notsanequarium/lib/ease.lua

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Lua
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2021-01-22 22:33:08 +00:00
local this = {}
local sqrt = math.sqrt
local sin = math.sin
local cos = math.cos
local pow = math.pow
local exp = math.exp
local pi = math.pi
local abs = math.abs
function this.linear(t) return t end
function this.inQuad(t) return t * t end
function this.outQuad(t) return -t * (t - 2) end
function this.inOutQuad(t)
t = t * 2
if t < 1 then
return 0.5 * t ^ 2
else
return 1 - 0.5 * (2 - t) ^ 2
end
end
function this.inCubic(t) return t * t * t end
function this.outCubic(t) return 1 - (1 - t) ^ 3 end
function this.inOutCubic(t)
t = t * 2
if t < 1 then
return 0.5 * t ^ 3
else
return 1 - 0.5 * (2 - t) ^ 3
end
end
function this.inQuart(t) return t * t * t * t end
function this.outQuart(t) return 1 - (1 - t) ^ 4 end
function this.inOutQuart(t)
t = t * 2
if t < 1 then
return 0.5 * t ^ 4
else
return 1 - 0.5 * (2 - t) ^ 4
end
end
function this.inQuint(t) return t ^ 5 end
function this.outQuint(t) return 1 - (1 - t) ^ 5 end
function this.inOutQuint(t)
t = t * 2
if t < 1 then
return 0.5 * t ^ 5
else
return 1 - 0.5 * (2 - t) ^ 5
end
end
function this.inExpo(t) return 1000 ^ (t - 1) - 0.001 end
function this.outExpo(t) return 0.999 - 1000 ^ -t end
function this.inOutExpo(t)
t = t * 2
if t < 1 then
return 0.5 * 1000 ^ (t - 1) - 0.0005
else
return 0.9995 - 0.5 * 1000 ^ (1 - t)
end
end
function this.inCirc(t) return 1 - sqrt(1 - t * t) end
function this.outCirc(t) return sqrt(-t * t + 2 * t) end
function this.inOutCirc(t)
t = t * 2
if t < 1 then
return 0.5 - 0.5 * sqrt(1 - t * t)
else
t = t - 2
return 0.5 + 0.5 * sqrt(1 - t * t)
end
end
function this.inElastic(t)
t = t - 1
return -(pow(2, 10 * t) * sin((t - 0.075) * (2 * pi) / 0.3))
end
function this.outElastic(t)
return pow(2, -10 * t) * sin((t - 0.075) * (2 * pi) / 0.3) + 1
end
function this.inOutElastic(t)
t = t * 2 - 1
if t < 0 then
return -0.5 * pow(2, 10 * t) * sin((t - 0.1125) * 2 * pi / 0.45)
else
return pow(2, -10 * t) * sin((t - 0.1125) * 2 * pi / 0.45) * 0.5 + 1
end
end
function this.inBack(t) return t * t * (2.70158 * t - 1.70158) end
function this.outBack(t)
t = t - 1
return (t * t * (2.70158 * t + 1.70158)) + 1
end
function this.inOutBack(t)
t = t * 2
if t < 1 then
return 0.5 * (t * t * (3.5864016 * t - 2.5864016))
else
t = t - 2
return 0.5 * (t * t * (3.5864016 * t + 2.5864016) + 2)
end
end
function this.outBounce(t)
if t < 1 / 2.75 then
return 7.5625 * t * t
elseif t < 2 / 2.75 then
t = t - 1.5 / 2.75
return 7.5625 * t * t + 0.75
elseif t < 2.5 / 2.75 then
t = t - 2.25 / 2.75
return 7.5625 * t * t + 0.9375
else
t = t - 2.625 / 2.75
return 7.5625 * t * t + 0.984375
end
end
function this.inBounce(t) return 1 - this.outBounce(1 - t) end
function this.inOutBounce(t)
if t < 0.5 then
return this.inBounce(t * 2) * 0.5
else
return this.outBounce(t * 2 - 1) * 0.5 + 0.5
end
end
function this.inSine(x)
return 1 - cos(x * (pi * 0.5))
end
function this.outSine(x)
return sin(x * (pi * 0.5))
end
function this.inOutSine(x)
return 0.5 - 0.5 * cos(x * pi)
end
return this