ref: dce196fc67de283c41269b95a5d14c5a6616f32f
dir: /src/m_fixed.c/
// Emacs style mode select -*- C++ -*- //----------------------------------------------------------------------------- // // 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. // // 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 ? 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; }