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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