raze/source/core/mathutil.cpp

64 lines
1.7 KiB
C++

/*
* mathutil.c
* Mathematical utility functions to emulate MACT
*
* by Jonathon Fowler
*
* Since we weren't given the source for MACT386.LIB so I've had to do some
* creative interpolation here.
*
*/
//-------------------------------------------------------------------------
/*
Duke Nukem Copyright (C) 1996, 2003 3D Realms Entertainment
This file is part of Duke Nukem 3D version 1.5 - Atomic Edition
Duke Nukem 3D 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.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
//-------------------------------------------------------------------------
#include <algorithm>
#include "types.h"
#include <stdlib.h>
// This extracted from the Rise of the Triad source RT_UTIL.C :-|
int FindDistance2D(int x, int y)
{
x= abs(x); /* absolute values */
y= abs(y);
if (x<y)
std::swap(x,y);
int t = y + (y>>1);
return (x - (x>>5) - (x>>7) + (t>>2) + (t>>6));
}
double fFindDistance2D(int x, int y)
{
x= abs(x); /* absolute values */
y= abs(y);
if (x<y)
std::swap(x,y);
double t = y + (y * (1. / 2.));
return (x - (x * (1. / 32.)) - (x * (1. / 128.)) + (t * (1. / 4.)) + (t * (1. / 64.)));
}