Is there a more efficient way to create this oscillating loop behavior?

UnknownUser

So I learned about linear interpolation and now I want to fiddle with this idea.

Given lerp formula from godot docs, which is interpolation = A + (B - A) * t, I want t to change its value from A to B and once it reaches B, it changes its value from B to A, then the loop repeats.

So I've come up with this:

extends Label
var t = 0
var a = 10
var b = 20
func _process(delta):
    t = wrapf(t + delta, -1, 1)
    text = str(a + (b - a) * abs(t))

So the question is, as the title suggests, is there a more efficient way to create this loop behavior?

vinpogo

t = fmod(t + delta, 1.0) this should lead to t being clamped between [0.0, 1.0].

But honestly i dont know if its more efficient.

UnknownUser

@vinpogo said: t = fmod(t + delta, 1.0) this should lead to t being clamped between [0.0, 1.0].

Ah, I wasn't clear enough in my post then, sorry about that! I want t to oscillate, so that it's gradually changing its value from A to B, and then it goes to B in the same fashion (gradually), and only then the loop repeats.

Megalomaniak

Know how abs(absolute) and sin(sinewave) work?

vinpogo

so with oscillation you mean t goes from A to B and then back from B to A?

If thats the case, you could set t = sin(t + delta) this leads to t being between [-1, 1]. If you only need positive values, just wrap the sin call inside an abs call.