Cocos2d中添加手势支持的三种方法

最近一直琢磨在Cocos2d里添加手势的功能，找了一些资料加上自己的理解，整理出了三种方法和大家分享。

第一种，很简单，就是知易cocos2d-iPhone教程-04所介绍的（其实这并不是真正的手势，只是也能实现部分手势功能而已），代码如下：

1） 单击、双击处理

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{ 
	//Get all the touches. 
	NSSet *allTouches = [event allTouches]; 
	//Number of touches on the screen 
	switch ([allTouches count]) 
	{ 
		case 1: 
		{ 
			//Get the first touch. 
			UITouch *touch = [[allTouches allObjects] objectAtIndex:0]; 
			switch([touch tapCount]) 
			{ 
				case 1://Single tap 
					// 单击！！ 
					break; 
				case 2://Double tap. 
					// 双击！！ 
					break; } 
			} 
			break; 
		}
	}
}

2） 两个指头的分开、合拢手势。

//计算两个点之间的距离函数
- (CGFloat)distanceBetweenTwoPoints:(CGPoint)fromPoint toPoint:(CGPoint)toPoint
{
	float x = toPoint.x - fromPoint.x;
	float y = toPoint.y - fromPoint.y;
	return sqrt(x * x + y * y);
}

//记录多触点之间的初始距离
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
	NSSet *allTouches = [event allTouches];
	switch ([allTouches count])
	{
		case 1: { //Single touch
			break;}
		case 2: { //Double Touch
			//Track the initial distance between two fingers.
			UITouch *touch1 = [[allTouches allObjects] objectAtIndex:0];
			UITouch *touch2 = [[allTouches allObjects] objectAtIndex:1];
			initialDistance = [self distanceBetweenTwoPoints:[touch1 locationInView:[self view]] toPoint:[touch2 locationInView:[self view]]];
			}
			break;
		default:
			break;
	}
}

//两个指头移劢时，判断是分开还是合拢
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
	NSSet *allTouches = [event allTouches];
	switch ([allTouches count])
	{
		case 1:
			break;
		case 2:{
			UITouch *touch1 = [[allTouches allObjects] objectAtIndex:0];
			UITouch *touch2 = [[allTouches allObjects] objectAtIndex:1];
			//Calculate the distance between the two fingers.
			CGFloat finalDistance = [self distanceBetweenTwoPoints: [touch1 locationInView:[self view]] toPoint:[touch2 locationInView:[self view]]];
			//Check if zoom in or zoom out.
			if(initialDistance > finalDistance) {
				NSLog(@"Zoom Out"); // 合拢！！
			}
			else {
				NSLog(@"Zoom In"); // 分开！！
			}
			} 
			break;
	}
}

第二种，是在Cocoa China中找的一种办法，它的原理是通过修改CCLayer，CCNode两个Cocos2d类的源码实现手势支持：

1.首先要修改两个Cocos2d类的源码分别为CCLayer，CCNode

2.增加手势类源码 CCGestureRecognizer

以上三个类的源码，可以在我的资源中找着（地址：http://download.csdn.net/detail/wangqiuyun/4460442），(记住CCLayer与CCNode要覆盖原来的文件)
CCGestureRecognizer.h与.m要拷贝到当前工程的libs/cocos2d/Platforms/iOS目录下
在工程文件中加入CCGestureRecognizer.h与.m

3.完成以上工作后所有Node的子类中都可以使用手势了，如在HelloWorld工程中：

1)修改HelloWorldLayer.m中的init方法加入以下代码：

        //定义响应的手势类(支持所有UI手势)
        UILongPressGestureRecognizer * longPress = [[[UILongPressGestureRecognizer alloc] init] autorelease];
        longPress.minimumPressDuration = 0.5f;
        longPress.allowableMovement = 5.0f;
        //将UI手势对象longPress作为CCGestureRecognizer类的初始化参数
        //@selector(longPress:node:) 为响应手势的触发方法
        CCGestureRecognizer * rescognizer = [CCGestureRecognizer CCRecognizerWithRecognizerTargetAction:longPress target:self action:@selector(longPress:node:)];
        //设置手势类的代理
        rescognizer.delegate = self;
        //为self (当前为CCLayer对象)注册手势
        [self addGestureRecognizer:rescognizer];
        //必须设置self可接收Touch事件
        self.isTouchEnabled = YES;

2)另需要增加响应方法的实现：

-(void) longPress:(UIGestureRecognizer *) recognizer node:(CCNode *) node
{
    CCLOG(@"%s",__FUNCTION__);
}

3)需要支持协议UIGestureRecognizerDelegate 头文件如下：

#import "cocos2d.h"

// HelloWorldLayer
@interface HelloWorldLayer : CCLayer<UIGestureRecognizerDelegate>
{
}

// returns a CCScene that contains the HelloWorldLayer as the only child
+(CCScene *) scene;
-(void) longPress:(UIGestureRecognizer *) recognizer node:(CCNode *) node;
@end

第三种，自己琢磨的一种办法，个人感觉也还不错。

1)默认情况下面，cocos2d 模板并没有在AppDelegate里面包含一个RootViewController的属性，因此必须手动添加一个：
跳转到AppDelegate.h文件，并添加下面的代码：

@property (nonatomic, retain) RootViewController*viewController;

然后跳转到AppDelegate.m，@synthesize之：

@synthesize viewController; 

2)在场景或者层中m文件中，#import "AppDelegate.h"

+(id) scene
{
	//给层添加手势支持
	CCScene *scene = [CCScene node];
	
	// 'layer' is an autorelease object.
	HelloWorld *layer = [HelloWorld node];
	
	UIPanGestureRecognizer *gestureRecognizer = [[[UIPanGestureRecognizer alloc] initWithTarget:layer action:@selector(handlePanFrom:)] autorelease];
    
	AppDelegate *delegate=(AppDelegate *)[UIApplication sharedApplication].delegate;

	[delegate.viewController.view addGestureRecognizer:gestureRecognizer];
	
	// add layer as a child to scene
	[scene addChild: layer];
	
	// return the scene
	return scene;
}

//手势识别函数
- (void)handlePanFrom:(UIPanGestureRecognizer *)recognizer {
    
    if (recognizer.state == UIGestureRecognizerStateBegan) {    
        
        CGPoint touchLocation = [recognizer locationInView:recognizer.view];
        touchLocation = [[CCDirector sharedDirector] convertToGL:touchLocation];
        touchLocation = [self convertToNodeSpace:touchLocation];                
        //实现的效果.. 
        
    } else if (recognizer.state == UIGestureRecognizerStateChanged) {    
        
        CGPoint translation = [recognizer translationInView:recognizer.view];
        translation = ccp(translation.x, -translation.y);
        //实现的效果.. 
        [recognizer setTranslation:CGPointZero inView:recognizer.view];    
        
    } else if (recognizer.state == UIGestureRecognizerStateEnded) {
        
        //实现的效果..        
        
    }        
}

以上是本人总结的三种在Cocos2d里添加手势支持的方法，不妥之处欢迎各位指教！