oxmox
a191a82bdc
git-subtree-dir: src/dp_doom git-subtree-split: 190992421c7c643afc99d7f7c511c162f65bea85
82 lines
1.5 KiB
C
82 lines
1.5 KiB
C
// Emacs style mode select -*- C++ -*-
|
|
//-----------------------------------------------------------------------------
|
|
//
|
|
// $Id:$
|
|
//
|
|
// Copyright (C) 1993-1996 by id Software, Inc.
|
|
//
|
|
// This program is free software; you can redistribute it and/or
|
|
// modify it under the terms of the GNU General Public License
|
|
// as published by the Free Software Foundation; either version 2
|
|
// of the License, or (at your option) any later version.
|
|
//
|
|
// This program is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU General Public License for more details.
|
|
//
|
|
// $Log:$
|
|
//
|
|
// DESCRIPTION:
|
|
// Fixed point implementation.
|
|
//
|
|
//-----------------------------------------------------------------------------
|
|
|
|
|
|
#include "stdlib.h"
|
|
|
|
#include "doomtype.h"
|
|
#include "i_system.h"
|
|
|
|
#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 1
|
|
long long c;
|
|
c = ((long long)a<<16) / ((long long)b);
|
|
return (fixed_t) c;
|
|
#else
|
|
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;
|
|
#endif
|
|
}
|