use proportional glyph width when mapping svg gradient to font space

Fixes the previously failing test

src/nanoemoji/color_glyph.py

@@ -86,9 +86,10 @@ def _get_gradient_transform(
  grad_el: etree.Element,
  shape_bbox: Rect,
  view_box: Rect,
+ glyph_width: int,
 ) -> Affine2D:
  transform = map_viewbox_to_font_space(
- view_box, config.ascent, config.descent, config.width, config.transform
+ view_box, config.ascent, config.descent, glyph_width, config.transform
  )
 
  gradient_units = grad_el.attrib.get("gradientUnits", "objectBoundingBox")
@@ -109,6 +110,7 @@ def _parse_linear_gradient(
  grad_el: etree.Element,
  shape_bbox: Rect,
  view_box: Rect,
+ glyph_width: int,
  shape_opacity: float = 1.0,
 ):
  gradient = SVGLinearGradient.from_element(grad_el, view_box)
@@ -119,7 +121,9 @@ def _parse_linear_gradient(
  # Set P2 to P1 rotated 90 degrees counter-clockwise around P0
  p2 = p0 + (p1 - p0).perpendicular()
 
- transform = _get_gradient_transform(config, grad_el, shape_bbox, view_box)
+ transform = _get_gradient_transform(
+ config, grad_el, shape_bbox, view_box, glyph_width
+ )
 
  p0 = transform.map_point(p0)
  p1 = transform.map_point(p1)
@@ -136,6 +140,7 @@ def _parse_radial_gradient(
  grad_el: etree.Element,
  shape_bbox: Rect,
  view_box: Rect,
+ glyph_width: int,
  shape_opacity: float = 1.0,
 ):
  gradient = SVGRadialGradient.from_element(grad_el, view_box)
@@ -146,7 +151,7 @@ def _parse_radial_gradient(
  r1 = gradient.r
 
  transform = map_viewbox_to_font_space(
- view_box, config.ascent, config.descent, config.width, config.transform
+ view_box, config.ascent, config.descent, glyph_width, config.transform
  )
 
  gradient_units = grad_el.attrib.get("gradientUnits", "objectBoundingBox")
@@ -244,7 +249,9 @@ def shape_cache_key(self):
  return (self.path, self.reuses)
 
 
-def _paint(debug_hint: str, config: FontConfig, picosvg: SVG, shape: SVGPath) -> Paint:
+def _paint(
+ debug_hint: str, config: FontConfig, picosvg: SVG, shape: SVGPath, glyph_width: int
+) -> Paint:
  if shape.fill.startswith("url("):
  el = picosvg.resolve_url(shape.fill, "*")
  try:
@@ -253,6 +260,7 @@ def _paint(debug_hint: str, config: FontConfig, picosvg: SVG, shape: SVGPath) ->
  el,
  shape.bounding_box(),
  picosvg.view_box(),
+ glyph_width,
  shape.opacity,
  )
  except ValueError as e:
@@ -264,12 +272,12 @@ def _paint(debug_hint: str, config: FontConfig, picosvg: SVG, shape: SVGPath) ->
 
 
 def _in_glyph_reuse_key(
- debug_hint: str, config: FontConfig, picosvg: SVG, shape: SVGPath
+ debug_hint: str, config: FontConfig, picosvg: SVG, shape: SVGPath, glyph_width: int
 ) -> Tuple[Paint, SVGPath]:
  """Within a glyph reuse shapes only when painted consistently.
  paint+normalized shape ensures this."""
  return (
- _paint(debug_hint, config, picosvg, shape),
+ _paint(debug_hint, config, picosvg, shape, glyph_width),
  normalize(shape, config.reuse_tolerance),
  )
 
@@ -278,18 +286,21 @@ def _painted_layers(
  debug_hint: str,
  config: FontConfig,
  picosvg: SVG,
+ glyph_width: int,
 ) -> Generator[PaintedLayer, None, None]:
  if config.reuse_tolerance < 0:
  # shape reuse disabled
  for path in picosvg.shapes():
- yield PaintedLayer(_paint(debug_hint, config, picosvg, path), path.d)
+ yield PaintedLayer(
+ _paint(debug_hint, config, picosvg, path, glyph_width), path.d
+ )
  return
 
  # Don't sort; we only want to find groups that are consecutive in the picosvg
  # to ensure we don't mess up layer order
  for (paint, normalized), paths in groupby(
  picosvg.shapes(),
- key=lambda s: _in_glyph_reuse_key(debug_hint, config, picosvg, s),
+ key=lambda s: _in_glyph_reuse_key(debug_hint, config, picosvg, s, glyph_width),
  ):
  paths = list(paths)
  transforms = ()
@@ -360,6 +371,7 @@ def create(
  filename,
  font_config,
  svg,
+ base_glyph.width,
  )
  )