ProjectBall.Unity/Assets/Scripts/Joystick.cs

using UnityEngine;
using System.Collections;
using System;

[Serializable]
public class ScreenSpacePosition{
	public bool Relative;
	public Vector2 Position;
	public Vector2 PixelPosition{
		get{
			if(Relative){
				return new Vector2(Position.x * Screen.width, Position.y * Screen.height);
			}else{
				return Position;
			}
		}
	}
}

[ExecuteInEditMode]
public class Joystick : MonoBehaviour {
	public bool Relative = false;
	public float BaseJoystickRadius;
	public float StickRadius;
	public Texture2D circleImage;
	private Rect baseRect;
	private Rect stickRect;
	private Vector2 basePosition;
	private bool pressed = false;
	private Vector2 pressPosition;
	private Vector2 stickOffset;
	private Vector2 stickPosition;
	public Material Mat;
	public Color BaseColor;
	public Color StickColor;
	private int fingerId = -1;
	private float angle;
	public ScreenSpacePosition ScreenPosition;

	// Use this for initialization
	void Start () {
	
	}

	public float Angle{
		get{
			return angle; 
		}
	}

	public bool Pressed{
		get{
			return pressed; 
		}
	}

	public float Value{
		get{
			return pressed ? Mathf.Clamp01(stickOffset.magnitude / BaseJoystickRadius) : 0; 
		}
	}

	public float ValueX{
		get{
			return pressed ? Mathf.Clamp((stickPosition.x - basePosition.x) / BaseJoystickRadius, -1, 1) : 0; 
		}
	}

	public float ValueY{
		get{
			return pressed ? Mathf.Clamp((stickPosition.y - basePosition.y) / BaseJoystickRadius, -1, 1) : 0; 
		}
	}

	public Vector2 Direction{
		get{
			return pressed ? stickOffset.normalized : Vector2.zero; 
		}
	}

	bool InsideDefaultStick(Vector2 position){
		Vector2 diff = position - basePosition;
		return diff.magnitude <= StickRadius;
	}

	bool GetPressPosition(ref Vector2 position){
		#if !UNITY_WP8 || UNITY_EDITOR
		if (Input.GetKeyDown (KeyCode.Mouse0)) {
			position = new Vector2(Input.mousePosition.x, Screen.height - Input.mousePosition.y);
			return InsideDefaultStick(position);
		}
		return false;
		#else
		for (var i = 0; i < Input.touchCount; ++i) {
			var tap = Input.GetTouch(i);
			if(tap.phase == TouchPhase.Began){
				position = new Vector2(tap.position.x, Screen.height - tap.position.y);
				if(InsideDefaultStick(position)){
					fingerId = tap.fingerId;
					return true;
				}
			}
		}
		return false;
		#endif
	}

	bool FindTouch(int finger, ref Touch t){
		foreach (var touch in Input.touches) {
			if(touch.fingerId == finger){
				t = touch;
				return true;
			}
		}
		return false;
	}

	bool Released(){
		#if !UNITY_WP8 || UNITY_EDITOR
		return Input.GetKeyUp (KeyCode.Mouse0);
		#else
		Touch t = new Touch();
		if(!FindTouch(fingerId, ref t)){
			return true;
		}
		return (t.phase == TouchPhase.Ended) || (t.phase == TouchPhase.Canceled);
		#endif
	}

	Vector2 GetMovePosition(){
		#if !UNITY_WP8 || UNITY_EDITOR
		return new Vector2(Input.mousePosition.x, Screen.height - Input.mousePosition.y);
		#else
		Touch t = new Touch();
		FindTouch(fingerId, ref t);
		return new Vector2(t.position.x, Screen.height - t.position.y);
		#endif
	}
	
	// Update is called once per frame
	void Update () {
		basePosition = ScreenPosition.PixelPosition;
		stickPosition = basePosition;
		baseRect = new Rect (
			basePosition.x - BaseJoystickRadius, 
			basePosition.y - BaseJoystickRadius,
			BaseJoystickRadius * 2.0f, 
			BaseJoystickRadius * 2.0f);

		if (!pressed) {
			if (GetPressPosition(ref pressPosition)) {
				pressed = true;
			}
		} else {
			if (Released()) {
				pressed = false;
				stickOffset = Vector2.zero;
				angle = 0;
			}else{
				Vector2 touchPosition = GetMovePosition();
				stickOffset = touchPosition - pressPosition;
				if (stickOffset.magnitude > BaseJoystickRadius) {
					stickPosition = basePosition + stickOffset.normalized * BaseJoystickRadius;
				} else {
					stickPosition = basePosition + stickOffset;
				}

				Vector2 joyDir = Direction; 
				angle = Mathf.Atan2(joyDir.x, joyDir.y);
				angle = (Mathf.PI - Mathf.Abs(angle)) * Mathf.Sign(angle);
			}

		}

		stickRect = new Rect (
			stickPosition.x - StickRadius, 
			stickPosition.y - StickRadius,
			StickRadius * 2.0f, 
			StickRadius * 2.0f);

	}

	void OnGUI(){
		//GUI.DrawTexture (stickRect, circleImage);
		if (Event.current.type == EventType.Repaint) {
			Mat.SetColor("_TintColor", BaseColor);
			Graphics.DrawTexture (baseRect, circleImage, Mat);
			Mat.SetColor("_TintColor", StickColor);
			Graphics.DrawTexture (stickRect, circleImage, Mat);
		}

		GUI.Label(new Rect (
			baseRect.x, 
			baseRect.y - 40,
			baseRect.width , 
			20), (ValueY).ToString("##.###"));
	}
}