feat: Initial prototype

renderer.js

@@ -0,0 +1,56 @@
+import figlet from './vendor/figlet.js';
+import {fonts} from './font-catalog.js';
+import {render as renderBitmap} from './bitmap.js';
+
+export const styles = [...fonts, 'compact'];
+export const FONT_CACHE = `ascii-pwa-fonts-${encodeURIComponent(new URL('./', import.meta.url).href)}-figlet-1.8.2`;
+const pendingFonts = new Map();
+
+// Keep existing lowercase font links working with the library's font names.
+export function resolveFont(name) {
+    if (name === 'compact') return name;
+    return fonts.find(font => font.toLowerCase() === String(name).toLowerCase()) || 'Standard';
+}
+
+export function registerFont(name, data) {
+    if (!fonts.includes(name)) throw new Error('Unknown lettering style');
+    figlet.parseFont(name, data);
+}
+
+export function renderLoaded(text, font = 'Standard') {
+    if (text.length > 500) throw new Error('Text is too long');
+    if (font === 'compact') return renderBitmap(text, font);
+    if (!fonts.includes(font)) throw new Error('Unknown lettering style');
+    return figlet.textSync(text, {
+        font, width: 80, whitespaceBreak: true,
+    }).split('\n').filter(line => line.trim()).join('\n');
+}
+
+export async function render(text, font = 'Standard') {
+    if (text.length > 500) throw new Error('Text is too long');
+    if (font === 'compact') return renderBitmap(text, font);
+    if (!fonts.includes(font)) throw new Error('Unknown lettering style');
+    if (!figlet.figFonts[font]) {
+        if (!pendingFonts.has(font)) {
+            pendingFonts.set(font, (async () => {
+                const url = new URL(`./fonts/figlet/${font}.flf`, import.meta.url).href;
+                let cache;
+                let cached;
+                try {
+                    if ('caches' in globalThis) {
+                        cache = await caches.open(FONT_CACHE);
+                        cached = await cache.match(url);
+                    }
+                } catch { /* Rendering still works if browser storage is unavailable. */ }
+                const response = cached || await fetch(url);
+                if (!response.ok) throw new Error('Cannot load font');
+                registerFont(font, await response.clone().text());
+                if (cache && !cached) {
+                    try { await cache.put(url, response); } catch { /* Storage may be full. */ }
+                }
+            })().finally(() => pendingFonts.delete(font)));
+        }
+        await pendingFonts.get(font);
+    }
+    return renderLoaded(text, font);
+}