doom3-bfg/doomclassic/doom/m_fixed.cpp
2012-11-26 12:58:24 -06:00

92 lines
2.4 KiB
C++

/*
===========================================================================
Doom 3 BFG Edition GPL Source Code
Copyright (C) 1993-2012 id Software LLC, a ZeniMax Media company.
This file is part of the Doom 3 BFG Edition GPL Source Code ("Doom 3 BFG Edition Source Code").
Doom 3 BFG Edition Source Code 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 3 of the License, or
(at your option) any later version.
Doom 3 BFG Edition Source Code 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.
You should have received a copy of the GNU General Public License
along with Doom 3 BFG Edition Source Code. If not, see <http://www.gnu.org/licenses/>.
In addition, the Doom 3 BFG Edition Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the Doom 3 BFG Edition Source Code. If not, please request a copy in writing from id Software at the address below.
If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.
===========================================================================
*/
#include "Precompiled.h"
#include "globaldata.h"
#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 fixed_t( ((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;
}