Iosevka/font-src/gen/otd-conv/glyphs.js

const { Ot } = require("ot-builder");
const { Point } = require("../../support/geometry/point");
const Gr = require("../../support/gr");
const { byCode, bySpacing, byGr, byBuildOrder } = require("./glyph-name");

exports.convertGlyphs = function convertGlyphs(gsOrig) {
	const sortedEntries = Array.from(gsOrig.namedEntries(Gr.Nwid, Gr.Wwid)).sort(byRank);

	const gs = new MappedGlyphStore();
	const cmap = new Ot.Cmap.Table();

	for (const [name, gSrc] of sortedEntries) {
		gs.declare(name, gSrc);
		const us = gsOrig.queryUnicodeOf(gSrc);
		if (us) {
			for (const u of us) {
				if (!(isFinite(u - 0) && u)) continue;
				cmap.unicode.set(u, gs.queryBySourceGlyph(gSrc));
				gs.setPrimaryUnicode(gSrc, u);
			}
		}
	}
	for (const [name, gSrc] of sortedEntries) gs.fill(name, gSrc);
	gs.fillOtGlyphNames();
	return { glyphs: gs, cmap };
};

function byRank([gna, a], [gnb, b]) {
	return (
		b.glyphRank - a.glyphRank ||
		a.grRank - b.grRank ||
		a.codeRank - b.codeRank ||
		a.subRank - b.subRank
	);
}

class MappedGlyphStore {
	constructor() {
		this.m_nameMapping = new Map();
		this.m_mapping = new Map();
		this.m_primaryUnicodeMapping = new Map();
	}
	declare(name, source) {
		const g = new Ot.Glyph();
		this.m_nameMapping.set(name, g);
		this.m_mapping.set(source, g);
	}
	setPrimaryUnicode(source, u) {
		this.m_primaryUnicodeMapping.set(u, source);
	}

	queryBySourceGlyph(source) {
		return this.m_mapping.get(source);
	}
	queryByName(name) {
		return this.m_nameMapping.get(name);
	}

	decideOrder() {
		const gs = Ot.ListGlyphStoreFactory.createStoreFromList([...this.m_mapping.values()]);
		return gs.decideOrder();
	}
	fill(name, source) {
		const g = this.queryBySourceGlyph(source);
		if (!g) throw new Error("Unreachable");

		// Fill metrics
		g.horizontal = { start: 0, end: source.advanceWidth };

		// Fill Geometry
		if (source.geometry.isEmpty()) return;
		const rs = source.geometry.asReferences();
		if (rs) {
			this.fillReferences(g, rs);
		} else {
			this.fillContours(g, source.geometry.asContours());
		}
	}
	fillOtGlyphNames() {
		let gid = 0;
		let conflictSet = new Set();
		let rev = new Map();
		for (const [u, g] of this.m_primaryUnicodeMapping) rev.set(g, u);

		const glyphsInBuildOrder = Array.from(this.m_mapping).sort(
			([a], [b]) => a.subRank - b.subRank
		);

		for (const [gSrc, gOt] of glyphsInBuildOrder) gOt.name = undefined;

		// Name by Unicode
		for (const [gSrc, gOt] of glyphsInBuildOrder) {
			gOt.name = byCode(gSrc, rev.get(gSrc), conflictSet);
		}
		// Name by NWID/WWID
		let nNewNames = 0;
		do {
			nNewNames = 0;
			for (const [gSrcBase, gOtBase] of glyphsInBuildOrder) {
				nNewNames += bySpacing(gSrcBase, gOtBase, this.m_nameMapping, conflictSet);
			}
		} while (nNewNames > 0);
		// Name by Gr
		do {
			nNewNames = 0;
			for (const [gSrcBase, gOtBase] of glyphsInBuildOrder) {
				nNewNames += byGr(gSrcBase, gOtBase, this.m_nameMapping, conflictSet);
			}
		} while (nNewNames > 0);
		// Name rest
		for (const [gSrc, gOt] of glyphsInBuildOrder) {
			gOt.name = byBuildOrder(gSrc.subRank, gSrc, gOt.name);
		}

		// validate
		{
			let gnSet = new Set();
			for (const [gSrc, gOt] of this.m_mapping) {
				if (gnSet.has(gOt.name)) throw new Error("Unreachable! duplicate name " + gOt.name);
				gnSet.add(gOt.name);
			}
		}
	}

	fillReferences(g, rs) {
		const gl = new Ot.Glyph.GeometryList();
		for (const ref of rs) {
			const target = this.queryBySourceGlyph(ref.glyph);
			if (!target) throw new Error("Unreachable");
			const tfm = Ot.Glyph.Transform2X3.Translate(ref.x, ref.y);
			gl.items.push(new Ot.Glyph.TtReference(target, tfm));
		}
		g.geometry = gl;
	}
	fillContours(g, contours) {
		const cs = new Ot.Glyph.ContourSet();
		for (const c of contours) {
			const c1 = [];
			for (const z of c) {
				c1.push(
					Ot.Glyph.Point.create(
						z.x,
						z.y,
						z.type === Point.Type.Quadratic
							? Ot.Glyph.PointType.Quad
							: Ot.Glyph.PointType.Corner
					)
				);
			}
			cs.contours.push(c1);
		}
		g.geometry = cs;
	}
}