/* * 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 / 2.); return (x - (x / 32.) - (x / 128.) + (t / 4.) + (t / 64.)); } int FindDistance3D(int x, int y, int z) { x= abs(x); /* absolute values */ y= abs(y); z= abs(z >> 4); if (x<y) std::swap(x,y); if (x<z) std::swap(x,z); int t = y + z; return (x - (x>>4) + (t>>2) + (t>>3)); }