OpenNI 1.0.0
Modules
Generator
Production Nodes Functionality

Modules

 Mirror Capability
 Alternative View Point Capability
 Frame-Sync Capability

Controlling Generation

The following functions allows controlling if a node is currently generating data or not.

XN_C_API XnStatus xnStartGenerating (XnNodeHandle hInstance)
XN_C_API XnBool xnIsGenerating (XnNodeHandle hInstance)
XN_C_API XnStatus xnStopGenerating (XnNodeHandle hInstance)
XN_C_API XnStatus xnRegisterToGenerationRunningChange (XnNodeHandle hInstance, XnStateChangedHandler handler, void *pCookie, XnCallbackHandle *phCallback)
XN_C_API void xnUnregisterFromGenerationRunningChange (XnNodeHandle hInstance, XnCallbackHandle hCallback)

Checking if new data is available

The following functions allows an application to know if and when a node has new data available. When new data is available, the node data is still not replaced, until explicitly done so using one of the update data functions.

XN_C_API XnStatus xnRegisterToNewDataAvailable (XnNodeHandle hInstance, XnStateChangedHandler handler, void *pCookie, XnCallbackHandle *phCallback)
XN_C_API void xnUnregisterFromNewDataAvailable (XnNodeHandle hInstance, XnCallbackHandle hCallback)
XN_C_API XnBool xnIsNewDataAvailable (XnNodeHandle hInstance, XnUInt64 *pnTimestamp)

Getting new data

XN_C_API XnStatus xnWaitAndUpdateData (XnNodeHandle hInstance)

Data properties

XN_C_API XnBool xnIsDataNew (XnNodeHandle hInstance)
XN_C_API XnUInt32 xnGetDataSize (XnNodeHandle hInstance)
XN_C_API XnUInt64 xnGetTimestamp (XnNodeHandle hInstance)
XN_C_API XnUInt32 xnGetFrameID (XnNodeHandle hInstance)

Detailed Description

A Generator node is a production node that also generates continuous data. It supports all Production Node functions, and adds additional functions.


Function Documentation

XN_C_API XnUInt32 xnGetDataSize ( XnNodeHandle  hInstance)

Gets the size of current data, in bytes.

Parameters:
hInstance[in] A handle to the instance.
Returns:
(XnUInt32)-1 if this production node is not a generator.
XN_C_API XnUInt32 xnGetFrameID ( XnNodeHandle  hInstance)

Gets the frame ID of current data.

Parameters:
hInstance[in] A handle to the instance.
Returns:
(XnUInt32)-1 if this production node is not a generator.
XN_C_API XnUInt64 xnGetTimestamp ( XnNodeHandle  hInstance)

Gets the timestamp of current data, in microseconds.

Parameters:
hInstance[in] A handle to the instance.
Returns:
(XnUInt64)-1 if this production node is not a generator.
XN_C_API XnBool xnIsDataNew ( XnNodeHandle  hInstance)

Checks whether current data is new. Meaning, did the data change on the last call to xnWaitAndUpdateAll(), xnWaitOneUpdateAll() or xnWaitAndUpdateData().

Parameters:
hInstance[in] A handle to the instance.
XN_C_API XnBool xnIsGenerating ( XnNodeHandle  hInstance)

Checks if this node is currently generating.

Parameters:
hInstance[in] A handle to the instance.
Returns:
FALSE if this production node is not a generator.
XN_C_API XnBool xnIsNewDataAvailable ( XnNodeHandle  hInstance,
XnUInt64 *  pnTimestamp 
)

Checks whether this node has new data (and so a call to xnWaitAndUpdateData() will not block).

Parameters:
hInstance[in] A handle to the instance.
pnTimestamp[out] [Optional] If not NULL, will be filled with that data timestamp.
XN_C_API XnStatus xnRegisterToGenerationRunningChange ( XnNodeHandle  hInstance,
XnStateChangedHandler  handler,
void *  pCookie,
XnCallbackHandle phCallback 
)

Registers a callback function to be called when generation starts or stops.

Parameters:
hInstance[in] A handle to the instance.
handler[in] A pointer to a function that will be called when generation starts/stops.
pCookie[in] A user cookie that will be passed to the callback function.
phCallback[out] Optional. Will be filled with a handle to be passed to xnUnregisterFromGenerationRunningChange().
XN_C_API XnStatus xnRegisterToNewDataAvailable ( XnNodeHandle  hInstance,
XnStateChangedHandler  handler,
void *  pCookie,
XnCallbackHandle phCallback 
)

Registers a callback function to be called when new data is available.

Parameters:
hInstance[in] A handle to the instance.
handler[in] A pointer to a function that will be called when new data is available.
pCookie[in] A user cookie that will be passed to the callback function.
phCallback[out] Optional. Will be filled with a handle to be passed to xnUnregisterFromNewDataAvailable().
XN_C_API XnStatus xnStartGenerating ( XnNodeHandle  hInstance)

Starts generation of the output. This will also cause all dependencies to start generating.

Parameters:
hInstance[in] A handle to the instance to start generating.
Returns:
XN_STATUS_INVALID_OPERATION if this production node is not a generator.
XN_C_API XnStatus xnStopGenerating ( XnNodeHandle  hInstance)

Stops generation of the output.

Parameters:
hInstance[in] A handle to the instance to stop generating.
Returns:
XN_STATUS_INVALID_OPERATION if this production node is not a generator.
XN_C_API void xnUnregisterFromGenerationRunningChange ( XnNodeHandle  hInstance,
XnCallbackHandle  hCallback 
)

Unregisters a callback function which was registered using xnRegisterToGenerationRunningChange().

Parameters:
hInstance[in] A handle to the instance.
hCallback[in] The handle to the callback returned from xnRegisterToGenerationRunningChange().
XN_C_API void xnUnregisterFromNewDataAvailable ( XnNodeHandle  hInstance,
XnCallbackHandle  hCallback 
)

Unregisters a callback function which was registered using xnRegisterToNewDataAvailable().

Parameters:
hInstance[in] A handle to the instance.
hCallback[in] The handle to the callback returned from xnRegisterToNewDataAvailable().
XN_C_API XnStatus xnWaitAndUpdateData ( XnNodeHandle  hInstance)

Updates the data to the latest available one. If needed, the call will block until new data is available.

Parameters:
hInstance[in] A handle to the instance to be updated.
Returns:
XN_STATUS_INVALID_OPERATION if this production node is not a generator.