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/* Emacs style mode select -*- C++ -*-
*-----------------------------------------------------------------------------
*
*
* PrBoom: a Doom port merged with LxDoom and LSDLDoom
* based on BOOM, a modified and improved DOOM engine
* Copyright (C) 1999 by
* id Software, Chi Hoang, Lee Killough, Jim Flynn, Rand Phares, Ty Halderman
* Copyright (C) 1999-2000 by
* Jess Haas, Nicolas Kalkhof, Colin Phipps, Florian Schulze
* Copyright 2005, 2006 by
* Florian Schulze, Colin Phipps, Neil Stevens, Andrey Budko
*
* 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
// Binary Angle Measument, BAM.
#define ANG45 0x20000000
#define ANG90 0x40000000
#define ANG180 0x80000000
#define ANG270 0xc0000000
#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif
#define SLOPERANGE 2048
#define SLOPEBITS 11
#define DBITS (FRACBITS-SLOPEBITS)
typedef unsigned angle_t;
// Load trig tables if needed
void R_LoadTrigTables(void);
// Effective size is 10240.
extern fixed_t finesine[5*FINEANGLES/4];
// Re-use data, is just PI/2 phase shift.
static fixed_t *const finecosine = finesine + (FINEANGLES/4);
// Effective size is 4096.
extern fixed_t finetangent[FINEANGLES/2];
// Effective size is 2049;
// The +1 size is to handle the case when x==y without additional checking.
extern angle_t tantoangle[SLOPERANGE+1];
// Utility function, called by R_PointToAngle.
int SlopeDiv(unsigned num, unsigned den);
#endif
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