// Emacs style mode select   -*- C++ -*-
//-----------------------------------------------------------------------------
//
// $Id: tables.h,v 1.3 1998/05/03 22:58:56 killough Exp $
//
// Copyright (C) 1993-1996 by id Software, Inc.
//
// This source is available for distribution and/or modification
// only under the terms of the DOOM Source Code License as
// published by id Software. All rights reserved.
//
// The source is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// FITNESS FOR A PARTICULAR PURPOSE. See the DOOM Source Code License
// for more details.
//
// DESCRIPTION:
//      Lookup tables.
//      Do not try to look them up :-).
//      In the order of appearance:
//
//      int finetangent[4096]   - Tangens LUT.
//       Should work with BAM fairly well (12 of 16bit,
//      effectively, by shifting).
//
//      int finesine[10240]             - Sine lookup.
//       Guess what, serves as cosine, too.
//       Remarkable thing is, how to use BAMs with this?
//
//      int tantoangle[2049]    - ArcTan LUT,
//        maps tan(angle) to angle fast. Gotta search.
//
//-----------------------------------------------------------------------------

#ifndef __TABLES__
#define __TABLES__

#include "m_fixed.h"

#define FINEANGLES              8192
#define FINEMASK                (FINEANGLES-1)

// 0x100000000 to 0x2000
#define ANGLETOFINESHIFT        19

// Effective size is 10240.
extern const fixed_t finesine[5*FINEANGLES/4];

// Re-use data, is just PI/2 pahse shift.
extern const fixed_t *const finecosine;

// Effective size is 4096.
extern const fixed_t finetangent[FINEANGLES/2];

// Binary Angle Measument, BAM.
#define ANG45   0x20000000
#define ANG90   0x40000000
#define ANG180  0x80000000
#define ANG270  0xc0000000

#define SLOPERANGE 2048
#define SLOPEBITS    11
#define DBITS      (FRACBITS-SLOPEBITS)

typedef unsigned angle_t;

// Effective size is 2049;
// The +1 size is to handle the case when x==y without additional checking.

extern const angle_t tantoangle[SLOPERANGE+1];

// Utility function, called by R_PointToAngle.
int SlopeDiv(unsigned num, unsigned den);

#endif

//----------------------------------------------------------------------------
//
// $Log: tables.h,v $
// Revision 1.3  1998/05/03  22:58:56  killough
// beautification
//
// Revision 1.2  1998/01/26  19:27:58  phares
// First rev with no ^Ms
//
// Revision 1.1.1.1  1998/01/19  14:03:05  rand
// Lee's Jan 19 sources
//
//----------------------------------------------------------------------------
