def _create_glyph(color_glyph: ColorGlyph,
painted_layer: PaintedLayer) -> Glyph:
ufo = color_glyph.ufo
glyph = ufo.newGlyph(
_next_name(ufo, lambda i: f"{color_glyph.glyph_name}.{i}"))
glyph_names = [glyph.name]
glyph.width = ufo.info.unitsPerEm
svg_units_to_font_units = color_glyph.transform_for_font_space()
if painted_layer.reuses:
# Shape repeats, form a composite
base_glyph = ufo.newGlyph(
_next_name(ufo, lambda i: f"{glyph.name}.component.{i}"))
glyph_names.append(base_glyph.name)
draw_svg_path(painted_layer.path, base_glyph.getPen(),
svg_units_to_font_units)
glyph.components.append(
Component(baseGlyph=base_glyph.name,
transformation=Affine2D.identity()))
for transform in painted_layer.reuses:
# We already redrew the component into font space, don't redo it
# scale x/y translation and flip y movement to match font space
transform = transform._replace(
e=transform.e * svg_units_to_font_units.a,
f=transform.f * svg_units_to_font_units.d,
)
glyph.components.append(
Component(baseGlyph=base_glyph.name, transformation=transform))
else:
# Not a composite, just draw directly on the glyph
draw_svg_path(painted_layer.path, glyph.getPen(),
svg_units_to_font_units)
ufo.glyphOrder += glyph_names
return glyph
def _migrate_paths_to_ufo_glyphs(color_glyph: ColorGlyph,
glyph_cache: GlyphReuseCache) -> ColorGlyph:
svg_units_to_font_units = color_glyph.transform_for_font_space()
# Walk through the color glyph, where we see a PaintGlyph take the path out of it,
# move the path into font coordinates, generate a ufo glyph, and push the name of
# the ufo glyph into the PaintGlyph
def _update_paint_glyph(paint):
if paint.format != PaintGlyph.format:
return paint
if glyph_cache.is_known_glyph(paint.glyph):
return paint
assert paint.glyph.startswith(
"M"), f"{paint.glyph} doesn't look like a path"
path_in_font_space = (SVGPath(
d=paint.glyph).apply_transform(svg_units_to_font_units).d)
reuse_result = glyph_cache.try_reuse(path_in_font_space)
if reuse_result is not None:
# TODO: when is it more compact to use a new transforming glyph?
child_transform = Affine2D.identity()
child_paint = paint.paint
if is_transform(child_paint):
child_transform = child_paint.gettransform()
child_paint = child_paint.paint
# sanity check: GlyphReuseCache.try_reuse would return None if overflowed
assert fixed_safe(*reuse_result.transform)
overflows = False
# TODO: handle gradient anywhere in subtree, not only as direct child of
# PaintGlyph or PaintTransform
if is_gradient(child_paint):
# We have a gradient so we need to reverse the effect of the
# reuse_result.transform. First we try to apply the combined transform
# to the gradient's geometry; but this may overflow OT integer bounds,
# in which case we pass through gradient unscaled
transform = Affine2D.compose_ltr(
(child_transform, reuse_result.transform.inverse()))
# skip reuse if combined transform overflows OT int bounds
overflows = not fixed_safe(*transform)
if not overflows:
try:
child_paint = child_paint.apply_transform(transform)
except OverflowError:
child_paint = transformed(transform, child_paint)
if not overflows:
return transformed(
reuse_result.transform,
PaintGlyph(
glyph=reuse_result.glyph_name,
paint=child_paint,
),
)
glyph = _create_glyph(color_glyph, paint, path_in_font_space)
glyph_cache.add_glyph(glyph.name, path_in_font_space)
return dataclasses.replace(paint, glyph=glyph.name)
return color_glyph.mutating_traverse(_update_paint_glyph)
def _add_glyph(svg: SVG, color_glyph: ColorGlyph, reuse_cache: ReuseCache):
svg_defs = svg.xpath_one("//svg:defs")
# each glyph gets a group of its very own
svg_g = svg.append_to("/svg:svg", etree.Element("g"))
svg_g.attrib["id"] = f"glyph{color_glyph.glyph_id}"
view_box = color_glyph.svg.view_box()
if view_box is None:
raise ValueError(f"{color_glyph.filename} must declare view box")
# https://github.com/googlefonts/nanoemoji/issues/58: group needs transform
svg_g.attrib["transform"] = _svg_matrix(
color_glyph.transform_for_otsvg_space())
vbox_to_upem = color_glyph.transform_for_font_space()
upem_to_vbox = vbox_to_upem.inverse()
# copy the shapes into our svg
el_by_path = {(): svg_g}
complete_paths = set()
nth_paint_glyph = 0
for root in color_glyph.painted_layers:
for context in root.breadth_first():
if any(c == context.path[:len(c)] for c in complete_paths):
continue
parent_el = svg_g
path = context.path
while path:
if path in el_by_path:
parent_el = el_by_path[path]
break
path = path[:-1]
if isinstance(context.paint, PaintGlyph):
glyph_name = _paint_glyph_name(color_glyph, nth_paint_glyph)
assert (glyph_name in reuse_cache.glyph_elements
), f"Missing entry for {glyph_name}"
reuse_result = reuse_cache.reuse_results.get(glyph_name, None)
if reuse_result:
reused_glyph_name = reuse_result.glyph_name
reused_el = reuse_cache.glyph_elements[reused_glyph_name]
reused_el_tag = etree.QName(reused_el.tag).localname
if reused_el_tag == "use":
# if reused_el is a <use> it means _migrate_to_defs has already
# replaced a parent-less <path> with a <use> pointing to it, and
# has appended the reused path to <defs>. Assert that's the case
assert _use_href(reused_el) == reused_glyph_name
reused_el = svg.xpath_one(
f'//svg:defs/svg:path[@id="{reused_glyph_name}"]',
)
elif reused_el_tag == "path":
# we need to refer to you, it's important you have identity
reused_el.attrib["id"] = reused_glyph_name
else:
raise AssertionError(reused_el_tag)
svg_use = _create_use_element(svg, parent_el, reuse_result)
_apply_paint(
svg_defs,
svg_use,
context.paint.paint, # pytype: disable=attribute-error
upem_to_vbox,
reuse_cache,
)
# In two cases, we need to push the reused element to the outer
# <defs> and replace its first occurence with a <use>:
# 1) If reuse spans multiple glyphs, as Adobe Illustrator
# doesn't support direct references between glyphs:
# https://github.com/googlefonts/nanoemoji/issues/264
# 2) If the reused_el has attributes <use> cannot override
# https://github.com/googlefonts/nanoemoji/issues/337
if color_glyph.glyph_name != _color_glyph_name(
reused_glyph_name) or _attrib_apply_paint_uses(
reused_el):
_migrate_to_defs(svg, reused_el, reuse_cache,
reuse_result)
else:
el = reuse_cache.glyph_elements[glyph_name]
_apply_paint(
svg_defs,
el,
context.paint.paint, # pytype: disable=attribute-error
upem_to_vbox,
reuse_cache,
)
parent_el.append(el) # pytype: disable=attribute-error
# don't update el_by_path because we're declaring this path complete
complete_paths.add(context.path + (context.paint, ))
nth_paint_glyph += 1
elif isinstance(context.paint, PaintColrLayers):
pass
elif isinstance(context.paint, PaintSolid):
_apply_solid_paint(parent_el, context.paint)
elif _is_svg_supported_composite(context.paint):
el = etree.SubElement(parent_el, f"{{{svg_meta.svgns()}}}g")
el_by_path[context.path + (context.paint, )] = el
# TODO: support transform types, either by introducing <g> or by applying context.transform to Paint
else:
raise ValueError(f"What do we do with {context}")