Map lighting by the time of day, lit tiles and events; A2 autotiles

manifest.json

@@ -11,7 +11,7 @@
   "test_sources": [
     "tests/*.cs"
   ],
-  "depends": ["shell2d_base>=1", "ui_base>=1", "dialog_base>=1", "turn_battle_base>=2"],
+  "depends": ["shell2d_base>=1", "ui_base>=1", "time_base>=1", "dialog_base>=1", "turn_battle_base>=2"],
   "test_suites": [
     {"id": "walk", "activate": ["--itest=rpg_walk"]}
   ]

shaders/rpg_lit.gdshader

@@ -0,0 +1,47 @@
+shader_type canvas_item;
+
+// Light of an RPG map (RpgLighting): the tiles and actors are multiplied by the ambient
+// colour of the time of day (time_weights blends the four phases like timed_sprite), and
+// point lights (the player, lit events) add to it. Lights only add up to white, so by day
+// they are invisible and at night they open circles in the dark. Positions and radii are
+// in canvas pixels, the space of world_pos below.
+
+uniform vec4 day_color : source_color = vec4(1.0, 1.0, 1.0, 1.0);
+uniform vec4 morning_color : source_color = vec4(0.86, 0.72, 0.84, 1.0);
+uniform vec4 evening_color : source_color = vec4(0.84, 0.72, 0.92, 1.0);
+uniform vec4 night_color : source_color = vec4(0.2, 0.26, 0.42, 1.0);
+uniform vec4 time_weights = vec4(0.0, 1.0, 0.0, 0.0);
+
+// A map that sets its own ambient (indoors) uses it instead of the time of day.
+uniform bool use_ambient = false;
+uniform vec4 ambient_color : source_color = vec4(1.0, 1.0, 1.0, 1.0);
+
+uniform vec2 light_positions[16];
+uniform vec4 light_colors[16];
+uniform float light_radii[16];
+uniform int light_count = 0;
+
+varying vec2 world_pos;
+
+void vertex() {
+	world_pos = (MODEL_MATRIX * vec4(VERTEX, 0.0, 1.0)).xy;
+}
+
+void fragment() {
+	vec4 color = texture(TEXTURE, UV) * COLOR;
+
+	vec3 ambient = use_ambient
+		? ambient_color.rgb
+		: (morning_color * time_weights.x + day_color * time_weights.y
+			+ evening_color * time_weights.z + night_color * time_weights.w).rgb;
+
+	vec3 light = vec3(0.0);
+	for (int i = 0; i < 16; i++) {
+		if (i >= light_count)
+			break;
+		float k = clamp(1.0 - distance(world_pos, light_positions[i]) / max(light_radii[i], 1.0), 0.0, 1.0);
+		light += light_colors[i].rgb * light_colors[i].a * k * k;
+	}
+
+	COLOR = vec4(color.rgb * min(ambient + light, vec3(1.0)), color.a);
+}

src/Data/RpgAutotiles.cs

@@ -0,0 +1,84 @@
+using Godot;
+
+namespace Cthangover.Mods.Rpg
+{
+    /// <summary>
+    /// Autotiles in the RPG Maker A2 layout: one picture of 2×3 tiles describes a terrain
+    /// (water, a path, a cliff top), and each map cell is assembled from four quarter tiles
+    /// chosen by its eight neighbours — so an author paints "water" and the shores draw
+    /// themselves. A tileset entry becomes an autotile by naming that picture
+    /// (<see cref="RpgTileInfo.Autotile"/>); its index is any number outside the atlas.
+    /// <para/>
+    /// The block in quarter units (4 columns × 6 rows): the top-left tile is the palette
+    /// preview; the top-right tile holds the four inner corners; the 2×2 tiles below are a
+    /// framed patch whose outer ring gives outer corners and edges and whose middle gives the
+    /// fill. For a quarter, the two neighbours along its sides and the one across its corner
+    /// decide: both sides alike and the corner too — fill; both sides alike but not the
+    /// corner — inner corner; only one side alike — the edge along the other; none — the
+    /// outer corner. Cells past the map edge count as alike, so a terrain runs off the map
+    /// without a border. The world (<see cref="RpgAutotileLayer"/>) and the map editor draw
+    /// through <see cref="Quarters"/> and <see cref="Draw"/>, so both show the same cells.
+    /// </summary>
+    public static class RpgAutotiles
+    {
+        /// <summary>
+        /// Source quarters (in quarter units of the block) for the top-left, top-right,
+        /// bottom-left and bottom-right quarter of a cell, from which neighbours are alike.
+        /// </summary>
+        public static Vector2I[] Quarters(bool up, bool down, bool left, bool right,
+            bool upLeft, bool upRight, bool downLeft, bool downRight)
+        {
+            return new[]
+            {
+                Quarter(up, left, upLeft, new Vector2I(2, 0), left ? 2 : 0, up ? 4 : 2),
+                Quarter(up, right, upRight, new Vector2I(3, 0), right ? 1 : 3, up ? 4 : 2),
+                Quarter(down, left, downLeft, new Vector2I(2, 1), left ? 2 : 0, down ? 3 : 5),
+                Quarter(down, right, downRight, new Vector2I(3, 1), right ? 1 : 3, down ? 3 : 5),
+            };
+        }
+
+        /// <summary>
+        /// The quarters of the cell (<paramref name="x"/>, <paramref name="y"/>) of
+        /// <paramref name="layer"/>, whose tile is the autotile <paramref name="index"/>.
+        /// </summary>
+        public static Vector2I[] QuartersAt(RpgMapGrid grid, RpgLayer layer, int x, int y, int index)
+        {
+            return Quarters(
+                Alike(grid, layer, x, y - 1, index), Alike(grid, layer, x, y + 1, index),
+                Alike(grid, layer, x - 1, y, index), Alike(grid, layer, x + 1, y, index),
+                Alike(grid, layer, x - 1, y - 1, index), Alike(grid, layer, x + 1, y - 1, index),
+                Alike(grid, layer, x - 1, y + 1, index), Alike(grid, layer, x + 1, y + 1, index));
+        }
+
+        /// <summary>Pixel rectangle of a quarter in the block picture of a tileset with <paramref name="tileSize"/>.</summary>
+        public static Rect2 SourceRect(Vector2I quarter, int tileSize)
+        {
+            var half = tileSize / 2f;
+            return new Rect2(quarter.X * half, quarter.Y * half, half, half);
+        }
+
+        /// <summary>Draws a cell of an autotile into <paramref name="cell"/> on <paramref name="target"/>.</summary>
+        public static void Draw(CanvasItem target, Texture2D block, Rect2 cell, Vector2I[] quarters, int tileSize, Color modulate)
+        {
+            var half = cell.Size / 2f;
+            for (var i = 0; i < 4; i++)
+            {
+                var offset = new Vector2(i % 2 * half.X, i / 2 * half.Y);
+                target.DrawTextureRectRegion(block, new Rect2(cell.Position + offset, half), SourceRect(quarters[i], tileSize), modulate);
+            }
+        }
+
+        /// <summary>Source rectangle of the block's preview tile (its top-left tile), for palettes.</summary>
+        public static Rect2 PreviewRect(int tileSize) => new(0, 0, tileSize, tileSize);
+
+        private static Vector2I Quarter(bool sideA, bool sideB, bool corner, Vector2I inner, int column, int row)
+        {
+            if (sideA && sideB && !corner)
+                return inner;
+            return new Vector2I(column, row);
+        }
+
+        private static bool Alike(RpgMapGrid grid, RpgLayer layer, int x, int y, int index)
+            => !grid.InBounds(x, y) || grid.GetTile(layer, x, y) == index;
+    }
+}

src/Data/RpgEventPage.cs

@@ -43,5 +43,8 @@ namespace Cthangover.Mods.Rpg
 
         /// <summary>Autonomous movement of the page.</summary>
         public RpgMoveRoute Route { get; set; }
+
+        /// <summary>Light of the page (a lamp lit by a page).</summary>
+        public RpgLight Light { get; set; }
     }
 }

src/Data/RpgEventPages.cs

@@ -60,6 +60,7 @@ namespace Cthangover.Mods.Rpg
                 Commands = page.Commands ?? mapEvent.Commands,
                 Teleport = page.Teleport ?? mapEvent.Teleport,
                 Route = page.Route ?? mapEvent.Route,
+                Light = page.Light ?? mapEvent.Light,
                 Condition = page.Condition,
                 ModId = mapEvent.ModId,
                 File = mapEvent.File,

src/Data/RpgLight.cs

@@ -0,0 +1,16 @@
+namespace Cthangover.Mods.Rpg
+{
+    /// <summary>
+    /// A light an event gives off (a lamp, a fire, a lit window), drawn by
+    /// <see cref="RpgLighting"/>. It brightens the cells around the event towards their
+    /// own colours, so it shows at dusk and at night and is lost in daylight.
+    /// </summary>
+    public class RpgLight
+    {
+        /// <summary>Reach in cells from the event's centre; the light fades to nothing there.</summary>
+        public float Radius { get; set; } = 3f;
+
+        /// <summary>Colour (<c>#rrggbb</c>, optionally <c>#rrggbbaa</c>: alpha is the strength).</summary>
+        public string Color { get; set; } = "#ffd8a0";
+    }
+}

src/Data/RpgMap.cs

@@ -55,5 +55,11 @@ namespace Cthangover.Mods.Rpg
 
         /// <summary>Random battles; null for a safe map.</summary>
         public RpgEncounterTable Encounters { get; set; }
+
+        /// <summary>
+        /// Fixed light colour of the map (<c>#rrggbb</c>), e.g. a lit room; null = the time of day
+        /// lights the map (<see cref="RpgLighting"/>).
+        /// </summary>
+        public string Ambient { get; set; }
     }
 }

src/Data/RpgMapEvent.cs

@@ -74,6 +74,9 @@ namespace Cthangover.Mods.Rpg
         /// <summary>Autonomous movement (<see cref="RpgMoveRoute"/>); null = the event stands still.</summary>
         public RpgMoveRoute Route { get; set; }
 
+        /// <summary>Light the event gives off (<see cref="RpgLight"/>); null = none.</summary>
+        public RpgLight Light { get; set; }
+
         /// <summary>Mod the event was read from (set by the event resolver, not stored).</summary>
         [JsonIgnore]
         public string ModId { get; set; }

src/Data/RpgTileInfo.cs

@@ -21,5 +21,14 @@ namespace Cthangover.Mods.Rpg
         /// "tree_crown"). Not a locale key: players never see it.
         /// </summary>
         public string Tag { get; set; }
+
+        /// <summary>Light the tile gives off wherever it lies on a map (a lamp, a lit window); null = none.</summary>
+        public RpgLight Light { get; set; }
+
+        /// <summary>
+        /// Picture of an autotile block (RPG Maker A2 layout, see <see cref="RpgAutotiles"/>) in the
+        /// tilesets group; set, the entry is an autotile and <see cref="Index"/> should lie outside the atlas.
+        /// </summary>
+        public string Autotile { get; set; }
     }
 }

src/Data/RpgTileset.cs

@@ -34,6 +34,30 @@ namespace Cthangover.Mods.Rpg
         /// <summary>Per-cell properties; cells without an entry are walkable.</summary>
         public List<RpgTileInfo> Tiles { get; set; } = new();
 
+        /// <summary>The autotile entry with this index (<see cref="RpgTileInfo.Autotile"/> set), or null.</summary>
+        public RpgTileInfo AutotileOf(int index)
+        {
+            if (index < 0)
+                return null;
+            foreach (var tile in Tiles ?? new List<RpgTileInfo>())
+            {
+                if (tile.Index == index && !string.IsNullOrEmpty(tile.Autotile))
+                    return tile;
+            }
+            return null;
+        }
+
+        /// <summary>Light of the atlas cell (<see cref="RpgTileInfo.Light"/>), or null.</summary>
+        public RpgLight LightOf(int index)
+        {
+            foreach (var tile in Tiles ?? new List<RpgTileInfo>())
+            {
+                if (tile.Index == index && tile.Light != null)
+                    return tile.Light;
+            }
+            return null;
+        }
+
         /// <summary>True when the atlas cell blocks walking. Built once from <see cref="Tiles"/>.</summary>
         public bool IsSolid(int index)
         {

src/World/RpgActor.cs

@@ -15,6 +15,7 @@ namespace Cthangover.Mods.Rpg
     /// <see cref="StepFinished"/>. The actor's <see cref="Cell"/> changes at the
     /// start of a step, so two actors never walk into the same cell. The actor
     /// layer sorts children by Y, which keeps whoever is lower in front.
+    /// The sprite uses the actor's material (the map's light, set by the view).
     /// </summary>
     public partial class RpgActor : Node2D
     {
@@ -78,7 +79,7 @@ namespace Cthangover.Mods.Rpg
         {
             if (texture == null)
                 return;
-            sprite = new Sprite2D { Texture = texture, Hframes = 3, Vframes = 4, Centered = false };
+            sprite = new Sprite2D { Texture = texture, Hframes = 3, Vframes = 4, Centered = false, UseParentMaterial = true };
             var frame = new Vector2(texture.GetWidth() / 3f, texture.GetHeight() / 4f);
             sprite.Position = new Vector2((tileSize - frame.X) / 2f, tileSize - frame.Y);
             AddChild(sprite);
@@ -94,6 +95,7 @@ namespace Cthangover.Mods.Rpg
             {
                 Texture = atlas,
                 Centered = false,
+                UseParentMaterial = true,
                 RegionEnabled = true,
                 RegionRect = new Rect2(atlasCoords * tileSize, new Vector2(tileSize, tileSize)),
             };
@@ -115,6 +117,7 @@ namespace Cthangover.Mods.Rpg
                 Position = new Vector2(tileSize, tileSize) / 2f,
                 Scale = new Vector2(fit, fit),
                 TextureFilter = TextureFilterEnum.Linear,
+                UseParentMaterial = true,
             };
             AddChild(sprite);
         }

src/World/RpgAutotileLayer.cs

@@ -0,0 +1,50 @@
+using System.Collections.Generic;
+using Godot;
+
+namespace Cthangover.Mods.Rpg
+{
+    /// <summary>
+    /// The autotile cells of one map layer, drawn as a child of that layer's
+    /// <see cref="TileMapLayer"/> — right above its plain tiles, below the next layer — with
+    /// the layer's material (the map's light). A tile map cannot hold them: each cell is four
+    /// quarters picked from its neighbours (<see cref="RpgAutotiles"/>), so the cells and their
+    /// quarters are worked out once when the map is built and drawn by <c>_Draw</c>, which
+    /// Godot caches until the next redraw.
+    /// </summary>
+    public partial class RpgAutotileLayer : Node2D
+    {
+        private readonly List<(Rect2 Cell, Texture2D Block, Vector2I[] Quarters)> cells = new();
+        private readonly int tileSize;
+
+        /// <summary>Collects the autotile cells of <paramref name="layer"/>; cells whose picture is missing stay empty.</summary>
+        public RpgAutotileLayer(RpgMapGrid grid, RpgLayer layer, RpgTileset tileset, RpgTextures textures)
+        {
+            Name = layer + "Autotiles";
+            UseParentMaterial = true;
+            tileSize = tileset.TileSize;
+            for (var y = 0; y < grid.Height; y++)
+            {
+                for (var x = 0; x < grid.Width; x++)
+                {
+                    var index = grid.GetTile(layer, x, y);
+                    var info = tileset.AutotileOf(index);
+                    var block = info == null ? null : textures.Tileset(info.Autotile);
+                    if (block == null)
+                        continue;
+                    var rect = new Rect2(x * tileSize, y * tileSize, tileSize, tileSize);
+                    cells.Add((rect, block, RpgAutotiles.QuartersAt(grid, layer, x, y, index)));
+                }
+            }
+        }
+
+        /// <summary>Number of drawn autotile cells.</summary>
+        public int Count => cells.Count;
+
+        /// <summary>Draws every collected cell.</summary>
+        public override void _Draw()
+        {
+            foreach (var (cell, block, quarters) in cells)
+                RpgAutotiles.Draw(this, block, cell, quarters, tileSize, Colors.White);
+        }
+    }
+}

src/World/RpgLighting.cs

@@ -0,0 +1,137 @@
+using System.Collections.Generic;
+using System.Linq;
+using Cthangover.Core.Mods.Resolvers;
+using Cthangover.Core.Settings;
+using Cthangover.Mods.Time;
+using Godot;
+
+namespace Cthangover.Mods.Rpg
+{
+    /// <summary>
+    /// Light of a mounted map. One <c>rpg_lit</c> material is shared by the tile layers and
+    /// every actor (their sprites use the parent's material), so the whole map is lit by the
+    /// same ambient and the same lights.
+    /// <para/>
+    /// The ambient follows the game clock with the phases and cross-fades of the novel
+    /// backgrounds (<see cref="UiLightController.CalculateTimeWeights"/>; dark mode forces night,
+    /// the light switch off keeps day), unless the map fixes its own (<see cref="RpgMap.Ambient"/>,
+    /// a lit room). The lights are the player's own glow, the tiles whose tileset entry has a
+    /// <see cref="RpgLight"/> (lamps and windows light every map they are drawn on, collected
+    /// once per map) and the shown events with a light on their active page. The nearest to the
+    /// player win, at most <see cref="MaxLights"/>. They are pushed every frame in canvas
+    /// pixels, because the view moves with the player and actors walk.
+    /// </summary>
+    public sealed class RpgLighting
+    {
+        /// <summary>Lights the shader takes (its arrays' size).</summary>
+        public const int MaxLights = 16;
+
+        /// <summary>Reach of the player's glow in cells.</summary>
+        public const float PlayerRadius = 3.5f;
+
+        private static readonly Color PlayerColor = new(1f, 0.9f, 0.75f, 0.75f);
+        private static readonly Vector4 Day = new(0, 1, 0, 0);
+        private static readonly Vector4 Night = new(0, 0, 0, 1);
+
+        private readonly Vector2[] positions = new Vector2[MaxLights];
+        private readonly Color[] colors = new Color[MaxLights];
+        private readonly float[] radii = new float[MaxLights];
+        private readonly List<(Vector2I Cell, RpgLight Light)> tileLights = new();
+        private readonly List<(Vector2 Centre, RpgLight Light)> candidates = new();
+
+        /// <summary>The shared material; null when the shader is missing (the map is drawn unlit).</summary>
+        public ShaderMaterial Material { get; }
+
+        /// <summary>Creates the material for <paramref name="map"/>, applies its fixed ambient and collects the lit tiles.</summary>
+        public RpgLighting(RpgMap map, RpgMapGrid grid, RpgTileset tileset)
+        {
+            if (tileset != null)
+                tileLights.AddRange(TileLights(grid, tileset));
+
+            var shader = Shaders.Resolve("rpg_lit");
+            if (shader == null)
+                return;
+            Material = new ShaderMaterial { Shader = shader };
+            var ambient = !string.IsNullOrEmpty(map.Ambient) && Color.HtmlIsValid(map.Ambient);
+            Material.SetShaderParameter("use_ambient", ambient);
+            if (ambient)
+                Material.SetShaderParameter("ambient_color", Color.FromHtml(map.Ambient));
+        }
+
+        /// <summary>
+        /// The ambient weights for an hour 0–24: night in dark mode, day while lighting is
+        /// switched off, otherwise the phase blend of the time shaders.
+        /// </summary>
+        public static Vector4 Weights(float hour, bool darkMode, bool useLight)
+        {
+            if (darkMode)
+                return Night;
+            if (!useLight)
+                return Day;
+            return UiLightController.CalculateTimeWeights(hour);
+        }
+
+        /// <summary>Cells of <paramref name="grid"/> whose tile (on any layer) gives off light, with that light.</summary>
+        public static List<(Vector2I Cell, RpgLight Light)> TileLights(RpgMapGrid grid, RpgTileset tileset)
+        {
+            var result = new List<(Vector2I, RpgLight)>();
+            for (var y = 0; y < grid.Height; y++)
+            {
+                for (var x = 0; x < grid.Width; x++)
+                {
+                    foreach (var layer in new[] { RpgLayer.Back, RpgLayer.Main, RpgLayer.Front })
+                    {
+                        var light = tileset.LightOf(grid.GetTile(layer, x, y));
+                        if (light == null)
+                            continue;
+                        result.Add((new Vector2I(x, y), light));
+                        break;
+                    }
+                }
+            }
+            return result;
+        }
+
+        /// <summary>Pushes the ambient of the current hour and the lights of <paramref name="view"/>.</summary>
+        public void Update(RpgWorldView view, IEnumerable<RpgActor> events)
+        {
+            if (Material == null || view.Player == null)
+                return;
+
+            var controller = UiLightController.Instance;
+            var hour = GameData.Instance?.Runtime?.Time?.Normalized ?? 12f;
+            Material.SetShaderParameter("time_weights", Weights(hour, controller?.IsDarkMode == true, controller?.IsUseLight != false));
+
+            var half = new Vector2(view.TileSize, view.TileSize) / 2f;
+            candidates.Clear();
+            foreach (var (cell, light) in tileLights)
+                candidates.Add((new Vector2(cell.X, cell.Y) * view.TileSize + half, light));
+            foreach (var actor in events)
+            {
+                if (actor.Visible && actor.Current?.Light != null)
+                    candidates.Add((actor.Position + half, actor.Current.Light));
+            }
+
+            var cellPixels = view.TileSize * view.GlobalScale.X;
+            var player = view.Player.Position + half;
+            positions[0] = view.ToGlobal(player);
+            colors[0] = PlayerColor;
+            radii[0] = PlayerRadius * cellPixels;
+            var count = 1;
+            foreach (var (centre, light) in candidates.OrderBy(c => c.Centre.DistanceSquaredTo(player)))
+            {
+                if (count >= MaxLights)
+                    break;
+                positions[count] = view.ToGlobal(centre);
+                colors[count] = Color.HtmlIsValid(light.Color ?? "") ? Color.FromHtml(light.Color) : Colors.White;
+                radii[count] = light.Radius * cellPixels;
+                count++;
+            }
+
+            Material.SetShaderParameter("light_count", count);
+            Material.SetShaderParameter("light_positions", positions);
+            Material.SetShaderParameter("light_colors", colors);
+            Material.SetShaderParameter("light_radii", radii);
+        }
+    }
+}

src/World/RpgWorldView.cs

@@ -12,7 +12,8 @@ namespace Cthangover.Mods.Rpg
     /// scene is entered and freed when the scene is left.
     /// <para/>
     /// Draw order (children, bottom to top): back tiles, main tiles, the actor
-    /// layer (Y-sorted: events and the player), front tiles. The whole node is
+    /// layer (Y-sorted: events and the player), front tiles; each tile layer draws its
+    /// autotile cells over its plain tiles (<see cref="RpgAutotileLayer"/>). The whole node is
     /// scaled by the map's zoom with nearest filtering and follows the player
     /// like a camera, clamped to the map edges; a map smaller than the screen is
     /// centred.
@@ -23,6 +24,9 @@ namespace Cthangover.Mods.Rpg
     /// event on the cell fires, else the encounter table rolls. The action key
     /// fires the action event in front of the player (or under them); during a
     /// dialog it advances the dialog instead.
+    /// <para/>
+    /// Layers and actors share the material of <see cref="RpgLighting"/> (time of day, the
+    /// player's glow, lit events), updated after the camera each frame.
     /// </summary>
     public partial class RpgWorldView : Node2D
     {
@@ -32,6 +36,7 @@ namespace Cthangover.Mods.Rpg
         private RpgMapGrid grid;
         private Node2D actorLayer;
         private Texture2D atlas;
+        private RpgLighting lighting;
 
         /// <summary>The mounted map.</summary>
         public RpgMap Map { get; private set; }
@@ -59,6 +64,7 @@ namespace Cthangover.Mods.Rpg
                 GameLogger.Log("RPG", $"map '{map.ID}': tileset '{map.Tileset}' not found", LogLevel.Error);
             atlas = Tileset != null ? textures.Tileset(Tileset.Image) : null;
             var tileSet = Tileset != null && atlas != null ? RpgTileSetBuilder.Build(Tileset, atlas) : null;
+            lighting = new RpgLighting(map, grid, Tileset);
 
             AddChild(BuildLayer(RpgLayer.Back, tileSet));
             AddChild(BuildLayer(RpgLayer.Main, tileSet));
@@ -70,7 +76,7 @@ namespace Cthangover.Mods.Rpg
                 AddEventActor(mapEvent);
             RefreshEvents();
 
-            Player = new RpgActor(TileSize) { Name = "Player" };
+            Player = new RpgActor(TileSize) { Name = "Player", Material = lighting.Material };
             Player.UseCharset(textures.Charset(RpgPlayerLook.Charset()));
             Player.StepFinished += OnPlayerStepFinished;
             actorLayer.AddChild(Player);
@@ -178,6 +184,7 @@ namespace Cthangover.Mods.Rpg
                 }
             }
             UpdateCamera();
+            lighting.Update(this, eventActors.Values);
         }
 
         /// <summary>The action key: advances a running dialog, otherwise interacts.</summary>
@@ -217,7 +224,7 @@ namespace Cthangover.Mods.Rpg
 
         private TileMapLayer BuildLayer(RpgLayer layer, TileSet tileSet)
         {
-            var node = new TileMapLayer { Name = layer.ToString(), TileSet = tileSet };
+            var node = new TileMapLayer { Name = layer.ToString(), TileSet = tileSet, Material = lighting.Material };
             if (tileSet == null)
                 return node;
             for (var y = 0; y < grid.Height; y++)
@@ -225,10 +232,15 @@ namespace Cthangover.Mods.Rpg
                 for (var x = 0; x < grid.Width; x++)
                 {
                     var index = grid.GetTile(layer, x, y);
-                    if (index >= 0)
+                    if (index >= 0 && Tileset.AutotileOf(index) == null)
                         node.SetCell(new Vector2I(x, y), RpgTileSetBuilder.SourceId, RpgTileSetBuilder.AtlasCoords(Tileset, index));
                 }
             }
+            var autotiles = new RpgAutotileLayer(grid, layer, Tileset, textures);
+            if (autotiles.Count > 0)
+                node.AddChild(autotiles);
+            else
+                autotiles.Free();
             return node;
         }
 
@@ -241,7 +253,7 @@ namespace Cthangover.Mods.Rpg
             }
 
             // The look and the cell come with the first page (RefreshEvents).
-            var actor = new RpgActor(TileSize, mapEvent) { Name = "Event_" + mapEvent.Id };
+            var actor = new RpgActor(TileSize, mapEvent) { Name = "Event_" + mapEvent.Id, Material = lighting.Material };
             actorLayer.AddChild(actor);
             eventActors[mapEvent.Id] = actor;
         }

test_suites/walk/src/RpgWalkTestDriver.cs

@@ -34,6 +34,9 @@ namespace Cthangover.Mods.Rpg.Tests
     public partial class RpgWalkTestDriver : Node
     {
         private const float TickSeconds = 0.1f;
+
+        // The battle opens with an intro animation (the backdrop zooms in): shots wait it out.
+        private const int BattleIntroTicks = 20;
         private const float TimeoutSeconds = 90f;
         private const string Village = "rpg_village";
         private const string House = "rpg_elder_house";
@@ -243,8 +246,8 @@ namespace Cthangover.Mods.Rpg.Tests
                     // core waits for the player, take the platform's victory path.
                     if (battle.ActiveBattleCore is not IBattleAutoPlayable auto || !auto.IsWaitingForPlayerInput)
                         return;
-                    // The shot waits for the fade-in too, otherwise it catches the blank transition.
-                    if (GodotSceneService.IsTransitioning)
+                    // The shot waits for the fade-in and the intro animation, otherwise it catches the zoomed backdrop.
+                    if (GodotSceneService.IsTransitioning || ++waitTicks < BattleIntroTicks)
                         return;
                     Shot("battle");
                     battle.ShowWinground();

tests/RpgAutotilesTests.cs

@@ -0,0 +1,64 @@
+namespace Cthangover.Mods.Rpg.Tests
+{
+    using Cthangover.Core.Mods.Testing;
+    using Godot;
+
+    /// <summary>Autotile cells are assembled from quarters of the A2 block picked by their neighbours.</summary>
+    public class RpgAutotilesTests
+    {
+        private const int Water = 40;
+
+        private static bool Is(Vector2I[] quarters, params int[] xy)
+        {
+            for (var i = 0; i < 4; i++)
+            {
+                if (quarters[i] != new Vector2I(xy[i * 2], xy[i * 2 + 1]))
+                    return false;
+            }
+            return true;
+        }
+
+        [ModTest("autotiles/quarters_by_neighbours")]
+        static void QuartersByNeighbours(ModTestContext ctx)
+        {
+            ModAssert.True(Is(RpgAutotiles.Quarters(false, false, false, false, false, false, false, false), 0, 2, 3, 2, 0, 5, 3, 5),
+                "alone: the four outer corners");
+            ModAssert.True(Is(RpgAutotiles.Quarters(true, true, true, true, true, true, true, true), 2, 4, 1, 4, 2, 3, 1, 3),
+                "surrounded: the fill of the patch");
+            ModAssert.True(Is(RpgAutotiles.Quarters(true, true, true, true, false, false, false, false), 2, 0, 3, 0, 2, 1, 3, 1),
+                "sides alike, corners not: the inner corners");
+            ModAssert.True(Is(RpgAutotiles.Quarters(false, true, true, true, false, false, true, true), 2, 2, 1, 2, 2, 3, 1, 3),
+                "the top row of a pond: top edge above, fill below");
+            ModAssert.True(Is(RpgAutotiles.Quarters(true, true, false, true, false, true, false, true), 0, 4, 1, 4, 0, 3, 1, 3),
+                "the left column: left edge");
+            var corner = RpgAutotiles.Quarters(true, true, true, true, false, true, true, true);
+            ModAssert.True(corner[0] == new Vector2I(2, 0) && corner[3] == new Vector2I(1, 3), "only the missing corner turns inner");
+        }
+
+        [ModTest("autotiles/cells_read_their_layer_and_the_map_edge_counts_alike")]
+        static void QuartersAt(ModTestContext ctx)
+        {
+            var grid = new RpgMapGrid(3, 3);
+            grid.SetTile(RpgLayer.Back, 0, 0, Water);
+            grid.SetTile(RpgLayer.Back, 1, 0, Water);
+            grid.SetTile(RpgLayer.Main, 0, 1, Water);
+
+            var corner = RpgAutotiles.QuartersAt(grid, RpgLayer.Back, 0, 0, Water);
+            ModAssert.True(corner[0] == new Vector2I(2, 4), "off the map counts as water: the top-left quarter is fill");
+            ModAssert.True(corner[2] == new Vector2I(2, 5), "below lies grass on this layer: bottom edge (the main layer is not read)");
+            ModAssert.True(corner[1] == new Vector2I(1, 4), "to the right is water");
+
+            var end = RpgAutotiles.QuartersAt(grid, RpgLayer.Back, 1, 0, Water);
+            ModAssert.True(end[1] == new Vector2I(3, 4), "the right end: right edge");
+            ModAssert.True(end[3] == new Vector2I(3, 5), "and its outer bottom-right corner");
+        }
+
+        [ModTest("autotiles/source_and_preview_rects")]
+        static void Rects(ModTestContext ctx)
+        {
+            ModAssert.True(RpgAutotiles.SourceRect(new Vector2I(3, 5), 32) == new Rect2(48, 80, 16, 16), "quarters are half tiles");
+            ModAssert.True(RpgAutotiles.SourceRect(Vector2I.Zero, 48) == new Rect2(0, 0, 24, 24), "of any tile size");
+            ModAssert.True(RpgAutotiles.PreviewRect(32) == new Rect2(0, 0, 32, 32), "the preview is the top-left tile");
+        }
+    }
+}

tests/RpgEventPagesTests.cs

@@ -7,7 +7,7 @@ namespace Cthangover.Mods.Rpg.Tests
     using Cthangover.Core.Utils;
     using Godot;
 
-    /// <summary>Event pages pick the last page whose condition holds; routes resolve their steps.</summary>
+    /// <summary>Event pages pick the last page whose condition holds; routes resolve their steps; a page light replaces the event's.</summary>
     public class RpgEventPagesTests
     {
         private static RpgMapEvent Chest() => JsonSerializer.Deserialize<RpgMapEvent>(@"{
@@ -87,5 +87,27 @@ namespace Cthangover.Mods.Rpg.Tests
             ModAssert.True(mapEvent.Route.Repeat, "repeats by default");
             ModAssert.Null(mapEvent.Pages, "no pages");
         }
+
+        [ModTest("lights/page_light_over_event_light_round_trip")]
+        static void PageLightOverEventLight(ModTestContext ctx)
+        {
+            var lamp = JsonSerializer.Deserialize<RpgMapEvent>(@"{
+                ""Id"": ""lamp"", ""Tile"": 12, ""Light"": { ""Radius"": 2.5, ""Color"": ""#ff8040"" },
+                ""Pages"": [ { ""Condition"": ""lamp_out == 1"", ""Tile"": 13, ""Light"": { ""Radius"": 1 } }, { ""Condition"": ""door == 1"" } ]
+            }", JsonOptionsProvider.ReadOptions);
+            ModAssert.CloseTo(2.5, lamp.Light.Radius, what: "the event's light");
+            ModAssert.Equal("#ff8040", lamp.Light.Color, "the event's colour");
+
+            var dim = RpgEventPages.Effective(lamp, 1);
+            ModAssert.CloseTo(1, dim.Light.Radius, what: "the page's light replaces it");
+            ModAssert.Equal("#ffd8a0", dim.Light.Color, "a page light without a colour is warm by default");
+            ModAssert.CloseTo(2.5, RpgEventPages.Effective(lamp, 2).Light.Radius, what: "a page without a light keeps the event's");
+
+            var again = JsonSerializer.Deserialize<RpgMapEvent>(JsonSerializer.Serialize(lamp), JsonOptionsProvider.ReadOptions);
+            ModAssert.CloseTo(2.5, again.Light.Radius, what: "radius survives the round trip");
+            ModAssert.Equal("#ff8040", again.Light.Color, "colour survives the round trip");
+            ModAssert.CloseTo(1, again.Pages[0].Light.Radius, what: "the page light survives the round trip");
+            ModAssert.Null(JsonSerializer.Deserialize<RpgMapEvent>(@"{ ""Id"": ""dark"" }", JsonOptionsProvider.ReadOptions).Light, "no light by default");
+        }
     }
 }

tests/RpgLightingTests.cs

@@ -0,0 +1,59 @@
+namespace Cthangover.Mods.Rpg.Tests
+{
+    using System.Collections.Generic;
+    using System.Text.Json;
+    using Cthangover.Core.Mods.Testing;
+    using Cthangover.Core.Utils;
+    using Godot;
+
+    /// <summary>The map's light: ambient weights from the clock, lit tiles, the fixed ambient of a map.</summary>
+    public class RpgLightingTests
+    {
+        [ModTest("lights/weights_follow_clock_dark_mode_and_switch")]
+        static void WeightsFollowClock(ModTestContext ctx)
+        {
+            ModAssert.CloseTo(1, RpgLighting.Weights(13f, false, true).Y, what: "noon is day");
+            ModAssert.CloseTo(1, RpgLighting.Weights(0.5f, false, true).W, what: "midnight is night");
+            ModAssert.CloseTo(1, RpgLighting.Weights(13f, true, true).W, what: "dark mode is night at noon");
+            ModAssert.CloseTo(1, RpgLighting.Weights(0.5f, false, false).Y, what: "lighting switched off keeps day at midnight");
+            var dawn = RpgLighting.Weights(5f, false, true);
+            ModAssert.CloseTo(1, dawn.X + dawn.W, what: "dawn blends night into morning");
+            ModAssert.True(dawn.X > 0 && dawn.W > 0, "both phases at dawn");
+        }
+
+        [ModTest("lights/tile_lights_on_any_layer_once_per_cell")]
+        static void TileLights(ModTestContext ctx)
+        {
+            var tileset = new RpgTileset
+            {
+                ID = "lit",
+                Tiles = new List<RpgTileInfo>
+                {
+                    new() { Index = 3, Light = new RpgLight { Radius = 4 } },
+                    new() { Index = 7, Light = new RpgLight { Radius = 1.5f, Color = "#ffd27a" } },
+                    new() { Index = 9, Solid = true },
+                },
+            };
+            var grid = new RpgMapGrid(4, 3);
+            grid.SetTile(RpgLayer.Front, 1, 0, 3);
+            grid.SetTile(RpgLayer.Main, 2, 2, 7);
+            grid.SetTile(RpgLayer.Back, 2, 2, 3);
+            grid.SetTile(RpgLayer.Main, 0, 1, 9);
+
+            var lights = RpgLighting.TileLights(grid, tileset);
+            ModAssert.Equal(2, lights.Count, "one light per lit cell, unlit tiles give none");
+            ModAssert.True(lights.Exists(l => l.Cell == new Vector2I(1, 0) && Mathf.IsEqualApprox(l.Light.Radius, 4f)), "a front-layer lamp");
+            ModAssert.True(lights.Exists(l => l.Cell == new Vector2I(2, 2)), "a cell lit on two layers counts once");
+        }
+
+        [ModTest("lights/map_ambient_json")]
+        static void MapAmbientJson(ModTestContext ctx)
+        {
+            var room = JsonSerializer.Deserialize<RpgMap>(@"{ ""ID"": ""room"", ""Ambient"": ""#e8dcc8"" }", JsonOptionsProvider.ReadOptions);
+            ModAssert.Equal("#e8dcc8", room.Ambient, "a lit room");
+            var again = JsonSerializer.Deserialize<RpgMap>(JsonSerializer.Serialize(room), JsonOptionsProvider.ReadOptions);
+            ModAssert.Equal("#e8dcc8", again.Ambient, "ambient survives the round trip");
+            ModAssert.Null(JsonSerializer.Deserialize<RpgMap>(@"{ ""ID"": ""field"" }", JsonOptionsProvider.ReadOptions).Ambient, "outdoors by default");
+        }
+    }
+}

tests/RpgRulesTests.cs

@@ -53,6 +53,26 @@ namespace Cthangover.Mods.Rpg.Tests
             ModAssert.False(tileset.IsSolid(-1), "empty cell");
         }
 
+        [ModTest("rules/tileset_light_and_autotile_lookup_round_trip")]
+        static void TilesetLightAndAutotileLookup(ModTestContext ctx)
+        {
+            var tileset = System.Text.Json.JsonSerializer.Deserialize<RpgTileset>(@"{
+                ""Id"": ""lit"", ""Tiles"": [
+                  { ""Index"": 29, ""Tag"": ""lamp_top"", ""Light"": { ""Radius"": 4, ""Color"": ""#ffcf80"" } },
+                  { ""Index"": 40, ""Solid"": true, ""Tag"": ""water"", ""Autotile"": ""village/water_auto"" }
+                ] }", Cthangover.Core.Utils.JsonOptionsProvider.ReadOptions);
+            tileset = System.Text.Json.JsonSerializer.Deserialize<RpgTileset>(System.Text.Json.JsonSerializer.Serialize(tileset), Cthangover.Core.Utils.JsonOptionsProvider.ReadOptions);
+
+            ModAssert.CloseTo(4, tileset.LightOf(29).Radius, what: "the lamp's light survives the round trip");
+            ModAssert.Equal("#ffcf80", tileset.LightOf(29).Color, "with its colour");
+            ModAssert.Null(tileset.LightOf(40), "the water gives no light");
+            ModAssert.Null(tileset.LightOf(-1), "an empty cell gives no light");
+            ModAssert.Equal("village/water_auto", tileset.AutotileOf(40)?.Autotile, "the autotile entry and its block");
+            ModAssert.Null(tileset.AutotileOf(29), "a plain tile is no autotile");
+            ModAssert.Null(tileset.AutotileOf(-1), "nor an empty cell");
+            ModAssert.True(tileset.IsSolid(40), "an autotile is solid like any tile");
+        }
+
         [ModTest("rules/encounter_off_without_table")]
         static void EncounterOffWithoutTable(ModTestContext ctx)
         {