title: Slopes not working in Phaser using arcade physics
body: <p>I'm currently having this issue when I am trying to get a sprite to go up a slope within phaser using the phaser-arcade-slopes.min.js plugin. I am using a .csv tilemap also with a tile size of 32x32. I'm unsure if my names are just incorrect or I am using the wrong type of file for the tilemap itself. I have been getting errors such as - Tilemap.createLayer: Invalid layer ID given: null &amp; Cannot read property 'resizeWorld' of undefined(…). Any help would be much appreciated.
  "snow_tiles_32.png" is the name of the tileset I created and I'm using
  "tiles.csv" the tilemap created inside Tiled.</p>
  
  <pre><code>var game = new Phaser.Game(800, 600, Phaser.AUTO, '', { preload: preload, create: create, update: update });
  
  function preload() {
  this.game.load.tilemap('tilemap', 'assets/tilemaps/csv/tiles.csv', null, Phaser.Tilemap.CSV);
  this.game.load.spritesheet('tiles', 'assets/tilemaps/tiles/snow_tiles_32.png', 32,32);
  this.game.load.spritesheet('player', 'assets/penguin.png', 32,48);
  }
  
  var player;
  var cursors;
  
  function create() {
  this.game.physics.startSystem(Phaser.Physics.ARCADE);
  this.game.plugins.add(Phaser.Plugin.ArcadeSlopes);
  cursors = game.input.keyboard.createCursorKeys();
  
  this.map = this.game.add.tilemap('tilemap');
  this.map.addTilesetImage('snow_tiles_32', 'tiles');
  
  this.game.stage.backgroundColor = '#80e3ff';
  
  this.ground = this.map.createLayer('collision');
  this.ground.resizeWorld();
  
  this.game.slopes.convertTilemapLayer(this.ground,{
      2:  'FULL',
      3:  'HALF_BOTTOM_LEFT',
      4:  'HALF_BOTTOM_RIGHT',
      6:  'HALF_TOP_LEFT',
      5:  'HALF_TOP_RIGHT',
      15: 'QUARTER_BOTTOM_LEFT_LOW',
      16: 'QUARTER_BOTTOM_RIGHT_LOW',
      17: 'QUARTER_TOP_RIGHT_LOW',
      18: 'QUARTER_TOP_LEFT_LOW',
      19: 'QUARTER_BOTTOM_LEFT_HIGH',
      20: 'QUARTER_BOTTOM_RIGHT_HIGH',
      21: 'QUARTER_TOP_RIGHT_HIGH',
      22: 'QUARTER_TOP_LEFT_HIGH',
      23: 'QUARTER_LEFT_BOTTOM_HIGH',
      24: 'QUARTER_RIGHT_BOTTOM_HIGH',
      25: 'QUARTER_RIGHT_TOP_LOW',
      26: 'QUARTER_LEFT_TOP_LOW',
      27: 'QUARTER_LEFT_BOTTOM_LOW',
      28: 'QUARTER_RIGHT_BOTTOM_LOW',
      29: 'QUARTER_RIGHT_TOP_HIGH',
      30: 'QUARTER_LEFT_TOP_HIGH',
      31: 'HALF_BOTTOM',
      32: 'HALF_RIGHT',
      33: 'HALF_TOP',
      34: 'HALF_LEFT'
  });
  
  this.map.setCollisionBetween(2,34, true, 'collision');
  
  //player
  this.player = this.game.add.sprite(100,50,'player');
  this.game.physics.arcade.enable(player);
  
  this.player.body.bounce.y = 0.2;
  this.player.body.gravity.y = 2000;
  this.player.body.collideWorldBounds = true;
  
  this.player.animations.add('left', [0,1,2,3], 10, true);
  this.player.animations.add('right', [5,6,7,8], 10, true);
  this.game.slopes.enable(this.player);
  this.game.camera.follow(this.player);
  
  }
  
  function update() {
  
  this.game.physics.arcade.collide(this.player, this.ground);
  
  this.player.body.velocity.x = 0;
  
  if(cursors.left.isDown){
      this.player.body.velocity.x = -150;
      this.player.animations.play('left');
  }
  else if (cursors.right.isDown){
      this.player.body.velocity.x = 150;
      this.player.animations.play('right');
  }
  else{
      this.player.animations.stop();
      this.player.frame = 4;
  }
  
  if(cursors.up.isDown &amp;&amp; player.body.onFloor()){
      this.player.body.velocity.y = -350;
  }
  </code></pre>
  
  <p>}</p>