sakuya/node_modules/neataptic/docs/js/articles/agar.ioai/player.js

function Player(genome){
  this.x = Math.floor(Math.random() * WIDTH);
  this.y = Math.floor(Math.random() * HEIGHT);
  this.vx = 0;
  this.vy = 0;

  this.brain = genome;
  this.brain.score = 0;

  this.area = MIN_AREA;
  this.visualarea = this.area;

  players.push(this);
}

Player.prototype = {
  /** Update the stats */
  update: function(){
    if(this.area > MAX_AREA) this.area = MAX_AREA;
    if(this.area < MIN_AREA) this.area = MIN_AREA;

    var input = this.detect();
    var output = this.brain.activate(input);

    var moveangle = output[0] * 2 * PI;
    var movespeed = output[1] > 1 ? 1 : output[1] < 0 ? 0 : output[1];

    this.vx = movespeed * Math.cos(moveangle) * SPEED;
    this.vy = movespeed * Math.sin(moveangle) * SPEED;

    // Large blobs move slower
    this.vx *= Math.max(1 - (this.area / MAX_AREA), MIN_SPEED / SPEED);
    this.vy *= Math.max(1 - (this.area / MAX_AREA), MIN_SPEED / SPEED);

    this.x += this.vx;
    this.y += this.vy;

    // Limit position to width and height
    this.x = this.x >= WIDTH ? this.x % WIDTH : this.x <= 0 ? this.x + WIDTH : this.x;
    this.y = this.y >= HEIGHT ? this.y % HEIGHT : this.y <= 0 ? this.y + HEIGHT : this.y;

    this.area *= DECREASE_SIZE;

    // Replace highest score to visualise
    this.brain.score = this.area;
    highestScore = this.brain.score > highestScore ? this.brain.score : highestScore;
  },

  /** Restart from new position */
  restart: function(){
    this.x = Math.floor(Math.random() * WIDTH);
    this.y = Math.floor(Math.random() * HEIGHT);
    this.vx = 0;
    this.vy = 0;
    this.area = MIN_AREA;
    this.visualarea = this.area;
  },

  /** Display the player on the field */
  show: function(){
    this.visualarea = lerp(this.visualarea, this.area, 0.2);
    var radius = Math.sqrt(this.visualarea / PI);
    var color = activationColor(this.brain.score, highestScore);

    fill(color);
    ellipse(this.x, this.y, radius);
  },

  /** Visualies the detection of the brain */
  showDetection: function(detected){
    noFill();
    for(var object in detected){
      object = detected[object];

      if(object != undefined){
        stroke(object instanceof Player ? 'red' : 'lightgreen');
        line(this.x, this.y, object.x, object.y);
      }
    }

    var color = activationColor(this.brain.score, highestScore);
    stroke(color);
    ellipse(this.x, this.y, DETECTION_RADIUS*2);
    noStroke();
  },

  /* Checks if object can be eaten */
  eat: function(object){
    var dist = distance(this.x, this.y, object.x, object.y);

    var radius1 = Math.sqrt(this.area / PI);
    var radius2 = Math.sqrt(object.area / PI);
    if(dist < (radius1 + radius2) / 2 && this.area > object.area * RELATIVE_SIZE){
      this.area += object.area;
      object.restart();
      return true;
    }
    return false;
  },

  /** Detect other genomes around */
  detect: function(){
    // Detect nearest objects
    var nearestPlayers = [];
    var playerDistances = Array.apply(null, Array(PLAYER_DETECTION)).map(Number.prototype.valueOf, Infinity);

    for(var player in players){
      player = players[player];
      if(player == this || this.eat(player)) continue;

      var dist = distance(this.x, this.y, player.x, player.y);
      if(dist < DETECTION_RADIUS){
        // Check if closer than any other object
        var maxNearestDistance = Math.max.apply(null, playerDistances);
        var index = playerDistances.indexOf(maxNearestDistance);

        if(dist < maxNearestDistance){
          playerDistances[index] = dist;
          nearestPlayers[index] = player;
        }
      }
    }

    // Detect nearest foods
    var nearestFoods = [];
    var foodDistances = Array.apply(null, Array(FOOD_DETECTION)).map(Number.prototype.valueOf, Infinity);

    for(var food in foods){
      food = foods[food];
      if(this.eat(food)) continue;

      var dist = distance(this.x, this.y, food.x, food.y);
      if(dist < DETECTION_RADIUS){
        // Check if closer than any other object
        var maxNearestDistance = Math.max.apply(null, foodDistances);
        var index = foodDistances.indexOf(maxNearestDistance);

        if(dist < maxNearestDistance){
          foodDistances[index] = dist;
          nearestFoods[index] = food;
        }
      }
    }

    // Create and normalize input
    var output = [this.area / MAX_AREA];

    for(var i = 0; i < PLAYER_DETECTION; i++){
      var player = nearestPlayers[i];
      var dist = playerDistances[i];

      if(player == undefined){
        output = output.concat([0, 0, 0]);
      } else {
        output.push(angleToPoint(this.x, this.y, player.x, player.y) / (2 * PI));
        output.push(dist / DETECTION_RADIUS);
        output.push(player.area / MAX_AREA);
      }
    }

    for(var i = 0; i < FOOD_DETECTION; i++){
      var food = nearestFoods[i];
      var dist = foodDistances[i];

      if(food == undefined){
        output = output.concat([0, 0]);
      } else {
        output.push(angleToPoint(this.x, this.y, food.x, food.y) / (2 * PI));
        output.push(dist / DETECTION_RADIUS);
      }
    }

    if(distance(mouseX, mouseY, this.x, this.y) < Math.sqrt(this.visualarea / PI)){
      var detected = nearestPlayers.concat(nearestFoods);
      this.showDetection(detected);
    }

    return output;
  },
};