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| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 | 1x 1x 1x 1x 1x 1x | "use strict";
let hasSyncZlib = true;
let zlib = require("zlib");
Iif (!zlib.deflateSync) {
hasSyncZlib = false;
}
let constants = require("./constants");
let Packer = require("./packer");
module.exports = function (metaData, opt) {
if (!hasSyncZlib) {
throw new Error(
"To use the sync capability of this library in old node versions, please pin pngjs to v2.3.0"
);
}
let options = opt || {};
let packer = new Packer(options);
let chunks = [];
// Signature
chunks.push(Buffer.from(constants.PNG_SIGNATURE));
// Header
chunks.push(packer.packIHDR(metaData.width, metaData.height));
if (metaData.gamma) {
chunks.push(packer.packGAMA(metaData.gamma));
}
let filteredData = packer.filterData(
metaData.data,
metaData.width,
metaData.height
);
// compress it
let compressedData = zlib.deflateSync(
filteredData,
packer.getDeflateOptions()
);
filteredData = null;
if (!compressedData || !compressedData.length) {
throw new Error("bad png - invalid compressed data response");
}
chunks.push(packer.packIDAT(compressedData));
// End
chunks.push(packer.packIEND());
return Buffer.concat(chunks);
};
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