MCUME/MCUME_teensy41/teensydoom/m_fixed.c

63 wiersze
1.1 KiB
C

//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// 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.
//
// 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 ((int64_t) a * (int64_t) b) >> FRACBITS;
}
//
// FixedDiv, C version.
//
fixed_t FixedDiv(fixed_t a, fixed_t b)
{
if ((abs(a) >> 14) >= abs(b))
{
return (a^b) < 0 ? INT_MIN : INT_MAX;
}
else
{
int64_t result;
result = ((int64_t) a << 16) / b;
return (fixed_t) result;
}
}