[Unity3D]手机3D游戏开发：关于自定义Joystick的相关设置和脚本源码

学习Unity脚本推荐：Unity3D官网索引

Joystick在手游开发中非常常见，也就是在手机屏幕上的虚拟操纵杆，但是Unity3D自带的Joystick贴图比较原始，所以经常有使用自定义贴图的需求。

下面就来演示一下如何实现自定义JoyStick贴图。

首先导入贴图，注意要把默认的Texture改为GUI要不然尺寸会发生改变：

在Inspector面板中点击Texture选项可以实现简单的贴图切换：

选中后便会发现场景中的Joystick已经发生了改变：

同理，可以对右边的Joystick做同样的修改：

当然很多时候这样简单的修改很难满足我们的需求。

下面来说说对Joystick的常见调整。

首先是坐标的调整，一般把Postition归零而在GUITexture中调整Pixel Inset：

但是这样依旧会出问题，全屏的时候因为采用了绝对坐标所以会出现这种情况：

所以我们还需要在脚本中稍作调整。

先来给Joystick加个背景图片。

创建一个JS脚本JoystickBackgroundGUI：

@script RequireComponent(Joystick)
@script ExecuteInEditMode ()


var background = new SwitchGUI();
var location = new Location();
private var GUIalpha:float = 1;


private var joystick : Joystick;
joystick = GetComponent (Joystick);

var noGuiStyle : GUIStyle;


function Update() {
	if (joystick.IsFingerDown()) {
		background.up();
	} else {
		background.down();
	}
	if (background.texture != null){
		location.updateLocation();
	}
}

function OnGUI () {
	GUI.color.a = GUIalpha;
	GUI.Box(Rect(location.offset.x + background.offset.x - background.texture.width/2,location.offset.y + background.offset.y - background.texture.height/2,background.texture.width,background.texture.height),background.texture,noGuiStyle);
}

joystick是Unity自己封装好的对象，其中有IsFingerDown等函数有需要的同学可以查阅一下Unity官网的说明文档。

脚本中用到了Location和SwitchGUI，这两个函数在另一个脚本   _GUIClasses   中定义：

import System.Collections.Generic;


// TextureGUI Class: create a basic class for creating and placing GUI elements
// texture = the texture to display
// offset = pixel offset from top left corner, can be modified for easy positioning

class TextureGUI {
	var texture:Texture; //useful: texture.width, texture.height
	var offset:Vector2; // .x and .y
	private var originalOffset:Vector2; //store the original to correctly reset anchor point
	enum Point { TopLeft, TopRight, BottomLeft, BottomRight, Center} //what part of texture to position around?
	
	var anchorPoint = Point.TopLeft; // Unity default is from top left corner of texture
		
	function setAnchor() { // meant to be run ONCE at Start.
		originalOffset = offset;
		if (texture) { // check for null texture
			switch(anchorPoint) { //depending on where we want to center our offsets
				case anchorPoint.TopLeft: // Unity default, do nothing
					break;
				case anchorPoint.TopRight: // Take the offset and go to the top right corner
					offset.x = originalOffset.x - texture.width;
					break;
					
				case anchorPoint.BottomLeft: // bottom left corner of texture
					offset.y = originalOffset.y - texture.height;
					break;
					
				case anchorPoint.BottomRight: //bottom right corner of texture
					offset.x = originalOffset.x - texture.width;
					offset.y = originalOffset.y - texture.height;
					break;
					
				case anchorPoint.Center: //and the center of the texture (useful for screen center textures)
					offset.x = originalOffset.x - texture.width/2;
					offset.y = originalOffset.y - texture.height/2;
					break;
			}
		}
	}	
}

//Timer Class:
	
	
class TimerGUI extends TextureGUI { // Extend functionality from TextureGUI for a depreciating timer graphic
	var textureLEnd:Texture; // left side of full texture (non stretching part)
	var offsetLEnd:Vector2; // left side of full texture (non stretching part) start position
	var textureCenter:Texture; // center of timer (will be stretched across width)
	var offsetCenter:Vector2; 
	var textureREnd:Texture;
	var offsetREnd:Vector2;
	var timerPerct:float = 1; // percentage (0 to 1) this stretches the center
	var desiredWidth:float = 403; // max width of the timer in pixels
	
	function setTime(newTime:float) {
		timerPerct = newTime; // sets the percent based on value
	}
}


// SwitchGUI Class: Extends the TextureGUI to be able to load in multiple textures and switch between them
class SwitchGUI extends TextureGUI {
	var switchableTextures = new List.();
	var currentTexture:int = 0;
	function Start() {
		if (switchableTextures.Count > 0) {
			texture = switchableTextures[currentTexture];
		}
	}
	function changeTexture(switchTo:int) {
		if (switchTo < switchableTextures.Count && switchTo >= 0) {
			texture = switchableTextures[switchTo];
			currentTexture = switchTo;
		} else {
			//Debug.Log( this + ": tried to call invalid part of switchTextures array!");
		}
	}
	
	function up() {
		if ((currentTexture+1) < switchableTextures.Count) {
			++currentTexture;
			texture = switchableTextures[currentTexture];
		} else {
			//Debug.Log( this + ": at the top!");
		}
	}
	
	function nextTexture() {
		if ((currentTexture+1) < switchableTextures.Count) { // if we are at the end of the array
			++currentTexture;
			texture = switchableTextures[currentTexture];
		} else {// loop to the beginning
			currentTexture = 0;
			texture = switchableTextures[currentTexture];
		}
	}
	
	function down() {
		if ((currentTexture-1) >= 0) {
			--currentTexture;
			texture = switchableTextures[currentTexture];
		} else {
			//Debug.Log( this + ": at the bottom!");
		}
	}

}

// Location class: 


class Location {
	enum Point { TopLeft, TopRight, BottomLeft, BottomRight, Center}
	
	var pointLocation = Point.TopLeft;
	var offset:Vector2;
	
		
	function updateLocation() {
		switch(pointLocation) {
			case pointLocation.TopLeft:
				offset = Vector2(0,0);
				break;
			case pointLocation.TopRight:
				offset = Vector2(Screen.width,0);
				break;
				
			case pointLocation.BottomLeft:
				offset = Vector2(0,Screen.height);
				break;
				
			case pointLocation.BottomRight:
				offset = Vector2(Screen.width,Screen.height);
				break;
				
			case pointLocation.Center:
				offset = Vector2(Screen.width/2,Screen.height/2);
				break;
		}		
	}
}

class TextureAnchor {
	enum Point { TopLeft, TopRight, BottomLeft, BottomRight, Center}
	
	var anchorPoint = Point.TopLeft;
	var offset:Vector2;
	
	function update() {
		switch(anchorPoint) {
			case anchorPoint.TopLeft:
				offset = Vector2(0,0);
				break;
			case anchorPoint.TopRight:
				offset = Vector2(Screen.width,0);
				break;
				
			case anchorPoint.BottomLeft:
				offset = Vector2(0,Screen.height);
				break;
				
			case anchorPoint.BottomRight:
				offset = Vector2(Screen.width,Screen.height);
				break;
				
			case anchorPoint.Center:
				offset = Vector2(Screen.width/2,Screen.height/2);
				break;
		}		
	}
}

将脚本拖拽到Joystick上面并且部署好贴图，运行可见Joystick的背景贴图，当然坐标还有点问题：

我们在脚本中将其设置为BottomLeft，并且设置好SwitchTexture：

配置好了之后点击运行，会发现Joystick 的贴图出现在了左下角：

通过脚本中的Pixel设置可以调整两个纹理贴图的坐标并使他们趋于一致：

调整之后的结果如图：

同时将Joystick的脚本换成下面的脚本，可以实现隐藏操纵杆而只在碰到摇杆区域才显示Joystick的效果：

//////////////////////////////////////////////////////////////
// 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
//////////////////////////////////////////////////////////////

#pragma strict

@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

private var alphaOff:float = 0.0;

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;
	
	gui.color.a = alphaOff;
    
    defaultRect.x += transform.position.x * Screen.width; // + gui.pixelInset.x; // -  Screen.width * 0.5;
    defaultRect.y += transform.position.y * Screen.height; //+ gui.pixelInset.y; // - 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;
	fingerDownPos = Vector2.zero;
	gui.color.a = alphaOff;	
}

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) as 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;
					gui.color.a = .5;
				}		
		
				// 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 );
		}
}

运行以下项目可以发现Joystick不见了：

但是点击屏幕就会出现了：