js/rpsls.js

   1 const nChoice = 5; //fixed for this game
   2
   3 const symbols = [ "Rock", "Lizard", "Spock", "Scissors", "Paper" ];
   4
   5 // Same order as in symbols
   6 const messages = [
   7     [ "can't win vs.", "crushes",        "is vaporized by", "cruches",           "is covered by"   ],
   8     [ "is crushed by", "can't win vs.",  "poisons",         "is decapitated by", "eats"            ],
   9     [ "vaporizes",     "is poisoned by", "can't win vs.",   "smashes",           "is disproved by" ],
  10     [ "is crushed by", "decapitates",    "is smashed by",   "can't win vs.",     "cuts"            ],
  11     [ "covers",        "is eaten by",    "disproves",       "is cut by",         "can't win vs."   ],
  12 ];
  13
  14 // Rewards matrix, order as in symbols
  15 const rewards = Array.from(Array(nChoice)).map( (e,i) => { //lines
  16     return Array.from(Array(nChoice)).map( (f,j) => { //columns
  17         // i against j: gain from i viewpoint
  18         if (j == (i+1) % nChoice || j == (i+3) % nChoice)
  19             return 1; //I win :)
  20         else if (i != j)
  21             return -1; //I lose :(
  22         return 0; //i==j
  23     });
  24 });
  25
  26 new Vue({
  27     el: "#rpsls",
  28     data: {
  29         nInput: 5, //default
  30         humanHistory: [ ], //your nInput last moves, stored (oldest first)
  31         humanMove: -1,
  32         gameState: 0, //total points of the human
  33         compMove: -1, //last move played by computer
  34         drawIsLost: false, //normal (or true: draw is considered loss)
  35         rewards: [ ], //initialized at first human move with new nInput
  36         weights: [ ], //same as above
  37         symbols: symbols,
  38         messages: messages,
  39     },
  40     created: function() {
  41         this.reinitialize();
  42     },
  43     methods: {
  44         // Called on nInput change
  45         reinitialize: function() {
  46             // weights[i][j][k]: output i -- input j/choice k
  47             this.weights = Array.from(Array(nChoice)).map( i => {
  48                 return Array.from(Array(this.nInput)).map( j => {
  49                     return Array.from(Array(nChoice)).map( k => {
  50                         return 0;
  51                     });
  52                 })
  53             });
  54             if (this.humanHistory.length > this.nInput)
  55                 this.humanHistory.splice(this.nInput);
  56         },
  57         // Play a move given current data (*after* human move)
  58         play: function(humanMove) {
  59             this.humanMove = humanMove;
  60             let candidates = [ ];
  61             Array.from(Array(nChoice)).forEach( (e,i) => {
  62                 // Sum all weights from an activated input to this output
  63                 let sumWeights = this.weights[i].reduce( (acc,input,j) => {
  64                     if (this.humanHistory.length <= j)
  65                         return 0;
  66                     return input[ this.humanHistory[j] ];
  67                 }, 0 );
  68                 let move = {
  69                     val: sumWeights,
  70                     index: i,
  71                 };
  72                 if (candidates.length == 0 || sumWeights > candidates[0].val)
  73                     candidates = [move];
  74                 else if (sumWeights == candidates[0].val)
  75                     candidates.push(move);
  76             });
  77             // Pick a choice at random in maxValue (total random for first move)
  78             let randIdx = Math.floor(Math.random() * candidates.length);
  79             this.compMove = candidates[randIdx].index;
  80             // Update game state
  81             let reward = rewards[this.compMove][humanMove]; //viewpoint of computer
  82             this.gameState -= reward;
  83             this.updateWeights(reward);
  84             // Update human moves history
  85             this.humanHistory.push(humanMove);
  86             if (this.humanHistory.length > this.nInput)
  87                 this.humanHistory.shift();
  88         },
  89         updateWeights: function(reward) {
  90             let delta = Math.sign(reward);
  91             if (this.drawIsLost && reward == 0)
  92                 delta = -1;
  93             this.weights[this.compMove].forEach( (input,i) => {
  94                 if (i < this.humanHistory.length)
  95                     input[ this.humanHistory[i] ] += delta;
  96             });
  97             // Re-center the weights
  98             let sumAllWeights = this.weights.reduce( (a,output) => {
  99                 return a + output.reduce( (b,input) => {
 100                     return b + input.reduce( (c,choiceWeight) => {
 101                         return c + choiceWeight;
 102                     }, 0);
 103                 }, 0);
 104             }, 0);
 105             let meanWeight = sumAllWeights / (this.nInput * nChoice * nChoice);
 106             this.weights.forEach( output => {
 107                 output.forEach( input => {
 108                     for (let i=0; i<input.length; i++)
 109                         input[i] -= meanWeight;
 110                 });
 111             });
 112         },
 113         imgSource: function(symbol) {
 114             return "img/" + symbol + ".png";
 115         },
 116     },
 117 });