Add linear_interpolation and other math functions #1

renatillas commented 2025年10月07日 12:51:30 +02:00

Working on the tiramisu game framwork I miss a function for lerping a vector like this:

pubfnlerp(a:Vec3,b:Vec3,t:Float)->Vec3{Vec3(a.x+.{b.x-.a.x}*.t,a.y+.{b.y-.a.y}*.t,a.z+.{b.z-.a.z}*.t,)}

Do you think it's sensible to add it to the library?

Working on the tiramisu game framwork I miss a function for lerping a vector like this: ```gleam pub fn lerp(a: Vec3, b: Vec3, t: Float) -> Vec3 { Vec3( a.x +. { b.x -. a.x } *. t, a.y +. { b.y -. a.y } *. t, a.z +. { b.z -. a.z } *. t, ) } ``` Do you think it's sensible to add it to the library?

NNB commented 2025年10月08日 04:10:42 +02:00

Ah yes, I was considered adding this function along with move_toward and sign but I'm not sure how...

Because all of these functions are all also useful to standard Float and Int type but none of them are in the stdlib (yet, maybe...).

If they are in the stdlib, it would be easy. We just need to add them like other functions in gleam/float and gleam/int to vec.

The sign function is in the gleam_comunity/maths lib, perhap we could make a PR to add lerp and move_toward to it, then make a subfoder vec/maths or a new lib vec_maths to house those functions and more.

Ah yes, I was considered adding this function along with [`move_toward`](https://docs.godotengine.org/en/stable/classes/class_vector3.html#class-vector3-method-move-toward) and [`sign`](https://docs.godotengine.org/en/stable/classes/class_vector3.html#class-vector3-method-sign) but I'm not sure how... Because all of these functions are all also useful to standard Float and Int type but none of them are in the `stdlib` (yet, maybe...). If they are in the `stdlib`, it would be easy. We just need to add them like other functions in `gleam/float` and `gleam/int` to `vec`. The `sign` function is in the `gleam_comunity/maths` lib, perhap we could make a PR to add `lerp` and `move_toward` to it, then make a subfoder `vec/maths` or a new lib `vec_maths` to house those functions and more.

NNB commented 2025年10月14日 17:49:14 +02:00

https://github.com/gleam-community/maths/issues/48

This will be added in the (削除) very near (削除ここまで) future.

https://github.com/gleam-community/maths/issues/48 This will be added in the ~~very near~~ future.

NNB commented 2026年01月29日 18:57:36 +01:00

I take it back, the gleam_comunity/maths is way too much T_T.

I take it back, the `gleam_comunity/maths` is way too much T_T.

NNB commented 2026年01月30日 10:03:34 +01:00

I'm thinking about adding map3 instead:

pubfnmap3(a:Vec3(a),b:Vec3(b),c:Vec3(c),withfun:fn(a,b,c)->d,)->Vec3(d){Vec3(fun(a.x,b.x,c.x),fun(a.y,b.y,c.y),fun(a.z,b.z,c.z))}

This will not only make using linear_interpolation easier but also other function that take 2 vectors and a weight/delta (with splash to turn a Float into a Vec(Float)). Like clamp, move_toward, inverse_linear_interpolation, ...

I'm thinking about adding `map3` instead: ```gleam pub fn map3( a: Vec3(a), b: Vec3(b), c: Vec3(c), with fun: fn(a, b, c) -> d, ) -> Vec3(d) { Vec3(fun(a.x, b.x, c.x), fun(a.y, b.y, c.y), fun(a.z, b.z, c.z)) } ``` This will not only make using `linear_interpolation` easier but also other function that take 2 vectors and a weight/delta (with `splash` to turn a Float into a `Vec(Float)`). Like `clamp`, `move_toward`, `inverse_linear_interpolation`, ...

NNB commented 2026年01月30日 15:51:45 +01:00

Year I'm in favor of map3 over making functions from or could be from maths lib to Vec. Since I find linear_interpolation is quite rare to use, not "never", just rare. So if someone want to use it 1 or 2 time in a project, using map3 is fine.

If anyone feel different, please reopen this issue, and add the reason.

Year I'm in favor of `map3` over making functions from or could be from `maths` lib to Vec. Since I find `linear_interpolation` is quite rare to use, not "never", just rare. So if someone want to use it 1 or 2 time in a project, using `map3` is fine. If anyone feel different, please reopen this issue, and add the reason.

NNB commented 2026年02月16日 16:58:00 +01:00

This is back on the table now!

This is back on the table now!