Live View Dynamic

This demo illustrates how to change fundamental scan parameters on the fly, most notably the scan shape. When the scan shape is changed, downstream buffers that are used for formatting and displaying the scan must also be resized, but not exactly until the change takes place. This demo uses the Event marker to schedule a callback precisely when the new scan shape propagates through vortex’s pipeline. When running the demo, the user can change the scan shape and move the scan center interactively using the keyboard.

Note

The introduction of new markers is planned to reduce the complexity required for scan resizing.

Initial scan resolution.

Scan resolution dynamically increased.

Scan resolution dynamically decreased.

Queueing Callbacks with Events

def handle_event(sample, eid):
    handler = self._handlers.pop(eid, None)
    if handler:
        handler(eid)

self._stack_tensor_endpoint.event_callback = handle_event

def handle_keypress(e):

    mapping = {
        Qt.Key_Right: ( 0, -1),
        Qt.Key_Left:  ( 0,  1),
        Qt.Key_Up:    ( 1,  0),
        Qt.Key_Down:  (-1,  0),
    }

    if delta := mapping.get(e.key()):
        config = self._raster_scan.config
        config.offset += delta
        self._raster_scan.change(config, False)

        config = self._radial_scan.config
        config.offset += delta
        self._radial_scan.change(config, False)

    if e.key() == Qt.Key_I:
        config = self._raster_scan.config
        config.bscans_per_volume += 50

        def h(eid):
            tensor = self._stack_tensor_endpoint.tensor
            with tensor:
                self._stack_tensor_endpoint.stream.synchronize()
                orig_shape = tensor.shape
                shape = orig_shape[:]
                shape[0] = config.bscans_per_volume
                tensor.resize(shape)
                print(eid, tensor.shape)

        eid = self._next_handler_id
        self._next_handler_id += 1
        # print(eid, config.bscans_per_volume)

        self._handlers[eid] = h
        self._raster_scan.change(config, False, eid)

    elif e.key() == Qt.Key_F:
        config = self._raster_scan.config
        config.bscans_per_volume = max([ config.bscans_per_volume - 50, 50 ])

        def h(eid):
            tensor = self._stack_tensor_endpoint.tensor
            with tensor:
                self._stack_tensor_endpoint.stream.synchronize()
                orig_shape = tensor.shape
                shape = orig_shape[:]
                shape[0] = config.bscans_per_volume
                tensor.resize(shape)
                print(eid, tensor.shape)

        eid = self._next_handler_id
        self._next_handler_id += 1
        # print(eid, config.bscans_per_volume)

        self._handlers[eid] = h
        self._raster_scan.change(config, False, eid)