rem unit?

[amytimed]

Would rem unit fit this project? it isn't in bevy UI directly, but would be super useful

For example if root font size is 16px, 1rem is 16px`

[eckz]

That's something that I thought of implementing at some point, but it requires doing work that should be done externally. rem and em are probably easy, but it opens a question for other non supported dimensions like rch, rcap o even cm, pc or pt.

At the end it would fit in the non-goal of

Implement missing Bevy UI features.

In any case, the specific rem issue can be solved by using vars.

:root {
  --font-size: 16px;
  font-size: var(--font-size);
}

.some-elem {
   /* Equivalent to 1.2rem */
  font-size: calc(var(--font-size) * 1.2);
}

it's more verbose but it's a solution.

[amytimed]

what about letting users define custom units in a UnitRegistry?

[eckz]

I've just published a new example (and a new create version, 0.4.1) https://github.com/eckz/bevy_flair/blob/main/examples/custom_parsing.rs that shows how you can override Val parsing and do something similar to what you are looking for.

I think is still not as powerful as using var(), but it could solve your current issue.

[eckz]

Its seems like Bevy will support rem units eventually: bevyengine/bevy#21331

Once it's supported I will add direct support from bevy_flair