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import { crc32 } from 'crc';
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/**
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 * Encodes PNG chunks into a PNG file format buffer.
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 * @param {Array<{ name: string; data: Uint8Array }>} chunks Array of PNG chunks
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 * @returns {Uint8Array} Encoded PNG data
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 * @copyright Based on https://github.com/hughsk/png-chunks-encode (MIT)
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 */
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export default function encode(chunks) {
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    const uint8 = new Uint8Array(4);
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    const int32 = new Int32Array(uint8.buffer);
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    const uint32 = new Uint32Array(uint8.buffer);
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    let totalSize = 8;
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    let idx = totalSize;
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    for (let i = 0; i < chunks.length; i++) {
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        totalSize += chunks[i].data.length;
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        totalSize += 12;
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    }
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    const output = new Uint8Array(totalSize);
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    output[0] = 0x89;
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    output[1] = 0x50;
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    output[2] = 0x4E;
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    output[3] = 0x47;
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    output[4] = 0x0D;
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    output[5] = 0x0A;
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    output[6] = 0x1A;
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    output[7] = 0x0A;
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    for (let i = 0; i < chunks.length; i++) {
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        const { name, data } = chunks[i];
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        const size = data.length;
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        const nameChars = [
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            name.charCodeAt(0),
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            name.charCodeAt(1),
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            name.charCodeAt(2),
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            name.charCodeAt(3),
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        ];
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        uint32[0] = size;
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        output[idx++] = uint8[3];
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        output[idx++] = uint8[2];
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        output[idx++] = uint8[1];
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        output[idx++] = uint8[0];
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        output[idx++] = nameChars[0];
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        output[idx++] = nameChars[1];
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        output[idx++] = nameChars[2];
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        output[idx++] = nameChars[3];
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        for (let j = 0; j < size;) {
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            output[idx++] = data[j++];
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        }
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        const crc = crc32(data, crc32(new Uint8Array(nameChars)));
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        int32[0] = crc;
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        output[idx++] = uint8[3];
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        output[idx++] = uint8[2];
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        output[idx++] = uint8[1];
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        output[idx++] = uint8[0];
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    }
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    return output;
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}