检测 Cocos2d-iphone 上是否触摸了特定精灵

Question

我正在按照 Ray 的教程制作一个简单的 iPhone 游戏（此处：http://goo.gl/fwPi ），并决定我希望敌人在被触碰时被消灭。

我最初的方法是在触摸位置生成一个小的 CCSprite 精灵，然后使用 CGRectMake 创建所述精灵的边界框以检测敌人精灵是否被触摸。就像雷对射弹/敌人所做的那样。但当然，我的方法行不通，我无法把自己从这个洞里挖出来。

这是相关的代码片段。任何帮助表示赞赏：

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

    // Choose one of the touches to work with
    UITouch *touch = [touches anyObject];
    CGPoint location = [self convertTouchToNodeSpace: touch];
    location = [[CCDirector sharedDirector] convertToGL:location];
    CCSprite *touchedarea = [CCSprite spriteWithFile:@"Icon-72.png" rect:CGRectMake(location.x, location.y, 2, 2)];
    touchedarea.tag = 2;
    [self addChild:touchedarea];
    [_touchedareas addObject:touchedarea];

}



- (void)update:(ccTime)dt {

    NSMutableArray *touchedareasToDelete = [[NSMutableArray alloc] init];
    for (CCSprite *touchedarea in _touchedareas) {
        CGRect touchedareaRect = CGRectMake(
                                           touchedarea.position.x, 
                                           touchedarea.position.y, 
                                           touchedarea.contentSize.width, 
                                           touchedarea.contentSize.height);

        NSMutableArray *targetsToDelete = [[NSMutableArray alloc] init];
        for (CCSprite *target in _targets) {
            CGRect targetRect = CGRectMake(
                                           target.position.x - (target.contentSize.width/2), 
                                           target.position.y - (target.contentSize.height/2), 
                                           target.contentSize.width, 
                                           target.contentSize.height);

            if (CGRectIntersectsRect(touchedareaRect, targetRect)) {
                [targetsToDelete addObject:target];             
            }                       
        }

        for (CCSprite *target in targetsToDelete) {
            [_targets removeObject:target];
            [self removeChild:target cleanup:YES];                                  
        }

        if (targetsToDelete.count > 0) {
            [touchedareasToDelete addObject:touchedarea];
        }
        [targetsToDelete release];
    }

    for (CCSprite *touchedarea in touchedareasToDelete) {
        [_touchedareas removeObject:touchedarea];
        [self removeChild:touchedarea cleanup:YES];
    }
    [touchedareasToDelete release];
}

Answer 1

这看起来是一种非常困难的方法。我自己编码时间不长，但也许以下内容可能对您有所帮助。
假设你有一个名为敌人的 nsmutable 数组，并且在创建敌人时将新的敌人对象添加到该数组中。敌人对象将是一个 ccnode，并且其中有一个名为 _enemySprite 的 ccsprite
然后触摸

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

    NSSet *allTouches = [event allTouches];
    UITouch * touch = [[allTouches allObjects] objectAtIndex:0];
    //UITouch* touch = [touches anyObject];
    CGPoint location = [touch locationInView: [touch view]];
    location = [[CCDirector sharedDirector] convertToGL:location]; 

    int arraysize = [enemies count];
    for (int i = 0; i < arraysize; i++) {


        if (CGRectContainsPoint( [[[enemies objectAtIndex:i] _enemySprite] boundingBox], location)) {

            //some code to destroy ur enemy here


        }
    }
    //  NSLog(@"TOUCH DOWN");

}

希望这有帮助

Answer 2

另一种方法是计算触摸位置和你的精灵之间的距离。如果触摸距离你的一个精灵足够近，你可以杀死它。像这样的事情..

for (CCSprite *sprite in anArrayThatCOntainsAllYourSprites) {

  float distance = pow(sprite.position.x - location.x, 2) + pow(sprite.position.y - location.y, 2);

   distance = sqrt(distance);

         if (distance <= 10) {
                sprite.dead  = YES;
         }

}