cocos2d for iPhone

A fast, easy to use, free, and community supported 2D game engine

1. 

   eshirt
   Member

   I'm trying to implement touches in my Layer and my app is crashing every time I tap the screen. I'm running 0.8.1, using Fast Director, touches are enabled on the layer. When the app crashes, it doesn't leave any info about the crash in the gdb console. I haven't run it through Instruments yet to get the stack trace, but I thought someone here might know why it's not working. Here's the code for ccTouchesBegan:

   - (BOOL)ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
   	UITouch *touch = [touches anyObject];
   	CGPoint location = [touch locationInView: [touch view]];
   	location = [[Director sharedDirector] convertCoordinate: location];
   	NSLog(@"touch registered at %@", location);
   	return kEventHandled;
   }

   Pretty simple, I'm just trying to get down to basics and record a touch point. Am I being stupid and missing something easy? This seems to be identical to the code that works for other members of this board.

   Posted 2 years ago #
2. 

   eshirt
   Member

   A little more info - the layer is using Box2D methods, but that shouldn't change how touch events are handled, right?

   Also, the debugger only give me this: “EXC_BAD_ACCESS”

   So, it seems to be a memory access error. Why would that be happening?

   Posted 2 years ago #
3. 

   eshirt
   Member

   Ugh, it's been that kind of day. Rookie mistake - I was trying to use %@ to return a float value. For future reference, here's the correct code:

   - (BOOL)ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
   
   	UITouch *touch = [touches anyObject];
   	CGPoint location = [touch locationInView:[touch view]];
   	CGPoint convertedLocation = [[Director sharedDirector] convertCoordinate: location];
   	NSLog(@"Touched at point: %f, %f", convertedLocation.x, convertedLocation.y);
   	return YES;
   
   }

   Sorry to clog up the forum with this. BTW - it was this brand new blog post that helped me out: http://www.cocos2d-iphone.org/archives/437 That free chapter from the Apress book mentioned an ObjC flag you put in the breakpoint editor to help trace EXC_BAD_ACCESS errors. I can't believe I've never seen that tip! Such a time saver!

   Posted 2 years ago #
4. 

   Codemattic
   Moderator

   I think you may have a problem with NSLog. You use the %@, but location is a CGPoint which isnt a Cocoa object. Some things to try:

   http://stackoverflow.com/questions/1476532/nslog-with-cgpoint-data

   [edit] OK - looks like you figured it out - but the above link has some other interesting solutions I wouldnt have thought of.

   Posted 2 years ago #
5. 

   eshirt
   Member

   Codemattic - thanks for your help, seems like you were probably typing your response right as I figured it out.

   Posted 2 years ago #

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