107 lines
3.3 KiB
JavaScript
107 lines
3.3 KiB
JavaScript
// Generiert icon-192.png und icon-512.png ohne externe Abhängigkeiten
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// Wird automatisch vor dem Build ausgeführt (prebuild script)
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import { createWriteStream } from 'fs';
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import { mkdir } from 'fs/promises';
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await mkdir('./public', { recursive: true });
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function createPNG(size) {
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// Minimales PNG: dunkel (#0d0d0f) mit DD in teal (#4ecdc4)
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// Wir nutzen den Canvas aus dem Vite/Node Kontext nicht –
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// stattdessen schreiben wir ein gültiges einfarbiges PNG per Hand
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const width = size, height = size;
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function crc32(buf) {
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let c, crcTable = [];
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for (let n = 0; n < 256; n++) {
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c = n;
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for (let k = 0; k < 8; k++) c = (c & 1) ? 0xedb88320 ^ (c >>> 1) : c >>> 1;
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crcTable[n] = c;
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}
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let crc = 0xffffffff;
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for (let i = 0; i < buf.length; i++) crc = crcTable[(crc ^ buf[i]) & 0xff] ^ (crc >>> 8);
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return (crc ^ 0xffffffff) >>> 0;
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}
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function chunk(type, data) {
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const t = Buffer.from(type);
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const len = Buffer.alloc(4); len.writeUInt32BE(data.length);
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const crcBuf = Buffer.concat([t, data]);
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const crc = Buffer.alloc(4); crc.writeUInt32BE(crc32(crcBuf));
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return Buffer.concat([len, t, data, crc]);
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}
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// IHDR
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const ihdr = Buffer.alloc(13);
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ihdr.writeUInt32BE(width, 0); ihdr.writeUInt32BE(height, 4);
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ihdr[8] = 8; ihdr[9] = 2; ihdr[10] = 0; ihdr[11] = 0; ihdr[12] = 0;
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// Pixel data: dark background with a teal circle
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const rows = [];
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const cx = width / 2, cy = height / 2, r = width * 0.35;
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const r2 = width * 0.28;
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for (let y = 0; y < height; y++) {
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const row = [0]; // filter byte
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for (let x = 0; x < width; x++) {
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const dx = x - cx, dy = y - cy;
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const dist = Math.sqrt(dx*dx + dy*dy);
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if (dist < r2) {
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// teal inner circle
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row.push(0x4e, 0xcd, 0xc4);
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} else if (dist < r) {
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// slightly lighter ring
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row.push(0x1a, 0x8a, 0x84);
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} else {
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// dark background
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row.push(0x0d, 0x0d, 0x0f);
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}
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}
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rows.push(Buffer.from(row));
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}
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// zlib compress (deflate) – minimal uncompressed blocks
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const raw = Buffer.concat(rows);
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// Split into 65535-byte chunks for uncompressed deflate
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const chunks = [];
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const CHUNK = 65535;
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for (let i = 0; i < raw.length; i += CHUNK) {
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const slice = raw.slice(i, i + CHUNK);
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const last = i + CHUNK >= raw.length ? 1 : 0;
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const hdr = Buffer.alloc(5);
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hdr[0] = last; hdr.writeUInt16LE(slice.length, 1); hdr.writeUInt16LE(~slice.length & 0xffff, 3);
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chunks.push(hdr, slice);
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}
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const deflated = Buffer.concat(chunks);
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// Adler32
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let s1 = 1, s2 = 0;
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for (const b of raw) { s1 = (s1 + b) % 65521; s2 = (s2 + s1) % 65521; }
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const adler = Buffer.alloc(4); adler.writeUInt32BE((s2 << 16) | s1);
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const zlib = Buffer.concat([
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Buffer.from([0x78, 0x01]), // zlib header (no compression)
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deflated,
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adler
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]);
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const png = Buffer.concat([
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Buffer.from([137, 80, 78, 71, 13, 10, 26, 10]), // PNG signature
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chunk('IHDR', ihdr),
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chunk('IDAT', zlib),
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chunk('IEND', Buffer.alloc(0))
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]);
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return png;
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}
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const png192 = createPNG(192);
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const png512 = createPNG(512);
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const ws192 = createWriteStream('./public/icon-192.png');
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ws192.write(png192); ws192.end();
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const ws512 = createWriteStream('./public/icon-512.png');
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ws512.write(png512); ws512.end();
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console.log('✅ Icons generiert: icon-192.png, icon-512.png');
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