#Milky2018/moon_skrifa

#Status

• The public API and behavior aim to match fontations/skrifa (fontations-reference/ in this repo).
• Embedded hinting (TrueType glyf) is implemented and wired into outline drawing via HintingInstance + DrawSettings::hinted(...).
  • Supports both simple and composite glyf glyphs (FreeType-style path building).
  • Non-pedantic hinting matches fontations behavior (interpreter errors may be ignored); pedantic mode returns errors.
• Runtime autohinting (for fonts without embedded instructions) is implemented and integrated:
  • style classification + outline topology (segments/edges)
  • edge fitting + point alignment for PathStyle::FreeType and PathStyle::HarfBuzz
• CFF/CFF2 outlines and Engine::Interpreter hinting are supported (including Type2 stem hinting parity tests).
• Remaining parity work is tracked in bd (primarily broader core-module parity sweeps and maintenance).

#Packages

• Milky2018/moon_skrifa: facade re-exporting Milky2018/moon_skrifa/core (+ OutlineGlyph*)
• Milky2018/moon_skrifa/core: core metadata (FontRef, charmap, names/strings, metrics, bitmaps, COLR traversal)
• Milky2018/moon_skrifa/outline: outline extraction (glyf/CFF/CFF2), pens + SVG path output

#Install / Import

{
  "import": [
    "moonbitlang/core/prelude",
    "moonbitlang/core/bytes",
    { "path": "Milky2018/moon_skrifa", "alias": "moon_skrifa" },
    { "path": "Milky2018/moon_skrifa/outline", "alias": "moon_skrifa_outline" }
  ]
}

let font = @moon_skrifa.FontRef::new(font_bytes).unwrap()
let outlines = @moon_skrifa_outline.OutlineGlyphCollection::from_font(font)

#Core APIs

#Variation Axes / Locations (fvar/avar)

let axes = font.axes()
let settings : Array[@moon_skrifa.VariationSetting] = Array::from_fixed_array([
  @moon_skrifa.Setting::new(@moon_skrifa.Tag::from_str("wght").unwrap(), 700.0),
])
let loc = axes.location(settings.op_as_view()).as_ref()

#Charmap (codepoint -> glyph id)

let cmap = font.charmap().unwrap()
let gid = cmap.glyph_id(0x41).unwrap() // 'A'

#Name / Localized Strings (name table)

let family = font.localized_strings(@moon_skrifa.STRING_ID_FAMILY_NAME)
match family.english_or_first() {
  None => ()
  Some(s) => {
    let lang = s.language() // Option[String]
    let value = s.to_string()
    // ...
  }
}

#Font / Glyph Metrics

let fm = font.metrics(@moon_skrifa.Size::new(16.0), @moon_skrifa.LocationRef::default())
let gm = font.glyph_metrics(@moon_skrifa.Size::unscaled(), @moon_skrifa.LocationRef::default())

let aw = gm.advance_width(gid).unwrap()
let lsb = gm.left_side_bearing(gid).unwrap()
let bounds = gm.bounds(gid) // Option[GlyphBounds]

• HVAR deltas when present
• gvar phantom-deltas fallback for advance/lsb when HVAR is missing

#Bitmap Strikes (sbix/CBDT/EBDT)

let strikes = font.bitmap_strikes()
for i in 0..<strikes.len() {
  let strike = strikes.get(i).unwrap()
  let bmp = strike.get(gid)
  // BitmapGlyph has format/data/ppem/origin/width/height
}

#COLRv1 Paint Traversal (gradients/var/clip)

let loc = @moon_skrifa.LocationRef::default()
try! font.paint_colr_v1_at(gid, loc, painter) |> ignore

• Solid(palette_index, alpha)
• LinearGradient(p0, p1, stops, extend)
• RadialGradient(c0, r0, c1, r1, stops, extend)
• SweepGradient(c0, start_deg, end_deg, stops, extend)

#Outline Package

let gid = 1

let settings =
  @moon_skrifa_outline.DrawSettings::unhinted(
    @moon_skrifa.Size::new(16.0),
    @moon_skrifa.LocationRef::default(),
  )

let svg = outlines.svg_path(gid, settings).unwrap()
let path = outlines.path(gid, settings).unwrap()

• size (@moon_skrifa.Size)
• location (@moon_skrifa.LocationRef)
  • normalized coords are Int in F2Dot14; 16384 == 1.0
  • if you have user coords, prefer font.axes().location(...).as_ref()
• path_style (PathStyle::FreeType or PathStyle::HarfBuzz)
• optional embedded hinting via HintingInstance + DrawSettings::hinted(...)

let outlines0 = @moon_skrifa_outline.OutlineGlyphCollection::from_font(font)
let hinter =
  @moon_skrifa_outline.HintingInstance::new(
    outlines0,
    @moon_skrifa.Size::new(16.0),
    @moon_skrifa.LocationRef::default(),
    @moon_skrifa_outline.HintingOptions::default(),
  ).unwrap()

let settings = @moon_skrifa_outline.DrawSettings::hinted(hinter, false)
let svg = outlines.svg_path(gid, settings).unwrap()

#Development

• moon check
• moon test
• moon fmt
• moon info