mirror of
https://github.com/Refactorio/RedMew.git
synced 2025-01-18 03:21:47 +02:00
42 lines
942 B
Lua
42 lines
942 B
Lua
--[[
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Random number generator.
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https://www.codeproject.com/Articles/25172/Simple-Random-Number-Generation
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]]
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local Random = {}
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Random.__index = Random
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function Random.new(seed1, seed2)
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seed1 = seed1 or 36969
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seed2 = seed2 or 18000
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local random = {z = seed1, w = seed2}
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setmetatable(random, Random)
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return random
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end
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local function get_uint(self)
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self.z = 36969 * bit32.band(self.z, 65535) + bit32.rshift(self.z, 16)
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self.w = 18000 * bit32.band(self.w, 65535) + bit32.rshift(self.w, 16)
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local ret = bit32.lshift(self.z, 16) + self.w
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return bit32.band(ret, 4294967295)
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end
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local e = 1 / (2 ^ 32 + 2)
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-- return float (0, 1) exclusive
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function Random:next()
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local u = get_uint(self)
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return (u + 1.0) * e
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end
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-- returns int [min, max] inclusive
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function Random:next_int(min, max)
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local u = self:next()
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u = u * (max - min + 1) + min
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return math.floor(u)
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end
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return Random
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