PlayerEntity - Code

package
{
    import net.flashpunk.*;
    import net.flashpunk.FP;
    import net.flashpunk.Entity;

    import net.flashpunk.graphics.Image;
    import net.flashpunk.utils.Input;
    import net.flashpunk.utils.Key;
    import net.flashpunk.graphics.Spritemap;

    import flash.display.BitmapData;
    import flash.geom.Point;

    /**
     * ...
     * @author JaydenB
     */

    public class PlayerReference extends Entity
    {
        private var v:Point = new Point();
        private var a:Point = new Point();

        public var speed:Number;
        public var jumpvelocity:Number;
        public var colour:uint;

        private var doubleJump:int = 0;
        private var _gravity:Number;

        public function PlayerReference()
        {
            _gravity = GameWorld.gravity;
            a.y = _gravity;

            type = "player";
            setHitbox(16, 16);
            graphic = new Image(new BitmapData(16, 16, false, colour));
        }

        override public function update():void
        {
            var hInput:int;

            if (Input.check("left"))
            {
                hInput -= 1;
            }
            if (Input.check("right"))
            {
                hInput += 1;
            }

            if (Input.pressed("jump"))
            {
                jump();
            }


            v.x = hInput * speed;
            v.y += a.y;

            updateCollision();

            super.update();
        }

        private function updateCollision():void
        {
            x += v.x * FP.elapsed;
            if (collide("level", x, y))
            {
                if (FP.sign(v.x) > 0)
                {
                    //hit left of block
                    v.x = 0;
                    x = Math.floor(x / GameWorld.tileSize) * GameWorld.tileSize;
                }
                else
                {
                    //hit right of block
                    v.x = 0;
                    x = (Math.floor(x / GameWorld.tileSize) * GameWorld.tileSize) + GameWorld.tileSize;
                }
            }

            y += v.y * FP.elapsed;
            if (collide("level", x, y))
            {
                if (FP.sign(v.y) > 0)
                {
                    //land on top of block
                    v.y = 0;
                    y = Math.floor(y / GameWorld.tileSize) * GameWorld.tileSize;
                    doubleJump = 0;

                }
                else
                {
                    //hit bottom of block
                    v.y = 0;
                    y = (Math.floor(y / GameWorld.tileSize) * GameWorld.tileSize) + GameWorld.tileSize;
                }
            }
        }

        private function jump():void
        {
            if (doubleJump < 2)
            {
                v.y = jumpvelocity;
                doubleJump++;
            }
        }
    }

}