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mod/PLibLighting/OctantBuilder.cs

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+/*
+ * Copyright 2022 Peter Han
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
+ * and associated documentation files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or
+ * substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
+ * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+using PeterHan.PLib.Core;
+using PeterHan.PLib.Detours;
+using System;
+using System.Collections.Generic;
+
+using BrightnessDict = System.Collections.Generic.IDictionary<int, float>;
+using Octant = DiscreteShadowCaster.Octant;
+
+namespace PeterHan.PLib.Lighting {
+	/// <summary>
+	/// A builder class which creates default light patterns based on octants.
+	/// </summary>
+	public sealed class OctantBuilder {
+		/// <summary>
+		/// The delegate type called to run the default DiscreteShadowCaster.ScanOctant.
+		/// </summary>
+		private delegate void ScanOctantFunc(Vector2I cellPos, int range, int depth,
+			Octant octant, double startSlope, double endSlope, List<int> visiblePoints);
+
+		/// <summary>
+		/// The method to call to scan octants.
+		/// </summary>
+		private static readonly ScanOctantFunc OCTANT_SCAN;
+
+		static OctantBuilder() {
+			// Cache the method for faster execution
+			OCTANT_SCAN = typeof(DiscreteShadowCaster).Detour<ScanOctantFunc>("ScanOctant");
+			if (OCTANT_SCAN == null)
+				PLightManager.LogLightingWarning("OctantBuilder cannot find default octant scanner!");
+		}
+
+		/// <summary>
+		/// The fallout to use when building the light.
+		/// </summary>
+		public float Falloff { get; set; }
+
+		/// <summary>
+		/// If false, uses the default game smoothing. If true, uses better smoothing.
+		/// </summary>
+		public bool SmoothLight { get; set; }
+
+		/// <summary>
+		/// The origin cell.
+		/// </summary>
+		public int SourceCell { get; }
+
+		/// <summary>
+		/// The location where light cells are added.
+		/// </summary>
+		private readonly BrightnessDict destination;
+
+		/// <summary>
+		/// Creates a new octant builder.
+		/// </summary>
+		/// <param name="destination">The location where the lit cells will be placed.</param>
+		/// <param name="sourceCell">The origin cell of the light.</param>
+		public OctantBuilder(BrightnessDict destination, int sourceCell) {
+			if (!Grid.IsValidCell(sourceCell))
+				throw new ArgumentOutOfRangeException(nameof(sourceCell));
+			this.destination = destination ?? throw new ArgumentNullException(nameof(
+				destination));
+			destination[sourceCell] = 1.0f;
+			Falloff = 0.5f;
+			// Use the default game's light algorithm
+			SmoothLight = false;
+			SourceCell = sourceCell;
+		}
+
+		/// <summary>
+		/// Adds an octant of light.
+		/// </summary>
+		/// <param name="range">The range of the light.</param>
+		/// <param name="octant">The octant to scan.</param>
+		/// <returns>This object, for call chaining.</returns>
+		public OctantBuilder AddOctant(int range, Octant octant) {
+			var points = ListPool<int, OctantBuilder>.Allocate();
+			OCTANT_SCAN?.Invoke(Grid.CellToXY(SourceCell), range, 1, octant, 1.0, 0.0, points);
+			// Transfer to our array using:
+			foreach (int cell in points) {
+				float intensity;
+				if (SmoothLight)
+					// Better, not rounded falloff
+					intensity = PLightManager.GetSmoothFalloff(Falloff, cell, SourceCell);
+				else
+					// Default falloff
+					intensity = PLightManager.GetDefaultFalloff(Falloff, cell, SourceCell);
+				destination[cell] = intensity;
+			}
+			points.Recycle();
+			return this;
+		}
+
+		public override string ToString() {
+			return string.Format("OctantBuilder[Cell {0:D}, {1:D} lit]", SourceCell,
+				destination.Count);
+		}
+	}
+}