精灵触摸检测

Question

Have a question here. I created a couple sprites (with tags) in my (id)init function, and then merely trying to detect which sprite was touched? A snippet of the code from my init function is pasted below.

    [[CCSpriteFrameCache sharedSpriteFrameCache] addSpriteFramesWithFile:@"blue_sheet.plist"];
    //create a sprite batch node
    CCSpriteBatchNode *TrainerSprites = [CCSpriteBatchNode batchNodeWithFile:@"blue_sheet.png"];
    [self addChild:TrainerSprites z:1];

    //create a sprite from that node
    CCSprite *Horse = [CCSprite spriteWithSpriteFrameName:@"horse_blue.png"];
    [TrainerSprites addChild:Horse z:1 tag:1];
    //Horse.position = ccp(winSize.width/5, winSize.height/2);
    [Horse setScaleX: 138.5/Horse.contentSize.width];
    [Horse setScaleY: 80/Horse.contentSize.height];

    //create a sprite from that node
    CCSprite *Cow = [CCSprite spriteWithSpriteFrameName:@"cow_blue.png"];
    [TrainerSprites addChild:Cow z:1 tag:2];
    //Cow.position = ccp(winSize.width/2, winSize.height/2);
    [Cow setScaleX: 126/Cow.contentSize.width];
    [Cow setScaleY: 100/Cow.contentSize.height];

    Horse.position = ccp(4*winSize.width/5, winSize.height/2);
    Cow.position = ccp(winSize.width/5, winSize.height/2);

    CGRect pos1 = CGRectMake(Cow.position.x, Cow.position.y, 200, 100);
    CGRect pos2 = CGRectMake(Horse.position.x, Horse.position.y, 200, 100);

    self.touchEnabled = YES;

All looks fine... and the sprites appear where they are supposed to. When I touch anywhere on screen my ccTouchBegan function fires. Not seeing anything happen with the CGRect and I suppose I need to determine which one fired by the assigned tag. Yes indeedy, I know I'm missing code, I just cannot locate good solid documentation anywhere how to do this seemingly basic ios functionality. I assume the "sprite touch detection" code should reside inside the ccTouchBegan function? Any help or guidance sincerely appreciated. :)

Answer 1

to detect the sprite touch you can use this

declare CCSprite *Cow in your .h section

and in .m section use this
in init method

//create a sprite from that node
    Cow = [CCSprite spriteWithSpriteFrameName:@"cow_blue.png"];
    [TrainerSprites addChild:Cow z:1 tag:2];
    //Cow.position = ccp(winSize.width/2, winSize.height/2);
    [Cow setScaleX: 126/Cow.contentSize.width];
    [Cow setScaleY: 100/Cow.contentSize.height];

in touches began method

 -(void)ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
    {    
        UITouch * touch =[touches anyObject];
        CGPoint location=[touch locationInView:[touch view]];
        location =[[CCDirector sharedDirector] convertToGL:location];
        if (CGRectContainsPoint( [Cow boundingBox], location)) {

               /* CCScene *scene = [CCScene node];
                [scene addChild:[ClassicScene node]];
                [[CCDirector sharedDirector] replaceScene:scene];*/
            }

    }

Answer 2

Another approach could be to subclass CCSprite and implement the TargetedTouchDelegate .

Something like:

@interface AnimalSprite:CCSprite<CCTargetedTouchDelegate>

The advantage of this approach is that you wont have to do a lot of "If" checks in the layer where you are adding the sprites. The link provides the method that you must implement in orer to implement the protocol and where and how you could register with the touch dispatcher.