Iphone Cocos2d 坐标系

基本的两个坐标系：屏幕坐标系和GL坐标系。

屏幕坐标系:x轴朝右，y轴朝下。默认原点在左上角。

GL坐标系 :x轴朝右，y轴朝上。默认原点在左下角。

调用CCNode类的setPosition函数，它使用的就是GL坐标系。

在处理触摸事件时CCTouch对象中的坐标就是屏幕坐标系。

讲屏幕坐标系转换成GL坐标系调用：convertTouchToNodeSpace方法，它是CCNode的成员方法：

其实现如下

- (CGPoint)convertTouchToNodeSpace:(UITouch *)touch

{

CGPoint point = [touch locationInView: [touch view]];

point = [[CCDirector sharedDirector] convertToGL: point];

return [self convertToNodeSpace:point];

}

调用时：

-(BOOL) ccTouchBegan:(UITouch *)touch withEvent:(UIEvent *)event

{

CGPoint touchPoint =[self convertTouchToNodeSpace:touch];

return YES;

}

cocos2d的事件在CCLayer中处理。

1.CCLayer的isTouchEnabled，和registerWithTouchDispatcher 默认是不响应，需要手动设置

self.isTouchEnabled = YES;

-(void) registerWithTouchDispatcher

{

[[CCTouchDispatcher sharedDispatcher] addTargetedDelegate:self

priority:1

swallowsTouches:YES];

[[CCTouchDispatcher sharedDispatcher] addStandardDelegate:self

priority:0];

[super registerWithTouchDispatcher];

}

2.CCLayer需要实现CCStandardTouchDelegate，CCTargetedTouchDelegate两个协议

CCStandardTouchDelegate是 实现多点触控，委托方法如下：

@optional

- (void)ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event;

- (void)ccTouchesMoved:(NSSet *)touches withEvent:(UIEvent *)event;

- (void)ccTouchesEnded:(NSSet *)touches withEvent:(UIEvent *)event;

- (void)ccTouchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event;

CCTargetedTouchDelegate是 一点触控，委托方法如下：

- (BOOL)ccTouchBegan:(UITouch *)touch withEvent:(UIEvent *)event;

@optional

// touch updates:

- (void)ccTouchMoved:(UITouch *)touch withEvent:(UIEvent *)event;

- (void)ccTouchEnded:(UITouch *)touch withEvent:(UIEvent *)event;

- (void)ccTouchCancelled:(UITouch *)touch withEvent:(UIEvent *)event;