Snake.js

class Snake {
  constructor(x, y) {
    this.x = x;
    this.y = y;
    this.xSpeed = 1;
    this.ySpeed = 0;
    this.total = 0;
    this.tail = [];
  }

  update() {
    if (this.total === this.tail.length) {
      for (let i = 0; i < this.tail.length - 1; i++) {
        this.tail[i] = this.tail[i + 1];
      }
    }
    this.tail[this.total - 1] = createVector(this.x, this.y);

    this.x += this.xSpeed * scale;
    this.y += this.ySpeed * scale;

    this.x = constrain(this.x, 0, width - scale);
    this.y = constrain(this.y, 0, height - scale);
  }

  show() {
    fill(255);
    for (let i = 0; i < this.tail.length; i++) {
      rect(this.tail[i].x, this.tail[i].y, scale, scale);
    }
    rect(this.x, this.y, scale, scale);
  }

  dir(x, y) {
    this.xSpeed = x;
    this.ySpeed = y;
  }

  eat(pos) {
    const d = dist(this.x, this.y, pos.x, pos.y);
    if (d < 1) {
      this.total++;
      return true;
    } else {
      return false;
    }
  }

  death() {
    for (let i = 0; i < this.tail.length; i++) {
      const pos = this.tail[i];
      const d = dist(this.x, this.y, pos.x, pos.y);
      if (d < 1) {
        this.total = 0;
        this.tail = [];
      }
    }
  }
}