context: #region Copyright & License Information
  /*
   * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
   * This file is part of OpenRA, which is free software. It is made
   * available to you under the terms of the GNU General Public License
   * as published by the Free Software Foundation, either version 3 of
   * the License, or (at your option) any later version. For more
   * information, see COPYING.
   */
  #endregion
  
  using System;
  using Eluant;
  using Eluant.ObjectBinding;
  using OpenRA.Scripting;
  
  namespace OpenRA
  {
  	/// <summary>
  	/// 1D angle - 1024 units = 360 degrees.
  	/// </summary>
  	public struct WAngle : IScriptBindable, ILuaAdditionBinding, ILuaSubtractionBinding, ILuaEqualityBinding, IEquatable<WAngle>
  	{
  		public readonly int Angle;
  		public int AngleSquared { get { return (int)Angle * Angle; } }
  
  		public WAngle(int a)
  		{
  			Angle = a % 1024;
  			if (Angle < 0)
  				Angle += 1024;
  		}
  
  		public static readonly WAngle Zero = new WAngle(0);
  		public static WAngle FromFacing(int facing) { return new WAngle(facing * 4); }
  		public static WAngle FromDegrees(int degrees) { return new WAngle(degrees * 1024 / 360); }
  		public static WAngle operator +(WAngle a, WAngle b) { return new WAngle(a.Angle + b.Angle); }
  		public static WAngle operator -(WAngle a, WAngle b) { return new WAngle(a.Angle - b.Angle); }
  		public static WAngle operator -(WAngle a) { return new WAngle(-a.Angle); }
  
  		public static bool operator ==(WAngle me, WAngle other) { return me.Angle == other.Angle; }
  		public static bool operator !=(WAngle me, WAngle other) { return !(me == other); }
  
  		public override int GetHashCode() { return Angle.GetHashCode(); }
  
  		public bool Equals(WAngle other) { return other == this; }
  		public override bool Equals(object obj) { return obj is WAngle && Equals((WAngle)obj); }
  
  		public int Facing { get { return Angle / 4; } }
  
  		public int Sin() { return new WAngle(Angle - 256).Cos(); }
  
  		public int Cos()
  		{
  			if (Angle <= 256)
  				return CosineTable[Angle];
  			if (Angle <= 512)
  				return -CosineTable[512 - Angle];
  			return -new WAngle(Angle - 512).Cos();
  		}
  
  		public int Tan()
  		{
  			if (Angle <= 256)
  				return TanTable[Angle];
  			if (Angle <= 512)
  				return -TanTable[512 - Angle];
  			return new WAngle(Angle - 512).Tan();
  		}
  
  		public static WAngle Lerp(WAngle a, WAngle b, int mul, int div)
  		{
  			// Map 1024 <-> 0 wrapping into linear space
  			var aa = a.Angle;
  			var bb = b.Angle;
  			if (aa > bb && aa - bb > 512)
  				aa -= 1024;
  
  			if (bb > aa && bb - aa > 512)
  				bb -= 1024;
  
  			return new WAngle(aa + (bb - aa) * mul / div);
  		}
  
  		public static WAngle ArcTan(int y, int x) { return ArcTan(y, x, 1); }
  		public static WAngle ArcTan(int y, int x, int stride)
  		{
  			if (y == 0)
  				return new WAngle(x >= 0 ? 0 : 512);
  
  			if (x == 0)
  				return new WAngle(Math.Sign(y) * 256);
  
  			var ay = Math.Abs(y);
  			var ax = Math.Abs(x);
  
  			// Find the closest angle that satisfies y = x*tan(theta)
  			// Uses a long to store bestVal to eliminate integer overflow issues in the common cases
  			// (may still fail for unrealistically large ax and ay)
  			var bestVal = long.MaxValue;
  			var bestAngle = 0;
  			for (var i = 0; i < 256; i += stride)
  			{
  				var val = Math.Abs(1024 * ay - (long)ax * TanTable[i]);
  				if (val < bestVal)
  				{
  					bestVal = val;
  					bestAngle = i;
  				}
  			}
  
  			// Calculate quadrant
  			if (x < 0 && y > 0)
  				bestAngle = 512 - bestAngle;
  			else if (x < 0 && y < 0)
  				bestAngle = 512 + bestAngle;
  			else if (x > 0 && y < 0)
  				bestAngle = 1024 - bestAngle;
  
  			return new WAngle(bestAngle);
  		}
  
  		// Must not be used outside rendering code
  		public float RendererRadians() { return (float)(Angle * Math.PI / 512f); }
  		public float RendererDegrees() { return Angle * 0.3515625f; }
  
  		public override string ToString() { return Angle.ToString(); }
  
  		static readonly int[] CosineTable =
  		{
  			1024, 1023, 1023, 1023, 1023, 1023, 1023, 1023, 1022, 1022, 1022, 1021,
  			1021, 1020, 1020, 1019, 1019, 1018, 1017, 1017, 1016, 1015, 1014, 1013,
  			1012, 1011, 1010, 1009, 1008, 1007, 1006, 1005, 1004, 1003, 1001, 1000,
  			999, 997, 996, 994, 993, 991, 990, 988, 986, 985, 983, 981, 979, 978,
  			976, 974, 972, 970, 968, 966, 964, 962, 959, 957, 955, 953, 950, 948,
  			946, 943, 941, 938, 936, 933, 930, 928, 925, 922, 920, 917, 914, 911,
  			908, 906, 903, 900, 897, 894, 890, 887, 884, 881, 878, 875, 871, 868,
  			865, 861, 858, 854, 851, 847, 844, 840, 837, 833, 829, 826, 822, 818,
  			814, 811, 807, 803, 799, 795, 791, 787, 783, 779, 775, 771, 767, 762,
  			758, 754, 750, 745, 741, 737, 732, 728, 724, 719, 715, 710, 706, 701,
  			696, 692, 687, 683, 678, 673, 668, 664, 659, 654, 649, 644, 639, 634,
  			629, 625, 620, 615, 609, 604, 599, 594, 589, 584, 579, 574, 568, 563,
  			558, 553, 547, 542, 537, 531, 526, 521, 515, 510, 504, 499, 493, 488,
  			482, 477, 471, 466, 460, 454, 449, 443, 437, 432, 426, 420, 414, 409,
  			403, 397, 391, 386, 380, 374, 368, 362, 356, 350, 344, 339, 333, 327,
  			321, 315, 309, 303, 297, 291, 285, 279, 273, 267, 260, 254, 248, 242,
  			236, 230, 224, 218, 212, 205, 199, 193, 187, 181, 175, 168, 162, 156,
  			150, 144, 137, 131, 125, 119, 112, 106, 100, 94, 87, 81, 75, 69, 62,
  			56, 50, 43, 37, 31, 25, 18, 12, 6, 0
  		};
  
  		static readonly int[] TanTable =
  		{
  			0, 6, 12, 18, 25, 31, 37, 44, 50, 56, 62, 69, 75, 81, 88, 94, 100, 107,
  			113, 119, 126, 132, 139, 145, 151, 158, 164, 171, 177, 184, 190, 197,
  			203, 210, 216, 223, 229, 236, 243, 249, 256, 263, 269, 276, 283, 290,
  			296, 303, 310, 317, 324, 331, 338, 345, 352, 359, 366, 373, 380, 387,
  			395, 402, 409, 416, 424, 431, 438, 446, 453, 461, 469, 476, 484, 492,
  			499, 507, 515, 523, 531, 539, 547, 555, 563, 571, 580, 588, 596, 605,
  			613, 622, 630, 639, 648, 657, 666, 675, 684, 693, 702, 711, 721, 730,
  			740, 749, 759, 769, 779, 789, 799, 809, 819, 829, 840, 850, 861, 872,
  			883, 894, 905, 916, 928, 939, 951, 963, 974, 986, 999, 1011, 1023, 1036,
  			1049, 1062, 1075, 1088, 1102, 1115, 1129, 1143, 1158, 1172, 1187, 1201,
  			1216, 1232, 1247, 1263, 1279, 1295, 1312, 1328, 1345, 1363, 1380, 1398,
  			1416, 1435, 1453, 1473, 1492, 1512, 1532, 1553, 1574, 1595, 1617, 1639,
  			1661, 1684, 1708, 1732, 1756, 1782, 1807, 1833, 1860, 1887, 1915, 1944,
  			1973, 2003, 2034, 2065, 2098, 2131, 2165, 2199, 2235, 2272, 2310, 2348,
  			2388, 2429, 2472, 2515, 2560, 2606, 2654, 2703, 2754, 2807, 2861, 2918,
  			2976, 3036, 3099, 3164, 3232, 3302, 3375, 3451, 3531, 3613, 3700, 3790,
  			3885, 3984, 4088, 4197, 4311, 4432, 4560, 4694, 4836, 4987, 5147, 5318,
  			5499, 5693, 5901, 6124, 6364, 6622, 6903, 7207, 7539, 7902, 8302, 8743,
  			9233, 9781, 10396, 11094, 11891, 12810, 13882, 15148, 16667, 18524, 20843,
  			23826, 27801, 33366, 41713, 55622, 83438, 166883, int.MaxValue
  		};
  
  		#region Scripting interface
  
  		public LuaValue Add(LuaRuntime runtime, LuaValue left, LuaValue right)
  		{
  			WAngle a, b;
  			int c;
  
  			if (!left.TryGetClrValue(out a))
  				throw new LuaException("Attempted to call WAngle.Add(WAngle, WAngle) with invalid arguments ({0}, {1})".F(left.WrappedClrType().Name, right.WrappedClrType().Name));
  
  			if (right.TryGetClrValue(out c))
  			{
  				Game.Debug("Support for facing calculations mixing Angle with integers is deprecated. Make sure all facing calculations use Angle");
  				return new LuaCustomClrObject(a + FromFacing(c));
  			}
  
  			if (right.TryGetClrValue(out b))
  				return new LuaCustomClrObject(a + b);
  
  			throw new LuaException("Attempted to call WAngle.Add(WAngle, WAngle) with invalid arguments ({0}, {1})".F(left.WrappedClrType().Name, right.WrappedClrType().Name));
  		}
  
  		public LuaValue Subtract(LuaRuntime runtime, LuaValue left, LuaValue right)
  		{
  			WAngle a, b;
  			int c;
  
  			if (!left.TryGetClrValue(out a))
  				throw new LuaException("Attempted to call WAngle.Subtract(WAngle, WAngle) with invalid arguments ({0}, {1})".F(left.WrappedClrType().Name, right.WrappedClrType().Name));
  
  			if (right.TryGetClrValue(out c))
  			{
  				Game.Debug("Support for facing calculations mixing Angle with integers is deprecated. Make sure all facing calculations use Angle");
  				return new LuaCustomClrObject(a - FromFacing(c));
  			}
  
  			if (right.TryGetClrValue(out b))
  				return new LuaCustomClrObject(a - b);
  
  			throw new LuaException("Attempted to call WAngle.Subtract(WAngle, WAngle) with invalid arguments ({0}, {1})".F(left.WrappedClrType().Name, right.WrappedClrType().Name));
  		}
  
  		public LuaValue Equals(LuaRuntime runtime, LuaValue left, LuaValue right)
  		{
  			WAngle a, b;
  			if (!left.TryGetClrValue(out a) || !right.TryGetClrValue(out b))
  				return false;
  
  
gt: 			return a == b;