Radar: nearby_objects every second and dungeon_map per dungeon landblock

start_radar/stop_radar from the backend drive it, as before. nearby_objects
keeps the original's shape: map coordinates on the surface, landblock-local
raw positions with zero map coordinates in a dungeon, ids as signed ints, the
same eight object classes, no wielded items or self. dungeon_map is built the
original's way from the landblock's cells (x a multiple of 10, whole metres,
6-metre floors, rotation = the orientation's stored W) and sent once per
landblock per session; the cells come through a small reader that the
plugin API's dungeon-cell data will fill (until then the map is not sent).

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

tests/OpenAC.MosswartMassacre.Tests/Fakes/FakeAutomation.cs

@@ -42,6 +42,8 @@ public sealed class FakeAutomation : IAutomationSurface
 
     public FakeNetwork Network { get; } = new();
 
+    public FakeDungeonMap DungeonMap { get; } = new();
+
     ICharacterInfo IAutomationSurface.Character => Character;
     ISpellCatalog IAutomationSurface.Spells => Spells;
     IMagicCommands IAutomationSurface.Magic => Magic;
@@ -58,6 +60,7 @@ public sealed class FakeAutomation : IAutomationSurface
     IVendorAutomation IAutomationSurface.Vendor => Vendor;
     ILoginAutomation IAutomationSurface.Login => Login;
     INetworkAutomation IAutomationSurface.Network => Network;
+    IDungeonMapAutomation IAutomationSurface.DungeonMap => DungeonMap;
 }
 
 /// <summary>A settable <see cref="ITradeAutomation"/>: a test drives <see cref="Raise*"/> and inspects <see cref="Calls"/>.</summary>

tests/OpenAC.MosswartMassacre.Tests/Fakes/FakeNetwork.cs

@@ -43,3 +43,12 @@ public sealed class FakeNetwork : INetworkAutomation
         return AcceptImports;
     }
 }
+
+/// <summary>A dungeon-map surface whose sealed landblocks a test names.</summary>
+public sealed class FakeDungeonMap : IDungeonMapAutomation
+{
+    public HashSet<uint> SealedLandblocks { get; } = [];
+
+    public bool IsSealedDungeon(uint cellId) =>
+        (cellId & 0xFFFFu) >= 0x100u && SealedLandblocks.Contains(cellId & 0xFFFF0000u);
+}

tests/OpenAC.MosswartMassacre.Tests/Radar/RadarTests.cs

@@ -0,0 +1,119 @@
+using System.Globalization;
+using AcDream.Plugin.Abstractions;
+using OpenAC.MosswartMassacre.Backend;
+using OpenAC.MosswartMassacre.Radar;
+using OpenAC.MosswartMassacre.Tests.Streams;
+
+namespace OpenAC.MosswartMassacre.Tests.Radar;
+
+/// <summary>The nearby_objects and dungeon_map frames as the original built them.</summary>
+public sealed class RadarTests
+{
+    private const string Stamp = "2026-09-25T08:30:15.1230000Z";
+
+    private static string D(double value) => value.ToString("R", CultureInfo.InvariantCulture);
+
+    private static PluginWorldObject Landscape(uint id, string name, PluginObjectClass cls, PluginNavigationPosition position, uint wielder = 0) =>
+        new(id, 1u, name, cls, 0u, 0u, wielder) { IsLandscape = true, HasPosition = true, Position = position };
+
+    [Fact]
+    public void Nearby_objects_on_the_surface()
+    {
+        // NearbyObjectsTracker.cs:124-231: objects with ew/ns to 7 places and
+        // z to 2; the player's own position both as map coordinates and as
+        // landblock-local metres; ids as signed ints; only the eight classes;
+        // no wielded items, no self.
+        using var harness = new PluginHarness("Mossy");
+        harness.Host.Automation.Navigation.Snapshot = new PluginNavigationSnapshot(
+            true, false, 1u, StreamGoldenTests.Position(), false, false);
+        harness.Host.Automation.Objects.Objects.AddRange(
+        [
+            Landscape(0x80001234, "Drudge Skulker", PluginObjectClass.Monster, StreamGoldenTests.Position(x: 108f, y: 120f, z: 44.25f)),
+            Landscape(0x80001235, "Sword", PluginObjectClass.MeleeWeapon, StreamGoldenTests.Position()),
+            Landscape(0x80001236, "Held", PluginObjectClass.Monster, StreamGoldenTests.Position(), wielder: 5),
+            Landscape(0x50000001, "Mossy", PluginObjectClass.Player, StreamGoldenTests.Position()),
+        ]);
+        harness.Login();
+
+        string json = Wire.Serialize(harness.Feature<RadarStream>().BuildNearbyObjects());
+
+        double monsterEw = StreamGoldenTests.Position(x: 108f).EastWest;
+        double monsterNs = StreamGoldenTests.Position(y: 120f).NorthSouth;
+        Assert.Equal(
+            "{\"type\":\"nearby_objects\",\"character_name\":\"Mossy\",\"timestamp\":\"" + Stamp + "\","
+            + "\"player_ew\":" + D(Math.Round((double)33.65f, 7)) + ",\"player_ns\":" + D(Math.Round((double)42.55f, 7))
+            + ",\"player_z\":42.5,\"player_heading\":90.0,\"is_dungeon\":false,\"landblock\":\"0xA9B40000\","
+            + "\"player_x\":96.0,\"player_y\":120.0,\"player_raw_z\":42.5,"
+            + "\"objects\":[{\"id\":-2147478988,\"name\":\"Drudge Skulker\",\"object_class\":\"Monster\","
+            + "\"ew\":" + D(Math.Round(monsterEw, 7)) + ",\"ns\":" + D(Math.Round(monsterNs, 7)) + ",\"z\":44.25}]}",
+            json);
+    }
+
+    [Fact]
+    public void In_a_dungeon_objects_carry_raw_positions_and_the_map_goes_out_once()
+    {
+        const uint cell = 0x01D90105u;
+        var here = StreamGoldenTests.Position(x: 30f, y: 40f, z: -12f, cell: cell);
+        var cells = new FakeCells(
+        [
+            new DungeonCellRecord(0x0123, 10.2f, 20f, 0.4f, 1f),
+            new DungeonCellRecord(0x0456, 15f, 20f, 0f, 0.7071f),
+            new DungeonCellRecord(0x0789, 30f, -10f, -6.4f, 0f),
+        ]);
+        using var harness = new PluginHarness("Mossy");
+        harness.Host.Automation.Navigation.Snapshot = new PluginNavigationSnapshot(true, false, 1u, here, false, false);
+        harness.Host.Automation.DungeonMap.SealedLandblocks.Add(0x01D90000u);
+        harness.Host.Automation.Objects.Objects.Add(
+            Landscape(0x80000001, "Lich", PluginObjectClass.Monster, StreamGoldenTests.Position(x: 31.5f, y: 41.25f, z: -12f, cell: cell)));
+        harness.Login();
+        var radar = new RadarStream(harness.Context, cells) ;
+        radar.Start();
+
+        radar.OnTick();
+        radar.OnTick();
+
+        Assert.Equal(
+            "{\"type\":\"dungeon_map\",\"character_name\":\"Mossy\",\"landblock\":\"0x01D90000\","
+            + "\"bounds\":{\"min_x\":10,\"max_x\":30,\"min_y\":-10,\"max_y\":20},"
+            + "\"z_levels\":[{\"z\":-6,\"cells\":[{\"env_id\":1929,\"x\":30,\"y\":-10,\"z\":-6,\"rotation\":0.0}]},"
+            + "{\"z\":0,\"cells\":[{\"env_id\":291,\"x\":10,\"y\":20,\"z\":0,\"rotation\":1.0}]}]}",
+            Assert.Single(harness.Frames, f => f.Contains("dungeon_map", StringComparison.Ordinal)));
+        string objects = harness.Frames.First(f => f.Contains("nearby_objects", StringComparison.Ordinal));
+        Assert.Contains("\"is_dungeon\":true", objects, StringComparison.Ordinal);
+        Assert.Contains(
+            "{\"id\":-2147483647,\"name\":\"Lich\",\"object_class\":\"Monster\",\"ew\":0.0,\"ns\":0.0,\"z\":0.0,"
+            + "\"raw_x\":31.5,\"raw_y\":41.25,\"raw_z\":-12.0}",
+            objects,
+            StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public void The_backend_turns_the_radar_on_and_off()
+    {
+        using var harness = new PluginHarness("Mossy");
+        harness.Login();
+        var radar = harness.Feature<RadarStream>();
+
+        harness.Receive("{\"player_name\":\"Mossy\",\"command\":\"start_radar\"}");
+        harness.Tick(0.01);
+        Assert.True(radar.IsActive);
+
+        harness.Run(2.05);
+        Assert.Equal(2, harness.FramesOfType("nearby_objects").Count());
+
+        harness.Receive("{\"player_name\":\"Mossy\",\"command\":\"stop_radar\"}");
+        harness.Tick(0.01);
+        Assert.False(radar.IsActive);
+    }
+
+    private sealed class FakeCells(IReadOnlyList<DungeonCellRecord> cells) : IDungeonCellSource
+    {
+        public int Reads { get; private set; }
+
+        public IReadOnlyList<DungeonCellRecord>? ReadCells(uint landblock)
+        {
+            Reads++;
+            return cells;
+        }
+    }
+}