简单来说

像漫画杂志那样，把两篇由四个格子组成的小漫画并排放在一页上：先从上到下读右边那篇，再读左边那篇。

成品一览

这是为本示例编写、用柔和的Q版画风绘制的四格漫画集《ねこ喫茶まどろみ》（打盹猫咖）中的一页：麦经营一家猫咖，店里有一只白猫、一只黑猫和一只三花猫。四格漫画就像把报纸上的连环漫画竖起来：四个一样大的格子从上往下叠，起、承、转、合。杂志一页并排放两篇，因为书从右边翻开，所以先读右边那篇。页面是A5，148 × 210 mm，跨页一边是日文原版，另一边是本页语言的版本（日文页上是英文版）。

这道食谱解答

怎样排一组四格漫画？

简短回答

script.js · 第44–62行在完整代码中

// content.<lang>.md splits the page `* [* / * / * / *] | * [* / * / * / *]`: two equal
// columns, each cut into four equal panels. The reading direction lays the first column
// out on the right, so the strip that opens the page is the right-hand one, as in a
// yonkoma magazine, and each strip still reads top to bottom. The gutter between the
// strips is wider than the gutters between their panels, so the eye drops down a strip
// before it crosses to the next.
const comics = (lang) => ({
  artDirection: 'rtl', // the right strip first, in every edition
  mirrorArt: false,
  gutter: { horizontal: mm(3), vertical: mm(9) }, // 3 mm between panels, 9 mm between strips
  panel: { borderWidth: pt(0.9), borderColor: col('ink'), background: col('paper') },
  lettering: {
    fontFamily: EDITIONS[lang].faces[0], color: col('ink'),
    fontSize: pt(['ja', 'zh'].includes(lang) ? 8 : 7), // a yonkoma letters smaller than a story
    writingMode: lang === 'zh' ? 'vertical' : 'auto',
    maxColumnChars: 6, // short columns: a yonkoma panel is wider than it is tall
  },
  balloonStyles: balloons(),
});

用料

功能: 分格阅读方向与日本漫画的顺序竖排中日韩字体格框与格间距格内画面与裁切多语言重新嵌字说话人与锚点漫画页漫画嵌字对话框样式拟声字右翻书语义调色板在Canvas上绘制页面导出PDF
还用到: 中文断行纸张颜色嵌入PDF的字体作为资源的图和表
类型: Zen Antique, Dela Gothic One, Comic Neue, Bangers, Noto Sans SC, ZCOOL KuaiLe, Playpen Sans Arabic, Lalezar（SIL OFL 1.1）
素材: neko-bowls.jpg
neko-door.jpg
neko-guest.jpg
neko-keyboard.jpg
neko-laptop.jpg
neko-nap.jpg
neko-onebowl.jpg
neko-toast.jpg
Mugi unlocking the cat café's door, three cats waiting inside (Generated With Diffusion Models, 原创)
Mugi setting out food bowls for the cats (Generated With Diffusion Models, 原创)
Three cats eating from one bowl (Generated With Diffusion Models, 原创)
The cats staring at Mugi's toast (Generated With Diffusion Models, 原创)
A tired office worker arriving at the café (Generated With Diffusion Models, 原创)
The three cats asleep on one cushion (Generated With Diffusion Models, 原创)
The office worker opening his laptop (Generated With Diffusion Models, 原创)
The cats sitting on the keyboard, the worker in happy tears (Generated With Diffusion Models, 原创)
API: buildDocumentclearMeasurementCachedecompressWoff2registerResourceImagerenderPageToCanvasrenderToPdf

做法

#1 · 把页面分成两列，每列四格

代码见上方的简短回答。整页是一个:::page，分格写作split="* [* / * / * / *] | * [* / * / * / *]"：两列等宽，每列切成四层等高。八行::panel按阅读顺序填入格子，所以前四格属于第一篇；从右往左读时，第一列排在右边（分格）。两篇之间的格间是9 mm，格子之间是3 mm，视线会先把一篇读到底再转到下一篇。

#2 · 每篇的标题放在第一格

script.js · 第66–73行在完整代码中

const balloons = () => [
  { id: 'speech', fill: col('paper'), stroke: col('ink'), strokeWidth: pt(0.6), roundness: 2.4 },
  { id: 'shout', fill: col('paper'), stroke: col('ink'), burstPoints: 16 },
  // caption{title}: the strip's title, white on black in the first panel's corner
  { id: 'title', shape: 'rectangle', fill: col('ink'), stroke: col('ink'), color: col('paper'),
    bold: true, tail: 'none', position: 'top-start', butt: true, align: 'center' },
  { id: 'sfx', color: col('ink'), haloColor: col('paper'), fontScale: 1.8 }, // chibi: small effects
];

四格漫画有标题，漫画集会把它印在每篇开头的方框里。这里标题也是脚本中的一行（caption{title}: 朝ごはん），title是一个单独的对话框样式：黑底白字，紧贴格子起始一侧的上角，在这本书里就是右上角。它和其他行一样按版本嵌字，所以英文页的同一个方框里写着Breakfast和Therapy。

#3 · 猫也标成说话人

script.js · 第206–320行在完整代码中

const cat = (id, x, y, fx, fy, w = 0.12, h = 0.15) => ({ id, x, y,
  face: { x: fx, y: fy, width: w, height: h } });
const nose = (id, x, y) => ({ id, x, y, head: { x, y: y - 0.04 } }); // cats asleep or eating
const ART = { // fractions of the picture: the same in every language
  door: {
    alt: t({ en: "Mugi unlocks the café's glass door; the white, black and calico cats wait.",
      es: 'Mugi abre la puerta de cristal del café; dentro esperan los tres gatos.',
      ca: 'La Mugi obre la porta de vidre del cafè; a dins esperen els tres gats.',
      zh: '麦打开猫咖的玻璃门，三只猫在里面等着。',
      ar: 'موغي تفتح باب المقهى الزجاجي، والقطط الثلاث تنتظر في الداخل.',
      ja: '猫カフェのガラス戸を開けるむぎ。中で3匹の猫が待っている。',
      pt: 'Mugi abre a porta de vidro do café; lá dentro, os três gatos esperam.' }),
  safeArea: { x: 0.09, y: 0.19, width: 0.81, height: 0.52 },
  anchors: [{ id: 'mugi', x: 0.205, y: 0.385, head: { x: 0.17, y: 0.25 },
    face: { x: 0.1, y: 0.2, width: 0.2, height: 0.23 } },
  cat('shiro', 0.5, 0.66, 0.44, 0.55, 0.13), cat('kuro', 0.66, 0.62, 0.61, 0.52, 0.12, 0.14),
  cat('mike', 0.83, 0.645, 0.77, 0.53, 0.12, 0.16)] },
  bowls: {
    alt: t({ en: 'Mugi sets out full food bowls in front of the three cats.',
      es: 'Mugi pone cuencos llenos delante de los tres gatos.',
      ca: 'La Mugi posa bols plens de menjar davant dels tres gats.',
      zh: '麦把装满猫粮的碗摆在三只猫面前。',
      ar: 'موغي تضع صحون طعام ممتلئة أمام القطط الثلاث.',
      ja: '3匹の猫の前に、ご飯を盛った器を並べるむぎ。',
      pt: 'Mugi põe tigelas cheias de comida na frente dos três gatos.' }),
  safeArea: { x: 0.16, y: 0.26, width: 0.74, height: 0.65 },
  anchors: [{ id: 'mugi', x: 0.27, y: 0.465, head: { x: 0.25, y: 0.3 },
    face: { x: 0.17, y: 0.26, width: 0.16, height: 0.24 } },
  cat('shiro', 0.37, 0.63, 0.31, 0.52, 0.13, 0.16), cat('kuro', 0.6, 0.64, 0.55, 0.52, 0.11, 0.16),
  cat('mike', 0.82, 0.62, 0.76, 0.52, 0.12, 0.14)] },
  onebowl: {
    alt: t({ en: 'All three cats push their heads into the same bowl; the others stay full.',
      es: 'Los tres gatos meten la cabeza en el mismo cuenco; los otros siguen llenos.',
      ca: 'Els tres gats fiquen el cap al mateix bol; els altres continuen plens.',
      zh: '三只猫把头挤进同一个碗里，另外两个碗还满着。',
      ar: 'القطط الثلاث تدسّ رؤوسها في الصحن نفسه، والصحنان الآخران ممتلئان.',
      ja: '3匹そろって同じ器に頭を突っこみ、ほかの器は手つかず。',
      pt: 'Os três gatos enfiam a cabeça na mesma tigela; as outras continuam cheias.' }),
  safeArea: { x: 0.05, y: 0.27, width: 0.88, height: 0.66 },
  anchors: [nose('shiro', 0.33, 0.66), nose('kuro', 0.5, 0.6), nose('mike', 0.66, 0.68),
    { id: 'sfx', x: 0.5, y: 0.3 }] },
  toast: {
    alt: t({ en: 'Mugi bites her toast while the three cats stare at it with shining eyes.',
      es: 'Mugi muerde su tostada mientras los tres gatos la miran con ojos brillantes.',
      ca: 'La Mugi mossega la torrada mentre els tres gats la miren amb ulls brillants.',
      zh: '麦咬着吐司，三只猫眼睛发亮地盯着。',
      ar: 'موغي تقضم خبزها المحمّص والقطط الثلاث تحدّق فيه بعيون لامعة.',
      ja: 'トーストをかじるむぎを、3匹がきらきらした目で見つめる。',
      pt: 'Mugi morde a torrada enquanto os três gatos olham para ela com olhos brilhando.' }),
  safeArea: { x: 0.09, y: 0.22, width: 0.85, height: 0.56 },
  avoid: [{ x: 0.6, y: 0.52, width: 0.15, height: 0.1 }],
  anchors: [{ id: 'mugi', x: 0.8, y: 0.5, head: { x: 0.85, y: 0.32 },
    face: { x: 0.75, y: 0.25, width: 0.2, height: 0.33 } },
  cat('shiro', 0.17, 0.71, 0.1, 0.6, 0.14, 0.16), cat('kuro', 0.32, 0.73, 0.26, 0.62, 0.12, 0.14),
  cat('mike', 0.46, 0.66, 0.4, 0.56, 0.12, 0.14)] },
  guest: {
    alt: t({ en: 'A tired office worker walks in, arms out; Mugi greets him from the counter.',
      es: 'Un oficinista cansado entra con los brazos abiertos; Mugi lo saluda desde la barra.',
      ca: 'Un oficinista cansat entra amb els braços oberts; la Mugi el saluda des de la barra.',
      zh: '一个疲惫的上班族张着双臂走进来，麦在柜台后招呼他。',
      ar: 'موظف متعب يدخل فاتحًا ذراعيه، وموغي ترحّب به من خلف المنضدة.',
      ja: '両手を広げて入ってくる疲れた会社員と、カウンターから迎えるむぎ。',
      pt: 'Um funcionário de escritório cansado entra de braços abertos; Mugi o recebe do '
        + 'balcão.' }),
  safeArea: { x: 0.13, y: 0.14, width: 0.74, height: 0.51 },
  anchors: [{ id: 'kyaku', x: 0.31, y: 0.42, head: { x: 0.28, y: 0.3 },
    face: { x: 0.19, y: 0.22, width: 0.21, height: 0.26 } },
  { id: 'mugi', x: 0.76, y: 0.39, head: { x: 0.76, y: 0.28 },
    face: { x: 0.68, y: 0.2, width: 0.18, height: 0.25 } }] },
  nap: {
    alt: t({ en: 'The three cats asleep in one pile on a round cushion.',
      es: 'Los tres gatos dormidos en un montón sobre un cojín redondo.',
      ca: 'Els tres gats adormits en un munt sobre un coixí rodó.',
      zh: '三只猫挤成一团睡在圆垫子上。',
      ar: 'القطط الثلاث نائمة كومةً واحدة على وسادة مستديرة.',
      ja: '丸いクッションの上で、ひとかたまりになって眠る3匹。',
      pt: 'Os três gatos dormem amontoados numa almofada redonda.' }),
  safeArea: { x: 0.27, y: 0.21, width: 0.52, height: 0.55 },
  anchors: [nose('shiro', 0.4, 0.42), nose('kuro', 0.41, 0.7), nose('mike', 0.72, 0.58),
    { id: 'sfx', x: 0.3, y: 0.25 }] },
  laptop: {
    alt: t({ en: 'The office worker sighs at a café table and opens his laptop.',
      es: 'El oficinista suspira en una mesa del café y abre el portátil.',
      ca: 'L’oficinista sospira en una taula del cafè i obre el portàtil.',
      zh: '上班族在咖啡桌前叹了口气，打开笔记本电脑。',
      ar: 'الموظف يتنهّد إلى طاولة في المقهى ويفتح حاسوبه.',
      ja: 'カフェのテーブルでため息をつき、ノートパソコンを開く会社員。',
      pt: 'O funcionário suspira numa mesa do café e abre o notebook.' }),
  safeArea: { x: 0.22, y: 0.25, width: 0.56, height: 0.55 },
  anchors: [{ id: 'kyaku', x: 0.45, y: 0.62, head: { x: 0.39, y: 0.4 },
    face: { x: 0.3, y: 0.3, width: 0.22, height: 0.38 } }] },
  keyboard: {
    alt: t({ en: 'The three cats sit on the keyboard; the worker cries tears of joy.',
      es: 'Los tres gatos se sientan en el teclado; el oficinista llora de alegría.',
      ca: 'Els tres gats seuen damunt del teclat; l’oficinista plora d’alegria.',
      zh: '三只猫坐在键盘上，上班族喜极而泣。',
      ar: 'القطط الثلاث تجلس على لوحة المفاتيح، والموظف يبكي من الفرح.',
      ja: 'キーボードの上に座る3匹と、うれし泣きする会社員。',
      pt: 'Os três gatos sentam no teclado; o funcionário chora de alegria.' }),
  safeArea: { x: 0.07, y: 0.1, width: 0.81, height: 0.78 },
  anchors: [{ id: 'kyaku', x: 0.29, y: 0.42, head: { x: 0.25, y: 0.2 },
    face: { x: 0.15, y: 0.1, width: 0.27, height: 0.4 } },
  cat('shiro', 0.42, 0.57, 0.36, 0.48, 0.13, 0.14), cat('kuro', 0.59, 0.6, 0.53, 0.5, 0.12, 0.14),
  cat('mike', 0.74, 0.62, 0.68, 0.52, 0.12, 0.14)] },
};
const panels = () => Promise.all([
  comicPanel('door', asset('neko-door.jpg'), ART.door),
  comicPanel('bowls', asset('neko-bowls.jpg'), ART.bowls),
  comicPanel('onebowl', asset('neko-onebowl.jpg'), ART.onebowl),
  comicPanel('toast', asset('neko-toast.jpg'), ART.toast),
  comicPanel('guest', asset('neko-guest.jpg'), ART.guest),
  comicPanel('nap', asset('neko-nap.jpg'), ART.nap),
  comicPanel('laptop', asset('neko-laptop.jpg'), ART.laptop),
  comicPanel('keyboard', asset('neko-keyboard.jpg'), ART.keyboard),
]);

猫也会说话（kuro: にゃ），所以每幅画像标出麦的嘴和脸那样标出猫的。两个小函数让列表更短：面向读者的猫用cat()，脸埋在碗里或垫子里的猫用nose()。第三格里麦不在画面中，她那一行mugi{tail=top}的尾巴指向格子的上边。

#4 · 用各版本自己的文字载入字体

script.js · 第324–336行在完整代码中

const SFX = /^sfx[^:：\n]*[:：](.*)$/gm; // sound-effect lines: the second face sets them
async function loadEdition(lang) {
  const text = TEXT[lang];
  const [face, sfx] = EDITIONS[lang].faces;
  const faces = { [face]: FONTS[face], [sfx]: FONTS[sfx] };
  if (['ja', 'zh'].includes(lang)) { // CJK: only the files that hold these characters
    const effects = [...text.matchAll(SFX)].map((m) => m[1]).join('');
    await loadCjkFonts({ [face]: FONTS[face] }, text.replace(SFX, ''), { vertical: true });
    await loadCjkFonts({ [sfx]: FONTS[sfx] }, effects, { vertical: true });
  }
  if (lang === 'ar') await loadArabicFonts(faces, text);
  await loadComicFonts(faces, text); // the bold and italic the faces do not ship
}

每种字体只拿到它要排的文字：Zen Antique排对话框，Dela Gothic One排拟声字（ガツガツ、じーっ、すやぁ、ずしっ）。四格漫画的格子宽大于高，所以日文竖列六个字就换列（maxColumnChars: 6），嵌字也比故事漫画的页面小半磅。

#5 · 把原版放在每个版本旁边

script.js · 第341–350行在完整代码中

const FACING = LANG === 'ja' ? 'en' : LANG; // Japanese readers see the English edition
const TEXT = { ja: original, [FACING]: LANG === 'ja' ? english : markdown };
await loadFonts(FONTS, Object.values(TEXT).join('\n'));
const resources = await panels();
const build = async (lang) => { // the same pictures and page; this language's lettering
  await loadEdition(lang);
  return buildWithFonts(() => buildDocument({ markdown: TEXT[lang], resources,
    continuation: { pageIndexOffset: lang === 'ja' ? 1 : 2 } }, edition(lang)), TEXT[lang]);
};
const docs = [await build('ja'), await build(FACING)];

本站的每种语言都在自己的文件里为这两篇嵌字，与跨页另一边的日文原版相对；日文页对着英文版。无论哪种语言，都先读右边那篇。

完整食谱

沙盒

// ═══ Postext Cookbook · Nº 151 · Two yonkoma strips on a page ═════════════════════════
// https://postext.dev/en/cookbook/yonkoma
// Code: MIT · Story: written for the recipe (CC BY 4.0) · Pictures: generated with diffusion models
// Fonts: Zen Antique, Comic Neue and six more (SIL OFL 1.1) · Needs postext ≥ 1.21.0
// A page of a cat-café yonkoma: two four-panel strips side by side, the right one first.
import {
  buildDocument, renderPageToCanvas, clearMeasurementCache, registerResourceImage,
  loadVerticalAlternates,
} from 'https://esm.sh/postext';
import { renderToPdf, decompressWoff2 } from 'https://esm.sh/postext-pdf';

const LANG = 'zh'; // @lang: this edition's language; the Japanese original faces it
const RECIPE = 'yonkoma';

// ─── 1 · Design ─────────────────────────────────────────────────────────────
// #region palette: black ink on a warm white, one screen-tone grey
const palette = {
  ink: '#151413', // panel borders, balloon outlines, the lettering
  paper: '#fdfcf9', // the page and the balloons
  tone: '#e8e6e1', // the inner-voice box, a light screen tone
  muted: '#6f6b64',
  accent: '#a8322b', // the cover red (the Folio case in recipe.json)
};
const col = (id) => ({ hex: palette[id], model: 'hex', paletteId: id });
const colorPalette = [
  ...Object.entries(palette).map(([id, hex]) => ({ id, name: id, value: { hex, model: 'hex' } })),
  { id: 'main-color', name: 'ink (defaults)', value: { hex: palette.ink, model: 'hex' } },
];
// #endregion

// The engine's lettering and sound-effect faces per language (defaultComicFont and
// defaultComicSfxFont), written out so FONTS and the PDF know them.
const EDITIONS = {
  ja: { locale: 'ja', faces: ['Zen Antique', 'Dela Gothic One'] },
  en: { locale: 'en-us', faces: ['Comic Neue', 'Bangers'] },
  es: { locale: 'es', faces: ['Comic Neue', 'Bangers'] },
  ca: { locale: 'ca', faces: ['Comic Neue', 'Bangers'] },
  zh: { locale: 'zh-Hans', faces: ['Noto Sans SC', 'ZCOOL KuaiLe'] },
  ar: { locale: 'ar', faces: ['Playpen Sans Arabic', 'Lalezar'] },
  pt: { locale: 'pt-BR', faces: ['Comic Neue', 'Bangers'] },
};

// #region answer: two columns of four, read from the right
// content.<lang>.md splits the page `* [* / * / * / *] | * [* / * / * / *]`: two equal
// columns, each cut into four equal panels. The reading direction lays the first column
// out on the right, so the strip that opens the page is the right-hand one, as in a
// yonkoma magazine, and each strip still reads top to bottom. The gutter between the
// strips is wider than the gutters between their panels, so the eye drops down a strip
// before it crosses to the next.
const comics = (lang) => ({
  artDirection: 'rtl', // the right strip first, in every edition
  mirrorArt: false,
  gutter: { horizontal: mm(3), vertical: mm(9) }, // 3 mm between panels, 9 mm between strips
  panel: { borderWidth: pt(0.9), borderColor: col('ink'), background: col('paper') },
  lettering: {
    fontFamily: EDITIONS[lang].faces[0], color: col('ink'),
    fontSize: pt(['ja', 'zh'].includes(lang) ? 8 : 7), // a yonkoma letters smaller than a story
    writingMode: lang === 'zh' ? 'vertical' : 'auto',
    maxColumnChars: 6, // short columns: a yonkoma panel is wider than it is tall
  },
  balloonStyles: balloons(),
});
// #endregion

// #region balloons: round speech, and a black box for each strip's title
const balloons = () => [
  { id: 'speech', fill: col('paper'), stroke: col('ink'), strokeWidth: pt(0.6), roundness: 2.4 },
  { id: 'shout', fill: col('paper'), stroke: col('ink'), burstPoints: 16 },
  // caption{title}: the strip's title, white on black in the first panel's corner
  { id: 'title', shape: 'rectangle', fill: col('ink'), stroke: col('ink'), color: col('paper'),
    bold: true, tail: 'none', position: 'top-start', butt: true, align: 'center' },
  { id: 'sfx', color: col('ink'), haloColor: col('paper'), fontScale: 1.8 }, // chibi: small effects
];
// #endregion

const config = () => ({ // a factory: the engine caches resolved configs per object
  // Each edition's language, written out (gotcha: ja-locale-tag); the original is built
  // with 'ja' in every edition (edition('ja') below).
  locale: t({ ja: 'ja', en: 'en-us', es: 'es', ca: 'ca', zh: 'zh-Hans', ar: 'ar', pt: 'pt-BR' }),
  colorPalette,
  page: {
    sizePreset: 'custom', width: mm(148), height: mm(210), dpi: 150, // A5, a yonkoma anthology
    binding: 'right', backgroundColor: col('paper'), // manga open from the right, in any language
    margins: { top: mm(15), bottom: mm(15), left: mm(14), right: mm(14), mirror: true },
  },
  bodyText: {
    fontFamily: 'Zen Antique', fontSize: pt(9), lineHeight: pt(15), color: col('ink'),
    boldColor: col('ink'), italicColor: col('ink'), referenceColor: col('ink'),
  },
  headings: { fontFamily: 'Zen Antique', color: col('ink'),
    levels: [{ level: 1, breakBefore: { enabled: true, parity: 'any' } }] }, // the H1 break
  header: { elements: [] }, // comic pages are all panels: no running heads, no folios
  footer: { elements: [] },
  comics: comics(LANG),
});
// Another edition changes the language and the faces; the strips and their order stay.
const edition = (lang) => ({ ...config(), locale: EDITIONS[lang].locale, comics: comics(lang) });

// ─── 2 · Content ────────────────────────────────────────────────────────────
const markdown = String.raw`---
Markdown样例 · 30行 · content.zh.md
title: "打盹猫咖"
author: "Postext Cookbook"
---

:::page{split="* [* / * / * / *] | * [* / * / * / *]"}
::panel{art=door}
caption{title}: 早饭
mugi: 大家早上好！
kuro: 喵
::panel{art=bowls}
mugi: 一人一碗哦
::panel{art=onebowl}
sfx: 吧唧吧唧
mugi{tail=top}: ……为什么全挤在一个碗里
::panel{art=toast}
sfx: 盯——
mugi: 你们刚吃过了吧！
::panel{art=guest}
caption{title}: 治愈
kyaku: 我是来被治愈的……
mugi: 欢迎光临～
::panel{art=nap}
sfx: 呼噜
kyaku{tail=top}: ……全都睡着了
::panel{art=laptop}
kyaku: 没办法，干活吧……
::panel{art=keyboard}
sfx{at="70% 80%" rotate=-10}: 咚
kyaku{shout}: 干不了活，可是好幸福！！
:::
`; // content.<lang>.md: this edition's lettering
const original = String.raw`---
Markdown样例 · 30行 · content.ja.md
title: "ねこ喫茶まどろみ"
author: "Postext Cookbook"
---

:::page{split="* [* / * / * / *] | * [* / * / * / *]"}
::panel{art=door}
caption{title}: 朝ごはん
mugi: おはよー、みんな！
kuro: にゃ
::panel{art=bowls}
mugi: ひとり一個ずつね
::panel{art=onebowl}
sfx: ガツガツ
mugi{tail=top}: ……なんで一個に集まるの
::panel{art=toast}
sfx: じーっ
mugi: さっき食べたでしょ！
::panel{art=guest}
caption{title}: いやし
kyaku: 猫ちゃんに癒されに来ました……
mugi: いらっしゃいませー
::panel{art=nap}
sfx: すやぁ
kyaku{tail=top}: ……全員寝てる
::panel{art=laptop}
kyaku: しかたない、仕事するか……
::panel{art=keyboard}
sfx{at="86% 84%" rotate=-10}: ずしっ
kyaku{shout break}: 仕事できないけど幸せーっ！！
:::
`; // content.ja.md, the original, in every edition
const english = String.raw`---
Markdown样例 · 30行 · content.en.md
title: "Café Doze"
author: "Postext Cookbook"
---

:::page{split="* [* / * / * / *] | * [* / * / * / *]"}
::panel{art=door}
caption{title}: Breakfast
mugi: Morning, everyone!
kuro: Mrrp.
::panel{art=bowls}
mugi: One bowl each, okay?
::panel{art=onebowl}
sfx: NOM NOM
mugi{tail=top}: …Why all in the same one?
::panel{art=toast}
sfx: STARE
mugi: You just ate!
::panel{art=guest}
caption{title}: Therapy
kyaku: I'm here to be healed by cats…
mugi: Welcome!
::panel{art=nap}
sfx: zzz
kyaku{tail=top}: …They're all asleep.
::panel{art=laptop}
kyaku: Fine. I'll get some work done…
::panel{art=keyboard}
sfx{at="70% 80%" rotate=-10}: THUMP
kyaku{shout}: Can't work. So happy!!
:::
`; // the Japanese edition faces the original with it
// The same panels and speaker ids in every file; only the words change.

// ─── 3 · Fonts ──────────────────────────────────────────────────────────────
const FONTS = {
  'Zen Antique': ['400'], 'Dela Gothic One': ['400'], 'Comic Neue': ['400', '700', '400i', '700i'],
  Bangers: ['400'], 'Noto Sans SC': ['400', '700'], 'ZCOOL KuaiLe': ['400'],
  'Playpen Sans Arabic': ['400', '700'], Lalezar: ['400'],
};

// #region art: eight chibi panels drawn for the recipe, speakers and faces marked once
const cat = (id, x, y, fx, fy, w = 0.12, h = 0.15) => ({ id, x, y,
  face: { x: fx, y: fy, width: w, height: h } });
const nose = (id, x, y) => ({ id, x, y, head: { x, y: y - 0.04 } }); // cats asleep or eating
const ART = { // fractions of the picture: the same in every language
  door: {
    alt: t({ en: "Mugi unlocks the café's glass door; the white, black and calico cats wait.",
      es: 'Mugi abre la puerta de cristal del café; dentro esperan los tres gatos.',
      ca: 'La Mugi obre la porta de vidre del cafè; a dins esperen els tres gats.',
      zh: '麦打开猫咖的玻璃门，三只猫在里面等着。',
      ar: 'موغي تفتح باب المقهى الزجاجي، والقطط الثلاث تنتظر في الداخل.',
      ja: '猫カフェのガラス戸を開けるむぎ。中で3匹の猫が待っている。',
      pt: 'Mugi abre a porta de vidro do café; lá dentro, os três gatos esperam.' }),
  safeArea: { x: 0.09, y: 0.19, width: 0.81, height: 0.52 },
  anchors: [{ id: 'mugi', x: 0.205, y: 0.385, head: { x: 0.17, y: 0.25 },
    face: { x: 0.1, y: 0.2, width: 0.2, height: 0.23 } },
  cat('shiro', 0.5, 0.66, 0.44, 0.55, 0.13), cat('kuro', 0.66, 0.62, 0.61, 0.52, 0.12, 0.14),
  cat('mike', 0.83, 0.645, 0.77, 0.53, 0.12, 0.16)] },
  bowls: {
    alt: t({ en: 'Mugi sets out full food bowls in front of the three cats.',
      es: 'Mugi pone cuencos llenos delante de los tres gatos.',
      ca: 'La Mugi posa bols plens de menjar davant dels tres gats.',
      zh: '麦把装满猫粮的碗摆在三只猫面前。',
      ar: 'موغي تضع صحون طعام ممتلئة أمام القطط الثلاث.',
      ja: '3匹の猫の前に、ご飯を盛った器を並べるむぎ。',
      pt: 'Mugi põe tigelas cheias de comida na frente dos três gatos.' }),
  safeArea: { x: 0.16, y: 0.26, width: 0.74, height: 0.65 },
  anchors: [{ id: 'mugi', x: 0.27, y: 0.465, head: { x: 0.25, y: 0.3 },
    face: { x: 0.17, y: 0.26, width: 0.16, height: 0.24 } },
  cat('shiro', 0.37, 0.63, 0.31, 0.52, 0.13, 0.16), cat('kuro', 0.6, 0.64, 0.55, 0.52, 0.11, 0.16),
  cat('mike', 0.82, 0.62, 0.76, 0.52, 0.12, 0.14)] },
  onebowl: {
    alt: t({ en: 'All three cats push their heads into the same bowl; the others stay full.',
      es: 'Los tres gatos meten la cabeza en el mismo cuenco; los otros siguen llenos.',
      ca: 'Els tres gats fiquen el cap al mateix bol; els altres continuen plens.',
      zh: '三只猫把头挤进同一个碗里，另外两个碗还满着。',
      ar: 'القطط الثلاث تدسّ رؤوسها في الصحن نفسه، والصحنان الآخران ممتلئان.',
      ja: '3匹そろって同じ器に頭を突っこみ、ほかの器は手つかず。',
      pt: 'Os três gatos enfiam a cabeça na mesma tigela; as outras continuam cheias.' }),
  safeArea: { x: 0.05, y: 0.27, width: 0.88, height: 0.66 },
  anchors: [nose('shiro', 0.33, 0.66), nose('kuro', 0.5, 0.6), nose('mike', 0.66, 0.68),
    { id: 'sfx', x: 0.5, y: 0.3 }] },
  toast: {
    alt: t({ en: 'Mugi bites her toast while the three cats stare at it with shining eyes.',
      es: 'Mugi muerde su tostada mientras los tres gatos la miran con ojos brillantes.',
      ca: 'La Mugi mossega la torrada mentre els tres gats la miren amb ulls brillants.',
      zh: '麦咬着吐司，三只猫眼睛发亮地盯着。',
      ar: 'موغي تقضم خبزها المحمّص والقطط الثلاث تحدّق فيه بعيون لامعة.',
      ja: 'トーストをかじるむぎを、3匹がきらきらした目で見つめる。',
      pt: 'Mugi morde a torrada enquanto os três gatos olham para ela com olhos brilhando.' }),
  safeArea: { x: 0.09, y: 0.22, width: 0.85, height: 0.56 },
  avoid: [{ x: 0.6, y: 0.52, width: 0.15, height: 0.1 }],
  anchors: [{ id: 'mugi', x: 0.8, y: 0.5, head: { x: 0.85, y: 0.32 },
    face: { x: 0.75, y: 0.25, width: 0.2, height: 0.33 } },
  cat('shiro', 0.17, 0.71, 0.1, 0.6, 0.14, 0.16), cat('kuro', 0.32, 0.73, 0.26, 0.62, 0.12, 0.14),
  cat('mike', 0.46, 0.66, 0.4, 0.56, 0.12, 0.14)] },
  guest: {
    alt: t({ en: 'A tired office worker walks in, arms out; Mugi greets him from the counter.',
      es: 'Un oficinista cansado entra con los brazos abiertos; Mugi lo saluda desde la barra.',
      ca: 'Un oficinista cansat entra amb els braços oberts; la Mugi el saluda des de la barra.',
      zh: '一个疲惫的上班族张着双臂走进来，麦在柜台后招呼他。',
      ar: 'موظف متعب يدخل فاتحًا ذراعيه، وموغي ترحّب به من خلف المنضدة.',
      ja: '両手を広げて入ってくる疲れた会社員と、カウンターから迎えるむぎ。',
      pt: 'Um funcionário de escritório cansado entra de braços abertos; Mugi o recebe do '
        + 'balcão.' }),
  safeArea: { x: 0.13, y: 0.14, width: 0.74, height: 0.51 },
  anchors: [{ id: 'kyaku', x: 0.31, y: 0.42, head: { x: 0.28, y: 0.3 },
    face: { x: 0.19, y: 0.22, width: 0.21, height: 0.26 } },
  { id: 'mugi', x: 0.76, y: 0.39, head: { x: 0.76, y: 0.28 },
    face: { x: 0.68, y: 0.2, width: 0.18, height: 0.25 } }] },
  nap: {
    alt: t({ en: 'The three cats asleep in one pile on a round cushion.',
      es: 'Los tres gatos dormidos en un montón sobre un cojín redondo.',
      ca: 'Els tres gats adormits en un munt sobre un coixí rodó.',
      zh: '三只猫挤成一团睡在圆垫子上。',
      ar: 'القطط الثلاث نائمة كومةً واحدة على وسادة مستديرة.',
      ja: '丸いクッションの上で、ひとかたまりになって眠る3匹。',
      pt: 'Os três gatos dormem amontoados numa almofada redonda.' }),
  safeArea: { x: 0.27, y: 0.21, width: 0.52, height: 0.55 },
  anchors: [nose('shiro', 0.4, 0.42), nose('kuro', 0.41, 0.7), nose('mike', 0.72, 0.58),
    { id: 'sfx', x: 0.3, y: 0.25 }] },
  laptop: {
    alt: t({ en: 'The office worker sighs at a café table and opens his laptop.',
      es: 'El oficinista suspira en una mesa del café y abre el portátil.',
      ca: 'L’oficinista sospira en una taula del cafè i obre el portàtil.',
      zh: '上班族在咖啡桌前叹了口气，打开笔记本电脑。',
      ar: 'الموظف يتنهّد إلى طاولة في المقهى ويفتح حاسوبه.',
      ja: 'カフェのテーブルでため息をつき、ノートパソコンを開く会社員。',
      pt: 'O funcionário suspira numa mesa do café e abre o notebook.' }),
  safeArea: { x: 0.22, y: 0.25, width: 0.56, height: 0.55 },
  anchors: [{ id: 'kyaku', x: 0.45, y: 0.62, head: { x: 0.39, y: 0.4 },
    face: { x: 0.3, y: 0.3, width: 0.22, height: 0.38 } }] },
  keyboard: {
    alt: t({ en: 'The three cats sit on the keyboard; the worker cries tears of joy.',
      es: 'Los tres gatos se sientan en el teclado; el oficinista llora de alegría.',
      ca: 'Els tres gats seuen damunt del teclat; l’oficinista plora d’alegria.',
      zh: '三只猫坐在键盘上，上班族喜极而泣。',
      ar: 'القطط الثلاث تجلس على لوحة المفاتيح، والموظف يبكي من الفرح.',
      ja: 'キーボードの上に座る3匹と、うれし泣きする会社員。',
      pt: 'Os três gatos sentam no teclado; o funcionário chora de alegria.' }),
  safeArea: { x: 0.07, y: 0.1, width: 0.81, height: 0.78 },
  anchors: [{ id: 'kyaku', x: 0.29, y: 0.42, head: { x: 0.25, y: 0.2 },
    face: { x: 0.15, y: 0.1, width: 0.27, height: 0.4 } },
  cat('shiro', 0.42, 0.57, 0.36, 0.48, 0.13, 0.14), cat('kuro', 0.59, 0.6, 0.53, 0.5, 0.12, 0.14),
  cat('mike', 0.74, 0.62, 0.68, 0.52, 0.12, 0.14)] },
};
const panels = () => Promise.all([
  comicPanel('door', asset('neko-door.jpg'), ART.door),
  comicPanel('bowls', asset('neko-bowls.jpg'), ART.bowls),
  comicPanel('onebowl', asset('neko-onebowl.jpg'), ART.onebowl),
  comicPanel('toast', asset('neko-toast.jpg'), ART.toast),
  comicPanel('guest', asset('neko-guest.jpg'), ART.guest),
  comicPanel('nap', asset('neko-nap.jpg'), ART.nap),
  comicPanel('laptop', asset('neko-laptop.jpg'), ART.laptop),
  comicPanel('keyboard', asset('neko-keyboard.jpg'), ART.keyboard),
]);
// #endregion

// #region fonts: each edition loads its two faces with the words they set
const SFX = /^sfx[^:：\n]*[:：](.*)$/gm; // sound-effect lines: the second face sets them
async function loadEdition(lang) {
  const text = TEXT[lang];
  const [face, sfx] = EDITIONS[lang].faces;
  const faces = { [face]: FONTS[face], [sfx]: FONTS[sfx] };
  if (['ja', 'zh'].includes(lang)) { // CJK: only the files that hold these characters
    const effects = [...text.matchAll(SFX)].map((m) => m[1]).join('');
    await loadCjkFonts({ [face]: FONTS[face] }, text.replace(SFX, ''), { vertical: true });
    await loadCjkFonts({ [sfx]: FONTS[sfx] }, effects, { vertical: true });
  }
  if (lang === 'ar') await loadArabicFonts(faces, text);
  await loadComicFonts(faces, text); // the bold and italic the faces do not ship
}
// #endregion

// ─── 4 · Build & show ───────────────────────────────────────────────────────
// #region editions: the original on the right-hand page, this edition's lettering facing it
const FACING = LANG === 'ja' ? 'en' : LANG; // Japanese readers see the English edition
const TEXT = { ja: original, [FACING]: LANG === 'ja' ? english : markdown };
await loadFonts(FONTS, Object.values(TEXT).join('\n'));
const resources = await panels();
const build = async (lang) => { // the same pictures and page; this language's lettering
  await loadEdition(lang);
  return buildWithFonts(() => buildDocument({ markdown: TEXT[lang], resources,
    continuation: { pageIndexOffset: lang === 'ja' ? 1 : 2 } }, edition(lang)), TEXT[lang]);
};
const docs = [await build('ja'), await build(FACING)];
// #endregion
const TITLE = t({
  en: 'Two yonkoma strips on a page', es: 'Dos tiras yonkoma en una página',
  ca: 'Dues tires yonkoma en una pàgina', zh: '一页并排两篇四格漫画', ar: 'شريطا يونكوما في صفحة واحدة',
  ja: '1ページに四コマを2本並べる', pt: 'Duas tiras yonkoma numa página' });
showBook(docs, { title: TITLE });
offerPdf(() => renderToPdf(docs, { fontProvider: comicPdfProvider, resourceBytes: imageBytes }),
  `${RECIPE}.pdf`);

工具包 · core, fonts, viewer, pdf, images, cjk, arabic, comics：每道食谱都相同 · 722行
// ─── Kit ── helpers shared by every Cookbook recipe · postext.dev/cookbook ─────

// ─── Kit · core v1 ── the same in every recipe · postext.dev/cookbook
function mm(value) { return { value, unit: 'mm' }; }
function pt(value) { return { value, unit: 'pt' }; }
function em(value) { return { value, unit: 'em' }; }
/** The sample language's string: t({ en: 'Figure', es: 'Figura' }). */
function t(strings) { return strings[LANG] ?? Object.values(strings)[0]; }
/** A file in this recipe's assets folder, served from the Postext repo by jsDelivr. */
function asset(file) { return `https://cdn.jsdelivr.net/gh/drnachio/postext@main/cookbook/${RECIPE}/assets/${file}`; }

// ─── Kit · fonts v2 ── the same in every recipe · postext.dev/cookbook
// Postext measures with the loaded faces and caches the widths: load every face
// before the first build, from Fontsource, the files the PDF embeds too.

/** faces = { 'Family Name': ['400', '400i', '700'] }. `text` is the sample:
 *  č ł † α χ also load latin-ext and greek files (kitSubsetsFor). With
 *  `optional`, a face Fontsource does not ship is skipped instead of failing.
 *  Resolves to the number of faces added. */
async function loadFonts(faces, text = '', { optional = false } = {}) {
  kitStatus('Loading fonts…');
  const ranges = {
    latin: 'U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,'
      + 'U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD',
    'latin-ext': 'U+0100-02BA,U+02BD-02C5,U+02C7-02CC,U+02CE-02D7,U+02DD-02FF,U+0304,U+0308,U+0329,'
      + 'U+1D00-1DBF,U+1E00-1E9F,U+1EF2-1EFF,U+2020,U+20A0-20AB,U+20AD-20C0,U+2113,U+2C60-2C7F,U+A720-A7FF',
    greek: 'U+0370-03FF',
  };
  const jobs = [];
  let added = 0;
  for (const [family, specs] of Object.entries(faces)) {
    const id = fontsourceId(family);
    const todo = [...new Set(specs)].map((spec) => [parseInt(spec, 10), spec.endsWith('i') ? 'italic' : 'normal'])
      .filter(([weight, style]) => !hasFace(family, weight, style)); // before any await
    const meta = optional || /[^\0-ÿ]/u.test(text) ? await fontsourceMeta(family) : null;
    const subsets = ['latin', ...kitSubsetsFor(text, meta)];
    for (const [weight, style] of todo) {
      if (optional && !(meta?.weights.includes(weight) && meta.styles.includes(style))) continue;
      for (const subset of subsets) {
        const url = `https://cdn.jsdelivr.net/npm/@fontsource/${id}@5/files/${id}-${subset}-${weight}-${style}.woff2`;
        const face = new FontFace(family, `url(${url}) format('woff2')`,
          { weight: String(weight), style, unicodeRange: ranges[subset] });
        jobs.push(face.load().then((ready) => { document.fonts.add(ready); added++; }, () => {
          if (subset === 'latin' && !optional) throw new Error(`Fontsource has no ${family} ${weight} ${style}`);
        }));
      }
    }
  }
  await Promise.all(jobs).catch((error) => { kitFail(error); throw error; });
  return added;
}

/** Runs `build` and loads any face the pages use that FONTS missed (a regular
 *  one with a warning), then clears the measurement cache and builds again. */
async function buildWithFonts(build, text = '') {
  const tried = new Set();
  for (let round = 0; round < 3; round++) {
    kitStatus('Laying out…');
    await new Promise(requestAnimationFrame);          // let the status paint first
    const result = await Promise.resolve().then(build).catch((error) => { kitFail(error); throw error; });
    const wanted = { base: {}, variants: {} };
    for (const { font, base } of [result].flat().flatMap(fontStringsOf)) {
      const { family, weight, style } = parseFont(font);
      const key = `${family}|${weight}|${style}`;
      if (tried.has(key) || hasFace(family, weight, style)) continue;
      tried.add(key);
      (wanted[base ? 'base' : 'variants'][family] ??= []).push(`${weight}${style === 'italic' ? 'i' : ''}`);
    }
    if (Object.keys(wanted.base).length) {
      console.warn(`[cookbook] FONTS does not list ${JSON.stringify(wanted.base)}: loading them.`);
    }
    const added = await loadFonts(wanted.base, text) + await loadFonts(wanted.variants, text, { optional: true });
    if (added === 0) return result;
    clearMeasurementCache();
  }
  throw new Error('The fonts did not settle after three builds.');
}

/** Every font string of the layout; `base` marks a block's own face. */
function fontStringsOf(doc) {
  const found = new Map();
  const walk = (node) => {
    if (!node || typeof node !== 'object') return;
    if (Array.isArray(node)) { node.forEach(walk); return; }
    for (const [key, value] of Object.entries(node)) {
      if (typeof value === 'string' && /fontString$/i.test(key)) {
        found.set(value, found.get(value) || key === 'fontString');
      } else if (value && typeof value === 'object') walk(value);
    }
  };
  walk(doc.pages);
  walk(doc.blocks);
  return [...found].map(([font, base]) => ({ font, base }));
}

/** '700 37.5px Open Sans' / 'italic 400 13px "Source Serif 4"' → { family, weight, style }.
 *  A string with no weight ('95.8px Young Serif', from a design text) is 400. */
function parseFont(font) {
  const m = /^(?:(italic|oblique)\s+)?(?:small-caps\s+)?(?:(\d+|bold|normal)\s+)?[\d.]+px\s+(.+)$/.exec(font.trim());
  if (!m) throw new Error(`Unexpected font string: ${font}`);
  const weight = m[2] === 'bold' ? 700 : !m[2] || m[2] === 'normal' ? 400 : Number(m[2]);
  return { family: m[3].replace(/^["']|["']$/g, ''), weight, style: m[1] ? 'italic' : 'normal' };
}

/** A loaded FontFace covers this family, weight and style (fonts.check() would
 *  also say yes for families nobody declared). */
function hasFace(family, weight, style) {
  for (const face of document.fonts) {
    if (face.status !== 'loaded' || face.style !== style) continue;
    if (face.family.replace(/^["']|["']$/g, '') !== family) continue;
    const [low, high = low] = face.weight.split(' ').map(Number);
    if (weight >= low && weight <= high) return true;
  }
  return false;
}

/** The files beyond latin `text` needs that `meta`'s family ships. */
function kitSubsetsFor(text, meta) {
  return [[/[Ā-˿ᴀ-ᶿḀ-ỿ†ℓⱠ-Ɀ꜠-ꟿ]/u, 'latin-ext'], [/[Ͱ-Ͽ]/u, 'greek']]
    .filter(([re, x]) => re.test(text) && meta?.subsets?.includes(x)).map(([, x]) => x);
}

/** Fontsource's id for a family: 'Source Serif 4' → 'source-serif-4'. */
function fontsourceId(family) { return family.toLowerCase().replace(/\s+/g, '-'); }

/** The family's Fontsource metadata (weights, styles, subsets), or null. */
function fontsourceMeta(family) {
  fontsourceMeta.cache ??= new Map();
  const id = fontsourceId(family);
  if (!fontsourceMeta.cache.has(id)) {
    fontsourceMeta.cache.set(id, fetch(`https://api.fontsource.org/v1/fonts/${id}`)
      .then((res) => (res.ok ? res.json() : null), () => null));
  }
  return fontsourceMeta.cache.get(id);
}

// ─── Kit · viewer v1 ── the same in every recipe · postext.dev/cookbook
/** The pages as spreads on a dark desk, page 1 alone, then verso | recto,
 *  each painted when it scrolls near. */
function showPages(docs, { title, width = 460 } = {}) {
  const root = viewer(title);
  const pages = [docs].flat().flatMap((doc) =>
    doc.pages.map((page) => ({ doc, page, n: (doc.pageIndexOffset ?? 0) + page.index })));
  const spreads = [];
  let verso = null;
  for (const p of pages) {
    if (p.n % 2 === 1) { if (verso) spreads.push([verso, null]); verso = p; }
    else { spreads.push([verso, p]); verso = null; }
  }
  if (verso) spreads.push([verso, null]);
  const density = Math.min(window.devicePixelRatio || 1, 2);
  showPages.painter?.disconnect();
  const painter = new IntersectionObserver((entries) => {
    for (const { isIntersecting, target } of entries) {
      if (!isIntersecting) continue;
      painter.unobserve(target);
      const { doc, page } = target.postext;
      renderPageToCanvas(page, doc, target, { scale: (width * density) / page.width });
    }
  }, { rootMargin: '800px' });
  showPages.painter = painter;
  root.replaceChildren(...spreads.map((pair) => {
    const spread = document.createElement('div');
    spread.className = 'pt-spread';
    for (const p of pair) {
      const figure = document.createElement('figure');
      if (p) {
        const label = p.page.pageLabel || String(p.n + 1);
        const canvas = document.createElement('canvas');
        canvas.postext = p;
        canvas.style.aspectRatio = `${p.page.width} / ${p.page.height}`;
        canvas.setAttribute('role', 'img');
        canvas.setAttribute('aria-label', `Page ${label}`);
        const folio = document.createElement('figcaption');
        folio.textContent = label;
        figure.append(canvas, folio);
        painter.observe(canvas);
      } else figure.className = 'pt-blank';
      spread.append(figure);
    }
    return spread;
  }));
  kitStatus(`${pages.length} ${pages.length === 1 ? 'page' : 'pages'}`);
  document.documentElement.dataset.postext = 'ready';
  return pages.length;
}

/** The desk, the bar and the error reporting, created once. */
function viewer(title) {
  if (!document.getElementById('pt-kit')) {
    document.head.insertAdjacentHTML('beforeend', `<style id="pt-kit">
      :root { color-scheme: dark; }
      body { margin: 0; background: #0e1014; color: #b9bcc4; font: 13px/1.45 system-ui, sans-serif; }
      #pt-bar { position: sticky; top: 0; z-index: 1; display: flex; flex-wrap: wrap; align-items: center;
        gap: 6px 16px; padding: 10px 16px; background: rgb(14 16 20 / .92); backdrop-filter: blur(6px);
        border-bottom: 1px solid #23262d; }
      #pt-bar strong { color: #f4f1ea; font-weight: 600; }
      #pt-actions { display: flex; gap: 12px; margin-left: auto; }
      #pt-actions a, #pt-actions button { color: #d8a21a; font: inherit; background: none; border: 0; padding: 0; cursor: pointer; }
      #pages { display: grid; justify-items: center; gap: 48px; padding: 32px 16px 72px; }
      .pt-spread { display: flex; }
      .pt-spread figure { margin: 0; width: min(460px, 44vw); }
      .pt-spread canvas { display: block; width: 100%; background: #fff;
        box-shadow: 0 1px 2px rgb(0 0 0 / .5), 0 22px 44px -16px rgb(0 0 0 / .8); }
      .pt-spread figure:first-child canvas { box-shadow: inset -14px 0 14px -14px rgb(0 0 0 / .18), 0 1px 2px rgb(0 0 0 / .5), 0 22px 44px -16px rgb(0 0 0 / .8); }
      .pt-spread figcaption { margin-top: 10px; text-align: center; font: 600 10px/1 system-ui, sans-serif;
        letter-spacing: .18em; text-transform: uppercase; color: #6c7079; }
      .pt-blank { visibility: hidden; }
      @media (max-width: 760px) {
        .pt-spread { flex-direction: column; gap: 32px; }
        .pt-spread figure { width: min(460px, 92vw); }
        .pt-blank { display: none; }
      }
    </style>`);
    document.body.insertAdjacentHTML('afterbegin',
      '<header id="pt-bar"><strong id="pt-title"></strong><span id="pt-status" role="status"></span><span id="pt-actions"></span></header>');
    document.getElementById('pt-title').textContent = document.title || 'Postext';
    addEventListener('error', (event) => kitFail(event.error ?? event.message));
    addEventListener('unhandledrejection', (event) => kitFail(event.reason));
  }
  if (title) document.getElementById('pt-title').textContent = title;
  return document.getElementById('pages')
    ?? document.body.appendChild(Object.assign(document.createElement('main'), { id: 'pages' }));
}

function kitStatus(text) {
  viewer();
  document.getElementById('pt-status').textContent = text;
}

function kitFail(error) {
  document.documentElement.dataset.postext = 'error';
  kitStatus(`Error: ${error?.message ?? error}`);
}

// ─── Kit · pdf v2 ── the same in every recipe that exports a PDF
/** The Fontsource files the screen used, as TrueType: the nearest weight the
 *  family ships, upright if it has no italic; latin, then what the face's
 *  letters need (kitSubsetsFor). */
async function fontsourceProvider(family, weight, style, request) {
  const id = fontsourceId(family);
  const meta = await fontsourceMeta(family);
  const weights = meta?.weights?.length ? meta.weights : [400, 700];
  const w = weights.reduce((a, b) => (Math.abs(b - weight) < Math.abs(a - weight) ? b : a));
  const s = style === 'italic' && meta && !meta.styles.includes('italic') ? 'normal' : style;
  const text = String.fromCodePoint(...(request?.codePoints ?? []));
  const more = kitSubsetsFor(text, meta);
  const files = await Promise.all(['latin', ...more].map(async (subset) => {
    const res = await fetch(`https://cdn.jsdelivr.net/npm/@fontsource/${id}@5/files/${id}-${subset}-${w}-${s}.woff2`);
    if (!res.ok) throw new Error(`Fontsource has no ${family} ${w} ${s} ${subset}`);
    return decompressWoff2(new Uint8Array(await res.arrayBuffer()));
  }));
  return files.length === 1 ? files[0] : files;
}

/** A "Build the PDF" button; then "Open the PDF" (a new tab: CodePen's frame
 *  shows no PDFs) and a download link. */
function offerPdf(makePdf, filename) {
  viewer();
  const button = Object.assign(document.createElement('button'), { type: 'button', textContent: 'Build the PDF' });
  button.dataset.postextPdf = filename;
  button.addEventListener('click', async () => {
    button.disabled = true;
    button.textContent = 'Building the PDF…';
    try {
      const bytes = await makePdf();
      const url = URL.createObjectURL(new Blob([bytes], { type: 'application/pdf' }));
      const size = `${Math.max(1, Math.round(bytes.length / 1024))} KB`;
      button.replaceWith(
        Object.assign(document.createElement('a'), { href: url, target: '_blank', rel: 'noopener', textContent: 'Open the PDF ↗' }),
        Object.assign(document.createElement('a'), { href: url, download: filename, textContent: `Download ${filename} · ${size}` }));
    } catch (error) {
      button.disabled = false;
      button.textContent = 'Build the PDF';
      kitFail(error);
    }
  });
  document.getElementById('pt-actions').append(button);
}

// ─── Kit · images v1 ── recipes with pictures · postext.dev/cookbook
/** Registers a photo or PNG for the canvas and keeps its bytes for the PDF.
 *  fetch → ImageBitmap never taints the canvas (a plain cross-origin <img> would). */
async function loadImage(fileId, url) {
  const res = await fetch(url);
  if (!res.ok) throw new Error(`Image not found (${res.status}): ${url}`);
  const bytes = new Uint8Array(await res.arrayBuffer());
  registerResourceImage(fileId, await createImageBitmap(new Blob([bytes])));
  (loadImage.bytes ??= new Map()).set(fileId, bytes);
}

/** Registers SVG markup (drawn in code, or fetched) as a vector image. */
async function loadSvg(fileId, svg) {
  const img = new Image();
  img.src = `data:image/svg+xml;charset=utf-8,${encodeURIComponent(svg)}`;
  await img.decode();
  registerResourceImage(fileId, img);
  (loadImage.bytes ??= new Map()).set(fileId, new TextEncoder().encode(svg));
}

/** renderToPdf({ resourceBytes: imageBytes }) */
function imageBytes(fileId) { return loadImage.bytes?.get(fileId); }

/** renderToHtml({ resourceImageUrl: imageUrl }) */
function imageUrl(fileId) {
  const bytes = imageBytes(fileId);
  if (!bytes) return undefined;
  imageUrl.urls ??= new Map();
  if (!imageUrl.urls.has(fileId)) {
    const type = /\.svg$/i.test(fileId) ? 'image/svg+xml' : /\.png$/i.test(fileId) ? 'image/png' : 'image/jpeg';
    imageUrl.urls.set(fileId, URL.createObjectURL(new Blob([bytes], { type })));
  }
  return imageUrl.urls.get(fileId);
}

// ─── Kit · cjk v1 ── Chinese, Japanese and Korean books · postext.dev/cookbook
// Fontsource ships a CJK family as about a hundred files per weight, each
// declared in its stylesheet with the unicode-range it covers. The screen
// loads the files the sample touches; the PDF gets the same files for the
// characters its pages set in each face, and embeds each as a subset.
// A book bound on the right (vertical text) is shown with its spreads
// mirrored: page 1 alone on the left of the spine, then [3 | 2].

/** The files of a Fontsource face, read from its stylesheet: { url, range,
 *  ranges }, the last declared first (the order the browser tries them in). */
function cjkSlices(family, weight, style) {
  cjkSlices.cache ??= new Map();
  const id = fontsourceId(family);
  const css = `https://cdn.jsdelivr.net/npm/@fontsource/${id}@5/${weight}${style === 'italic' ? '-italic' : ''}.css`;
  if (!cjkSlices.cache.has(css)) {
    cjkSlices.cache.set(css, fetch(css)
      .then((res) => {
        if (!res.ok) throw new Error(`Fontsource has no ${family} ${weight} ${style} (${res.status})`);
        return res.text();
      })
      .then((text) => [...text.matchAll(/@font-face\s*{([^}]*)}/g)].map(([, rule]) => {
        const range = /unicode-range:\s*([^;]+);/.exec(rule)?.[1].trim() ?? 'U+0-10FFFF';
        const ranges = range.split(',').map((part) => {
          const [lo, hi = lo] = part.trim().slice(2).split('-');
          return [parseInt(lo, 16), parseInt(hi, 16)];
        });
        return { url: new URL(/url\(([^)]+?\.woff2)\)/.exec(rule)[1], css).href, range, ranges };
      }).reverse()));
  }
  return cjkSlices.cache.get(css);
}

/** The file of `slices` that holds code point `cp`, if any. */
function cjkSliceFor(slices, cp) {
  return slices.find((slice) => slice.ranges.some(([lo, hi]) => cp >= lo && cp <= hi));
}

/** Whether Fontsource serves `family` as a Chinese, Japanese or Korean
 *  family (its subsets name the script). Fails when the API does not
 *  answer: a CJK face taken for a Latin one would paint in a system face. */
async function isCjkFamily(family) {
  const meta = await fontsourceMeta(family);
  if (!meta) throw new Error(`api.fontsource.org did not describe ${family}: reload to try again`);
  return !!meta.subsets?.some((subset) => /^(chinese|japanese|korean)/.test(subset));
}

/** faces = { 'Noto Serif TC': ['400', '700'] }, as for loadFonts: the
 *  whole FONTS object may be passed, its other families are left to
 *  loadFonts. Adds one FontFace per file of each CJK face with its
 *  unicodeRange, then loads the files `text` touches. `text` is what the
 *  faces set: the sample for the text face; a book in several voices calls
 *  it once per voice (loadCjkFonts({ 'LXGW WenKai TC': ['400'] }, quotes)),
 *  so the heading and quotation faces fetch and check only their own
 *  characters. Fails when a character of `text` is in no file of a face.
 *  List every weight the pages use: a weight left to buildWithFonts gets
 *  the latin file only. With { vertical: true } it also loads each
 *  family's vertical forms (brackets, quotes, pause marks) for the canvas,
 *  which needs loadVerticalAlternates imported from postext. Resolves to
 *  the number of files loaded. */
async function loadCjkFonts(faces, text, { vertical = false } = {}) {
  kitStatus('Loading fonts…');
  let loaded = 0;
  try {
    if (vertical && typeof loadVerticalAlternates !== 'function') {
      throw new Error('loadCjkFonts(…, { vertical: true }) needs loadVerticalAlternates imported from postext');
    }
    for (const [family, specs] of Object.entries(faces)) {
      if (!(await isCjkFamily(family))) continue;
      const twin = [];
      for (const spec of new Set(specs)) {
        const weight = parseInt(spec, 10);
        const style = spec.endsWith('i') ? 'italic' : 'normal';
        const slices = await cjkSlices(family, weight, style);
        const missing = [...new Set(text)].filter((ch) => /\S/.test(ch) && !cjkSliceFor(slices, ch.codePointAt(0)));
        if (missing.length) {
          throw new Error(`${family} ${spec} has no file for ${missing.slice(0, 12).join(' ')}: `
            + `give each face the text it sets (loadCjkFonts({ '${family}': ['${spec}'] }, text))`);
        }
        for (const slice of slices) {
          document.fonts.add(new FontFace(family, `url(${slice.url}) format('woff2')`,
            { weight: String(weight), style, unicodeRange: slice.range }));
          twin.push({ source: slice.url, weight: String(weight), style, unicodeRange: slice.range });
        }
        const font = `${style === 'italic' ? 'italic ' : ''}${weight} 16px "${family}"`;
        loaded += (await document.fonts.load(font, text)).length;
        if (!document.fonts.check(font, text)) throw new Error(`${family} ${spec} did not load for the sample`);
      }
      // The same files under a twin name with the `vert` feature on: the
      // canvas paints the punctuation of vertical lines with it.
      if (vertical && twin.length) await loadVerticalAlternates(family, twin);
    }
  } catch (error) {
    kitFail(error);
    throw error;
  }
  return loaded;
}

/** The PDF font provider for recipes with CJK faces: a family whose
 *  Fontsource subsets are Chinese, Japanese or Korean gets the files that
 *  hold the characters its pages set (`request.codePoints`); any other
 *  family gets the latin file fontsourceProvider fetches (the "pdf" block)
 *  and, when the face sets letters only latin-ext has, that file too. */
async function cjkPdfProvider(family, weight, style, request) {
  if (!(await isCjkFamily(family))) return cjkLatinPdfFiles(family, weight, style, request);
  const meta = await fontsourceMeta(family);
  const weights = meta.weights?.length ? meta.weights : [400, 700];
  const w = weights.reduce((a, b) => (Math.abs(b - weight) < Math.abs(a - weight) ? b : a));
  const s = style === 'italic' && !meta.styles.includes('italic') ? 'normal' : style;
  const slices = await cjkSlices(family, w, s);
  const picked = new Set();
  for (const cp of request?.codePoints ?? []) {
    const slice = cjkSliceFor(slices, cp);
    if (slice) picked.add(slice);
  }
  if (!picked.size) picked.add(slices[0]);
  return Promise.all(slices.filter((slice) => picked.has(slice)).map(async (slice) => {
    const res = await fetch(slice.url);
    if (!res.ok) throw new Error(`Fontsource file ${slice.url} (${res.status})`);
    return decompressWoff2(new Uint8Array(await res.arrayBuffer()));
  }));
}

/** A Latin family set next to the CJK faces: its latin file, then its
 *  latin-ext file when the face sets letters only latin-ext has (ō ū in
 *  Hepburn rōmaji, ǎ in pinyin), the file loadFonts adds on screen for
 *  them. Latin comes first: postext-pdf draws a character from the first
 *  file that has it, as the browser takes a character both files hold from
 *  latin. A face Fontsource ships without latin-ext, or whose file does
 *  not come, gets latin alone, and the PDF names the letters it lacks. */
async function cjkLatinPdfFiles(family, weight, style, request) {
  const meta = await fontsourceMeta(family);
  const beyond = [...(request?.codePoints ?? [])].some(cjkLatinExtOnly);
  if (!beyond || !meta?.subsets?.includes('latin-ext')) return fontsourceProvider(family, weight, style);
  const weights = meta.weights?.length ? meta.weights : [400, 700];
  const w = weights.reduce((a, b) => (Math.abs(b - weight) < Math.abs(a - weight) ? b : a));
  const s = style === 'italic' && !meta.styles.includes('italic') ? 'normal' : style;
  const id = fontsourceId(family);
  const url = `https://cdn.jsdelivr.net/npm/@fontsource/${id}@5/files/${id}-latin-ext-${w}-${s}.woff2`;
  const [latin, ext] = await Promise.all([fontsourceProvider(family, weight, style), fetch(url)
    .then(async (res) => (res.ok ? decompressWoff2(new Uint8Array(await res.arrayBuffer())) : null), () => null)]);
  return ext ? [latin, ext] : latin;
}

/** Whether code point `cp` is in Fontsource's latin-ext file and not in
 *  its latin file: Latin Extended-A and -B, IPA, the spacing modifiers and
 *  Latin Extended Additional (loadFonts's test for latin-ext), less the
 *  few latin holds too (ı Œ œ ʻ ʼ ˆ ˚ ˜). */
function cjkLatinExtOnly(cp) {
  if (!((cp >= 0x100 && cp <= 0x2ff) || (cp >= 0x1e00 && cp <= 0x1eff))) return false;
  return ![0x131, 0x152, 0x153, 0x2bb, 0x2bc, 0x2c6, 0x2da, 0x2dc].includes(cp);
}

/** showPages for a book bound on either edge. A right-bound book (the
 *  document says so: doc.binding is 'right' for page.binding 'right' and
 *  for vertical text) lies on the desk as it opens: page 1 alone on the
 *  left of the spine, then [3 | 2], the spine shade on each page's inner
 *  edge. `binding` ('left' | 'right') overrides the document's. */
function showBook(docs, { binding, ...options } = {}) {
  const count = showPages(docs, options);
  const right = (binding ?? [docs].flat()[0]?.binding) === 'right';
  if (!document.getElementById('pt-kit-cjk')) {
    // The pages keep direction ltr: a canvas draws text in the direction its
    // element inherits, and under rtl each run would end where the engine
    // starts it, its brackets mirrored.
    document.head.insertAdjacentHTML('beforeend', `<style id="pt-kit-cjk">
      .pt-spread[dir="rtl"] canvas { direction: ltr; }
      .pt-spread[dir="rtl"] figure:first-child canvas { box-shadow: inset 14px 0 14px -14px rgb(0 0 0 / .18),
        0 1px 2px rgb(0 0 0 / .5), 0 22px 44px -16px rgb(0 0 0 / .8); }
    </style>`);
  }
  // Each pair stays [verso, recto] in the page; right to left, the verso
  // sits on the right. Phones stack the pages in reading order either way.
  for (const spread of document.querySelectorAll('#pages > .pt-spread')) spread.dir = right ? 'rtl' : 'ltr';
  document.getElementById('pages').dataset.binding = right ? 'right' : 'left';
  return count;
}

// ─── Kit · arabic v1 ── Arabic-script faces · postext.dev/cookbook
// Fontsource ships an Arabic family as one file per subset and weight: the
// `arabic` file holds the letters, the harakat, the Arabic-Indic digits, the
// Arabic punctuation and the presentation forms; `latin` and `latin-ext`
// hold the rest. loadFonts loads the latin files; this block adds the arabic
// file of every Arabic family, for the canvas and for the PDF, which shapes
// the letters with HarfBuzz from the same bytes.

/** The code points of Fontsource's `arabic` subset, as its stylesheets
 *  declare them (the same unicode-range the browser picks the file by). A
 *  function, not a const: the kit is inlined after the recipe's top-level
 *  awaits, and a const read before its line throws, where a function
 *  declaration is hoisted. */
function arabicRange() {
  return 'U+0600-06FF,U+0750-077F,U+0870-088E,U+0890-0891,U+0897-08E1,U+08E3-08FF,'
    + 'U+200C-200E,U+2010-2011,U+204F,U+2E41,U+FB50-FDFF,U+FE70-FE74,U+FE76-FEFC,U+102E0-102FB,'
    + 'U+10E60-10E7E,U+10EC2-10EC4,U+10EFC-10EFF,U+1EE00-1EEFF';
}

/** Whether code point `cp` is in the arabic file. */
function inArabicRange(cp) {
  inArabicRange.ranges ??= arabicRange().split(',').map((part) => {
    const [lo, hi = lo] = part.slice(2).split('-');
    return [parseInt(lo, 16), parseInt(hi, 16)];
  });
  return inArabicRange.ranges.some(([lo, hi]) => cp >= lo && cp <= hi);
}

/** Whether Fontsource serves `family` with an `arabic` subset. Fails when
 *  the API does not answer: an Arabic face taken for a Latin one would set
 *  its letters in a system face. */
async function isArabicFamily(family) {
  const meta = await fontsourceMeta(family);
  if (!meta) throw new Error(`api.fontsource.org did not describe ${family}: reload to try again`);
  return !!meta.subsets?.includes('arabic');
}

/** The arabic file of a face. */
function arabicFileUrl(family, weight, style) {
  const id = fontsourceId(family);
  return `https://cdn.jsdelivr.net/npm/@fontsource/${id}@5/files/${id}-arabic-${weight}-${style}.woff2`;
}

/** faces = { Amiri: ['400', '700'] }, as for loadFonts, after it: the whole
 *  FONTS object may be passed, its families without an arabic subset are
 *  left alone. Adds the arabic file of every listed weight of each Arabic
 *  family (the latin files come from loadFonts) and loads it. `text` is
 *  the sample: fails when it holds an Arabic-script character the arabic
 *  file does not cover. List every weight the pages set in Arabic: a weight
 *  left to buildWithFonts gets the latin file only, and its Arabic letters
 *  fall back to a system face. Resolves to the number of files loaded. */
async function loadArabicFonts(faces, text = '') {
  kitStatus('Loading fonts…');
  let loaded = 0;
  try {
    const outside = [...new Set(text)].filter((ch) => /\p{Script=Arabic}/u.test(ch) && !inArabicRange(ch.codePointAt(0)));
    if (outside.length) throw new Error(`Fontsource's arabic files have no ${outside.slice(0, 12).join(' ')}`);
    for (const [family, specs] of Object.entries(faces)) {
      if (!(await isArabicFamily(family))) continue;
      for (const spec of new Set(specs)) {
        const weight = parseInt(spec, 10);
        const style = spec.endsWith('i') ? 'italic' : 'normal';
        const face = new FontFace(family, `url(${arabicFileUrl(family, weight, style)}) format('woff2')`,
          { weight: String(weight), style, unicodeRange: arabicRange() });
        document.fonts.add(await face.load().catch(() => {
          throw new Error(`Fontsource has no arabic file for ${family} ${weight} ${style}`);
        }));
        loaded++;
      }
    }
  } catch (error) {
    kitFail(error);
    throw error;
  }
  return loaded;
}

/** The PDF font provider for recipes with Arabic faces: a family with an
 *  arabic subset gets its arabic file when its pages set Arabic letters
 *  (`request.codePoints`), then its latin file, and its latin-ext file for
 *  the letters beyond latin (transliteration: ā ḥ ʿ). The arabic file comes
 *  first: it also holds the space and the brackets, so a line of Arabic is
 *  shaped as one run and not cut at every space. Any other family goes to
 *  fontsourceProvider (the "pdf" block). */
async function arabicPdfProvider(family, weight, style, request) {
  if (!(await isArabicFamily(family))) return fontsourceProvider(family, weight, style, request);
  const meta = await fontsourceMeta(family);
  const weights = meta.weights?.length ? meta.weights : [400, 700];
  const w = weights.reduce((a, b) => (Math.abs(b - weight) < Math.abs(a - weight) ? b : a));
  const s = style === 'italic' && !meta.styles.includes('italic') ? 'normal' : style;
  const wanted = [...(request?.codePoints ?? [])];
  const id = fontsourceId(family);
  const urls = [];
  if (!wanted.length || wanted.some(inArabicRange)) urls.push(arabicFileUrl(family, w, s));
  urls.push(`https://cdn.jsdelivr.net/npm/@fontsource/${id}@5/files/${id}-latin-${w}-${s}.woff2`);
  if (meta.subsets.includes('latin-ext') && wanted.some((cp) => /[Ā-˿Ḁ-ỿ]/u.test(String.fromCodePoint(cp)))) {
    urls.push(`https://cdn.jsdelivr.net/npm/@fontsource/${id}@5/files/${id}-latin-ext-${w}-${s}.woff2`);
  }
  return Promise.all(urls.map(async (url) => {
    const res = await fetch(url);
    if (!res.ok) throw new Error(`Fontsource file ${url} (${res.status})`);
    return decompressWoff2(new Uint8Array(await res.arrayBuffer()));
  }));
}

// ─── Kit · comics v1 ── comic pages · postext.dev/cookbook
// The engine letters a comic in a face per language (defaultComicFont:
// Comic Neue, Zen Antique for Japanese, Noto Sans SC, LXGW WenKai TC,
// Playpen Sans Arabic; defaultComicSfxFont: Bangers, Dela Gothic One,
// ZCOOL KuaiLe, Lalezar) and asks for the bold of a shout or a sound effect
// and the italic of an inner voice. Most of these faces ship one weight and
// no italic: this block declares the file Fontsource does ship for those
// variants, so the canvas measures and paints the letters the PDF embeds
// (the providers snap to the shipped file) and not a bold or a slant the
// browser makes up. It also turns the art manifest into panel resources.

/** faces = { 'Comic Neue': ['400', '700'], Bangers: ['400'] }, as for
 *  loadFonts, after it (and after loadCjkFonts or loadArabicFonts for the
 *  faces of those scripts); the whole FONTS object may be passed. List in
 *  FONTS only what Fontsource ships (Bangers: ['400']): loadFonts fails on
 *  the rest. For each family, the regular, bold, italic and bold italic it
 *  lacks are declared with its nearest file (the regular for the bold, the
 *  upright for the italic) and loaded for `text`. A CJK face needs the cjk
 *  block; an Arabic face setting Arabic, the arabic block. Resolves to the
 *  number of variants added. */
async function loadComicFonts(faces, text = '') {
  kitStatus('Loading fonts…');
  let added = 0;
  try {
    for (const family of Object.keys(faces)) {
      const meta = await fontsourceMeta(family);
      if (!meta) throw new Error(`api.fontsource.org did not describe ${family}: reload to try again`);
      const weights = meta.weights?.length ? meta.weights : [400, 700];
      const styles = meta.styles?.length ? meta.styles : ['normal'];
      for (const [weight, style] of [[400, 'normal'], [700, 'normal'], [400, 'italic'], [700, 'italic']]) {
        if ((weights.includes(weight) && styles.includes(style)) || hasFace(family, weight, style)) continue;
        const w = weights.reduce((a, b) => (Math.abs(b - weight) < Math.abs(a - weight) ? b : a));
        const s = style === 'italic' && styles.includes('italic') ? 'italic' : 'normal';
        for (const { url, range } of await comicFaceFiles(family, w, s, meta, text)) {
          document.fonts.add(new FontFace(family, `url(${url}) format('woff2')`,
            { weight: String(weight), style, unicodeRange: range }));
        }
        await document.fonts.load(`${style === 'italic' ? 'italic ' : ''}${weight} 16px "${family}"`, text || 'A');
        added++;
      }
    }
  } catch (error) {
    kitFail(error);
    throw error;
  }
  return added;
}

/** The files of a shipped face ({ url, range }): a CJK face's slices (the
 *  cjk block reads them from its stylesheet), else latin, the latin-ext
 *  and greek files `text` needs, and the arabic file when `text` holds
 *  Arabic. */
async function comicFaceFiles(family, weight, style, meta, text) {
  if (meta.subsets?.some((subset) => /^(chinese|japanese|korean)/.test(subset))) {
    if (typeof cjkSlices !== 'function') throw new Error(`${family} is a CJK face: list the cjk kit block`);
    return (await cjkSlices(family, weight, style)).map(({ url, range }) => ({ url, range }));
  }
  const id = fontsourceId(family);
  const file = (subset) => `https://cdn.jsdelivr.net/npm/@fontsource/${id}@5/files/${id}-${subset}-${weight}-${style}.woff2`;
  const files = ['latin', ...kitSubsetsFor(text, meta)].map((subset) => ({ url: file(subset), range: comicRange(subset) }));
  if (meta.subsets?.includes('arabic') && /\p{Script=Arabic}/u.test(text)) {
    if (typeof arabicRange !== 'function') throw new Error(`${family} sets Arabic: list the arabic kit block`);
    files.unshift({ url: file('arabic'), range: arabicRange() });
  }
  return files;
}

/** The unicode-range loadFonts gives a Fontsource file. A function, not a
 *  const: the kit is inlined after the recipe's top-level awaits. */
function comicRange(subset) {
  return {
    latin: 'U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,'
      + 'U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD',
    'latin-ext': 'U+0100-02BA,U+02BD-02C5,U+02C7-02CC,U+02CE-02D7,U+02DD-02FF,U+0304,U+0308,U+0329,'
      + 'U+1D00-1DBF,U+1E00-1E9F,U+1EF2-1EFF,U+2020,U+20A0-20AB,U+20AD-20C0,U+2113,U+2C60-2C7F,U+A720-A7FF',
    greek: 'U+0370-03FF',
  }[subset];
}

/** The PDF font provider of a comic in any script: a CJK face goes to
 *  cjkPdfProvider, an Arabic face to arabicPdfProvider, any other to
 *  fontsourceProvider (the "pdf" block). Each embeds the shipped weight
 *  and style nearest to the one asked for, the file loadComicFonts
 *  declared for the canvas. */
async function comicPdfProvider(family, weight, style, request) {
  const subsets = (await fontsourceMeta(family))?.subsets ?? [];
  if (subsets.some((subset) => /^(chinese|japanese|korean)/.test(subset))) {
    if (typeof cjkPdfProvider !== 'function') throw new Error(`${family} is a CJK face: list the cjk kit block`);
    return cjkPdfProvider(family, weight, style, request);
  }
  if (subsets.includes('arabic') && typeof arabicPdfProvider === 'function') {
    return arabicPdfProvider(family, weight, style, request);
  }
  return fontsourceProvider(family, weight, style, request);
}

/** A panel picture as a resource for art= (and pop=): loads `url`
 *  (write asset('lh-arrive.jpg') in the call, so the lint checks the file)
 *  and declares it with `meta`, its entry in the art manifest:
 *  { width, height, alt, safeArea, anchors, avoid }. The safe area is what
 *  every crop keeps, the anchors the speakers' mouths, heads and faces,
 *  the avoid zones what no balloon covers; all in fractions of the picture,
 *  the same in every language. Without width and height, the picture's own
 *  size. Needs the images block. Resolves to the resource. */
async function comicPanel(id, url, meta = {}) {
  const fileId = decodeURIComponent(url.split('/').pop());
  await loadImage(fileId, url);
  let { width, height } = meta;
  if (!width || !height) {
    const bitmap = await createImageBitmap(new Blob([imageBytes(fileId)]));
    ({ width, height } = bitmap);
    bitmap.close();
  }
  return {
    id, typeId: meta.typeId ?? 'figure', kind: 'bitmap', createdAt: 0, updatedAt: 0,
    bitmap: { fileId, format: /\.png$/i.test(fileId) ? 'png' : 'jpeg', width, height },
    ...(meta.alt && { altText: meta.alt }),
    ...(meta.safeArea && { safeArea: meta.safeArea }),
    ...(meta.anchors?.length && { anchors: meta.anchors }),
    ...(meta.avoid?.length && { avoid: meta.avoid }),
  };
}

// ─── /Kit ───────────────────────────────────────────────────────────────────────

组合好的script.js可以直接运行：把它粘贴到任何页面的模块脚本中，或在CodePen上打开这道食谱。 GitHub上的食谱文件夹 ↗ (在新标签页中打开)

常见问题

易错点

日文文本标记为'ja'，不要用zh-Hans或LANG

食谱的版本是en和es，但日文示例在两个版本里都是日文：`locale: LANG`会把它标记为英文或西班牙文，中文标记则会按中文规则排它（开明式标点、小假名可以出现在行首、图代替図、PDF中用中文字形）。写'ja'：它选用日本地区（JLReq断行和标点、芝麻着重号、振假名的分布、図和表标签），并关闭断词。lint会让带假名却标记为zh或ko的文本失败。日文禁则处理 →

易错点

中文字体通过cjk块分片加载

Fontsource把一个中文、日文或韩文字体家族按每个字重约一百个文件提供，每个文件覆盖一段字符范围。loadFonts只获取latin文件，所以屏幕上的汉字来自系统字体，测量不准；fontsourceProvider交给PDF的也是这个latin文件，汉字印出来是空框。列出kit中的cjk块，在loadFonts之后调用loadCjkFonts(FONTS, markdown)（书中用到几种CJK字体时，每种字体调用一次，并传入它所排的文字），并给renderToPdf传fontProvider: cjkPdfProvider：两者都会取用包含文中字符的那些文件。中日韩字体 →

易错点

配置按对象身份缓存：每次新建一个对象

引擎按对象身份缓存解析后的配置，所以就地修改配置再构建，会复用旧的结果。每次构建都新建一个对象，这也是食谱的配置写成工厂函数config()的原因。在Canvas上绘制页面 →

易错点

排版前加载所有字体

排版用浏览器已加载的字体测量文字，并缓存宽度，所以首次构建之后才到的字体会造成断行错误，PDF也不再与屏幕一致。先加载所有字重和样式；有字体迟到时，重新构建前调用clearMeasurementCache()。排版前加载字体 →

在小格子里，竖排对话框先不够高，然后才不够宽：引擎会把它排成更多、更短的竖行，并在词与词之间断开。上班族最后那声喊叫在日文版里对下面那格来说还是太高，所以给它加上break（kyaku{shout break}）：它向上冲进上面那一格，而不是盖住猫，也不会冲进页边。
大号拟声字也像对话框一样要避开脸，它的固定点放在这一格的安全区里，怎么裁都留得住：咚放在70% 80%，猫爪上。日文版的ずしっ竖排，个子更高，放在那里会盖住三花猫的脸，构建时警告comicBalloonOverflow，所以那里改放在她旁边的86% 84%。

致谢

食谱: Ignacio Ferro
文本: ねこ喫茶まどろみ (Café Doze), two yonkoma strips written for this recipe, with their English, Spanish, Catalan, Chinese and Arabic letterings · Postext Cookbook · CC BY 4.0
图片: Mugi unlocking the cat café's door, three cats waiting inside · Generated With Diffusion Models · 原创
Mugi setting out food bowls for the cats · Generated With Diffusion Models · 原创
Three cats eating from one bowl · Generated With Diffusion Models · 原创
The cats staring at Mugi's toast · Generated With Diffusion Models · 原创
A tired office worker arriving at the café · Generated With Diffusion Models · 原创
The three cats asleep on one cushion · Generated With Diffusion Models · 原创
The office worker opening his laptop · Generated With Diffusion Models · 原创
The cats sitting on the keyboard, the worker in happy tears · Generated With Diffusion Models · 原创
字体: Zen Antique (SIL OFL 1.1) · Dela Gothic One (SIL OFL 1.1) · Comic Neue (SIL OFL 1.1) · Bangers (SIL OFL 1.1) · Noto Sans SC (SIL OFL 1.1) · ZCOOL KuaiLe (SIL OFL 1.1) · Playpen Sans Arabic (SIL OFL 1.1) · Lalezar (SIL OFL 1.1)
代码: MIT，与Postext相同

编辑这篇说明 ↗ (在新标签页中打开)GitHub上的食谱文件夹 ↗ (在新标签页中打开)

简单来说

#成品一览

#简短回答

#用料

#做法

#1 · 把页面分成两列，每列四格

#2 · 每篇的标题放在第一格

#3 · 猫也标成说话人

#4 · 用各版本自己的文字载入字体

#5 · 把原版放在每个版本旁边

#完整食谱

#常见问题

#致谢

排版食谱中的更多内容

从右往左读、竖排嵌字的漫画

按词组空格的平假名图画书

用六种语言嵌字的一页漫画

成品一览

简短回答

用料

做法

完整食谱

常见问题

致谢