quantize.h

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/******************************************************************************
The MIT License(MIT)
 
Embedded Template Library.
https://github.com/ETLCPP/etl
https://www.etlcpp.com
 
Copyright(c) 2021 John Wellbelove
 
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#ifndef ETL_QUANTIZE_INCLUDED
#define ETL_QUANTIZE_INCLUDED
 
#include "platform.h"
#include "functional.h"
#include "type_traits.h"
 
#include <stddef.h>

 
namespace etl
{
  //***************************************************************************
  //***************************************************************************
  template <typename TInput, typename TCompare = etl::less<TInput> >
  class quantize : public etl::unary_function<TInput, TInput>
  {
  public:
 
    //*****************************************************************
    // Constructor.
    //*****************************************************************
    quantize(const TInput* p_thresholds_, const TInput* p_quantizations_, size_t n_quantizations_, TCompare compare_ = TCompare())
      : p_thresholds(p_thresholds_)
      , p_quantizations(p_quantizations_)
      , n_levels(n_quantizations_ - 1U)
      , compare(compare_)
    {
    }
 
    //*****************************************************************
    // operator ()
    //*****************************************************************
    TInput operator()(TInput value) const
    {
      for (size_t i = 0UL; i < n_levels; ++i)
      {
        if (compare(value, p_thresholds[i]))
        {
          return p_quantizations[i];
        }
      }
 
      return p_quantizations[n_levels];
    }
 
  private:
 
    const TInput* const p_thresholds;
    const TInput* const p_quantizations;
    const size_t        n_levels;
    const TCompare      compare;
  };
} // namespace etl
 
#endif