51 lines
1.5 KiB
JavaScript
51 lines
1.5 KiB
JavaScript
// 生成 icons/app.png（256x256 纯蓝方块图标）
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const zlib = require("zlib");
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const fs = require("fs");
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const path = require("path");
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const W = 256, H = 256;
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const row = Buffer.alloc(1 + W * 4);
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row[0] = 0;
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for (let x = 0; x < W; x++) {
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row[1 + x * 4] = 0;
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row[2 + x * 4] = 110;
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row[3 + x * 4] = 255;
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row[4 + x * 4] = 255;
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}
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const raw = Buffer.concat(Array(H).fill(row));
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const crcTable = [];
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for (let n = 0; n < 256; n++) {
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let 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 >>> 0;
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}
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function crc32(buf) {
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let c = 0xffffffff;
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for (const b of buf) c = crcTable[(c ^ b) & 0xff] ^ (c >>> 8);
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return (c ^ 0xffffffff) >>> 0;
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}
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function chunk(type, data) {
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const len = Buffer.alloc(4);
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len.writeUInt32BE(data.length);
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const t = Buffer.from(type, "ascii");
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const crc = Buffer.alloc(4);
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crc.writeUInt32BE(crc32(Buffer.concat([t, data])));
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return Buffer.concat([len, t, data, crc]);
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}
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const ihdr = Buffer.alloc(13);
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ihdr.writeUInt32BE(W, 0);
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ihdr.writeUInt32BE(H, 4);
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ihdr[8] = 8; // bit depth
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ihdr[9] = 6; // color type RGBA
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const png = Buffer.concat([
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Buffer.from([0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a]),
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chunk("IHDR", ihdr),
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chunk("IDAT", zlib.deflateSync(raw)),
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chunk("IEND", Buffer.alloc(0)),
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]);
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fs.mkdirSync(path.join(__dirname, "icons"), { recursive: true });
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fs.writeFileSync(path.join(__dirname, "icons", "app.png"), png);
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console.log("icon generated:", png.length, "bytes");
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