Color interpolation

[tmcw]

Support an interpolation property on functions that allows
users to choose LAB or HCL color interpolation.

[mourner]

This looks great! My only concern is that conversion from RGB to LAB/HCL and back is relatively expensive and will happen on every function call, even though the stops will have the same values. Can we refactor the code in a way that caches the converted colors so that the work on an actual call is limited to simple interpolation?

[tmcw]

Yep, I think that's very possible. We'd still have to convert back out to RGB, so it wouldn't be zero-cost. I'll work on a second iteration.

[tmcw]

55bdcb3 now translates colors on the way in and allows for an "outputFunction" that translates them on the way out. To do this we need to clone the parameters to avoid mutating it, so a JSON.parse/JSON.stringify loop. Do you think that's okay?

[lucaswoj]

Thanks for tackling this @tmcw! I like your syntax and implementation 👍

My 2¢: the word interpolation is vague in the context of a generic function library relative to what it does

interpolation is a method of constructing new data points within the range of a discrete set of known data points

vs

interpolation property on functions that allows users to choose LAB or HCL color interpolation.

What do you think about using something like colorInterpolation or colorSpace?

[tmcw]

Yep, I agree. Changed interpolation to colorSpace

[lucaswoj]

@mourner are you ready to give this a ✅ ?