feat(desktop): P26 夜晚冷月光 veil（纯渲染层）+ 灯笼光晕径向无方斑回归

1 files changed, 24 insertions, 0 deletions

diff --git a/src/LivingVillage.Desktop.Tests/DesktopTests.fs b/src/LivingVillage.Desktop.Tests/DesktopTests.fs
index b78f4e0..7e4a849 100644
--- a/src/LivingVillage.Desktop.Tests/DesktopTests.fs
+++ b/src/LivingVillage.Desktop.Tests/DesktopTests.fs
@@ -160,6 +160,30 @@ type DesktopTests () =
         Assert.IsTrue(noon.Background.B > noon.Background.R)
 
     [<TestMethod>]
+    member _.MoonlightVeilIsCoolAndOnlyAtNight () =
+        let noonTick = 12L * Sim.ticksPerDay / 24L
+        let midnightTick = 0L
+        let deepNightTick = 23L * Sim.ticksPerDay / 24L
+        Assert.IsTrue(M6Presentation.moonlightVeilAlpha noonTick = 0, "daytime must have no moonlight")
+
+        let moon = M6Presentation.moonlightVeilAlpha midnightTick
+        Assert.IsTrue(moon > 0, "deep night must get a cool moonlight wash")
+        Assert.AreEqual<int>(moon, M6Presentation.moonlightVeilAlpha deepNightTick)
+        Assert.IsTrue(moon <= 72, "moonlight veil stays a low alpha so the scene is not washed out")
+
+        let r, g, b = M6Presentation.moonlightRgb
+        Assert.IsTrue(b > g && g > r, "moonlight must be cool: blue-dominant channels")
+
+        // Dusk is owned by the warm golden veil, so moonlight is suppressed there.
+        let duskTick = M6Presentation.startTickForHour 20.75
+        Assert.IsTrue(M6Presentation.moonlightVeilAlpha duskTick < moon, "dusk is warmed, not moonlit")
+
+        // Premultiplied premultiply of this colour never saturates to white.
+        let veiled = VillageArt.premultiply r g b moon
+        Assert.IsTrue(int veiled.B <= int veiled.A)
+        Assert.IsTrue(int (max veiled.R (max veiled.G veiled.B)) < 250)
+
+    [<TestMethod>]
     member _.DaylightAutoplayBootstrapStartsAtDawnAndPreservesDefaultStart () =
         let dawnTick = 6L * Sim.ticksPerDay / 24L
         let daylightWorld = WorldBootstrap.initialWorldForDaylight true 42UL Sim.npcCount