--
-- melisma - extensible and scriptable audio engine
-- Copyright (C) 2026  Ludvig Gunne Lindström
--
-- This program is free software: you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation, either version 3 of the License, or
-- (at your option) any later version.
--
-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-- GNU General Public License for more details.
--
-- You should have received a copy of the GNU General Public License
-- along with this program.  If not, see <https://www.gnu.org/licenses/>.
--

local M = {}

function M.uniform(lo,hi)
  return lo + math.random()*(hi - lo)
end

function M.normal(mean,dev)
  local u,v,s,t,z0,z1
  repeat
    u = M.uniform(-1,1)
    v = M.uniform(-1,1)
    s = u^2 + v^2
  until s > 0 and s < 1
  t = math.sqrt(-2*math.log(s) / s)
  z0 = mean + u*t*dev
  z1 = mean + v*t*dev
  return z0,z1
end

return M