//Filename:       xx-abfheadr.cxx
//Author:         Pamela Y. C. Fong
//Maintainer:     Qi Huang
//PI:             Henry A. Lester
//Organization:   California Institute of Technology
//
//                Reformulated and adapted from API copyrighted
//                by Axon Instruments, Inc.
//
//Created:        February 12, 2004
//Last Modified:  Mon Mar  1 13:15:46 PST 2004
//
//This code was created by modifying excerpts copied from Axon API file, ABFHEADR.CPP
//PYCF


#include "xx-abfheadr.h"
 

//==============================================================================================
// FUNCTION:   GetADCtoUUFactors
// PURPOSE:    Calculates the scaling factors used to convert ADC values to UserUnits.
// PARAMETERS:
//    nChannel        - The physical channel number to get the factors for.
//    pfADCToUUFactor - Pointers to return locations for scale and offset.
//    pfADCToUUShift    UserUnits = ADCValue * fADCToUUFactor + fADCToUUShift;
//
void ABFH_GetADCtoUUFactors(const ABFFileHeader *pFH, int nChannel, 
                                    float *pfADCToUUFactor, float *pfADCToUUShift )
{
   float fTotalScaleFactor = pFH->fInstrumentScaleFactor[nChannel] *
                             pFH->fADCProgrammableGain[nChannel];
 
   if (pFH->nSignalType != 0)
      fTotalScaleFactor *= pFH->fSignalGain[nChannel];
 
   // Adjust for the telegraphed gain.
   if( pFH->nTelegraphEnable[nChannel] )
      fTotalScaleFactor *= pFH->fTelegraphAdditGain[nChannel];
 
   if (fTotalScaleFactor==0.0F)
      fTotalScaleFactor = 1.0F;
 
   // InputRange and InputOffset is the range and offset of the signal in
   // user units when it hits the Analog-to-Digital converter
 
   float fInputRange = pFH->fADCRange / fTotalScaleFactor;
   float fInputOffset= -pFH->fInstrumentOffset[nChannel];
   if (pFH->nSignalType != 0)
      fInputOffset += pFH->fSignalOffset[nChannel];
 
   *pfADCToUUFactor = fInputRange / pFH->lADCResolution;
   *pfADCToUUShift  = -fInputOffset;
}