apps/plugins/doom/tables.h

   1 /* Emacs style mode select   -*- C++ -*-
   2  *-----------------------------------------------------------------------------
   3  *
   4  *
   5  *  PrBoom a Doom port merged with LxDoom and LSDLDoom
   6  *  based on BOOM, a modified and improved DOOM engine
   7  *  Copyright (C) 1999 by
   8  *  id Software, Chi Hoang, Lee Killough, Jim Flynn, Rand Phares, Ty Halderman
   9  *  Copyright (C) 1999-2000 by
  10  *  Jess Haas, Nicolas Kalkhof, Colin Phipps, Florian Schulze
  11  *
  12  *  This program is free software; you can redistribute it and/or
  13  *  modify it under the terms of the GNU General Public License
  14  *  as published by the Free Software Foundation; either version 2
  15  *  of the License, or (at your option) any later version.
  16  *
  17  *  This program is distributed in the hope that it will be useful,
  18  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  *  GNU General Public License for more details.
  21  *
  22  *  You should have received a copy of the GNU General Public License
  23  *  along with this program; if not, write to the Free Software
  24  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  25  *  02111-1307, USA.
  26  *
  27  * DESCRIPTION:
  28  *      Lookup tables.
  29  *      Do not try to look them up :-).
  30  *      In the order of appearance:
  31  *
  32  *      int finetangent[4096]   - Tangens LUT.
  33  *       Should work with BAM fairly well (12 of 16bit,
  34  *      effectively, by shifting).
  35  *
  36  *      int finesine[10240]             - Sine lookup.
  37  *       Guess what, serves as cosine, too.
  38  *       Remarkable thing is, how to use BAMs with this?
  39  *
  40  *      int tantoangle[2049]    - ArcTan LUT,
  41  *        maps tan(angle) to angle fast. Gotta search.
  42  *
  43  *-----------------------------------------------------------------------------*/
  44
  45 #ifndef __TABLES__
  46 #define __TABLES__
  47
  48 #include "m_fixed.h"
  49 #include "rockmacros.h"
  50
  51 #define FINEANGLES              8192
  52 #define FINEMASK                (FINEANGLES-1)
  53
  54 // 0x100000000 to 0x2000
  55 #define ANGLETOFINESHIFT        19
  56
  57 #ifndef ALL_IN_ONE
  58
  59 // TABLES_AS_LUMPS causes the tables to be loaded from a wad lump, and the normal
  60 // data to be stored as a predefined lump.
  61 // Only really useful for dumping the trig tables or with NO_PREDEFINED_LUMPS
  62 #define TABLES_AS_LUMPS
  63 #endif
  64
  65 // Binary Angle Measument, BAM.
  66 #define ANG45   0x20000000
  67 #define ANG90   0x40000000
  68 #define ANG180  0x80000000
  69 #define ANG270  0xc0000000
  70
  71 #define SLOPERANGE 2048
  72 #define SLOPEBITS    11
  73 #define DBITS      (FRACBITS-SLOPEBITS)
  74
  75 typedef unsigned angle_t;
  76
  77 // Load trig tables if needed
  78 #ifdef TABLES_AS_LUMPS
  79 void R_LoadTrigTables(void);
  80 #define TRIG_CONST
  81 #else
  82 #define TRIG_CONST const
  83 #endif
  84
  85 // Effective size is 10240.
  86 extern TRIG_CONST fixed_t *finesine;
  87
  88 // Re-use data, is just PI/2 phase shift.
  89 extern TRIG_CONST fixed_t *finecosine;
  90
  91 // Effective size is 4096.
  92 extern TRIG_CONST fixed_t *finetangent;
  93
  94 // Effective size is 2049;
  95 // The +1 size is to handle the case when x==y without additional checking.
  96
  97 extern TRIG_CONST angle_t *tantoangle;
  98
  99 // Utility function, called by R_PointToAngle.
 100 int SlopeDiv(unsigned num, unsigned den);
 101
 102 #undef TRIG_CONST
 103 #endif