如何检测圆圈中的触摸 [英] how to detect touch in a circle

问题描述

我真的很帮助。我有点困惑。
i有一个圆形精灵，这个代码

I really assistance. Im a little confused. i have a circle sprite, and this code

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

CGSize winSize =[[CCDirector sharedDirector] winSize];
UITouch* myTouch = [touches anyObject];
CGPoint location = [myTouch locationInView: [myTouch view]];
location = [[CCDirector sharedDirector]convertToGL:location];

CCSprite *circleSprite = (CCSprite*)[self getChildByTag:30];
CGRect correctColorSprite1 = [circleSprite boundingBox];

   if (CGRectContainsPoint(correctColorSprite1, location)) {
   NSLog(@"inside");

}

因为我知道有一个边框

我已经读过一些论坛，我需要检测中心的精灵和触摸点的距离。但我真的不知道如何写的代码。我的圈子大小约为50分。

i have read in some forums that i need to detect distance of the centre of the sprite and the touch point. But i really don't know how to write that code. My circle size is around 50 points.

我希望有人可以帮助我给我一些改进的代码片段，以检测只在圆圈中的触摸。不与边界框。

I hope someone can help me out give me some snippets of a improved code to detect the touch only in the circle. Not with the bounding box. Your help is very great full.

推荐答案

请尝试以下操作：

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

CGSize winSize =[[CCDirector sharedDirector] winSize];
UITouch* myTouch = [touches anyObject];
CGPoint location = [myTouch locationInView: [myTouch view]];
location = [[CCDirector sharedDirector]convertToGL:location];

CCSprite *circleSprite = (CCSprite*)[self getChildByTag:30];
//CGRect correctColorSprite1 = [circleSprite boundingBox];
CGRect correctColorSprite1 = CGRectMake(
    circleSprite.position.x - (circleSprite.contentSize.width/2), 
    circleSprite.position.y - (circleSprite.contentSize.height/2), 
    circleSprite.contentSize.width, 
    circleSprite.contentSize.height);

//find the center of the bounding box
CGPoint center=ccp(correctColorSprite1.size.width/2,correctColorSprite1.size.height/2);

//now test against the distance of the touchpoint from the center
   if (ccpDistance(center, location)<50) 
   {
     NSLog(@"inside");

   }
}

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