org.firstinspires.ftc.robotcore.external.navigation

Interface VuforiaLocalizer

public interface VuforiaLocalizer

Robot "localization" denotes a robot's ability to establish its own position and orientation within its frame of reference. The VuforiaLocalizer interface provides an interface for interacting with subsystems that can help support localization through visual means.

See Also:

Mobile robot navigation

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	VuforiaLocalizer.CameraDirection VuforiaLocalizer.CameraDirection enumerates the identities of the builtin phone cameras that Vuforia can use.
static class	VuforiaLocalizer.CloseableFrame VuforiaLocalizer.CloseableFrame exposes a close() method so that one can proactively reduce memory pressure when we're done with a Frame
static class	VuforiaLocalizer.Parameters VuforiaLocalizer.Parameters provides configuration information for instantiating the Vuforia localizer

Method Summary

Modifier and Type	Method and Description
android.graphics.Bitmap	convertFrameToBitmap(Frame frame) (Advanced) A helper utility that converts a Vuforia Frame into an Android Bitmap.
void	enableConvertFrameToBitmap() (Advanced) Ensures that Vuforia exposes necessary data formats in Frames that allows convertFrameToBitmap(Frame) to function
boolean[]	enableConvertFrameToFormat(int... pixelFormats) (Advanced) Ask Vuforia to convert frames to the given requested formats.
Camera	getCamera() Provides access to the Camera used by Vuforia.
CameraCalibration	getCameraCalibration() (Advanced) Returns information about Vuforia's knowledge of the camera that it is using.
CameraName	getCameraName() Provides access to the name of the camera used by Vuforia.
void	getFrameOnce(<any> frameConsumer) (Advanced) Calls the indicated code with a frame from the video stream, exactly once.
java.util.concurrent.BlockingQueue<VuforiaLocalizer.CloseableFrame>	getFrameQueue() (Advanced) Returns a queue into which, if requested, Vuforia Frames are placed as they become available.
int	getFrameQueueCapacity() (Advanced) Returns the current capacity of the frame queue.
VuforiaTrackables	loadTrackablesFromAsset(java.lang.String assetName) Loads a Vuforia dataset from the indicated application asset, which must be of type .XML.
VuforiaTrackables	loadTrackablesFromFile(java.lang.String absoluteFileName) Loads a Vuforia dataset from the indicated file, which must be a .XML file and contain the full file path.
void	setFrameQueueCapacity(int capacity) (Advanced) Sets the maximum number of Frames that will simultaneously be stored in the frame queue.

Method Detail

loadTrackablesFromAsset

VuforiaTrackables loadTrackablesFromAsset(java.lang.String assetName)

Loads a Vuforia dataset from the indicated application asset, which must be of type .XML. The corresponding .DAT asset must be a sibling. Note that this operation can be extremely lengthy, possibly taking a few seconds to execute. Loading datasets from an asset you stored in your application APK is the recommended approach to packaging datasets so they always travel along with your code.

Datasets are created using the Vuforia Target Manager

Parameters:

assetName - the name of the .XML dataset asset to load

Returns:

a DataSet that can be used to manipulate the loaded data

See Also:

loadTrackablesFromFile(String)

loadTrackablesFromFile

VuforiaTrackables loadTrackablesFromFile(java.lang.String absoluteFileName)

Loads a Vuforia dataset from the indicated file, which must be a .XML file and contain the full file path. The corresponding .DAT file must be a sibling file in the same directory. Note that this operation can be extremely lengthy, possibly taking a few seconds to execute.

Datasets are created using the Vuforia Target Manager

Parameters:

absoluteFileName - the full path to the .XML file of the dataset

Returns:

a DataSet that can be used to manipulate the loaded data

See Also:

loadTrackablesFromAsset(String)

getCamera

Camera getCamera()

Provides access to the Camera used by Vuforia. Will be null if a built-in camera is in use. Note that Vuforia is usually actively interacting with this Camera; users should on their own not initiate streaming, close the camera, or the like.

getCameraName

CameraName getCameraName()

Provides access to the name of the camera used by Vuforia.

getCameraCalibration

CameraCalibration getCameraCalibration()

(Advanced) Returns information about Vuforia's knowledge of the camera that it is using.

Returns:

information about Vuforia's knowledge of the camera that it is using.

See Also:

com.vuforia.Tool#getProjectionGL(CameraCalibration, float, float)

getFrameQueue

java.util.concurrent.BlockingQueue<VuforiaLocalizer.CloseableFrame> getFrameQueue()

(Advanced) Returns a queue into which, if requested, Vuforia Frames are placed as they become available. This provides a means by which camera image data can be accessed even while the Vuforia engine is running.

While the Vuforia engine is running, it takes exclusive ownership of the camera it is using. This impedes the ability to also use that camera image data in alternative visual processing algorithms. However, periodically (at a rate of tens of Hz), the Vuforia engine makes available Frames containing snapshots from the camera, and through which camera image data can be retrieved. These can optionally be retrieved through the frame queue.

To access these Frames, call setFrameQueueCapacity(int) to enable the frame queue. Once enabled, the frame queue can be accessed using getFrameQueue() and the methods thereon used to access Frames as they become available.

When setFrameQueueCapacity(int) is called, any frame queue returned previously by getFrameQueue() becomes invalid and must be re-fetched.

Returns:

a queue through which Vuforia Frames may be retrieved.

See Also:

setFrameQueueCapacity(int), Frame (Java), Frame (C++), BlockingQueue

setFrameQueueCapacity

void setFrameQueueCapacity(int capacity)

(Advanced) Sets the maximum number of Frames that will simultaneously be stored in the frame queue. If the queue is full and new Frames become available, older frames will be discarded. The frame queue initially has a capacity of zero.

Note that calling this method invalidates any frame queue retrieved previously through getFrameQueue().

Parameters:

capacity - the maximum number of items that may be stored in the frame queue

See Also:

getFrameQueue(), getFrameQueueCapacity()

getFrameQueueCapacity

int getFrameQueueCapacity()

(Advanced) Returns the current capacity of the frame queue.

Returns:

the current capacity of the frame queue.

See Also:

setFrameQueueCapacity(int), getFrameQueue()

getFrameOnce

void getFrameOnce(<any> frameConsumer)

(Advanced) Calls the indicated code with a frame from the video stream, exactly once.

Parameters:

frameConsumer - the code to call with the to-be-processed frame.

enableConvertFrameToBitmap

void enableConvertFrameToBitmap()

(Advanced) Ensures that Vuforia exposes necessary data formats in Frames that allows convertFrameToBitmap(Frame) to function

enableConvertFrameToFormat

boolean[] enableConvertFrameToFormat(int... pixelFormats)

(Advanced) Ask Vuforia to convert frames to the given requested formats. Returns success/failure result for each format.

Parameters:

pixelFormats - Formats to request Vuforia to convert to.

convertFrameToBitmap

android.graphics.Bitmap convertFrameToBitmap(Frame frame)

(Advanced) A helper utility that converts a Vuforia Frame into an Android Bitmap.