Hi @metacreator and thanks for your query. The Tobii Core SDK (which is .NET C#) is included as a Nuget Package which you download via the Visual Studio IDE package manager.

A full guide to getting started is available @ https://developer.tobii.com/consumer-eye-trackers/core-sdk/getting-started/
with a number of sample applications to help you get up and running @ https://github.com/Tobii/CoreSDK

Should you wish to remain with C++, then you can use the Stream Engine API which operates at a lower level than the Core SDK and so requires more expertise to use, but you can view the getting started guide @ https://developer.tobii.com/consumer-eye-trackers/stream-engine/getting-started/ which include download links at the bottom.

Please don’t hesitate to get in touch again should you require any further assistance. Best Wishes.

Hi @x-luo, thanks for getting in touch. I am afraid that the Core SDK has now been deprecated and replaced with the Tobii Stream Engine API and Interaction API, so I am afraid we cannot support using the ET5 with the Core SDK however our general licencing model still holds in that so long as your are not storing gaze data or using the data for analysis, and are developing only for interaction purposes, then you do not need to purchase a special licence from Tobii. If you would care to clarify your situation, I would be happy to provide further details or suggestions. Best Wishes.

Hi @x-luo, I am afriad that custom calibration is only available through the Stream Engine and requires the purchase of a special licence to do.

Hopefully the standard 5 points will suffice for your needs, our apologies for any inconvenience. Best Wishes.