// Emacs style mode select -*- C++ -*- //----------------------------------------------------------------------------- // // $Id: m_fixed.c 19 2005-07-23 19:17:11Z fraggle $ // // Copyright(C) 1993-1996 Id Software, Inc. // Copyright(C) 2005 Simon Howard // // This program 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. // // $Log$ // Revision 1.4 2005/07/23 19:17:11 fraggle // Use ANSI-standard limit constants. Remove LINUX define. // // Revision 1.3 2005/07/23 18:56:07 fraggle // Remove unneccessary pragmas // // Revision 1.2 2005/07/23 16:44:55 fraggle // Update copyright to GNU GPL // // Revision 1.1.1.1 2005/07/23 16:19:54 fraggle // Initial import // // // DESCRIPTION: // Fixed point implementation. // //----------------------------------------------------------------------------- static const char rcsid[] = "$Id: m_fixed.c 19 2005-07-23 19:17:11Z fraggle $"; #include "stdlib.h" #include "doomtype.h" #include "i_system.h" #include "m_fixed.h" // Fixme. __USE_C_FIXED__ or something. fixed_t FixedMul ( fixed_t a, fixed_t b ) { return ((long long) a * (long long) b) >> FRACBITS; } // // FixedDiv, C version. // fixed_t FixedDiv ( fixed_t a, fixed_t b ) { if ( (abs(a)>>14) >= abs(b)) return (a^b)<0 ? INT_MIN : INT_MAX; return FixedDiv2 (a,b); } fixed_t FixedDiv2 ( fixed_t a, fixed_t b ) { #if 0 long long c; c = ((long long)a<<16) / ((long long)b); return (fixed_t) c; #endif double c; c = ((double)a) / ((double)b) * FRACUNIT; if (c >= 2147483648.0 || c < -2147483648.0) I_Error("FixedDiv: divide by zero"); return (fixed_t) c; }