Add bundled TTF fonts, page geometry, column allocator and render model

Static TTF fonts (IBM Plex Sans/Mono, Noto Devanagari/Kannada) with a fontkit-generated manifest, a verifier and OFL licences. Every family registers a normal and italic source so fallback stacks cannot throw. Adds A4/Letter geometry with margin presets, an exact column allocator, deterministic Indian-grouping money and date formatting, text sanitising and a pure buildRenderModel.
2026-10-04 04:38:03 +05:30
parent fbed18a0bd
commit 92ba3d9590
40 changed files with 2162 additions and 49 deletions
@@ -0,0 +1,79 @@
+// Shared helpers for the font manifest builder and verifier (Node only).
+import { createHash } from "node:crypto";
+import { readdirSync, readFileSync, statSync } from "node:fs";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import * as fontkit from "fontkit";
+
+export const ROOT = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "../..");
+export const FONTS_DIR = path.join(ROOT, "public/fonts");
+export const MANIFEST_PATH = path.join(FONTS_DIR, "manifest.json");
+
+export const sha256 = (bytes) => createHash("sha256").update(bytes).digest("hex");
+
+/** Folders under public/fonts that hold bundled families (everything that is a directory). */
+export function familyFolders() {
+  return readdirSync(FONTS_DIR)
+    .filter((name) => statSync(path.join(FONTS_DIR, name)).isDirectory())
+    .sort();
+}
+
+export function ttfFiles(folder) {
+  return readdirSync(path.join(FONTS_DIR, folder))
+    .filter((name) => /\.ttf$/i.test(name))
+    .sort();
+}
+
+/** First four bytes as a tag: "\0\1\0\0" is reported as "0x00010000". */
+export function sfntTag(bytes) {
+  const b = bytes.subarray(0, 4);
+  if (b[0] === 0 && b[1] === 1 && b[2] === 0 && b[3] === 0) return "0x00010000";
+  return String.fromCharCode(...b);
+}
+
+/** Raw OS/2 fsType (fontkit only exposes decoded flags). */
+function rawFsType(bytes) {
+  const dv = new DataView(bytes.buffer, bytes.byteOffset, bytes.byteLength);
+  const numTables = dv.getUint16(4);
+  for (let i = 0; i < numTables; i++) {
+    const rec = 12 + i * 16;
+    const tag = String.fromCharCode(bytes[rec], bytes[rec + 1], bytes[rec + 2], bytes[rec + 3]);
+    if (tag === "OS/2") return dv.getUint16(dv.getUint32(rec + 8) + 8);
+  }
+  return null;
+}
+
+/** Reads a TTF with fontkit and returns the facts the manifest records. */
+export function inspectFont(folder, file) {
+  const bytes = new Uint8Array(readFileSync(path.join(FONTS_DIR, folder, file)));
+  const font = fontkit.create(Buffer.from(bytes));
+  if (font.fonts) throw new Error(`${folder}/${file}: font collections are not supported`);
+  const os2 = font["OS/2"];
+  return {
+    bytes,
+    tag: sfntTag(bytes),
+    variable: Boolean(font.directory?.tables?.fvar),
+    // Name ID 16 (typographic family) groups SemiBold etc. under the base family.
+    familyName: font.name?.records?.preferredFamily?.en ?? font.familyName,
+    info: {
+      file,
+      weight: os2.usWeightClass,
+      style: os2.fsSelection.italic || os2.fsSelection.oblique ? "italic" : "normal",
+      sha256: sha256(bytes),
+      fsType: rawFsType(bytes),
+      upm: font.unitsPerEm,
+      ascent: font.ascent,
+      descent: font.descent,
+      lineGap: font.lineGap,
+      capHeight: font.capHeight,
+      xHeight: font.xHeight,
+      hasRupee: font.hasGlyphForCodePoint(0x20b9),
+      hasTabularNums: font.availableFeatures.includes("tnum"),
+    },
+  };
+}
+
+export const WEIGHT_WORDS = {
+  Thin: 100, ExtraLight: 200, Light: 300, Regular: 400, Italic: 400, Text: 450,
+  Medium: 500, SemiBold: 600, Bold: 700, ExtraBold: 800, Black: 900,
+};