88 lines
1.6 KiB
C
88 lines
1.6 KiB
C
// 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"
|
|
|
|
|
|
|
|
|
|
// Fixme. __USE_C_FIXED__ or something.
|
|
|
|
fixed_t
|
|
FixedMul
|
|
( fixed_t a,
|
|
fixed_t b )
|
|
{
|
|
return ((long long) a * (long long) b) >> FRACBITS;
|
|
}
|
|
|
|
|
|
|
|
//
|
|
// 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);
|
|
}
|
|
|
|
|
|
|
|
fixed_t
|
|
FixedDiv2
|
|
( fixed_t a,
|
|
fixed_t b )
|
|
{
|
|
#if 0
|
|
long long c;
|
|
c = ((long long)a<<16) / ((long long)b);
|
|
return (fixed_t) c;
|
|
#endif
|
|
|
|
double c;
|
|
|
|
c = ((double)a) / ((double)b) * FRACUNIT;
|
|
|
|
if (c >= 2147483648.0 || c < -2147483648.0)
|
|
I_Error("FixedDiv: divide by zero");
|
|
return (fixed_t) c;
|
|
}
|