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ST-Computer Leser-CD 2000 January
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LCD_01_2000.iso
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doom
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pmdoom
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m_fixed.c
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C/C++ Source or Header
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1999-12-17
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2KB
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87 lines
/* 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. */
/* */
/* ----------------------------------------------------------------------------- */
#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. */
#ifndef ATARI
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;
}
#endif