raze/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 "types.h"
#if 0
// Ken's reverse-engineering job
int32 FindDistance2D(int32 x, int32 y)
{
int32 i;
x = labs(x);
y = labs(y);
if (!x) return(y);
if (!y) return(x);
if (y < x) { i = x; x = y; y = i; } //swap x, y
x += (x>>1);
return ((x>>6)+(x>>2)+y-(y>>5)-(y>>7)); //handle 1 octant
}
// My abomination
#define square(x) ((x)*(x))
/*
int32 FindDistance2D(int32 dx, int32 dy)
{
// return (int32)floor(sqrt((double)(sqr(dx)+sqr(dy))));
return ksqrt(square(dx)+square(dy));
}
*/
int32 FindDistance3D(int32 dx, int32 dy, int32 dz)
{
// return (int32)floor(sqrt((double)(sqr(dx)+sqr(dy)+sqr(dz))));
return ksqrt(square(dx)+square(dy)+square(dz));
}
#else
#include <stdlib.h>
// This extracted from the Rise of the Triad source RT_UTIL.C :-|
#define SWAP(a,b) \
{ \
a=(a)^(b); \
b=(a)^(b); \
a=(a)^(b); \
}
int32 FindDistance2D(int32 x, int32 y)
{
int32 t;
x= abs(x); /* absolute values */
y= abs(y);
if (x<y)
SWAP(x,y);
t = y + (y>>1);
return (x - (x>>5) - (x>>7) + (t>>2) + (t>>6));
}
int32 FindDistance3D(int32 x, int32 y, int32 z)
{
int32 t;
x= abs(x); /* absolute values */
y= abs(y);
z= abs(z);
if (x<y)
SWAP(x,y);
if (x<z)
SWAP(x,z);
t = y + z;
return (x - (x>>4) + (t>>2) + (t>>3));
}
#endif