/* Copyright (C) 1978-2001 Ken Turkowski. <turk@computer.org>
 *
 * All rights reserved.
 *
 * Warranty Information
 *  Even though I have reviewed this software, I make no warranty
 *  or representation, either express or implied, with respect to this
 *  software, its quality, accuracy, merchantability, or fitness for a
 *  particular purpose.  As a result, this software is provided "as is,"
 *  and you, its user, are assuming the entire risk as to its quality
 *  and accuracy.
 *
 * This code may be used and freely distributed as long as it includes
 * this copyright notice and the above warranty information.
 */



#ifdef macintosh
# include <MacTypes.h>
#else /* !macintosh */
  typedef long Fract;       /* 2.30: 2 integral bits and 30 fractional bits */
#endif /* !macintosh */


/* Prototype for FractSqrt.h header */
Fract FractSqrt(Fract a);


/********************************************************************************
 * FractSqrt
 ********************************************************************************/

Fract
FractSqrt(Fract a)
{
    register unsigned long root, remHi, remLo, testDiv, count;

    root = 0;       /* Clear root */
    remHi = 0;      /* Clear high part of partial remainder */
    remLo = a;      /* Get argument into low part of partial remainder */
    count = 30;     /* Load loop counter */

    do {
        remHi = (remHi << 2) | (remLo >> 30); remLo <<= 2;  /* get 2 bits of arg */
        root <<= 1; /* Get ready for the next bit in the root */
        testDiv = (root << 1) + 1;  /* Test divisor */
        if (remHi >= testDiv) {
            remHi -= testDiv;
            root += 1;
        }
    } while (count-- != 0);

    return(root);
}