mirror of https://github.com/nealey/vail.git
117 lines
2.5 KiB
JavaScript
117 lines
2.5 KiB
JavaScript
const morseToAlphabet = new Map([
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["12", "A"],
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["2111", "B"],
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["2121", "C"],
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["211", "D"],
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["1", "E"],
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["1121", "F"],
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["221", "G"],
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["1111", "H"],
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["11", "I"],
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["1222", "J"],
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["212", "K"],
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["1211", "L"],
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["22", "M"],
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["21", "N"],
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["222", "O"],
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["1221", "P"],
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["2212", "Q"],
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["121", "R"],
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["111", "S"],
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["2", "T"],
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["112", "U"],
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["1112", "V"],
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["122", "W"],
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["2112", "X"],
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["2122", "Y"],
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["2211", "Z"],
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["12222", "1"],
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["11222", "2"],
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["11122", "3"],
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["11112", "4"],
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["11111", "5"],
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["21111", "6"],
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["22111", "7"],
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["22211", "8"],
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["22221", "9"],
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["22222", "0"],
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]);
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class Decoder {
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constructor() {
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this.lastLetter = '';
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this.decodeArray = '';
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this.unit = 80; // adjustment: short dit reduces, long dah lengthens
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this.keyStartTime = null;
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this.keyEndTime = null;
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this.spaceTimer = null;
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this.farnsworth = 3;
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}
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keyOn() {
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clearTimeout(this.spaceTimer);
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this.keyStartTime = Date.now();
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//var pauseDuration = (this.keyEndTime) ? this.keyStartTime - this.keyEndTime : 0;
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//if (pauseDuration > this.unit + (this.unit/10)) { // end sequence and decode letter
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//this.registerLetter();
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//}
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}
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keyOff() {
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this.keyEndTime = Date.now();
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var keyDuration = (this.keyStartTime) ? this.keyEndTime - this.keyStartTime : 0;
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if (keyDuration < this.unit) {
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// reduce unit based on short dit
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this.unit = (keyDuration + this.unit) / 2;
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this.registerDit();
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} else if (keyDuration > this.unit * 3) {
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// lengthen unit based on long dah
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this.unit = ((keyDuration / 3) + this.unit) / 2;
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this.registerDah();
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} else {
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var ditAndDahThreshold = (this.unit * 2);
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if (keyDuration >= ditAndDahThreshold) {
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this.registerDah();
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} else {
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this.registerDit();
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}
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}
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let spaceTime = this.unit * this.farnsworth;
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this.spaceTimer = setTimeout(() => { // end sequence and decode letter
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this.updateLastLetter(this.morseToLetter(this.decodeArray));
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this.decodeArray = '';
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}, spaceTime, "keyOff");
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}
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registerDit() {
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this.decodeArray += '1';
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}
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registerDah() {
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this.decodeArray += '2';
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}
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updateLastLetter(letter) {
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updateCurrentLetter(letter);
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this.lastLetter = letter;
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//console.log(this.lastLetter);
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}
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morseToLetter(sequence) {
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var letter = morseToAlphabet.get(sequence);
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if (letter) {
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return letter;
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} else {
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return '*';
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}
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}
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calculateWpm() {
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return 60000 / (this.unit * 50);
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}
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setFarnsworth(farnsworth) {
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this.farnsworth = farnsworth;
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}
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}
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