CCSprite disappears for unknown reason - objective-c

Question

-(void)touchBegan:(UITouch*)touch withEvent:(UIEvent*)event {
CGPoint touchPoint = [touch locationInNode:self];
[_gameBall setPosition:CGPointMake(touchPoint.x,self.gameBall.position.y)];
}
After a touch the _gameball sprite is not visible anymore, any reason why this happens?I logged it and isvisible for gameball is true and the touchpoint is always within the content size of my CCNode.
#import "GameScene.h"
#interface GameScene()
#property (nonatomic,strong) CCSprite* gameBall;
#end
#implementation GameScene
#synthesize gameBall = _gameBall;
+(GameScene*)gameInstance
{
return [[self alloc]init];
}
-(id)init
{
self = [super init];
if (self) {
//Implement
//user interaction
self.userInteractionEnabled = YES;
//Create the ball
_gameBall = [CCSprite spriteWithImageNamed:#"small_blue_ball.png"];
_gameBall.position = ccp(0.5f,0.1f);
_gameBall.positionType = CCPositionTypeNormalized;
[self addChild:_gameBall];
}
return self;
}
-(void)onEnter
{
[super onEnter];
}
-(void)onExit
{
[super onExit];
}
-(void)touchBegan:(UITouch *)touch withEvent:(UIEvent *)event
{
CGPoint touchPoint = [touch locationInNode:self];
touchPoint = [self convertToNodeSpace:touchPoint];
[_gameBall setPosition:CGPointMake(touchPoint.x, self.gameBall.position.y)];
NSLog(#"%f , %f",_gameBall.position.x,_gameBall.position.y);
}
-(void)touchMoved:(UITouch *)touch withEvent:(UIEvent *)event
{
}
#end
that was the .m file
now the .h file
#import "cocos2d-ui.h"
#import "cocos2d.h"
#interface IntroScene : CCScene
+(CCScene*)scene;
#end

Answer 1

CGPoint touchPoint = [touch locationInNode:self];
touchPoint = [self convertToNodeSpace:touchPoint];
might be your problem.. try changing it to:
CGPoint touchPoint = [touch locationInView:[touch view]];
touchPoint = [self convertToNodeSpace:touchPoint];
-edit-
ok, try:
CGPoint touchPoint = [touch locationInView:[touch view]];
touchPoint = [[self parent] convertToNodeSpace:touchPoint];
-edit2-
just noticed the cgpointmake:
[_gameBall setPosition:CGPointMake(touchPoint.x, self.gameBall.position.y)];
might not do anything special, but you should keep your code monotone, as in if you used _gameball.position then also use _gameball.position.y
So might want to change it to:
_gameBall setPosition:CGPointMake(touchPoint.x, _gameBall.position.y)];
-edit3-
this seems to work for me:
CGPoint touchPoint = [touch locationInView:[touch view]];
touchPoint = [[_gameBall parent] convertToNodeSpace:touchPoint];
[_gameBall setPosition:ccp(touchPoint.x, _gameBall.position.y)];
-Final edit-
Since you are using cocos2d, also use their ccTouchesBegan function.. Change it to:
-(void)ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
NSArray* touchArray = [touches allObjects];
for (UITouch* touch in touchArray)
{
CGPoint touchPoint = [touch locationInView:[touch view]];
touchPoint = [_gameBall convertToNodeSpace:touchPoint];
[_gameBall setPosition:ccp(touchPoint.x, _gameBall.position.y)];
break;
}
}
if it doesn't register touches, then add: [self setTouchEnabled:YES]; to your scene.