/*  sdmrefrm.cpp  by K.Tsuru  */
// fuction ID = 314   DRADIX, BRADIX
/***************************************************************************
SDouble and SDecimal classes
It reforms int an appropriate form considering the present operation mode
(fixed or floating point mode).
It adjusts the size of figure[] and removes lower zeros.
**************************************************************************/
#ifndef SN_H
#include "sn.h"
#endif
void SDouble::Reform(int id){
    if(abs(rdxExp) > DRADIX_EXP_MAX) SetError(TOO_LARGE_EXP,"SD",id);
    if(SNSign() == 0){
        if(!IsPointFixed()) DoCutDown(); //cutting down lower zeros
        return;
    }
    uint cms = CurrentMaxSize();
    if(Type() == BIN_DEC){
#ifndef NDEBUG
assert(rdxExp == 0);
#endif
        if(aHead < cms) return;
        figure.clear(cms);   //cutting down over figures
        while( !figure[aHead] && (aHead > aTail)) aHead--;
        if( (aHead == aTail) && !figure[aHead]) SetSign(0);
        return;
    }
/*
SDouble variable here
When figure[0]>0 by carry, in either mode it makes figure[0]=0 by the moving
figures.
*/
    int f = (int)aTail;     //top position
    int m;                  //the quantity of moving figures
// f+m : top position after moving figures
    if( IsPointFixed() ){   //fixed point mode
    /*
    The quantity of moving figures in the fixed point mode is evaluated as
    x*R^e = x*R^(e-fe)*R^(fe) = {x*R^(-m)}*R^(fe)
    m = fe - e
    */
        m = fixedExp - rdxExp;
        if(f + m >= (int)cms ) { SetZero();     return; }
    //When f+m <=0,i.e.the value of fixed exponent cannot be taken as "fe",
    //the top figure is placed at first position figure[1].
        if(f + m <= 0) m = f ? (1 - f) : 1; //m=1 for f=0(figure[0]>0)
    } else m = 1 - f; //In the floating point mode,it sets the top figure at first position.
    if(m){  SetRdxExp(rdxExp + m);  ShiftArray(m);  }

//It cutss down extra figures.
    if( aHead >= cms ){
     //It is better to include the rouning off, but the processing becomes complex.
        figure.clear(cms);  // set figure[i] = 0 for i >= cms
        if(aTail >= cms){   // cms <= aTail <= aHead
            rdxExp = 0;     SetSign(0); //All the elements of figure[] are zero.
        } else {    // figure[aTail] != 0
            aHead = cms - 1u;
            while( !figure(aHead) ) aHead--;    //Maybe there are zeros in intermediate region.
        }
    }
//It cuts down the figures which has zero.
    uint fs = figure.size();
    if(IsPointFixed()){
        uint ms = ceilpow2( MaxSize() );//Not CurrentMaxSize(), because the size must be fixed.
        //If the effective figures decreased, it cuts down the size.
        if(fs > ms) figure.size(ms, 1); // cms <= ms
    } else if( 2u*(aHead+1u) <= fs ) DoCutDown();
}