20240422

Core/mapbox-sdk-cs/Map/CanonicalTileId.cs

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+//-----------------------------------------------------------------------
+// <copyright file="CanonicalTileId.cs" company="Mapbox">
+//     Copyright (c) 2016 Mapbox. All rights reserved.
+// </copyright>
+//-----------------------------------------------------------------------
+
+namespace Mapbox.Map
+{
+	using System;
+	using Mapbox.Utils;
+
+	/// <summary>
+	/// Data type to store  <see href="https://en.wikipedia.org/wiki/Web_Mercator"> Web Mercator</see> tile scheme.
+	/// <see href="http://www.maptiler.org/google-maps-coordinates-tile-bounds-projection/"> See tile IDs in action. </see>
+	/// </summary>
+	public struct CanonicalTileId : IEquatable<CanonicalTileId>
+	{
+		/// <summary> The zoom level. </summary>
+		public readonly int Z;
+
+		/// <summary> The X coordinate in the tile grid. </summary>
+		public readonly int X;
+
+		/// <summary> The Y coordinate in the tile grid. </summary>
+		public readonly int Y;
+
+		/// <summary>
+		///     Initializes a new instance of the <see cref="CanonicalTileId"/> struct,
+		///     representing a tile coordinate in a slippy map.
+		/// </summary>
+		/// <param name="z"> The z coordinate or the zoom level. </param>
+		/// <param name="x"> The x coordinate. </param>
+		/// <param name="y"> The y coordinate. </param>
+		public CanonicalTileId(int z, int x, int y)
+		{
+			this.Z = z;
+			this.X = x;
+			this.Y = y;
+		}
+
+		internal CanonicalTileId(UnwrappedTileId unwrapped)
+		{
+			var z = unwrapped.Z;
+			var x = unwrapped.X;
+			var y = unwrapped.Y;
+
+			var wrap = (x < 0 ? x - (1 << z) + 1 : x) / (1 << z);
+
+			this.Z = z;
+			this.X = x - wrap * (1 << z);
+			this.Y = y < 0 ? 0 : Math.Min(y, (1 << z) - 1);
+		}
+
+		/// <summary>
+		///     Get the cordinate at the top left of corner of the tile.
+		/// </summary>
+		/// <returns> The coordinate. </returns>
+		public Vector2d ToVector2d()
+		{
+			double n = Math.PI - ((2.0 * Math.PI * this.Y) / Math.Pow(2.0, this.Z));
+
+			double lat = 180.0 / Math.PI * Math.Atan(Math.Sinh(n));
+			double lng = (this.X / Math.Pow(2.0, this.Z) * 360.0) - 180.0;
+
+			// FIXME: Super hack because of rounding issues.
+			return new Vector2d(lat - 0.0001, lng + 0.0001);
+		}
+
+		/// <summary>
+		///     Returns a <see cref="T:System.String"/> that represents the current
+		///     <see cref="T:Mapbox.Map.CanonicalTileId"/>.
+		/// </summary>
+		/// <returns>
+		///     A <see cref="T:System.String"/> that represents the current
+		///     <see cref="T:Mapbox.Map.CanonicalTileId"/>.
+		/// </returns>
+		public override string ToString()
+		{
+			return this.Z + "/" + this.X + "/" + this.Y;
+		}
+
+		#region Equality 
+		public bool Equals(CanonicalTileId other)
+		{
+			return this.X == other.X && this.Y == other.Y && this.Z == other.Z;
+		}
+		
+		public override int GetHashCode()
+		{
+			return X ^ Y ^ Z;
+		}
+
+		public static bool operator ==(CanonicalTileId a, CanonicalTileId b)
+		{
+			return a.X == b.X && a.Y == b.Y && a.Z == b.Z;
+		}
+
+		public static bool operator !=(CanonicalTileId a, CanonicalTileId b)
+		{
+			return !(a == b);
+		}
+
+		public override bool Equals(object obj)
+		{
+			if (obj is CanonicalTileId)
+			{
+				return this.Equals((CanonicalTileId)obj);
+			}
+			else
+			{
+				return false;
+			}
+		}
+
+		#endregion
+	}
+}