Function buildFamilySettings

packages/core/src/processor.ts:130–212

(
		variableConfig?: VariableAxisConfig,
	)

	// Build Glypht FamilySettings for each family.
	const buildFamilySettings = (
		variableConfig?: VariableAxisConfig,
	): FamilySettings[] =>
		families.map((family) => {
			const styleValues: Partial<Record<string, SubsetAxisSetting>> = {};
			const axes: Partial<Record<string, SubsetAxisSetting>> = {};

			if (isVariableFont && variableConfig) {
				for (const [tag, axis] of Object.entries(variableConfig)) {
					if (!axis) continue;

					const styleKey = VARIABLE_STYLE_AXIS_MAP[tag];
					const setting: SubsetAxisSetting = {
						type: 'variable',
						value: { min: Number(axis.min), max: Number(axis.max) },
					};

					// If this is a known axis, map it to a style value. Otherwise, treat it as a custom axis.
					if (styleKey) {
						styleValues[styleKey] = setting;
					} else {
						axes[tag] = setting;
					}
				}
			} else {
				// If weights aren't explicitly configured, extract them from the font metadata.
				let weights = config.weights;
				if (!weights || weights.length === 0) {
					weights = Array.from(
						new Set(
							family.fonts.map((f) => {
								const w = f.font.styleValues.weight;
								return w.type === 'single' ? w.value : w.value.defaultValue;
							}),
						),
					);
				}

				// If styles aren't explicitly configured, extract them from the font metadata. Variable fonts need to be treated differently
				// since style axes like italic/slant may be represented as variable axes rather than discrete styles.
				let styles = config.styles;
				if (!styles || styles.length === 0 || config.type === 'variable') {
					styles = Array.from(
						new Set(
							family.fonts.map(
								(f) => extractFontStyle(f.font.styleValues).style,
							),
						),
					);
				}

				styleValues.weight = {
					type: 'multiple',
					value: { ranges: weights },
				};

				const hasItalic = styles.some(
					(s) => s === 'italic' || s.startsWith('oblique'),