mario.cs

using UnityEngine;
using System.Collections;

public class Mario : MonoBehaviour {

	public MarioState _state;
	public tk2dSpriteAnimator animator;
	public tk2dSprite sprite;


	void Start () {

		animator = gameObject.GetComponent<tk2dSpriteAnimator>();
		sprite = gameObject.GetComponent<tk2dSprite>();

		_state = new IdleState();
	
	}
	
	void Update () {
		_state = _state.Update( this );

		Debug.Log(_state);
	}

	void OnCollisionEnter2D( Collision2D other ){
		if (other.gameObject.layer == LayerMask.NameToLayer("Ground")) {
			_state.SendMessage( StateMessages.message.HIT_FLOOR );		
		}
	}
	

}

public interface MarioState {

	MarioState Update( Mario mario );
	void SendMessage( StateMessages.message message );

}

public class IdleState: MarioState {
	
	public MarioState Update( Mario mario ){
		
		mario.animator.Play("SM_Idle");

		Vector2 _vel = mario.rigidbody2D.velocity;
		_vel.x = 0;

		if (Input.GetKey(KeyCode.A) || Input.GetKey(KeyCode.D) ) 
		{
			return new WalkState();
		}

		if( Input.GetKey(KeyCode.W) ){
			return new JumpState();
		}

		if( mario.transform.position.y < 0 ){
			return new DieState();
		}

		mario.rigidbody2D.velocity = _vel;


		return this;

	}

	public void SendMessage( StateMessages.message message ){
		return;
	}

}

public class WalkState: MarioState {
	
	public MarioState Update( Mario mario ){

		Vector2 _vel = mario.rigidbody2D.velocity;

		mario.animator.Play("SM_Walk");

		if( Input.GetKey(KeyCode.A) ){
			mario.sprite.FlipX = false;
			_vel.x = -1f;
		}

		if( Input.GetKey(KeyCode.D) ){
			mario.sprite.FlipX = true;
			_vel.x = 1f;
		}

		if( Input.GetKey(KeyCode.A) && Input.GetKey(KeyCode.D) ){
			_vel.x = 0;
		}

		if( Input.GetKey(KeyCode.W) ){
			return new JumpState();
		}

		if (!Input.GetKey (KeyCode.A) && !Input.GetKey(KeyCode.D) ) 
		{
			return new IdleState();
		}

		if( mario.transform.position.y < 0 ){
			return new DieState();
		}

		mario.rigidbody2D.velocity = _vel;

		return this;

	}

	public void SendMessage( StateMessages.message message ){
		return;
	}
	
}

public class JumpState: MarioState {
	
	public MarioState Update( Mario mario ){
		
		Vector2 _vel = mario.rigidbody2D.velocity;

		mario.animator.Play("SM_Jump");

		_vel.y = 3f;
		
		mario.rigidbody2D.velocity = _vel;
		
		return new FallingState();
		
	}

	public void SendMessage( StateMessages.message message ){
		return;
	}
	
}

public class FallingState: MarioState {

	bool hasHitFloor = false;

	public MarioState Update( Mario mario ){

		if( mario.transform.position.y < 0 ){
			return new DieState();
		}

		if ( hasHitFloor ) {
			return new IdleState();
		}
		return this;

	}

	public void SendMessage( StateMessages.message message ){

		if( message == StateMessages.message.HIT_FLOOR ){
			hasHitFloor = true;
		}
		return;
	}

}

public class DieState: MarioState {

	private bool hasDied = false;

	public MarioState Update( Mario mario ){

		if( !hasDied ){

			Vector2 _vel = mario.rigidbody2D.velocity;

			mario.collider2D.isTrigger = true;
			
			mario.animator.Play("SM_Die");
			
			_vel.y = 3f;
			_vel.x = 1.5f;


			mario.rigidbody2D.velocity = _vel;
			hasDied = true;
		}

		return this;
		
	}


	public void SendMessage( StateMessages.message message ){}

}

public class StateMessages {
	public enum message {
		HIT_FLOOR
	}
}