In version 3.0.0 of the TanvasTouch Windows SDK, the Engine runs as a per-monitor DPI-aware application. This was done to simplify mapping coordinates on the TanvasTouch display to coordinates on the virtual desktop. This change means that views and sprites now exist in the virtual desktop’s coordinate space.
The exact procedure to update an existing Windows application to use the Engine and APIs shipped in SDK 3.0.0 depends on the UI technology used by your application, but in general you will need to ensure that you specify the position and size of views and sprites in desktop (or screen) coordinates.
Currently, Tanvas has a guide for updating WPF applications at https://api-docs.tanvas.co/tanvastouch/dotnet/5.0.1/articles/moving-from-v4-to-v5.html. We may publish guides for other UI toolkits in the future.