/*  sdclog10.cpp  by K.Tsuru  */
// function ID 3522  DARDIX
// constant log(10)
/*************************
In header "snmath.h" the function prototype is declared below
--------
SDouble Log10(const SDouble* ln10 = NULL, SDouble (*pfCalcFunc)() = SNLog10);
--------
Remade at version 2.30.
**************************/
#ifndef SN_H
#include "sn.h"
#endif

static SDouble* ln10 = NULL;    //keep in the static memory
static uint ln10Size = 0;
void Log10Free(){
    if(ln10Size == 0) return;
    delete ln10;        ln10 = NULL;        ln10Size = 0;
}
uint Log10Size() { return ln10Size; }
SDouble Log10(const SDouble* userln10, SDouble (*pfCalcFunc)()){
    if(ln10 == NULL) ln10 = new SDouble;
    uint curMaxSize = ln10->MaxSize(); // current max size
    if( ln10Size < curMaxSize ){  // renew
#if UsesSNConstantFile
    if(userln10 == NULL){   //called by default argument
        int enough;
/**********************************************************************************
UpdateConstantFile() recursively calls this function Log10() via SetConstByFile()
of which userln10 != NULL, then does not come here and processing below has been
done.
**********************************************************************************/
        enough = UpdateConstantFile(Log10_FILE, Log10, pfCalcFunc, curMaxSize);
        if(enough != NO_SNC_FILE) return *ln10;
    }
#endif
        ln10->ShowMessage("Evaluating Log10() now.....");
        EntryConst(userln10, ln10, pfCalcFunc,  &ln10Size);
        ln10->ShowMessage(" Finished.\n"); // ver. 2.17

        ln10Size = curMaxSize;
    }
    return *ln10;
}