// Emacs style mode select -*- C++ -*- //----------------------------------------------------------------------------- // // $Id:$ // // Copyright (C) 1993-1996 by id Software, Inc. // // 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. // // $Log:$ // // DESCRIPTION: // Fixed point implementation. // //----------------------------------------------------------------------------- #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 ? MININT : MAXINT; return FixedDiv2 (a,b); } fixed_t FixedDiv2 ( fixed_t a, fixed_t b ) { #if 1 long long c; c = ((long long)a<<16) / ((long long)b); return (fixed_t) c; #else 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; #endif }