// Emacs style mode select   -*- C++ -*-
//-----------------------------------------------------------------------------
//
// $Id: 2ca929bb605d6eef22712efdb67b0c84be072bd4 $
//
// Copyright (C) 1993-1996 by id Software, Inc.
// Copyright (C) 2006-2025 by The Odamex Team.
//
// 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.
//
//-----------------------------------------------------------------------------


#pragma once

#include "m_fixed.h"

#define PI				3.141592657

#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 phase 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 ANG135			0x60000000
#define ANG180			0x80000000
#define ANG225			0xa0000000
#define ANG270			0xc0000000
#define ANG315			0xe0000000
#define ANG(n)			((ANG45/45)*(n))

#define ANG360  0xffffffff

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

typedef DWORD			angle_t;


// Effective size is 2049;
// The +1 size is to handle the case when x==y without additional checking.
// [ML] 2/2/10: Updated with R_PointToAngle2 changes (from EE)
extern const angle_t tantoangle[2049];
extern angle_t tantoangle_acc[2049];

extern const angle_t *p_tantoangle;

void Table_InitTanToAngle(void);
void Table_SetTanToAngle(int version);

// More utility functions, courtesy of Quasar (James Haley).
// These are straight from Eternity so demos stay in sync.
inline static angle_t FixedToAngle(fixed_t a)
{
	return (angle_t)(((uint64_t)a * ANG(1)) >> FRACBITS);
}
