2 files changed, 106 insertions, 0 deletions
diff --git a/src/LivingVillage.Desktop.Tests/LivingVillage.Desktop.Tests.fsproj b/src/LivingVillage.Desktop.Tests/LivingVillage.Desktop.Tests.fsproj
index a3c1e45..951e59b 100644
--- a/src/LivingVillage.Desktop.Tests/LivingVillage.Desktop.Tests.fsproj
+++ b/src/LivingVillage.Desktop.Tests/LivingVillage.Desktop.Tests.fsproj
@@ -33,6 +33,7 @@
     <Compile Include="P53InteractionPromptTests.fs" />
     <Compile Include="P54ProfessionDailyTests.fs" />
     <Compile Include="P55ProfessionRewardTests.fs" />
+    <Compile Include="P57MenuHighlightTests.fs" />
     <Compile Include="SampleTests.fs" />
   </ItemGroup>
 
diff --git a/src/LivingVillage.Desktop.Tests/P57MenuHighlightTests.fs b/src/LivingVillage.Desktop.Tests/P57MenuHighlightTests.fs
new file mode 100644
index 0000000..74f8eba
--- /dev/null
+++ b/src/LivingVillage.Desktop.Tests/P57MenuHighlightTests.fs
@@ -0,0 +1,105 @@
+namespace LivingVillage.Desktop.Tests
+
+open Microsoft.VisualStudio.TestTools.UnitTesting
+open LivingVillage.Desktop
+
+/// P57 美术 A3：菜单/启动水面第二层高光波光（P46 遗留短板）。
+///
+/// 高光层必须与主水带**可分辨**：更亮更窄、列相位错开、推进速度略不同；
+/// 全为帧计数纯函数（无随机），且**不得改变**既有 waterPhase / lantern / 云影输出。
+[<TestClass>]
+type P57MenuHighlightTests () =
+
+    let twoPi = 2.0f * float32 System.Math.PI
+    let assertClose (expected: float32) (actual: float32) (message: string) =
+        Assert.IsTrue((abs (expected - actual) < 1e-4f), sprintf "%s: expected %f actual %f" message expected actual)
+    let assertInt (expected: int) (actual: int) (message: string) =
+        Assert.IsTrue((expected = actual), sprintf "%s: expected %d actual %d" message expected actual)
+
+    let visibleColumn (frame: int64) (rowIndex: int) : int =
+        [ 0 .. 63 ]
+        |> List.tryFind (fun column -> MenuAmbience.highlightVisible frame column rowIndex)
+        |> Option.defaultValue -1
+
+    [<TestMethod>]
+    member _.HighlightPhaseOffsetsAdjacentColumnsByANonZeroStep () =
+        for frame in [ 0L; 16L; 150L; 4097L ] do
+            for rowIndex in [ 0; 1 ] do
+                for column in [ 0; 5; 21; 38 ] do
+                    let step =
+                        MenuAmbience.highlightPhase frame (column + 1) rowIndex
+                        - MenuAmbience.highlightPhase frame column rowIndex
+                    assertClose MenuAmbience.highlightColumnStep step (sprintf "frame %d col %d row %d" frame column rowIndex)
+                    Assert.IsTrue(abs step > 1e-3f, "adjacent highlight columns must be phase-shifted")
+
+    [<TestMethod>]
+    member _.HighlightMovesAtADifferentSpeedThanTheMainWaterBand () =
+        // 主水带连续相位速率 = (2π/3)/32；高光层 = 2π/period，二者比值应略偏离 1（本实现 1.2）。
+        let mainDelta =
+            MenuAmbience.waterPhase 151L 5 0 - MenuAmbience.waterPhase 150L 5 0
+        let highlightDelta =
+            MenuAmbience.highlightPhase 151L 5 0 - MenuAmbience.highlightPhase 150L 5 0
+        Assert.IsTrue(highlightDelta > 0.0f && mainDelta > 0.0f, "both layers must advance with the frame")
+        let ratio = highlightDelta / mainDelta
+        assertClose 1.2f ratio "highlight speed must be slightly different (1.2x)"
+        Assert.IsTrue(abs (highlightDelta - mainDelta) > 1e-3f, "the two layers must not move at the same speed")
+
+    [<TestMethod>]
+    member _.HighlightLayerIsBrighterAndNarrowerThanTheMainBand () =
+        // 更窄：条更薄、更短。
+        Assert.IsTrue(MenuAmbience.highlightThickness < 3, "highlight bar must be thinner than the 3px main crest")
+        Assert.IsTrue(MenuAmbience.highlightBarWidth < 32, "highlight bar must be narrower than a tile")
+        // 更亮：纯白高光 > 主水带波峰色 (225,240,245) 的 luma。
+        let r, g, b = MenuAmbience.highlightRgb
+        let highlightLuma = 0.299f * float32 r + 0.587f * float32 g + 0.114f * float32 b
+        let crestLuma = 0.299f * 225.0f + 0.587f * 240.0f + 0.114f * 245.0f
+        Assert.IsTrue(highlightLuma > crestLuma, sprintf "highlight luma %.1f must exceed crest luma %.1f" highlightLuma crestLuma)
+        // 更窄的可见条件（阈值更高 → 亮列更稀疏），但仍有可见列。
+        let frame = 150L
+        let highlightCount = [ 0 .. 39 ] |> List.filter (fun c -> MenuAmbience.highlightVisible frame c 0) |> List.length
+        let mainCount = [ 0 .. 39 ] |> List.filter (fun c -> MenuAmbience.waterColumnCrest frame c 0) |> List.length
+        Assert.IsTrue(highlightCount > 0, "some highlight columns must be lit")
+        Assert.IsTrue(highlightCount <= mainCount, sprintf "highlight %d must be no denser than main crest %d" highlightCount mainCount)
+
+    [<TestMethod>]
+    member _.HighlightIsDeterministicAndBounded () =
+        for frame in [ 0L; 1L; 33L; 173L; 99999L; 100000L; 500000L ] do
+            for column in [ 0; 13; 39 ] do
+                for rowIndex in [ 0; 1 ] do
+                    assertClose
+                        (MenuAmbience.highlightPhase frame column rowIndex)
+                        (MenuAmbience.highlightPhase frame column rowIndex)
+                        "highlight phase must be deterministic"
+                    let alpha = MenuAmbience.highlightAlpha MenuAmbience.highlightDayLight frame column rowIndex
+                    Assert.IsTrue(alpha >= 0 && alpha <= 255, sprintf "alpha %d out of [0,255]" alpha)
+
+    [<TestMethod>]
+    member _.NightLightDimmsTheHighlightButKeepsItReadable () =
+        let frame = 150L
+        let column = visibleColumn frame 0
+        Assert.IsTrue(column >= 0, "need a lit column to compare day/night")
+        let day = MenuAmbience.highlightAlpha MenuAmbience.highlightDayLight frame column 0
+        let night = MenuAmbience.highlightAlpha MenuAmbience.highlightNightLight frame column 0
+        Assert.IsTrue(night < day, sprintf "night alpha %d must be below day %d" night day)
+        Assert.IsTrue(night >= int (0.35f * float32 day), sprintf "night alpha %d must stay readable (>= 35%% of day)" night)
+        Assert.IsTrue(night >= 20, sprintf "night alpha %d must not vanish" night)
+
+    [<TestMethod>]
+    member _.ExistingWaterLanternCloudOutputsArePinned () =
+        // 回归：高光层不得改变既有 waterPhase / lantern / 云影输出帧。
+        assertInt 0 (VillageArt.waterFrameTickAt 150L 5 0) "waterFrameTickAt pin"
+        assertClose 1.317237f (MenuAmbience.waterColumnBrightness 150L 5 0) "main water brightness pin"
+        assertInt 89 (MenuAmbience.lanternBreathAlpha 50L 0) "lantern breath pin"
+        assertInt 70 (MenuAmbience.cloudOffsetPx 0 140L 1280) "cloud offset pin"
+        Assert.AreEqual<int list>([ 624; 656 ], (TitleScreen.layout 1280 720).WaterRows)
+
+    [<TestMethod>]
+    member _.P57ShotScriptWaterFramesAreOrderedAndDistinct () =
+        Assert.IsTrue(P57ShotScript.splashFrame > 0L && P57ShotScript.splashFrame < LaunchScreen.durationFrames)
+        Assert.IsTrue(P57ShotScript.menuFrame >= 120L, "menu frame must wait for the entrance to settle")
+        let names =
+            [ P57ShotScript.splashBaseName
+              P57ShotScript.splashHighlightName
+              P57ShotScript.menuBaseName
+              P57ShotScript.menuHighlightName ]
+        assertInt names.Length (names |> List.distinct |> List.length) "shot names distinct"