http://blog.csdn.net/xys289187120/article/details/6941061

     移动开发游戏中使用到的触摸游戏摇杆在iPhone上是非常普遍的，毕竟是全触摸屏手机，今天MOMO 通过一个小例子和大家讨论Unity3D 中如何自定义一个漂亮的全触摸游戏摇杆。

 

       值得高兴的是，Unity3D 游戏引擎的标准资源中已经帮助我们封装了一个游戏摇杆脚本，所以实现部分的代码可以完全借助它的，具体调用需要我们自己来。

 

 Joystick.js是官方提供的脚本，具体代码如下，有兴趣的朋友可以仔细研究研究，MOMO就不多说啦。哇咔咔～

 

 

//
// Joystick.js
// 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
//

@script RequireComponent( GUITexture )

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

static private var joysticks : Joystick[];                  // A static collection of all joysticks
static private var enumeratedJoysticks : boolean = false;
static private var tapTimeDelta : float = 0.3;              // Time allowed between taps

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

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

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

function Start()
{
    // Cache this component at startup instead of looking up every frame
    gui = GetComponent( GUITexture );

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

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

    transform.position.x = 0.0;
    transform.position.y = 0.0;

    if ( touchPad )
    {
        // If a texture has been assigned, 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 * 0.5;
        guiTouchOffset.y = defaultRect.height * 0.5;

        // Cache the center of the GUI, since it doesn'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;
    }
}

function Disable()
{
    gameObject.active = false;
    enumeratedJoysticks = false;
}

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

    if ( touchPad )
        gui.color.a = 0.025;
}

function IsFingerDown() : boolean
{
    return (lastFingerId != -1);
}

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

function Update()
{
    if ( !enumeratedJoysticks )
    {
        // Collect all joysticks in the game, so we can relay finger latching messages
        joysticks = FindObjectsOfType( Joystick );
        enumeratedJoysticks = true;
    }

    var count = Input.touchCount;

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

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

            var 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 )
                {
                    gui.color.a = 0.15;

                    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
                for ( var j : Joystick in joysticks )
                {
                    if ( j != this )
                        j.LatchedFinger( touch.fingerId );
                }
            }

            if ( lastFingerId == touch.fingerId )
            {
                // Override the tap count with what the iPhone 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 from 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 the joystick graphic to match where the touch is
                    gui.pixelInset.x =  Mathf.Clamp( guiTouchPos.x, guiBoundary.min.x, guiBoundary.max.x );
                    gui.pixelInset.y =  Mathf.Clamp( guiTouchPos.y, guiBoundary.min.y, guiBoundary.max.y );
                }

                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
    var absoluteX = Mathf.Abs( position.x );
    var 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;
    }
    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 );
    }
}

 

 

 

 

 

 

单击Create 创建一个GUI Texture，命名为Joy ，它用来显示游戏摇杆，如下图所示将摇杆的图片资源，与摇杆的脚本连线赋值给Joy.  Pixel Inset 中可以设置摇杆的显示位置与显示宽高。

 

 

 

 

 

到这一步 build and run 就可以在iPhone上看到这个游戏摇杆，并且可以通过触摸它，360度平滑过度。

 

 

在屏幕中绘制一个飞机，通过游戏摇杆去控制飞机的移动。

 

创建一个脚本，命名为Main.js 如下图所示  将 Main.js 、joy、plan 分别 绑定在Main Camera 上。

 

 

 

 

moveJoystick.position.x;

moveJoystick.position.y;

 

这两个值是非常重要的两个信息，它们的取值范围是 -1 到 +1 ，表示 用户触摸摇杆的位置， 上 下 左 右 的信息。

 

 

//游戏摇杆对象
var moveJoystick : Joystick;

//飞机的贴图
var plan : Texture;

//飞机在屏幕中的坐标
var x = 0;
var y = 0;

//避免飞机飞出屏幕，分别是X、Y最大坐标，最小坐标是0、0
var cross_x = 0;
var cross_y = 0;

//飞机移动的速度
var planSpeed = 20;

function Start() {
    //初始化赋值
    x = 100;
    y = 100;
    cross_x = Screen.width -  plan.width;
    cross_y = Screen.height -  plan.height;

}

function Update () {
    //得到游戏摇杆的反馈信息，得到的值是 -1 到 +1 之间

    var touchKey_x =  moveJoystick.position.x;
    var touchKey_y =  moveJoystick.position.y;

    //摇杆向左
    if(touchKey_x == -1){
        x -= planSpeed;

    }
    //摇杆向右
    else if(touchKey_x == 1){
        x += planSpeed;

    }
    //摇杆向上
    if(touchKey_y == -1){
        y += planSpeed;

    }
    //摇杆向下
    else if(touchKey_y == 1){
        y -= planSpeed;

    }

    //防止飞机飞出屏幕，出界检测
    if(x < 0){
        x = 0;
    }else if(x > cross_x){
        x = cross_x;
    }

    if(y < 0){
        y = 0;
    }else if(y > cross_y){
        y = cross_y;
    }
}




function OnGUI () {


  //将飞机绘制在屏幕中
  GUI.DrawTexture(Rect(x,y,128,128),plan);

}

 

导出 build and run  看看在iPhone 上的效果，通过触摸游戏摇杆可以控制飞机的移动啦，不错吧，哇咔咔～～

 

 

 

 

 

 

 

最后欢迎各位盆友可以和MOMO一起讨论Unity3D游戏开发，最近感冒的盆友越来越多，大家要多多注意身体健康噢。哇咔咔～～～ 附上Unity3D工程的下载地址，Xcode项目我就不上传了，须要的自己导出。

 

下载地址：