zazaulola’s gists

zazaulola / geodistance.js

Last active October 15, 2022 18:10

	function geodistance(lat1,lon1,lat2,lon2){
	const R = 6371e3; // in metres
	const φ1 = lat1 * Math.PI/180; // φ, λ in radians
	const φ2 = lat2 * Math.PI/180;
	const Δφ = (lat2-lat1) * Math.PI/180;
	const Δλ = (lon2-lon1) * Math.PI/180;

	const a = Math.sin(Δφ/2) * Math.sin(Δφ/2) +
	Math.cos(φ1) * Math.cos(φ2) *
	Math.sin(Δλ/2) * Math.sin(Δλ/2);

zazaulola / detab.js

Last active October 15, 2022 18:05

zazaulola / koi8r-to-utf8.js

Created September 23, 2022 21:30

	function koi8rToUtf8 ( buf ) {
	if( buf instanceof ArrayBuffer ) {
	buf = new Uint8Array ( buf );
	}
	if( ! Array.isArray ( buf ) ) {
	buf = [ ... buf ];
	}
	const map = new Map ( [
	[0x80,0x2500], [0x81,0x2502], [0x82,0x250C], [0x83,0x2510],
	[0x84,0x2514], [0x85,0x2518], [0x86,0x251C], [0x87,0x2524],

zazaulola / cp1251-to-utf8.js

Created August 21, 2022 03:07


	function cp1251ToUtf8(buf){
	if(buf instanceof ArrayBuffer) buf = new Uint8Array(buf);
	if(!Array.isArray(buf)) buf = [...buf];
	const map = new Map([
	[128,1026], [129,1027], [130,8218], [131,1107],
	[132,8222], [133,8230], [134,8224], [135,8225],
	[136,8364], [137,8240], [138,1033], [139,8249],
	[140,1034], [141,1036], [142,1035], [143,1039],
	[144,1106], [145,8216], [146,8217], [147,8220],

zazaulola / crypto-captcha.js

Last active August 4, 2022 14:56

PoW captcha for Node. All code is static - no sessions needed, no cookies needed, no database needed.

	/** @format */

	/**
	*
	* The principle of the algorithm is very simple.
	*
	* The module exports three functions:
	*
	* getTask()
	* The first function does not need any arguments.

zazaulola / create-worker.js

Created July 5, 2022 16:10

	function createWorker(callable) {
	const code = `onmessage=${callable.toString()}`;
	const blob = new Blob([code], { type: 'text/javascript' });
	const url = URL.createObjectURL(blob);
	const worker = new Worker(url);
	URL.revokeObjectURL(url);
	return worker;
	}

zazaulola / jpeg.js

Created June 15, 2022 21:08

	/** @format */

	/**
	* Функция отчищает JPEG-картинку от метаданных
	*
	* @param {ArrayBuffer} buf буфер с изображением
	* @returns {Blob\|null}
	*/
	function clearJpegMetadata(buf) {
	if (!(buf instanceof ArrayBuffer)) {

zazaulola / glitch.html

Created December 3, 2021 17:47

Glitch effect with CSS

	<!-- @format -->

	<!DOCTYPE html>
	<html lang="en">
	<head>
	<meta charset="UTF-8" />
	<title>CodePen - CSS Glitched Text</title>
	<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/normalize/5.0.0/normalize.min.css" />

	<style>

zazaulola / base64.js

Last active April 26, 2022 07:45

base64 and TypedArray conversion

	function arrayToBase64(array) {
	let base64 = '';
	const encodings = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';

	const arrayLength = array.byteLength;
	const remainder = arrayLength % 3;
	const mainLength = arrayLength - remainder;

	let a, b, c, d;
	let chunk;

zazaulola / ajax.js

Last active December 3, 2021 17:50

Ajax via XMLHTTPRequest

	/** @format */
	/**
	* @interface
	* @name RequestParams
	* @property {string} url адрес отправки
	* @property {string} method метод
	* @property {string} responseType
	* @property {array} data
	* @property {object} headers
	* @property {function} uploadProgress