Zo3

var Snake = (function () {

const INITIAL_TAIL = 4; var fixedTail = true;

var intervalID;

var tileCount = 10; var gridSize = 400/tileCount;

const INITIAL_PLAYER = { x: Math.floor(tileCount / 2), y: Math.floor(tileCount / 2) };

var velocity = { x:0, y:0 }; var player = { x: INITIAL_PLAYER.x, y: INITIAL_PLAYER.y };

var walls = false;

var fruit = { x:1, y:1 };

var trail = []; var tail = INITIAL_TAIL;

var reward = 0; var points = 0; var pointsMax = 0;

var ActionEnum = { 'none':0, 'up':1, 'down':2, 'left':3, 'right':4 }; Object.freeze(ActionEnum); var lastAction = ActionEnum.none;

function setup () { canv = document.getElementById('gc'); ctx = canv.getContext('2d');

game.reset();

}

var game = {

reset: function () {
  ctx.fillStyle = 'grey';
  ctx.fillRect(0, 0, canv.width, canv.height);

  tail = INITIAL_TAIL;
  points = 0;
  velocity.x = 0;
  velocity.y = 0;
  player.x = INITIAL_PLAYER.x;
  player.y = INITIAL_PLAYER.y;
  // this.RandomFruit();
  reward = -1;

  lastAction = ActionEnum.none;

  trail = [];
  trail.push({ x: player.x, y: player.y });
  // for(var i=0; i<tail; i++) trail.push({ x: player.x, y: player.y });
},

action: {
  up: function () {
    if (lastAction != ActionEnum.down){
      velocity.x = 0;
      velocity.y = -1;
    }
  },
  down: function () {
    if (lastAction != ActionEnum.up){
      velocity.x = 0;
      velocity.y = 1;
    }
  },
  left: function () {
    if (lastAction != ActionEnum.right){
      velocity.x = -1;
      velocity.y = 0;
    }
  },
  right: function () {
    if (lastAction != ActionEnum.left){
      velocity.x = 1;
      velocity.y = 0;
    }
  }
},

RandomFruit: function () {
  if(walls){
    fruit.x = 1+Math.floor(Math.random() * (tileCount-2));
    fruit.y = 1+Math.floor(Math.random() * (tileCount-2));
  }
  else {
    fruit.x = Math.floor(Math.random() * tileCount);
    fruit.y = Math.floor(Math.random() * tileCount);
  }
},

log: function () {
  console.log('====================');
  console.log('x:' + player.x + ', y:' + player.y);
  console.log('tail:' + tail + ', trail.length:' + trail.length);
},

loop: function () {

  reward = -0.1;

  function DontHitWall () {
    if(player.x < 0) player.x = tileCount-1;
    if(player.x >= tileCount) player.x = 0;
    if(player.y < 0) player.y = tileCount-1;
    if(player.y >= tileCount) player.y = 0;
  }
  function HitWall () {
    if(player.x < 1) game.reset();
    if(player.x > tileCount-2) game.reset();
    if(player.y < 1) game.reset();
    if(player.y > tileCount-2) game.reset();

    ctx.fillStyle = 'grey';
    ctx.fillRect(0,0,gridSize-1,canv.height);
    ctx.fillRect(0,0,canv.width,gridSize-1);
    ctx.fillRect(canv.width-gridSize+1,0,gridSize,canv.height);
    ctx.fillRect(0, canv.height-gridSize+1,canv.width,gridSize);
  }

  var stopped = velocity.x == 0 && velocity.y == 0;

  player.x += velocity.x;
  player.y += velocity.y;

  if (velocity.x == 0 && velocity.y == -1) lastAction = ActionEnum.up;
  if (velocity.x == 0 && velocity.y == 1) lastAction = ActionEnum.down;
  if (velocity.x == -1 && velocity.y == 0) lastAction = ActionEnum.left;
  if (velocity.x == 1 && velocity.y == 0) lastAction = ActionEnum.right;

  ctx.fillStyle = 'rgba(40,40,40,0.8)';
  ctx.fillRect(0,0,canv.width,canv.height);

  if(walls) HitWall();
  else DontHitWall();

  // game.log();

  if (!stopped){
    trail.push({x:player.x, y:player.y});
    while(trail.length > tail) trail.shift();
  }

  if(!stopped) {
    ctx.fillStyle = 'rgba(200,200,200,0.2)';
    ctx.font = "small-caps 14px Helvetica";
    ctx.fillText("(esc) reset", 24, 356);
    ctx.fillText("(space) pause", 24, 374);
  }

  ctx.fillStyle = 'green';
  for(var i=0; i<trail.length-1; i++) {
    ctx.fillRect(trail[i].x * gridSize+1, trail[i].y * gridSize+1, gridSize-2, gridSize-2);

    // console.debug(i + ' => player:' + player.x, player.y + ', trail:' + trail[i].x, trail[i].y);
    if (!stopped && trail[i].x == player.x && trail[i].y == player.y){
      game.reset();
    }
    ctx.fillStyle = 'lime';
  }
  ctx.fillRect(trail[trail.length-1].x * gridSize+1, trail[trail.length-1].y * gridSize+1, gridSize-2, gridSize-2);

  if (player.x == fruit.x && player.y == fruit.y) {
    if(!fixedTail) tail++;
    points++;
    if(points > pointsMax) pointsMax = points;
    reward = 1;
    game.RandomFruit();
    // make sure new fruit didn't spawn in snake tail
    while((function () {
      for(var i=0; i<trail.length; i++) {
        if (trail[i].x == fruit.x && trail[i].y == fruit.y) {
          game.RandomFruit();
          return true;
        }
      }
      return false;
    })());
  }

  ctx.fillStyle = 'red';
  ctx.fillRect(fruit.x * gridSize+1, fruit.y * gridSize+1, gridSize-2, gridSize-2);

  if(stopped) {
    ctx.fillStyle = 'rgba(250,250,250,0.8)';
    ctx.font = "small-caps bold 14px Helvetica";
    ctx.fillText("press ARROW KEYS to START...", 24, 374);
  }

  ctx.fillStyle = 'white';
  ctx.font = "bold small-caps 16px Helvetica";
  ctx.fillText("points: " + points, 288, 40);
  ctx.fillText("top: " + pointsMax, 292, 60);

  return reward;
}

}

function keyPush (evt) { switch(evt.keyCode) { case 37: //left game.action.left(); evt.preventDefault(); break;

  case 38: //up
  game.action.up();
  evt.preventDefault();
  break;

  case 39: //right
  game.action.right();
  evt.preventDefault();
  break;

  case 40: //down
  game.action.down();
  evt.preventDefault();
  break;

  case 32: //space
  Snake.pause();
  evt.preventDefault();
  break;

  case 27: //esc
  game.reset();
  evt.preventDefault();
  break;
}

}

return { start: function (fps = 15) { window.onload = setup; intervalID = setInterval(game.loop, 1000 / fps); },

loop: game.loop,

reset: game.reset,

stop: function () {
  clearInterval(intervalID);
},

setup: {
  keyboard: function (state) {
    if (state) {
      document.addEventListener('keydown', keyPush);
    } else {
      document.removeEventListener('keydown', keyPush);
    }
  },
  wall: function (state) {
    walls = state;
  },
  tileCount: function (size) {
    tileCount = size;
    gridSize = 400 / tileCount;
  },
  fixedTail: function (state) {
    fixedTail = state;
  }
},

action: function (act) {
  switch(act) {
    case 'left':
      game.action.left();
      break;

    case 'up':
      game.action.up();
      break;

    case 'right':
      game.action.right();
      break;

    case 'down':
      game.action.down();
      break;
  }
},

pause: function () {
  velocity.x = 0;
  velocity.y = 0;
},

clearTopScore: function () {
  pointsMax = 0;
},

data: {
  player: player,
  fruit: fruit,
  trail: function () {
    return trail;
  }
},

info: {
  tileCount: tileCount
}

};

})();

Snake.start(8); Snake.setup.keyboard(true); Snake.setup.fixedTail(false);