Easing Function Definitions

scale_anim_02.py

import bpy
import bmesh
import math
from mathutils import Vector


def lerp_vec_array(arr, step=0.5, easing_func=None):
    len_arr = len(arr)
    if len_arr == 0:
        return Vector((0.0, 0.0, 0.0))

    if len_arr == 1 or step <= 0.0:
        return arr[0].copy()

    if step >= 1.0:
        return arr[len_arr - 1].copy()

    t_scaled = step * (len_arr - 1)
    i = int(t_scaled)
    t = t_scaled - i
    u = easing_func(t)
    a = arr[i]
    b = arr[i + 1]
    return a.lerp(b, u)


def linear_step(t):
    return t


def smooth_step(t):
    return t * t * (3.0 - (t + t))


def smoother_step(t):
    return t * t * t * (t * (t * 6.0 - 15.0) + 10.0)