GY-63_MS5611/libraries/MultiMap/MultiMap.h

#pragma once
//
//    FILE: MultiMap.h
//  AUTHOR: Rob Tillaart
// VERSION: 0.1.4
//    DATE: 2011-01-26
// PURPOSE: Arduino library for fast non-linear mapping or interpolation of values
//     URL: https://github.com/RobTillaart/MultiMap
//     URL: http://playground.arduino.cc/Main/MultiMap
//
//  HISTORY:
//  0.0.1   2011-01-26 initial version (see forum)
//  .....
//  0.1.0   2015-03-29
//  0.1.1   2020-04-09
//  0.1.2   2020-06-19  fix library.json
//  0.1.3   2021-01-02  add arduino-CI 
//  0.1.4   2021-05-27  fix arduino-lint


#define MULTIMAP_LIB_VERSION        (F("0.1.4"))


#include "Arduino.h"

// note: the in array should have increasing values
template<typename T>
T multiMap(T val, T* _in, T* _out, uint8_t size)
{
    // take care the value is within range
    // val = constrain(val, _in[0], _in[size-1]);
    if (val <= _in[0]) return _out[0];
    if (val >= _in[size-1]) return _out[size-1];

    // search right interval
    uint8_t pos = 1;  // _in[0] allready tested
    while(val > _in[pos]) pos++;

    // this will handle all exact "points" in the _in array
    if (val == _in[pos]) return _out[pos];

    // interpolate in the right segment for the rest
    return (val - _in[pos-1]) * (_out[pos] - _out[pos-1]) / (_in[pos] - _in[pos-1]) + _out[pos-1];
}


/*
 * speed optimized version if inputs do not change often e.g.  2 2 2 2 2 3 3 3 3 5 5 5 5 5 5 8 8 8 8 5 5 5 5 5 
 *
// note: the in array should have increasing values

template<typename T>
T multiMap(T val, T* _in, T* _out, uint8_t size)
{
  static T lastvalue = -1;
  static T cache = -1;  

  if (val == lastvalue)
  {
    return cache;
  }
  lastvalue = val;

  // take care the value is within range
  // val = constrain(val, _in[0], _in[size-1]);
  if (val <= _in[0])
  {
    cache = _out[0];
  }
  else if (val >= _in[size-1])
  {
    cache = _out[size-1];
  }
  else
  {
    // search right interval; index 0 _in[0] already tested
    uint8_t pos = 1;  
    while(val > _in[pos]) pos++;
    
    // this will handle all exact "points" in the _in array
    if (val == _in[pos]) 
    {
      cache = _out[pos];
    }
    else
    {
      // interpolate in the right segment for the rest
      cache = (val - _in[pos-1]) * (_out[pos] - _out[pos-1]) / (_in[pos] - _in[pos-1]) + _out[pos-1];
    }
  }
  return cache;
}
*/


// -- END OF FILE --