98 lines
3.3 KiB
JavaScript
98 lines
3.3 KiB
JavaScript
// Pure JS PNG Generator for QR codes
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// Write a minimal valid PNG with no external dependencies
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const fs = require('fs');
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const zlib = require('zlib');
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function crc32(buf) {
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let crc = 0xFFFFFFFF;
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const table = new Uint32Array(256);
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for (let i = 0; i < 256; i++) {
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let c = i;
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for (let k = 0; k < 8; k++) c = (c & 1) ? 0xEDB88320 ^ (c >>> 1) : c >>> 1;
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table[i] = c;
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}
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for (let i = 0; i < buf.length; i++) crc = table[(crc ^ buf[i]) & 0xFF] ^ (crc >>> 8);
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return (crc ^ 0xFFFFFFFF) >>> 0;
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}
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function makeChunk(type, data) {
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const typeB = Buffer.from(type);
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const lenB = Buffer.alloc(4);
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lenB.writeUInt32BE(data.length);
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const crcB = Buffer.alloc(4);
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crcB.writeUInt32BE(crc32(Buffer.concat([typeB, data])));
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return Buffer.concat([lenB, typeB, data, crcB]);
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}
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function createPNG(matrix) {
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const size = matrix.length;
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const scale = 10;
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const outSize = size * scale;
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// Raw image data: filter byte (0) + RGB pixels per row
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const raw = Buffer.alloc((1 + size * 3) * outSize);
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for (let y = 0; y < outSize; y++) {
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const rowOffset = y * (1 + outSize * 3);
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raw[rowOffset] = 0; // filter type: none
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const moduleY = Math.floor(y / scale);
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for (let x = 0; x < outSize; x++) {
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const moduleX = Math.floor(x / scale);
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const pixel = matrix[moduleY][moduleX] ? 0 : 255;
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const offset = rowOffset + 1 + x * 3;
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raw[offset] = pixel; // R
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raw[offset + 1] = pixel; // G
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raw[offset + 2] = pixel; // B
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}
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}
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const compressed = zlib.deflateSync(raw);
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// PNG signature
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const signature = Buffer.from([0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A]);
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// IHDR chunk
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const ihdr = Buffer.alloc(13);
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ihdr.writeUInt32BE(outSize, 0); // width
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ihdr.writeUInt32BE(outSize, 4); // height
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ihdr[8] = 8; // bit depth
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ihdr[9] = 2; // color type (RGB)
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ihdr[10] = 0; // compression
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ihdr[11] = 0; // filter
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ihdr[12] = 0; // interlace
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const ihdrChunk = makeChunk('IHDR', ihdr);
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const idatChunk = makeChunk('IDAT', compressed);
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const iendChunk = makeChunk('IEND', Buffer.alloc(0));
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return Buffer.concat([signature, ihdrChunk, idatChunk, iendChunk]);
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}
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// Matrix from our QR generator (21x21 for "TEST")
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const matrix = [
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[1,1,1,1,1,1,1,0,1,1,1,0,1,1,1,0,1,1,1,1,1],
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[1,0,0,0,0,0,1,0,1,0,1,0,1,0,1,0,0,0,0,0,1],
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[1,0,1,1,1,0,1,0,1,1,0,1,0,1,0,1,1,1,0,0,1],
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[1,0,1,1,1,0,1,0,0,1,1,0,1,0,1,0,1,1,1,0,1],
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[1,0,1,1,1,0,1,0,1,0,1,0,0,1,0,1,1,1,0,0,1],
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[1,0,0,0,0,0,1,0,1,1,0,1,1,1,1,1,0,0,0,0,1],
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[1,1,1,1,1,1,1,0,0,0,0,0,1,0,1,1,1,1,1,1,1],
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[0,0,0,0,0,0,0,0,1,0,1,0,1,0,0,0,0,0,0,0,0],
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[1,0,1,0,1,0,1,0,0,0,1,1,0,1,0,1,0,1,1,0,1],
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[0,1,0,1,0,1,0,1,1,0,0,1,0,1,0,1,1,0,0,1,0],
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[0,0,1,0,0,1,0,1,0,1,0,1,0,1,0,0,1,0,0,0,0],
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[1,1,0,1,0,0,1,0,1,0,1,0,1,0,1,1,0,1,1,1,1],
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[0,0,0,1,1,1,0,1,0,1,0,1,0,1,1,0,1,1,0,0,0],
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[1,1,1,0,0,0,1,0,0,0,1,0,0,1,0,1,1,0,1,1,0],
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[1,0,1,1,1,0,1,0,1,1,0,1,0,1,0,0,0,0,0,1,0],
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[1,0,0,0,0,0,1,0,0,1,1,0,1,0,1,1,1,0,1,0,1],
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[1,1,1,1,1,1,1,0,1,0,1,0,1,1,0,1,0,1,0,0,1],
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[0,0,0,0,0,0,0,0,1,0,1,1,0,1,0,1,1,0,1,1,0],
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[1,1,1,1,1,1,1,0,0,1,0,1,0,0,0,1,1,0,0,0,0],
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[1,0,0,0,0,0,1,0,1,0,1,0,1,0,1,1,0,1,1,1,1],
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[1,1,1,1,1,1,1,0,1,0,1,1,0,0,1,0,0,0,0,0,0],
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];
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const png = createPNG(matrix);
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fs.writeFileSync('/home/node/.openclaw/workspace/assets/qr-test.png', png);
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console.log('PNG written:', png.length, 'bytes');
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