Park-Miller-Carta PNRG

Park-Miller-Carta.lua

--[[
Copyright (c) 2009 Michael Baczynski, http://www.polygonal.de

Permission is hereby granted, free of charge, to any person obtaining
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"Software"), to deal in the Software without restriction, including
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The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
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NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
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--]]

-- Implementation of the Park Miller (1988) "minimal standard" linear 
-- congruential pseudo-random number generator.
-- @author Michael Baczynski, www.polygonal.de
-- @author Thomas R. Koll, www.ananasblau.com
-- MIT License
local PM_PRNG
do
  local _parent_0 = nil
  local _base_0 = {
    prime = math.pow(2, 31) - 1,
    nextInt = function(self)
      return self:generate()
    end,
    nextDouble = function(self)
      return self:generate() / self.prime
    end,
    nextIntRange = function(self, min, max)
      min = min - 0.4999
      max = max + 0.4999
      return math.floor(0.5 + min + ((max - min) * self:nextDouble()))
    end,
    nextDoubleRange = function(self, min, max)
      return min + ((max - min) * self:nextDouble())
    end,
    generate = function(self)
      self.seed = (self.seed * 16807) % self.prime
      return self.seed
    end
  }
  _base_0.__index = _base_0
  if _parent_0 then
    setmetatable(_base_0, _parent_0.__base)
  end
  local _class_0 = setmetatable({
    __init = function(self, seed)
      self.seed = seed or 1
    end,
    __base = _base_0,
    __name = "PM_PRNG",
    __parent = _parent_0
  }, {
    __index = function(cls, name)
      local val = rawget(_base_0, name)
      if val == nil and _parent_0 then
        return _parent_0[name]
      else
        return val
      end
    end,
    __call = function(cls, ...)
      local _self_0 = setmetatable({}, _base_0)
      cls.__init(_self_0, ...)
      return _self_0
    end
  })
  _base_0.__class = _class_0
  if _parent_0 and _parent_0.__inherited then
    _parent_0.__inherited(_parent_0, _class_0)
  end
  PM_PRNG = _class_0
end