formula/source/core/api/random.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  */
   9
  10 #include <time.h>
  11
  12 #include <random>
  13
  14 #include <formula/random.hxx>
  15 #include <rtl/instance.hxx>
  16
  17 namespace {
  18
  19 struct CalcFormulaRandomGenerator
  20 {
  21     std::mt19937 aRng;
  22     CalcFormulaRandomGenerator()
  23     {
  24         // initialises the state of this RNG.
  25         // should only be called once.
  26         bool bRepeatable = (getenv("SC_RAND_REPEATABLE") != 0);
  27         aRng.seed(bRepeatable ? 42 : time(NULL));
  28     }
  29 };
  30
  31 class theCalcFormulaRandomGenerator : public rtl::Static<CalcFormulaRandomGenerator, theCalcFormulaRandomGenerator> {};
  32
  33 }
  34
  35 namespace formula
  36 {
  37
  38 namespace rng
  39 {
  40
  41 double fRandom(double a, double b)
  42 {
  43     std::uniform_real_distribution<double> dist(a, b);
  44     return dist(theCalcFormulaRandomGenerator::get().aRng);
  45 }
  46
  47 sal_Int32 nRandom(sal_Int32 a, sal_Int32 b)
  48 {
  49     std::uniform_int_distribution<sal_Int32> dist(a, b);
  50     return dist(theCalcFormulaRandomGenerator::get().aRng);
  51 }
  52
  53 } // rng
  54 } // formula
  55
  56 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */