between-api-minetest/docs/interpolation.md

Interpolation Functions

BeTweenApi.interpolation is a table that contain interpolation functions, here are listed all of the and what their porpuse is for.

Each function require a start and end movement to interpolate and the position in time, or something like this:

function (start: number, end: number, time: float) : number

Currently interpolation can be done only with numbers (float and integer).

Function	Description
linear	straight increment from x to y in time.
quadratic_in	straight increment from x to y in time.
quadratic_out	movement increment slower from x to y in time.
quadratic_in_out	movement is faster between x to y but slow down on begin and end in time.
cubic_in	movement increment faster from x to y in time.
cubic_out	movement increment slower from x to y in time.
cubic_in_out	movement is faster between x to y but slow down on begin and end in time.
quartic_in	movement increment faster from x to y in time.
quartic_out	movement increment slower from x to y in time.
quartic_in_out	movement is faster between x to y but slow down on begin and end in time.
elastic	movement jump from x to y like an elastic, movement is very fast but slow down in time.
sinusoidal_in	movement increment faster from x to y in time, the movement has the shape of a curve.
sinusoidal_out	movement increment faster from x to y in time, the movement has the shape of a curve.
sinusoidal_in_out	movement is faster between x to y but slow down on begin and end in time, the movement has the shape of a curve.
circular_in	movement increment faster esponentially from x to y in time.
circular_out	movement increment slower esponentially from x to y in time.
circular_in_out	movement increment slower from the start to the end but speed up esponentially in the middle.

---

Usage example:

BeTweenApi.interpolation.linear(0, 4, 0.5) -- 2
BeTweenApi.interpolation.quadratic_in(0, 8, 0.5) -- 2
BeTweenApi.interpolation.quadratic_out(0, 8, 0.5) -- 4.5