手机3D游戏开发：自定义Joystick的相关设置和脚本源码

浏览数：32 / 时间：2015年06月11日

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：

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@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：

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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.<Texture>();
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：

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//////////////////////////////////////////////////////////////
// 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 );
}
}