baseline: OpenMU upstream b5a0961 (fresh source)

src/GameLogic/BucketMap{T}.cs

@@ -0,0 +1,129 @@
+// <copyright file="BucketMap{T}.cs" company="MUnique">
+// Licensed under the MIT License. See LICENSE file in the project root for full license information.
+// </copyright>
+
+namespace MUnique.OpenMU.GameLogic;
+
+using MUnique.OpenMU.Pathfinding;
+
+/// <summary>
+/// A two-dimensional map of buckets.
+/// </summary>
+/// <typeparam name="T">The type of objects which should be hold.</typeparam>
+internal class BucketMap<T>
+{
+    private const int DefaultListCapacity = 4;
+
+    private readonly Bucket<T>[] _list;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="BucketMap{T}"/> class.
+    /// </summary>
+    public BucketMap()
+    {
+        this.BucketSideLength = 4;
+        this._list = new Bucket<T>[0x100 / this.BucketSideLength * 0x100 / this.BucketSideLength];
+        this.InitList(DefaultListCapacity);
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="BucketMap{T}"/> class.
+    /// </summary>
+    /// <param name="sideLength">Length of the side.</param>
+    /// <param name="createLists">if set to <c>true</c> the all lists are created now, and not by demand.</param>
+    /// <param name="listCapacity">The list capacity.</param>
+    /// <param name="bucketSideLength">Length of the bucket side.</param>
+    /// <exception cref="System.ArgumentException">SideLength must be a multiple of BucketSideLength.</exception>
+    public BucketMap(int sideLength, bool createLists, int listCapacity, int bucketSideLength)
+    {
+        if (sideLength % bucketSideLength != 0)
+        {
+            throw new ArgumentException($"SideLength ({sideLength}) must be a multiple of BucketSideLength ({bucketSideLength}).");
+        }
+
+        this.BucketSideLength = bucketSideLength;
+        this.SideLength = sideLength / bucketSideLength;
+        this._list = new Bucket<T>[this.SideLength * this.SideLength];
+        if (createLists)
+        {
+            this.InitList(listCapacity);
+        }
+    }
+
+    /// <summary>
+    /// Gets or sets the length of a side of the map. This value should be a multiple of <see cref="BucketSideLength"/>.
+    /// </summary>
+    public int SideLength { get; set; }
+
+    /// <summary>
+    /// Gets or sets the length of the bucket side.
+    /// </summary>
+    /// <value>
+    /// The length of the bucket side.
+    /// </value>
+    public int BucketSideLength { get; set; }
+
+    /// <summary>
+    /// Gets or sets the <see cref="Bucket{T}"/> at the specified coordinates.
+    /// </summary>
+    /// <value>
+    /// The <see cref="Bucket{T}"/>.
+    /// </value>
+    /// <param name="point">The coordinates.</param>
+    /// <returns>The <see cref="Bucket{T}"/> at the specified coordinates.</returns>
+    public Bucket<T> this[Point point]
+    {
+        get => this._list[this.GetListIndex(point)];
+
+        set => this._list[this.GetListIndex(point)] = value;
+    }
+
+    /// <summary>
+    /// Gets the items which are in range of the specified coordinates and range.
+    /// </summary>
+    /// <param name="point">The coordinates.</param>
+    /// <param name="range">The maximum range.</param>
+    /// <returns>The items which are in range of the specified coordinate and range.</returns>
+    public IEnumerable<ILocateable> GetInRange(Point point, int range)
+    {
+        var result = new List<ILocateable>();
+        var buckets = this.GetBucketsInRange(point, range);
+        foreach (var bucket in buckets)
+        {
+            result.AddRange(bucket.OfType<ILocateable>().Where(obj => obj.IsInRange(point, range)));
+        }
+
+        return result;
+    }
+
+    /// <summary>
+    /// Gets the buckets in the specified range of the specified coordinates.
+    /// </summary>
+    /// <param name="point">The coordinates.</param>
+    /// <param name="range">The range.</param>
+    /// <returns>The buckets in the specified range of the specified coordinate.</returns>
+    public IEnumerable<Bucket<T>> GetBucketsInRange(Point point, int range)
+    {
+        int maxX = Math.Min(point.X + range, (this.SideLength - 1) * this.BucketSideLength) / this.BucketSideLength;
+        int maxY = Math.Min(point.Y + range, (this.SideLength - 1) * this.BucketSideLength) / this.BucketSideLength;
+        int minX = Math.Max(point.X - range, 0) / this.BucketSideLength;
+        int minY = Math.Max(point.Y - range, 0) / this.BucketSideLength;
+        for (int i = minX; maxX >= i; ++i)
+        {
+            for (int j = minY; maxY >= j; ++j)
+            {
+                yield return this._list[i + (j * this.SideLength)];
+            }
+        }
+    }
+
+    private int GetListIndex(Point point) => (point.X / this.BucketSideLength) + ((point.Y / this.BucketSideLength) * this.SideLength);
+
+    private void InitList(int listCapacity)
+    {
+        for (int i = 0; i < this._list.Length; ++i)
+        {
+            this._list[i] = new Bucket<T>(listCapacity);
+        }
+    }
+}