Sierra mouse tracking issues using track pad or magic mouse

Apparently, under the new Sierra OS, there are changes to the way the track pad and magic mouse report mouse movements. We have users reporting intermittent responsiveness of our software that allows the user to draw in graphical data for use in processing audio. The problem seems to be that if you move the mouse too slowly, then the movements are not being seen by our software at all. The problem goes away if your mouse movements are larger/faster. And the problem does not happen with other input devices (at least that we’ve tried so far), or in earlier operating systems.

I need to install some software to be able to debug this issue in Sierra, but does anyone know what might have changed in the new OS that could cause small mouse movements to simply not show as movements in our VSTGUI-based views? (Perhaps the OS is now sending movements that are less than one pixel, and so our software is not seeing any change in mouse position, so it is not doing anything?)

My guess was correct. Movements of less than a pixel are being reported, and my code was checking if the movement was at least one pixel. I added a call to CCoord::makeIntegral() on the mouse coordinates upon entering onMouseMoved(), and now my code behaves like it used to.