// Emacs style mode select   -*- C++ -*-
//-----------------------------------------------------------------------------
//
// $Id:$
//
// Copyright (C) 1993-1996 by id Software, Inc.
//
// This source is available for distribution and/or modification
// only under the terms of the DOOM Source Code License as
// published by id Software. All rights reserved.
//
// The source is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// FITNESS FOR A PARTICULAR PURPOSE. See the DOOM Source Code License
// for more details.
//
// $Log:$
//
// DESCRIPTION:
//	Fixed point implementation.
//
//-----------------------------------------------------------------------------


static const char
rcsid[] = "$Id: m_bbox.c,v 1.1 1997/02/03 22:45:10 b1 Exp $";

#include "stdlib.h"

#include "doomtype.h"
#include "i_system.h"

#ifdef __GNUG__
#pragma implementation "m_fixed.h"
#endif
#include "m_fixed.h"


static fixed_t FixedDiv2 (fixed_t a, fixed_t b);

// Fixme. __USE_C_FIXED__ or something.

fixed_t
FixedMul
( fixed_t	a,
  fixed_t	b )
{
#ifndef USE_FLOAT_FIXED
    return ((long long) a * (long long) b) >> FRACBITS;
#else
	return (fixed_t)(((float)a * (float)b) * FRACINV);
#endif
}



//
// FixedDiv, C version.
//

fixed_t
FixedDiv
( fixed_t	a,
  fixed_t	b )
{
    if ( (abs(a)>>14) >= abs(b))
	return (a^b)<0 ? MININT : MAXINT;
    return FixedDiv2 (a,b);
}



static fixed_t
FixedDiv2
( fixed_t	a,
  fixed_t	b )
{
#ifndef USE_FLOAT_FIXED
    long long c;

    c = ((long long)a<<16) / ((long long)b);

    return (fixed_t) c;
#else
    float c;

    c = ((float)a) / ((float)b) * FRACUNITF;

    if (c >= 2147483648.0f || c < -2147483648.0f)
		I_Error("FixedDiv: divide by zero");

    return (fixed_t) c;
#endif
}
