TargetTracker Class¶

Description¶

TargetTracker is the base class for trackers that can load and track targets.

You need to call attachStreamer to attach a FrameStreamer to tracker first, then the images from the FrameStreamer are used for by the tracker. You can call start/stop to enable/disable the track process. start and stop are very lightweight calls.

Before a Target can be tracked by tracker, you have to load it using async method loadTarget/unloadTarget or synchronized loadTargetBlocked/unloadTargetBlocked. The async interfaces are recommended if you desire an unblocked process. You can get load/unload results from callbacks passed into the interfaces.

You can get a Frame by FrameStreamer.peek which contains current camera image and tracked TargetInstance.

loadTarget¶

Load a Target into the tracker. A Target can only be tracked by tracker after a successful load.

This method is an async method. A load operation may take some time to finish and detection of a new/lost target may take more time during the load. The track time after detection will not be affected. If you want to know the load result, you have to handle the callback data. The callback will be called from a different thread; it will not block the track thread or any other operations except other load/unload.

C: void easyar_TargetTracker_loadTarget(easyar_TargetTracker * This, easyar_Target * target, easyar_FunctorOfVoidFromPointerOfTargetAndBool callback)¶

C++11: void loadTarget(std::shared_ptr<Target> target, std::function<void(std::shared_ptr<Target>, bool)> callback)¶

Traditional C++: void loadTarget(Target * target, FunctorOfVoidFromPointerOfTargetAndBool callback)¶

Java: public native void loadTarget(Target target, FunctorOfVoidFromPointerOfTargetAndBool callback)¶

Objective-C: - (void)loadTarget:(easyar_Target *)target callback:(void (^)(easyar_Target * target, bool status))callback¶

Swift (since EasyAR SDK 2.1.0): public func loadTarget(_ target: Target, _ callback: @escaping (Target, Bool) -> Void) -> Void¶

unloadTarget¶

Unload a Target from the tracker.

This method is an async method. An unload operation may take some time to finish and detection of a new/lost target may take more time during the unload. If you want to know the unload result, you have to handle the callback data. The callback will be called from a different thread; it will not block the track thread or any other operations except other load/unload.

C: void easyar_TargetTracker_unloadTarget(easyar_TargetTracker * This, easyar_Target * target, easyar_FunctorOfVoidFromPointerOfTargetAndBool callback)¶

C++11: void unloadTarget(std::shared_ptr<Target> target, std::function<void(std::shared_ptr<Target>, bool)> callback)¶

Traditional C++: void unloadTarget(Target * target, FunctorOfVoidFromPointerOfTargetAndBool callback)¶

Java: public native void unloadTarget(Target target, FunctorOfVoidFromPointerOfTargetAndBool callback)¶

Objective-C: - (void)unloadTarget:(easyar_Target *)target callback:(void (^)(easyar_Target * target, bool status))callback¶

Swift (since EasyAR SDK 2.1.0): public func unloadTarget(_ target: Target, _ callback: @escaping (Target, Bool) -> Void) -> Void¶

loadTargetBlocked¶

Load a Target into the tracker. A Target can only be tracked by tracker after a successful load.

This is a synchronized method. A load operation may take some time to finish and detection of a new/lost target may take more time during the load. It will block the calling thread. However, the track thread or camera thread will not be blocked.

C: bool easyar_TargetTracker_loadTargetBlocked(easyar_TargetTracker * This, easyar_Target * target)¶

C++11: bool loadTargetBlocked(std::shared_ptr<Target> target)¶

Traditional C++: bool loadTargetBlocked(Target * target)¶

Java: public native boolean loadTargetBlocked(Target target)¶

Objective-C: - (bool)loadTargetBlocked:(easyar_Target *)target¶

Swift (since EasyAR SDK 2.1.0): public func loadTargetBlocked(_ target: Target) -> Bool¶

unloadTargetBlocked¶

Unload a Target from the tracker.

This is a synchronized method. An unload operation may take some time to finish and detection of a new/lost target may take more time during the unload. It will block the calling thread. However, the track thread or camera thread will not be blocked.

C: bool easyar_TargetTracker_unloadTargetBlocked(easyar_TargetTracker * This, easyar_Target * target)¶

C++11: bool unloadTargetBlocked(std::shared_ptr<Target> target)¶

Traditional C++: bool unloadTargetBlocked(Target * target)¶

Java: public native boolean unloadTargetBlocked(Target target)¶

Objective-C: - (bool)unloadTargetBlocked:(easyar_Target *)target¶

Swift (since EasyAR SDK 2.1.0): public func unloadTargetBlocked(_ target: Target) -> Bool¶

targets¶

Returns current loaded targets in the tracker. If an async load/unload is in progress, the returned value will not reflect the result until all load/unload finish.

C: void easyar_TargetTracker_targets(easyar_TargetTracker * This, easyar_ListOfPointerOfTarget * * Return)¶

C++11: std::vector<std::shared_ptr<Target>> targets()¶

Traditional C++: void targets(ListOfPointerOfTarget * * Return)¶

Java: public native java.util.ArrayList<Target> targets()¶

Objective-C: - (NSArray<easyar_Target *> *)targets¶

Swift (since EasyAR SDK 2.1.0): public func targets() -> [Target]¶

setSimultaneousNum¶

Set the max number of targets which will be the simulatneously tracked by the tracker. The default value is 1.

C: bool easyar_TargetTracker_setSimultaneousNum(easyar_TargetTracker * This, int num)¶

C++11: bool setSimultaneousNum(int num)¶

Traditional C++: bool setSimultaneousNum(int num)¶

Java: public native boolean setSimultaneousNum(int num)¶

Objective-C: - (bool)setSimultaneousNum:(int)num¶

Swift (since EasyAR SDK 2.1.0): public func setSimultaneousNum(_ num: Int32) -> Bool¶

simultaneousNum¶

Get the max number of targets which will be the simulatneously tracked by the tracker. The default value is 1.

C: int easyar_TargetTracker_simultaneousNum(easyar_TargetTracker * This)¶

C++11: int simultaneousNum()¶

Traditional C++: int simultaneousNum()¶

Java: public native int simultaneousNum()¶

Objective-C: - (int)simultaneousNum¶

Swift (since EasyAR SDK 2.1.0): public func simultaneousNum() -> Int32¶

attachStreamer¶

Attach FrameStreamer to the tracker. Tracker will not start to track until a FrameStreamer is attached.

Attach null object will detach previous attached FrameStreamer from tracker.

C: bool easyar_TargetTracker_attachStreamer(easyar_TargetTracker * This, easyar_FrameStreamer * obj)¶

C++11: bool attachStreamer(std::shared_ptr<FrameStreamer> obj)¶

Traditional C++: bool attachStreamer(FrameStreamer * obj)¶

Java: public native boolean attachStreamer(FrameStreamer obj)¶

Objective-C: - (bool)attachStreamer:(easyar_FrameStreamer *)obj¶

Swift (since EasyAR SDK 2.1.0): public override func attachStreamer(_ obj: FrameStreamer?) -> Bool¶

start¶

Starts the track algorithm. The track will not actually start until a FrameStreamer is attached.

C: bool easyar_TargetTracker_start(easyar_TargetTracker * This)¶

C++11: bool start()¶

Traditional C++: bool start()¶

Java: public native boolean start()¶

Objective-C: - (bool)start¶

Swift (since EasyAR SDK 2.1.0): public override func start() -> Bool¶

stop¶

Stops the track algorithm. Call start to start the track again.

C: bool easyar_TargetTracker_stop(easyar_TargetTracker * This)¶

C++11: bool stop()¶

Traditional C++: bool stop()¶

Java: public native boolean stop()¶

Objective-C: - (bool)stop¶

Swift (since EasyAR SDK 2.1.0): public override func stop() -> Bool¶