I think we are using two different units (physical pixels, and dip) for scroll offsets and transforms. This makes animations that correlate transform and scroll offsets brittle and impossible to do well.

For example load parallax example [1] in Chrome (with CW and threaded-scrolling flags). Run them under device emulation with different device-pixel-ratio and rate of parallax varies.

We should use a consistent unit here e.g., dips or CSS .


[1] https://github.com/flackr/compositor-worker/blob/gh-pages/parallax-static/parallax.html