objective c - Detect touch within a radius of a node in SpriteKit -

i have player object in spritekit game , @ moment i'm moving using following code:

-(void)touchesbegan:(nsset *)touches withevent:(uievent *)event {     if (touches.count == 1)     {         [self touchesmoved:touches withevent:event];     } }   -(void)touchesmoved:(nsset*)touches withevent:(uievent*)event {     if (touches.count == 1)     {         [_player runaction:[skaction moveto:[[touches anyobject] locationinnode:self] duration:0.01]];     } } 

but want move player node when touch within specific range of location.

since looks care distance of touch _player object, move radius detection logic _player object , use skregion handle it.

note: if need know if touch within radius of multiple nodes might want use method this question instead.

to use skregion determine if touch within radius of _player, add skregion instance _player object , initialize radius want. in [_player init] or wherever makes sense project:

self.touchregion = [[skregion alloc] initwithradius:radius];

then add method determine if point within region:

- (bool)pointisintouchregion:(cgpoint)point {     return [self.touchregion containspoint: point]; } 

next change touchesmoved method like:

-(void)touchesmoved:(nsset*)touches withevent:(uievent*)event {     if (touches.count == 1)     {         uitouch *touch = [touches anyobject];         cgpoint point = [self locationinnode:_player]; // note: it's important use _player here!         if ([_player pointisintouchregion: point]) {             [_player runaction:[skaction moveto:[[touches anyobject] locationinnode:self] duration:0.01]];         }     } } 

note: using _player in [self locationinnode:_player]; critical since skregion defined in _player node's coordinate system.

one more note: don't have put logic in _player, that's way it. store skregion in scene's class , call [region containspoint: point] on directly.

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update: ios 7 method

the main difference doing ios 7 need store actual radius you're interested in rather skregion (since it's available in ios 8), , calculation in pointisintouchregion:.

so, in _player, set touch radius setting touchregion before:

self.touchradius = radius

then change pointisintouchregion: method actual distance calculation.

- (bool)pointisintouchregion:(cgpoint)point {     cgpoint centerofnode = cgpointmake(self.frame.size.width / 2.0, self.frame.size.height / 2.0); // note: if in skspritenode, might want use self.anchorpoint instead     cgfloat distancetocenter = return hypotf(point.x - centerofnode.x, point.y - centerofnode.y);     return (distancetocenter <= self.radius); } 

the code in touchesmoved should not need changes.