let rez = 20;

let food;

let w;

let h;

​

function setup() {

  w = floor(width / rez);

  h = floor(height / rez);

  createCanvas(400, 400);

  frameRate(10);

  Snake = new snake();

  Snake.foodLocation();

}

​

function draw() {

  scale(rez);

  background(220);

  if (Snake.eat(food)) {

    Snake.foodLocation();

  }

  Snake.update();

  Snake.display();

​

  if (Snake.endGame()) {

    background(255, 0, 0);

    noStroke();

    noLoop();

  }

​

  noStroke();

  fill(255, 0, 0);

  rect(food.x, food.y, 1, 1);

}

​

function keyPressed() {

  if (keyCode === LEFT_ARROW && Snake.xdir != 1) {

    Snake.setDir(-1, 0);

  } else if (keyCode === RIGHT_ARROW && Snake.xdir != -1) {

    Snake.setDir(1, 0);

  } else if (keyCode === UP_ARROW && Snake.ydir != 1) {

    Snake.setDir(0, -1);

  } else if (keyCode === DOWN_ARROW && Snake.ydir != -1) {

    Snake.setDir(0, 1);

  }

}

​

class snake {

  constructor() {

    this.len = 0;

    this.body = [];

    this.body[0] = createVector(0, 0);

    this.xdir = 0;

    this.ydir = 0;

  }

​

  setDir(x, y) {

    this.xdir = x;

    this.ydir = y;

  }

​

​

  grow() {

    let head = this.body[this.body.length - 1].copy();

    this.len++;

    this.body.push(head);

  }

​

  foodLocationIsInsideSnake(fx, fy) {

    let insideSnake = false;

    for(let i=0; i<this.body.length-1; i++) {

      let part = this.body[i];

      if(part.x == fx) {

        insideSnake = true;

      }

      if(part.y == fy) {

        insideSnake = true;

      }

    }

    return insideSnake;

  }

  foodLocation() {

    let fx = floor(random(w));

    let fy = floor(random(h));

​

    // for (let i = 0; i < this.body.length - 1; i++) {

    //   let part = this.body[i];

    //   if (part.x == fx && part.y == fy) {

    //     fx = floor(random(w - fx));

    //     fy = floor(random(h - fy));

    //   }

    // }

    while(this.foodLocationIsInsideSnake(fx, fy)) {

          fx = floor(random(w));

          fy = floor(random(w));

    }

​

    food = createVector(fx, fy);

  }

​

  eat(pos) {

    let x = this.body[this.body.length - 1].x;

    let y = this.body[this.body.length - 1].y;

    if (x == pos.x && y == pos.y) {

      this.grow();

      print("Food Eaten");

      return true;

    }

    return false;

  }

​

  update() {

    let head = this.body[this.body.length - 1].copy();

    this.body.shift();

    head.x += this.xdir;

    head.y += this.ydir;

    this.body.push(head);

  }

​

  endGame() {

    let x = this.body[this.body.length - 1].x;

    let y = this.body[this.body.length - 1].y;

​

    for (let i = 0; i < this.body.length - 1; i++) {

      let part = this.body[i];

      if (part.x == x && part.y == y) {

        print("Game over!!");

        return true;

      }

    }

    return false;

  }

​

  display() {

    for (let i = 0; i < this.body.length; i++) {

      fill(0);

      if (this.body[0].x > width) {

        this.body[i].x = 0 - (i * 10);

      } else if (this.body[0].y > height) {

        this.body[0].y = 0 - (i * 10);

      } else if (this.body[0].x < 0) {

        this.body[0].x = width + (i * 10);

      } else if (this.body[0].y < 0) {

        this.body[0].x = height + (i * 10);

      }

      rect(this.body[i].x, this.body[i].y, 1, 1);

    }

  }

​

}