local function p(p,E,u,z,a,X)if p==0 then return E end p=(p/z)*2 if p==2 then return E+u end if not X then X=z*.45 end if not a then a=0 end local F if not a or a<abs(u)then a=u F=X/4 else F=(X/(2*pi))*asin(u/a)end if p<1 then p=p-1 return-0.5*((a*pow(2,10*p))*sin(((p*z-F)*(2*pi))/X))+E else p=p-1 return(((a*pow(2,-10*p))*sin(((p*z-F)*(2*pi))/X))*.5+u)+E end end
-- p = period
-- a = amplitud
local function inOutElastic(t, b, c, d, a, p)
	if t == 0 then
		return b
	end

	t = t / d * 2

	if t == 2 then
		return b + c
	end

	if not p then
		p = d * (0.3 * 1.5)
	end
	if not a then
		a = 0
	end

	local s

	if not a or a < abs(c) then
		a = c
		s = p / 4
	else
		s = p / (2 * pi) * asin(c / a)
	end

	if t < 1 then
		t = t - 1
		return -0.5 * (a * pow(2, 10 * t) * sin((t * d - s) * (2 * pi) / p)) + b
	else
		t = t - 1
		return a * pow(2, -10 * t) * sin((t * d - s) * (2 * pi) / p) * 0.5 + c + b
	end
end
