用C#重写Unity3D的Joystick

/// <summary>
//Joystick.cs
//Penelope iPhone Tutorial
//
//Joystick creates a movable joystick (via GUITexture) that
//handles touch input, taps, and phases. Dead zones can control
//where the joystick input gets picked up and can be normalized.]
//
//Optionally, you can enable the touchPad property from the editor
//to treat this Joystick as a TouchPad. A TouchPad allows the finger
//to touch down at any point and it tracks the movement relatively
//without moving the graphic.
/// </summary>

using UnityEngine;
using System.Collections;

[RequireComponent(typeof(GUITexture))]

//A simple class for bounding how far the GUITexture will move
public class Boundary
{
public Vector2 min = Vector2.zero;
public Vector2 max = Vector2.zero;
}

public class Joystick : MonoBehaviour {
private static Joystick[] joysticks;				//A static collection of all joysticks
private static bool enumeratedJoysticks = false;
private static float tapTimeDelta = 0.3f;			//Time allowed between taps

public bool touchPad;								//Is this a TouchPad?
public Rect touchZone;
public Vector2 deadZone = Vector2.zero;				//Control when position is output
public bool normalize = false;						//Normalize output after the dead-done
public Vector2 position;							//[-1,1] in x,y
public int tapCount;								//Current tap count

private int lastFingerId = -1;						//Finger last used for this joystick
private float tapTimeWindow;						//how much time there is left for a tap to occur
private Vector2 fingerDownPos;
private float fingerDownTime;
private float firstDeltaTime = 0.5f;

private GUITexture gui;								//Joystick grapic
private Rect defaultRect;							//Default position / extents of the joystick graphic
private Boundary guiBoundary = new Boundary();		//Boundary for joystick graphic
private Vector2 guiTouchOffset;						//Offset to apply to touch input
private Vector2 guiCenter;							//Center of joystick

// Use this for initialization
void Start () {
//Cache this component at startup instead of looking up every frame
gui = GetComponent<GUITexture>();

//Store the default rect for gui, so we can snap back to it
defaultRect = gui.pixelInset;

defaultRect.x += transform.position.x * Screen.width;//+ gui.poxelInset.x;  //- Screen.width * 0.5;
defaultRect.y += transform.position.y * Screen.height;// -Screen.height * 0.5

transform.position = new Vector2 (0, 0);

if (touchPad)
{
//If a texture has been assigend, then use the rect ferom the gui as our touchZone
if (gui.texture)
touchZone = defaultRect;
}
else
{
//This is an offset for touch input to match with the top left
//corner of the GUI
guiTouchOffset.x = defaultRect.width * 0.5f;
guiTouchOffset.y = defaultRect.height * 0.5f;

//Cache the center of the GUI, since if donesn't change
guiCenter.x = defaultRect.x + guiTouchOffset.x;
guiCenter.y = defaultRect.y + guiTouchOffset.y;

//Let's build the GUI boundary, so we can clamp joystick movement
guiBoundary.min.x = defaultRect.x - guiTouchOffset.x;
guiBoundary.max.x = defaultRect.x + guiTouchOffset.x;
guiBoundary.min.y = defaultRect.y - guiTouchOffset.y;
guiBoundary.max.y = defaultRect.y + guiTouchOffset.y;
}
}

void Disable()
{
gameObject.SetActive (false);
enumeratedJoysticks = false;
}

void ResetJoystick()
{
//Release the finger control and set the joystick back to the default position
gui.pixelInset = defaultRect;
lastFingerId = -1;
position = Vector2.zero;
fingerDownPos = Vector2.zero;

if (touchPad)
{
Color c= gui.color;
c.a = 0.025f;
gui.color = c;
}
}

bool IsFingerDown()
{
return (lastFingerId != -1);
}

public void LatchedFinger(int fingerId)
{
//If another joystick has latched this finger, then we must releast it
if (lastFingerId == fingerId)
ResetJoystick();
}

// Update is called once per frame
void Update ()
{
if (!enumeratedJoysticks)
{
//Collect all joysticks in the game, so wo can relay finger latching messages
joysticks = (Joystick[])FindObjectsOfType(typeof(Joystick));
enumeratedJoysticks = true;
}

int count = Input.touchCount;

//Adjust the tap time window thile it stil available
if (tapTimeWindow > 0)
tapTimeWindow -= Time.deltaTime;
else
tapCount = 0;

if (count == 0)
ResetJoystick();
else
{
for(int i = 0; i < count; i++)
{
Touch touch = Input.GetTouch(i);
Vector2 guiTouchpos = touch.position - guiTouchOffset;

bool shouldLatchFinger = false;
if (touchPad)
{
if (touchZone.Contains(touch.position))
shouldLatchFinger = true;
}
else if (gui.HitTest(touch.position))
{
shouldLatchFinger = true;
}

//Latch the finger if this is a new touch
if (shouldLatchFinger && (lastFingerId == -1 || lastFingerId != touch.fingerId))
{
if (touchPad)
{
Color c = gui.color;
c.a = 0.15f;
gui.color = c;

lastFingerId = touch.fingerId;
fingerDownPos = touch.position;
fingerDownTime = Time.time;
}

lastFingerId = touch.fingerId;

//Accumulate taps if it is within the time window
if (tapTimeWindow > 0)
tapCount++;
else
{
tapCount = 1;
tapTimeWindow = tapTimeDelta;
}

//Tell other joysticks we've latched this finger
foreach(Joystick j in joysticks)
{
if (j != this)
j.LatchedFinger(touch.fingerId);
}
}
if (lastFingerId == touch.fingerId)
{
//Override the tap count with what the iPone SDK reports if it is greater
//This is a workaround, since the iPhone SDK does not currently track taps
//for multiple touches
if (touch.tapCount > tapCount)
tapCount = touch.tapCount;

if (touchPad)
{
//For a touchpad, let's just set the position directly based on distance form initial touchdown
position.x = Mathf.Clamp((touch.position.x - fingerDownPos.x) / (touchZone.width / 2), -1, 1);
position.y = Mathf.Clamp((touch.position.y - fingerDownPos.y) / (touchZone.height / 2), -1, 1);
}
else
{
//Change the location of teh joystick graphic to match where the touch is
Rect r = gui.pixelInset;
r.x = Mathf.Clamp(guiTouchpos.x, guiBoundary.min.x, guiBoundary.max.x);
r.y = Mathf.Clamp(guiTouchpos.y, guiBoundary.min.y, guiBoundary.max.y);
gui.pixelInset = r;
}

if (touch.phase == TouchPhase.Ended || touch.phase == TouchPhase.Canceled)
ResetJoystick();
}
}
}

if (!touchPad)
{
//Get a value between -1 and 1 based on the joystick graphic location
position.x = (gui.pixelInset.x + guiTouchOffset.x - guiCenter.x) / guiTouchOffset.x;
position.y = (gui.pixelInset.y + guiTouchOffset.y - guiCenter.y) / guiTouchOffset.y;
}

//Adjust for dead zone
float absoluteX = Mathf.Abs(position.x);
float absoluteY = Mathf.Abs(position.y);

if (absoluteX < deadZone.x)
{
//Report the joystick as being at the center if it is within the dead zone
position.x = 0.0f;
}
else if (normalize)
{
//Rescale the output after taking the dead zone into account
position.x = Mathf.Sign(position.x) * (absoluteX - deadZone.x) / (1 - deadZone.x);
}

if (absoluteY < deadZone.y)
{
//Report the joystick as being at the center if it is within the dead zone
position.y = 0;
}
else if (normalize)
{
//Rescale the output after taking the dead zone into account
position.y = Mathf.Sign(position.y) * (absoluteY - deadZone.y) / (1 - deadZone.y);
}
}
}