touchesEnded

Question

I have a simple OpenGL:ES application running (it is a game). The game loads and presents the user with a "new game button" and then you are in the game. I'm using touchesBegan / touchesEnded to handle the touches. Then I take the coordinates and process them accordingly.

I also have an NSTimer running at 30Hz that calls renderScene which draws the on screen graphics.

Every once in a while on the device (I have yet to have this happen on the simulator) I don't get anymore touch events after the first one. I have attempted to debug this on the device and it appears that after I get the first touchesEnded event come in, the device is bombarded by touchesEnded calls. I NEVER get another touchesBegan call when this happens. If I press home and come back into the game, everything will usually work fine.

Here is the code for my input, as it exists in my EAGLView.m code

#pragma mark    
#pragma mark UserInputStuff
#pragma mark    

#pragma mark 
#pragma mark touchesBegan
#pragma mark    

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [touches anyObject];
firstTouch = [touch locationInView:self];
lastTouch = [touch locationInView:self];
[(MyGameAppDelegate*)[[UIApplication sharedApplication] delegate]   HandleTouchEvent:firstTouch]; 

}

#pragma mark    
#pragma mark touchesEnded
#pragma mark    

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent*)event 
{
UITouch *touch = [touches anyObject];
lastTouch = [touch locationInView:self];
[(MyGameAppDelegate*)[[UIApplication sharedApplication] delegate] HandleTouchEnded:lastTouch]; 
}

And here is the code as it exist in my app delegate

#pragma mark 
#pragma mark HandleTouchEnded
#pragma mark A function to react to the touch that is no longer present on the screen
#pragma mark

- (void)HandleTouchEnded:(CGPoint)coordinate
{
if(_state == kState_Title)
{
 [self TitleCollisionDetection:coordinate];
 if(_buttonHighlighted)
 {
  _textures[kTexture_Background] = [[Texture2D alloc] initWithImage:[UIImage imageNamed:@"T4Background.png"]];
  glBindTexture(GL_TEXTURE_2D, [_textures[kTexture_Background] name]);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);   
  [self resetGame];
 }
}
}

And here is the code that configures the timer that fires to handle the renderer.

//Start rendering timer
_timer = [NSTimer scheduledTimerWithTimeInterval:(1.0 / kRenderingFPS) target:self   selector:@selector(renderScene) userInfo:nil repeats:YES];
[UIApplication sharedApplication].idleTimerDisabled = YES;

I'm obviously doing something dumb. What am I missing? Why is touchesEnded firing so often?

Answer 1

[(MyGameAppDelegate*)[[UIApplication sharedApplication] delegate] HandleTouchEnded: firstTouch];

is the exact same as

[(MyGameAppDelegate*)[[UIApplication sharedApplication] delegate] HandleTouchEnded: lastTouch];

You aren't getting bombarded by TouchsEnded. You are getting bombarded by the fact that your firstTouch and your lastTouch objects are the same object!

You should put NSLog fuctions in you touchesBegan: and touchesEnded: next time to confirm the behavour.

Answer 2

Actually it turned out that there was an errant second call to start the NSTimer

_timer = [NSTimer scheduledTimerWithTimeInterval:(1.0 / kRenderingFPS) target:self selector:@selector(renderScene) userInfo:nil repeats:YES];

This caused the program to be starved for mainline execution time as it was constantly servicing the timer routines.

The PERFORMANCE ANALYZER IS YOUR FRIEND!!! I found this because while I thought my app was supposed to be running at 30fps, I was seeing results north of 50fps. At first I thought the performance analyzer was broken. As it turns out, it was my code.