diag: ACDREAM_PROBE_LIGHT [light-detail] — per-light range/intensity/cone (#133 A7)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/AcDream.App/Rendering/GameWindow.cs

@@ -7641,7 +7641,8 @@ public sealed class GameWindow : IDisposable
                 sunIntensity:      Lighting.Sun?.Intensity ?? 0f,
                 registeredLights:  Lighting.RegisteredCount,
                 activeLights:      (int)ubo.CellAmbient.W,
-                playerCellId:      playerRoot?.CellId ?? 0u);
+                playerCellId:      playerRoot?.CellId ?? 0u,
+                lights:            Lighting);
 
             // Never cull the landblock the player is currently on.
             uint? playerLb = null;

src/AcDream.Core/Rendering/RenderingDiagnostics.cs

@@ -372,12 +372,25 @@ public static class RenderingDiagnostics
 
     /// <summary>
     /// #133 A7 — emit ONE rate-limited <c>[light]</c> line describing the
-    /// current scene-lighting state. Cheap no-op when
+    /// current scene-lighting state, followed (when <paramref name="lights"/>
+    /// is supplied) by up to three <c>[light-detail]</c> lines for the nearest
+    /// ACTIVE point/spot lights. Cheap no-op when
     /// <see cref="ProbeLightEnabled"/> is false; otherwise fires at most
     /// once per second. Pull the values from the spot where
     /// <c>GameWindow.UpdateSunFromSky</c> set <c>Lighting.CurrentAmbient</c>
     /// / <c>Lighting.Sun</c> and where <c>SceneLightingUbo.Build</c> computed
     /// the active-slot count.
+    /// <para>
+    /// The <c>[light-detail]</c> lines are the answer to the "candle-spotlight"
+    /// question — they expose each torch's REAL dat-derived runtime values
+    /// (<c>range=</c> Falloff metres, <c>intensity=</c>, <c>cone=</c> radians,
+    /// <c>color=</c>, <c>distToViewer=</c>) so it is visible in launch.log
+    /// whether dungeon torches are tiny-range points or wide cones and at what
+    /// intensity — without a screenshot:
+    /// <code>
+    /// [light-detail] kind=Point range=&lt;Falloff m&gt; intensity=&lt;I&gt; cone=&lt;rad&gt; color=(r,g,b) distToViewer=&lt;m&gt;
+    /// </code>
+    /// </para>
     /// </summary>
     /// <param name="insideCell">The <c>playerInsideCell</c> value driving the indoor branch.</param>
     /// <param name="ambientR">Cell ambient red (xyz of <c>uCellAmbient</c>).</param>
@@ -387,12 +400,16 @@ public static class RenderingDiagnostics
     /// <param name="registeredLights">Total point/spot lights registered with the LightManager.</param>
     /// <param name="activeLights"><c>uCellAmbient.w</c> — shader active-slot count (includes the zeroed sun slot indoors).</param>
     /// <param name="playerCellId">The player's current cell id (0 if unresolved → outside).</param>
+    /// <param name="lights">The ticked <c>LightManager</c> (its <c>Active</c> list, sorted nearest-first by the
+    /// just-completed Tick). When non-null, drives the <c>[light-detail]</c> lines. Optional so existing call
+    /// sites / tests that only want the aggregate line keep compiling.</param>
     public static void EmitLight(bool insideCell,
                                  float ambientR, float ambientG, float ambientB,
                                  float sunIntensity,
                                  int registeredLights,
                                  int activeLights,
-                                 uint playerCellId)
+                                 uint playerCellId,
+                                 AcDream.Core.Lighting.LightManager? lights = null)
     {
         if (!ProbeLightEnabled) return;
 
@@ -406,6 +423,32 @@ public static class RenderingDiagnostics
             "[light] insideCell={0} ambient=({1:0.###},{2:0.###},{3:0.###}) sun={4:0.###} registeredLights={5} activeLights={6} playerCell=0x{7:X8}",
             insideCell, ambientR, ambientG, ambientB, sunIntensity,
             registeredLights, activeLights, playerCellId));
+
+        // #133 A7 (2026-06-13) — per-light detail for the "spotlight bubble"
+        // question. Dump the actual runtime dat-derived values of the nearest
+        // ~3 ACTIVE point/spot lights so the real Falloff/Intensity/ConeAngle
+        // are visible in launch.log (are torch ranges 1m or 10m? points or
+        // spots? what intensity?). The sun (Directional, slot 0) is skipped —
+        // it carries no Range/cone meaning. DistSq is already cached by
+        // LightManager.Tick this frame, so the active list is sorted nearest-
+        // first; we just take the first few non-directional entries.
+        if (lights is null) return;
+        var active = lights.Active;
+        int shown = 0;
+        const int MaxDetail = 3;
+        for (int i = 0; i < active.Length && shown < MaxDetail; i++)
+        {
+            var ls = active[i];
+            if (ls is null) continue;
+            if (ls.Kind == AcDream.Core.Lighting.LightKind.Directional) continue;
+
+            float dist = ls.DistSq >= 0f ? MathF.Sqrt(ls.DistSq) : 0f;
+            Console.WriteLine(string.Format(ci,
+                "[light-detail] kind={0} range={1:0.###} intensity={2:0.###} cone={3:0.####} color=({4:0.###},{5:0.###},{6:0.###}) distToViewer={7:0.###}",
+                ls.Kind, ls.Range, ls.Intensity, ls.ConeAngle,
+                ls.ColorLinear.X, ls.ColorLinear.Y, ls.ColorLinear.Z, dist));
+            shown++;
+        }
     }
 
     private static bool _probeEnvCellEnabled =