💿🐜 Antkeeper source code https://antkeeper.com
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  1. /*
  2. * Copyright (C) 2021 Christopher J. Howard
  3. *
  4. * This file is part of Antkeeper source code.
  5. *
  6. * Antkeeper source code is free software: you can redistribute it and/or modify
  7. * it under the terms of the GNU General Public License as published by
  8. * the Free Software Foundation, either version 3 of the License, or
  9. * (at your option) any later version.
  10. *
  11. * Antkeeper source code is distributed in the hope that it will be useful,
  12. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14. * GNU General Public License for more details.
  15. *
  16. * You should have received a copy of the GNU General Public License
  17. * along with Antkeeper source code. If not, see <http://www.gnu.org/licenses/>.
  18. */
  19. #ifndef ANTKEEPER_MATH_RANDOM_HPP
  20. #define ANTKEEPER_MATH_RANDOM_HPP
  21. #include <cstdlib>
  22. #include <type_traits>
  23. namespace math {
  24. /**
  25. * Generates a pseudo-random floating point number on `[start, end)` using std::rand().
  26. *
  27. * @warning Don't forget to seed with std::srand() before using!
  28. *
  29. * @param start Start of the range (inclusive).
  30. * @param end End of the range (exclusive).
  31. * @return Pseudo-random floating point number.
  32. */
  33. template <typename T = float>
  34. T random(T start, T end);
  35. template <typename T>
  36. inline T random(T start, T end)
  37. {
  38. static_assert(std::is_floating_point<T>::value);
  39. constexpr T rand_max_inverse = T(1) / static_cast<T>(RAND_MAX);
  40. return static_cast<T>(std::rand()) * rand_max_inverse * (end - start) + start;
  41. }
  42. } // namespace math
  43. #endif // ANTKEEPER_MATH_RANDOM_HPP