cocos2d for iPhone

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

1. 

   dnsolo
   Member

   Hi all,

   I've been trying to convert the code from the article below to v0.8.1 of Cocos2D.

   http://juanmunozar.blogspot.com/2009/02/cocos2d-iphone-dynamically-touch.html

   I understand from Riq that I need to replace 'absolutePosition' with 'convertToWorldSpace:CGPointZero'.

   I've tried making these changes but when testing no touches are being registered.

   Does my new code look okay?

   // OLD CODE
   - (CGRect) rect {// rectangle that contains the sides coords of each sprite.
   float x = [self absolutePosition].x - [self contentSize].width/2;
   float y = [self absolutePosition].y - [self contentSize].height/2;
   float h = [self contentSize].height;
   float w = [self contentSize].width;
   return CGRectMake(x,y,w,h);
   }

   // NEW CODE
   - (CGRect) rect {
   float x = [self convertToWorldSpace:CGPointZero].x - [self contentSize].width / 2;
   float y = [self convertToWorldSpace:CGPointZero].y - [self contentSize].height / 2;
   float h = [self contentSize].height;
   float w = [self contentSize].width;
   return CGRectMake(x, y, w, h);
   }

   Posted 2 years ago #
2. 

   dnsolo
   Member

   I'm still really struggling with this problem. any ideas?

   Posted 2 years ago #
3. 

   PhilM
   Member

   Try adding an NSLog statement either in your rect method, or the touch method your calling this from to see what co-ords your getting.

   e.g. at the bottom of your rect method (before the return) try adding something like:
   NSLog(@"x: %0.2f y: %0.2f w: %0.2f h: %0.2f", x, y, w, h);

   That should hopefully point out if theres an issue here, or somewhere else...

   Posted 2 years ago #
4. 

   dnsolo
   Member

   Hi PhilM,

   I've inserted your code and the output (when clicking on the approximate 'centre' of the sprite) was:

   x: 115.00 y: 120.00 w: 40.00 h: 40.00

   The width and height values are correct but I'm not sure about the 'X' and 'Y' values.

   The sprite is being positioned like this:

   [mySprite setPosition: ccp(160, 160)];

   My touch detection code looks like this:

   UITouch *touch = [touches anyObject];
   CGPoint location = [touch locationInView: [touch view]];
   CGPoint cLoc = [[Director sharedDirector] convertCoordinate: location];

   if([TouchSprite SomethingWasTouched:cLoc]) {
   NSArray *mySprites = [TouchSprite allSprites];
   NSUInteger i, count = [mySprites count];
   for(i = 0; i < count; i++) {
   TouchSprite *obj = (TouchSprite *)[mySprites objectAtIndex:i];
   if([obj visible] && CGRectContainsPoint([obj rect], location) && [obj GetCanTrack]) {
   // The code here is only executed if a trackable sprite has been touched
   if([obj tag] == kMySprite1) {
   [obj runAction: [FadeOut actionWithDuration:1.0]]; // Fade out the sprite that was touched
   }
   }
   }
   return kEventHandled;
   }

   I've done some more investigation and discovered where the problem lies.

   It's in this method:

   +(BOOL)SomethingWasTouched:(CGPoint) pos {
   NSUInteger i, count = [allSprites count];
   for (i = 0; i < count; i++) {
   TouchSprite *obj = (TouchSprite *)[allSprites objectAtIndex:i];
   if(CGRectContainsPoint([obj rect], pos) && [obj GetCanTrack]) {
   return YES;
   }
   }
   return NO;
   }

   The 'if(CGRectContainsPoint([obj rect], pos)' condition always fails.

   In this example I also printed out the 'pos' x and y values, these were:

   x: 154.00
   y: 162.00

   Any ideas why this is failing?

   Posted 2 years ago #
5. 

   Steve Oldmeadow
   Administrator

   What is wrong with using TouchDispatcher/TouchHandler as per the TouchesTest example? The way I see it the code in that article is redundant now.

   Posted 2 years ago #
6. 

   dnsolo
   Member

   Hi Steve,

   Yes, I was thinking about using the TouchDispatcher system as an alternative approach.

   But I'm treating this as a learning exercise and would really like to get it working properly.

   The only difference in my code (compared to: http://juanmunozar.blogspot.com/2009/02/cocos2d-iphone-dynamically-touch.html) is I'm using Riq's suggested approach to replacing the 'absolutePosition' method (now no longer available in v0.8.1):

   So this old code...

   - (CGRect) rect {
   float x = [self absolutePosition].x - [self contentSize].width/2;
   float y = [self absolutePosition].y - [self contentSize].height/2;
   float h = [self contentSize].height;
   float w = [self contentSize].width;
   return CGRectMake(x,y,w,h);
   }

   Is changed to this...

   - (CGRect) rect {
   CGPoint absolutePosition = [self convertToWorldSpace:CGPointZero];
   float x = absolutePosition.x - [self contentSize].width / 2;
   float y = absolutePosition.y - [self contentSize].height / 2;
   float w = [self contentSize].width;
   float h = [self contentSize].height;
   return CGRectMake(x, y, w, h);
   }

   I don't know why this doesn't work. I do remember though that a bug was found in the 'convertToWorldSpace' method a couple of months ago, but I don't know if that was fixed though.

   Posted 2 years ago #
7. 

   PhilM
   Member

   Yea it certainly looks like your x & y are off. I haven't used the convertToWorldSpace method yet, so not too sure I'm afraid.

   I'd try Steve's suggestion of the touch dispatcher for now, and perhaps keep this code on the side, something may pop out at you as you implement the other method. Or perhaps someone else will confirm whether its a bug or not. Perhaps your scene/layer/node structure is triggering an issue no one else has come across yet.

   Posted 2 years ago #
8. 

   dnsolo
   Member

   After much trial and error I've finally managed to get this touch code working!

   To clarify this solution to other games developers, if you want to use the Touch system (for Cocos2D v0.8.1) described by Juan Sebastian at:

   http://juanmunozar.blogspot.com/2009/02/cocos2d-iphone-dynamically-touch.html

   Then you will need to change the code in Juan's example project from this...

   - (CGRect) rect {
   float x = [self absolutePosition].x - [self contentSize].width/2;
   float y = [self absolutePosition].y - [self contentSize].height/2;
   float h = [self contentSize].height;
   float w = [self contentSize].width;
   return CGRectMake(x,y,w,h);
   }

   To this...

   - (CGRect) rect {
   float x = [self position].x - [self contentSize].width / 2;
   float y = [self position].y - [self contentSize].height / 2;
   float w = [self contentSize].width;
   float h = [self contentSize].height;
   return CGRectMake(x,y,w,h);
   }

   Please note, you could also use the new TouchDispatcher/TouchHandler system (see the 'TouchesTest' example) to achieve the same (and even greater) functionality.

   Personally, I only currently need to track single touches for moving objects and so Juan's approach works great.

   If you need to track moving sprites (and therefore moving touch points) on the screen then I can highly recommend
   Juan's touch system.

   Posted 2 years ago #

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