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83 lines
2 KiB
C++
83 lines
2 KiB
C++
/*
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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 <algorithm>
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#include "types.h"
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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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int FindDistance2D(int x, int y)
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{
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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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std::swap(x,y);
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int 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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double fFindDistance2D(int x, int y)
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{
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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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std::swap(x,y);
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double t = y + (y * (1. / 2.));
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return (x - (x * (1. / 32.)) - (x * (1. / 128.)) + (t * (1. / 4.)) + (t * (1. / 64.)));
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}
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int FindDistance3D(int x, int y, int z)
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{
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x= abs(x); /* absolute values */
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y= abs(y);
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z= abs(z >> 4);
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if (x<y)
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std::swap(x,y);
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if (x<z)
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std::swap(x,z);
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int t = y + z;
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return (x - (x>>4) + (t>>2) + (t>>3));
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}
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