class_name SpringDamper extends Object # Based on: allenchou.net/2015/04/game-math-precise-control-over-numeric-springing/ var omega var zeta var v:Variant = null # Called when the node enters the scene tree for the first time. func _ready(): pass # Replace with function body. func _init(v0:Variant, osc_freq:float = 4, osc_red:float = 0.003, osc_red_h:float = 0.003): assert (osc_red > 0.001 and osc_red < 0.999) omega = osc_freq * 2 * PI zeta = log(1.0 - osc_red) / (-omega * osc_red_h) v = v0 func calc(x, xt, h:float): var f = 1.0 + 2.0 * h * zeta * omega var oo = omega * omega var hoo = oo * h var hhoo = hoo * h var det_inv = 1.0 / (f + hhoo) var det_x = f * x + h * v + hhoo * xt var det_v = v + hoo * (xt - x) x = det_x * det_inv v = det_v * det_inv return x func calc_clamped_speed(x, xt, h:float, s_max:float): var x_old = x var x_new = calc(x, xt, h) var vel_new = (x_new - x_old) / h var speed_new = vel_new.length() if speed_new > s_max: vel_new = (vel_new / speed_new) * s_max x = x_old + vel_new * h return x