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// 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:
// 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 *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 ANG_MAX 0xffffffff
#define ANG1 (ANG45 / 45)
#define ANG60 (ANG180 / 3)
// Heretic code uses this definition as though it represents one
// degree, but it is not! This is actually ~1.40 degrees.
#define ANG1_X 0x01000000
#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 int num, unsigned int den);
#endif
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