5 The Use of Pico OpenXR Play Boundary

The use of the play boundary requires to set a synchronous semaphore gsIndex by extension, so that the HMD sensor can correspond to the camera sensor.

For this part, Pico provides an extension XR_PICO_view_state_ext_enable that needs to be turned on when xrCreateInstance is called.

By passing the declared instance address of the XrViewStatePICOEXT to the next pointer of viewState and calling xrLocateViews , the synchronous semaphore gsIndex will be returned.

Then, at xrEndFrame , it will be passed in by extension. The sample code is as follows. Please refer to the HelloXR Sample for details.

Getting gsIndex :

int mGsIndex;
XrViewStatePICOEXT xrViewStatePICOEXT;
XrViewState viewState{XR_TYPE_VIEW_STATE};
viewState.next = (void*)&xrViewStatePICOEXT;
xrLocateViews(mSession, &viewLocateInfo, &viewState, viewCapacityInput, &viewCountOutput, mViews.data());
mGsIndex = xrViewStatePICOEXT.gsIndex;

Passing in gsIndex :

XrFrameEndInfoEXT xrFrameEndInfoEXT;
xrFrameEndInfoEXT.useHeadposeExt = 1;
xrFrameEndInfoEXT.gsIndex = mGsIndex ;
frameEndInfo.next = (void*)&xrFrameEndInfoEXT;
xrEndFrame(mSession, &frameEndInfo);

Synchronization can be achieved with the above code, and the play boundary can be used normally.

Note: At present, when using the play boundary, it is necessary to ensure that the layer is submitted all the time.