Extending device imaging parameter control through Slicer/OpenIGTLink

[adamaji]

Hi folks, I'm looking for some guidance on extending imaging parameters for new Plus devices to be controlled through Slicer (re: #723).

If I have an ultrasound device that I want to fully control through OpenIGTLink, but the set of parameters and functionality is not entirely covered by the set of generic ultrasound imaging parameters as defined by UsImagingParameters (http://perk-software.cs.queensu.ca/plus/doc/nightly/user/UsImagingParameters.html), what is the intended path forward?

Do I extend the defined UsImagingParameters directly? Based on #404 (comment), it seems like it's instead intended for devices to handle their own specific parameter subset individually. However it doesn't appear that there is currently a command interface for those generic parameters (http://perk-software.cs.queensu.ca/plus/doc/nightly/user/PlusServerCommands.html)?

Does a new vtkPlusCommand subclass need to be created for each new device to handle this separate parameter set (like e.g., vtkPlusAtracsysCommand)? Or perhaps does something similar to a SetUsParameter command need to be made for the generic Parameters to be accessible through Slicer/OpenIGTLink? Or maybe there is existing functionality which I'm missing?

EDIT: @adamrankin maybe you have a good sense on this having authored #479 ?

[adamaji]

@adamrankin bump :) basically I'm wondering to what extent vtkPlusSetUsParameter should be extended, and what to save for a device specific vtkPlusMyDeviceCommand, or if there's any preference at all.

As an example, vtkPlusSetUsParameter currently assumes a 3 region TGC input in its string parsing, but I'd like to control a device with 8 TGC regions. Is that better served as an addition to vtkPlusSetUsParameter?

Also, for complete control of devices such as freezing probes, is it preferable to have generic commands (e.g., vtkPlusFreezeDeviceCommand) versus putting that inside device specific commands (e.g., vtkPlusCapistranoCommand including some sub command name "FreezeDevice")?