
+                (PathVerb.LINE, ((10.0, 20.0),)),
+                (PathVerb.LINE, ((4.0, 20.0),)),
+                (PathVerb.LINE, ((4.0, 4.0),)),
+                (PathVerb.CLOSE, ()),
             ),
             "M4,4 L10,4 L10,20 L4,20 L4,4 Z",
         ),
         (
             SVGCircle(cx=5, cy=5, r=4),
             (
-                ("moveTo", ((9.0, 5.0),)),
-                ("curveTo", ((9.0, 7.2091), (7.2091, 9.0), (5.0, 9.0))),
-                ("curveTo", ((2.7909, 9.0), (1.0, 7.2091), (1.0, 5.0))),
-                ("curveTo", ((1.0, 2.7909), (2.7909, 1.0), (5.0, 1.0))),
-                ("curveTo", ((7.2091, 1.0), (9.0, 2.7909), (9.0, 5.0))),
-                ("closePath", ()),
+                (PathVerb.MOVE, ((9.0, 5.0),)),
+                (PathVerb.CUBIC, ((9.0, 7.2091), (7.2091, 9.0), (5.0, 9.0))),
+                (PathVerb.CUBIC, ((2.7909, 9.0), (1.0, 7.2091), (1.0, 5.0))),
+                (PathVerb.CUBIC, ((1.0, 2.7909), (2.7909, 1.0), (5.0, 1.0))),
+                (PathVerb.CUBIC, ((7.2091, 1.0), (9.0, 2.7909), (9.0, 5.0))),
+                (PathVerb.CLOSE, ()),
             ),
             "M9,5 C9,7.2091 7.2091,9 5,9 C2.7909,9 1,7.2091 1,5 C1,2.7909 2.7909,1 5,1 C7.2091,1 9,2.7909 9,5 Z",
         ),
+        # All-quad closed contour; when using Path.segments iterator (matching FontTools
+        # SegmentPen protocol), the on-curve point would become implied (None), leading
+        # to uncaught TypeError; but we don't have to use that for converting to SVG
+        # commands; in fact we now simply iterate over the Path verbs as is, that
+        # already yields individual curve segments that are SVG compatible.
+        # https://github.com/googlefonts/picosvg/issues/304
+        (
+            SVGPath(
+                d=(
+                    "M0.117,0.055 Q0.117,0.029 0.107,0.029 Q0.097,0.029 0.097,0.055 "
+                    "Q0.097,0.081 0.107,0.081 Q0.117,0.081 0.117,0.055 Z"
+                )
+            ),
+            (
+                (PathVerb.MOVE, ((0.117, 0.055),)),
+                (PathVerb.QUAD, ((0.117, 0.029), (0.107, 0.029))),
+                (PathVerb.QUAD, ((0.097, 0.029), (0.097, 0.055))),
+                (PathVerb.QUAD, ((0.097, 0.081), (0.107, 0.081))),
+                (PathVerb.QUAD, ((0.117, 0.081), (0.117, 0.055))),
+                (PathVerb.CLOSE, ()),
+            ),
+            "M0.117,0.055 Q0.117,0.029 0.107,0.029 Q0.097,0.029 0.097,0.055 "
+            "Q0.097,0.081 0.107,0.081 Q0.117,0.081 0.117,0.055 Z",
+        )
         # TODO: round-trip SVGPath with fill_rule="evenodd"
     ],
 )
 def test_skia_path_roundtrip(shape, expected_segments, expected_path):
     # We round to 4 decimal places to confirm custom value works
     skia_path = svg_pathops.skia_path(shape.as_cmd_seq(), shape.fill_rule)
-    rounded_segments = list(skia_path.segments)
-    for idx, (cmd, points) in enumerate(rounded_segments):
-        rounded_segments[idx] = (cmd, tuple(_round(pt, 4) for pt in points))
+    rounded_segments = list(skia_path)
+    for idx, (verb, points) in enumerate(rounded_segments):
+        rounded_segments[idx] = (
+            verb,
+            tuple(_round(pt, 4) if pt is not None else None for pt in points),
+        )
     assert tuple(rounded_segments) == expected_segments
     assert (
         SVGPath.from_commands(svg_pathops.svg_commands(skia_path))