/*  sdcmpi4.cpp  by K.Tsuru  */
// function ID 3550  DRADIX, constant
/********************************
SDouble class
pi/4
Used in Atan(), etc.
*********************************/
#ifndef SN_H
#include "sn.h"
#endif

static SDouble* mpi4 = NULL;    //keep in the static memory
static uint mpi4_size = 0;

void MPi4Free(){        //free the memory of mpi4
    if(mpi4_size == 0) return;
    delete mpi4;        mpi4 = NULL;        mpi4_size = 0;
}

/* pi/4 */
SDouble MPi4(){
    uint ms = SNManager::SNMaxSize(SNManager::REAL);
    if(mpi4_size < ms){
        if(mpi4 == NULL) mpi4 = new SDouble;

        SDouble pi;
        pi = Pi();
        *mpi4 = DsDiv(pi, 4uL); // pi/4
        mpi4_size = ms;
    }
    return *mpi4;
}