Wikitude

If I adjust the iOS native example to present a view controller on successful target recognition like: 

- (void)baseTracker:(nonnull WTBaseTracker *)baseTracker didRecognizedTarget:(nonnull WTImageTarget *)recognizedTarget
{
  NSLog(@"recognized target '%@'", [recognizedTarget name]);
  _isTracking = YES;
  
  [self presentViewController:[UIViewController new] animated:YES completion:^{
    sleep(3);
    [self dismissViewControllerAnimated:YES completion:nil];
  }];
}

  I get the following error message: "unable to set renderbuffer storage from drawable".

My example is kind of artificial but the same error occurs with a real view controller.

Do you have any hint for me? Thank you very much for any help.

Hi Andreas,

yes, I checked that, but I extended the minimal example to be sure:

 

- (void)baseTracker:(nonnull WTBaseTracker *)baseTracker didRecognizedTarget:(nonnull WTImageTarget *)recognizedTarget
{
    NSLog(@"recognized target '%@'", [recognizedTarget name]);
    _isTracking = YES;
    
    NSLog(@"is main thread: '%@'", [NSThread isMainThread] ? @"yes" : @"no");
    
    dispatch_async(dispatch_get_main_queue(), ^(void){
        sleep(3);
        
        [self presentViewController:[UIViewController new] animated:YES completion:^{
            dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^(void){
                sleep(3);
                
                dispatch_async(dispatch_get_main_queue(), ^(void){
                    [self dismissViewControllerAnimated:YES completion:nil];
                });
            });
        }];
    });
}

 

The problem stays the same. Some time after the error message ("unable to set renderbuffer storage from drawable") is logged the debugger hangs on this call:

#0 0x000000010085bf14 in wikitude::sdk_foundation::impl::CameraService::newPlatformCameraFrameAvailable(wikitude::sdk_foundation::impl::FrameInfo) ()

Do you have any other idea?

Thank you for your help!

Hi Andreas,

in the Wikitude example the '-stop' method is called in the viewDidDisappear method:

 

- (void)viewDidDisappear:(BOOL)animated
{
    [super viewDidDisappear:animated];

    [self.wikitudeSDK stop];
    
    [self.renderer stopRenderLoop];
    [self.renderer teardownRendering];
    
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

 

I tried viewWillDisappear instead of viewDidDisappear but it doesn't help.

Hi Andreas,

thank you very much for your help. The crash does not occur anymore and we are really happy!

I have only one more question regarding your last hint: Sometimes our tracker file has to be updated while the app is running and the view is displayed. For Android there is a method called "destroyTracker" on the tracker manager. Is there any equivalent for iOS?

Thank you very much.

Hi Andreas,

alright, thanks again!

Hi Andreas,

I made some tests and unfortunately setting the clientTracker to nil results in a crash for me when trying to create a new tracker. The app crashs too if I don't set the old one to nil. Do you have an idea what I might be doing wrong?

I only have this stack trace:

#0 0x000000010071bf14 in wikitude::sdk_foundation::impl::CameraService::newPlatformCameraFrameAvailable(wikitude::sdk_foundation::impl::FrameInfo) ()

#1 0x00000001005c4ed4 in _ZNSt3__110__function6__funcIZZ97-[WTNativeSDKManager cameraPlatformService:didOutputNextCameraFrameWithId:presentationTimestamp:]EUb_E3$_2NS_9allocatorIS2_EEFvRN8wikitude14sdk_foundation4impl13CameraServiceEEEclES9_ ()

#2 0x00000001005c401c in __97-[WTNativeSDKManager cameraPlatformService:didOutputNextCameraFrameWithId:presentationTimestamp:]_block_invoke ()

Hi Andreas,

thanks for your reply. I'm not in the office today so I unfortunately can't build an example right now. What I tried was doing it like in the original example (without your suggested last fix which checks if _clientTracker is still nil before creating a new one). So everytimes when entering the view, when the SDK gets started I set _clientTracker to nil and call [self.wikitudeSDK.trackerManagercreate2DClientTrackerFromURL:clientTrackerURL extendedTargets:nil andDelegate:self];
After presenting a modal view controller and coming back like in our example a few times I got the crash.
I can send a full code example next week if needed.

Thanks,
Ole

Hi Andreas,

here is my customized Wikitude example code:

https://cap3gmbh.s3.amazonaws.com/public/Examples-01.zip

Perhaps it will not crash the first time coming back from the dummy view controller but on my test device (iPhone 6, iOS 10.1.1) the example always crashes.

I hope you can reproduce the problem.