Icard/angular-clarity-master(work.../node_modules/pngjs/lib/packer-async.js

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2024-07-16 14:55:36 +00:00
"use strict";
let util = require("util");
let Stream = require("stream");
let constants = require("./constants");
let Packer = require("./packer");
let PackerAsync = (module.exports = function (opt) {
Stream.call(this);
let options = opt || {};
this._packer = new Packer(options);
this._deflate = this._packer.createDeflate();
this.readable = true;
});
util.inherits(PackerAsync, Stream);
PackerAsync.prototype.pack = function (data, width, height, gamma) {
// Signature
this.emit("data", Buffer.from(constants.PNG_SIGNATURE));
this.emit("data", this._packer.packIHDR(width, height));
if (gamma) {
this.emit("data", this._packer.packGAMA(gamma));
}
let filteredData = this._packer.filterData(data, width, height);
// compress it
this._deflate.on("error", this.emit.bind(this, "error"));
this._deflate.on(
"data",
function (compressedData) {
this.emit("data", this._packer.packIDAT(compressedData));
}.bind(this)
);
this._deflate.on(
"end",
function () {
this.emit("data", this._packer.packIEND());
this.emit("end");
}.bind(this)
);
this._deflate.end(filteredData);
};