In search for a more precise cursor

One of the casualties of Apple’s otherwise brilliantly executed transition to retina pixels has been the mouse pointer, which remains aligned to what “traditional pixels” used to be, rather than the retina/​physical/smaller pixels.

Turn on the zoom gesture from a few weeks ago, and you can see the challenge. The gridlines are ½ logical pixel and 1 physical pixel wide:

This limitation is inherited by most tools: Photoshop, Affinity, xScope, even the built-in Digital Color Meter. It’s not the end of the world, of course, but it can be maddening if you are trying to sample a color from a “half pixel” and the cursor stubbornly skips it no matter how delicately you move. Here it is in Figma:

Of the few tools I tested, only Pixelmator allows to sample at the correct, precise level:

I was curious how would a truly precise cursor feel in general – would there be any disadvantages? – so I built a little simulator that allows a regular arrow cursor to be aligned to “half pixels” or “retina pixels.”

In the process, I discovered that both Chrome and Firefox already receive sub-traditional-pixel measurements for mousing events, so this was even easier to build than I expected. Now, precise targeting in Chrome and Firefox becomes possible:

I don’t personally see any big difference in terms of either upsides or downsides, and I’m curious if you do. iPadOS and its Safari already seems to support the precise mouse pointer, too. That makes me curious: why isn’t it available in macOS? I imagine you could even turn it on by default for apps – or, if you want to be more conservative, make it opt-in.

Pixelmator also shows that the apps can do it without waiting for macOS as the data is already there; they would just need to render the cursor on their own with more precision.