raze-gles/polymer/eduke32/source/jmact/mathutil.c

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/*
* 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 <limits.h>
#include "compat.h"
#include "pragmas.h"
// I wonder if it's faster to use Ken's functions here...
int FindDistance2D(int x, int y)
{
x= klabs(x);
y= klabs(y);
if (x<y) swaplong(&x,&y);
{
int t = y + (y>>1);
return (x - (x>>5) - (x>>7) + (t>>2) + (t>>6));
}
}
int FindDistance3D(int x, int y, int z)
{
x= klabs(x);
y= klabs(y);
z= klabs(z);
if (x<y) swaplong(&x,&y);
if (x<z) swaplong(&x,&z);
{
int t = y + z;
return (x - (x>>4) + (t>>2) + (t>>3));
}
}