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113 lines
2.5 KiB
C
113 lines
2.5 KiB
C
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/*
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* mathutil.c
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* Mathematical utility functions to emulate MACT
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*
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* by Jonathon Fowler
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*
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* Since we weren't given the source for MACT386.LIB so I've had to do some
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* creative interpolation here.
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*
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*/
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//-------------------------------------------------------------------------
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/*
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Duke Nukem Copyright (C) 1996, 2003 3D Realms Entertainment
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This file is part of Duke Nukem 3D version 1.5 - Atomic Edition
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Duke Nukem 3D is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License
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as published by the Free Software Foundation; either version 2
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of the License, or (at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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See the GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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//-------------------------------------------------------------------------
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#include "types.h"
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#if 0
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// Ken's reverse-engineering job
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int32 FindDistance2D(int32 x, int32 y)
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{
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int32 i;
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x = labs(x);
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y = labs(y);
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if (!x) return(y);
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if (!y) return(x);
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if (y < x) { i = x; x = y; y = i; } //swap x, y
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x += (x>>1);
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return ((x>>6)+(x>>2)+y-(y>>5)-(y>>7)); //handle 1 octant
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}
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// My abomination
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#define square(x) ((x)*(x))
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/*
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int32 FindDistance2D(int32 dx, int32 dy)
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{
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// return (int32)floor(sqrt((double)(sqr(dx)+sqr(dy))));
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return ksqrt(square(dx)+square(dy));
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}
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*/
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int32 FindDistance3D(int32 dx, int32 dy, int32 dz)
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{
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// return (int32)floor(sqrt((double)(sqr(dx)+sqr(dy)+sqr(dz))));
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return ksqrt(square(dx)+square(dy)+square(dz));
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}
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#else
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#include <stdlib.h>
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// This extracted from the Rise of the Triad source RT_UTIL.C :-|
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#define SWAP(a,b) \
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{ \
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a=(a)^(b); \
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b=(a)^(b); \
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a=(a)^(b); \
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}
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int32 FindDistance2D(int32 x, int32 y)
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{
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int32 t;
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x= abs(x); /* absolute values */
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y= abs(y);
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if (x<y)
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SWAP(x,y);
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t = y + (y>>1);
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return (x - (x>>5) - (x>>7) + (t>>2) + (t>>6));
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}
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int32 FindDistance3D(int32 x, int32 y, int32 z)
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{
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int32 t;
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x= abs(x); /* absolute values */
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y= abs(y);
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z= abs(z);
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if (x<y)
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SWAP(x,y);
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if (x<z)
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SWAP(x,z);
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t = y + z;
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return (x - (x>>4) + (t>>2) + (t>>3));
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}
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#endif
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