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/*  Visualization Library                                                             */
/*  http://visualizationlibrary.org                                                   */
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#ifndef Random_INCLUDE_ONCE
#define Random_INCLUDE_ONCE

#include <vlCore/Object.hpp>

namespace vl
{
  //! Cryptographic random number generator.
  //! For non-ryptographic fast and high quality random number generation use vl::MersenneTwister.
  class VLCORE_EXPORT Random: public Object
  {
    VL_INSTRUMENT_CLASS(vl::Random, Object)

  public:
    //! Constructor.
    Random();

    //! Destructor.
    virtual ~Random();

    //! Fills the specified buffer with random data generated using the best quality random number generation facilities available.
    //! Under Windows (including MinGW) \p CryptGenRandom is used, while under Unix-like operating systems \p /dev/urandom is used.
    //! If no special random number generation facility is detected the function falls back to use a MersenneTwister.
    //! \return This method returns \p false if the function had to fallback to MersenneTwister otherwise returns \p true.
    virtual bool fillRandom(void* ptr, size_t bytes) const;

    //! Fills the specified buffer with random data generated using a defMersienneTwister().
    //! MersienneTwister produces high quality random number and can be much faster than fillRandom().
    void fillRandomMersenneTwister(void* ptr, size_t bytes) const;

  private:
#if defined(_MSC_VER) || defined(__MINGW32__)
    void* hCryptProv;
#elif defined(__GNUG__) && !defined(__MINGW32__)
  FILE* mDefURandom;
#endif
  };
}

#endif