/*  sdfsinSR.cpp  by K.Tsuru  */
// function ID 3105   DRADIX
/***************
SDouble class
sin x
using sereies and reduction method.
Old version's Sin(x) before ver 2.2.
****************/
#ifndef SN_H
#include "sn.h"
#endif

#define usesSinSeriesInSin 1        // for a test.

SDouble SinS_RN(const SDouble& x){
    if(x.Sign() == 0) return x;     // x = 0
#if usesSinSeriesInSin
    // |x| is very small.
    if(x.NetRdxExp() < -4) return SinSeries(x); // |x| < 1.0e-16    ver.2.18

    uint fig = x.Last() - x.First() +1u;
    double c;

    if(fig <= 5u){  // x has the figures les than five.
        double dblX = doubleD(x, 0), absX = fabs(dblX);
        // x is short and small, then call SinSeries()
        c = (absX > M_PI_4) ? 1.0 : log10((double)x.MaxSize()*absX) - 1.6;
        if(c < 0) return SinSeries(x);
    }
#endif
    SDouble y, r;
    int func = SIN_CALC;
    int sgn = GetTriCalcMethod(x, y, &func);// |y| < pi/4
    if(sgn == 0){   // y = -1, 0, 1
        x.upToTerm = 0;
        return y;
    }
#if usesSinSeriesInSin
    // x is long but small.
    double dblY = doubleD(y), absY = fabs(dblY);
    c = (double)x.MaxSize()/64 + log10(absY) + 0.2;
    if(c < 0){
        if(func == COS_CALC) r = CosSeries(y);
        else r = SinSeries(y);
        goto Ret;
    }
#endif
//RN : using x/R^n reduction method
    if(func == COS_CALC) r = CosRN(y);
    else r = SinRN(y);
Ret:
    if(sgn < 0) r.ChangeSign();     // r = -r;
    return r;
}