p57: 菜单/启动水面第二层高光波光——逐列相位错开(步进2.4rad)/更快(周期80 vs 96 tick)/更亮更窄细高光条 + 昼夜 tint 衰减参数 + 帧计数纯函数回归；ANALYZE splash hl/main std=274.97 corr=-0.017、menu hl/main std=279.77 corr=-0.011、层间相关<0.95、相位差2.4rad、无黑块白块

4 files changed, 260 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"
diff --git a/src/LivingVillage.Desktop/Game.fs b/src/LivingVillage.Desktop/Game.fs
index 8162351..b51c7f0 100644
--- a/src/LivingVillage.Desktop/Game.fs
+++ b/src/LivingVillage.Desktop/Game.fs
@@ -333,6 +333,14 @@ type LivingVillageGame() as this =
     let mutable p46CloudLateDone = false
     let mutable p46MenuADone = false
     let mutable p46MenuBDone = false
+    // P57 证据钩子：LV_P57_SHOT=1 时对同一 splash/menu 帧各拍「高光层关 / 开」两帧
+    // （像素差即第二层高光贡献），并打印逐列主水带亮度/高光 alpha/相位供 analyze 计算。
+    // p57HighlightDisabled 仅供取证时开关高光层，缺省 false（正常渲染始终开启）。
+    let p57ShotMode = Environment.GetEnvironmentVariable("LV_P57_SHOT") = "1"
+    let mutable p57HighlightDisabled = false
+    let mutable p57Step = 0
+    let mutable p57PendingName = ""
+    let mutable p57Pending = false
     // P47 证据钩子：LV_P47_SHOT=1 时在真实生成器世界里拍「白天河道 / 夜晚河道 / 近景」三帧。
     let p47ShotMode = Environment.GetEnvironmentVariable("LV_P47_SHOT") = "1"
     let mutable p47Step = 0
@@ -1030,6 +1038,62 @@ type LivingVillageGame() as this =
             else p46MenuBDone <- true
             save p46PendingName
 
+    /// P57 取证：把当前水面帧的逐列主水带亮度/高光 alpha/两层相位打印成逗号数组。
+    member private this.LogP57Columns (name: string) =
+        let frame = if splashActive then splashFrame else menuEntranceFrame
+        let columns = [ 0 .. 39 ]
+        let fmt (values: float32 list) =
+            values |> List.map (fun v -> sprintf "%.4f" v) |> String.concat ","
+        let main = columns |> List.map (fun c -> MenuAmbience.waterColumnBrightness frame c 0)
+        let hl = columns |> List.map (fun c -> float32 (MenuAmbience.highlightAlpha MenuAmbience.highlightDayLight frame c 0))
+        let mainPhase = columns |> List.map (fun c -> MenuAmbience.waterPhase frame c 0)
+        let hlPhase = columns |> List.map (fun c -> MenuAmbience.highlightPhase frame c 0)
+        printfn "p57-status=%s pendingName=%s disabled=%b frame=%d main=%s hl=%s mainphase=%s hlphase=%s"
+            name (if String.IsNullOrEmpty p57PendingName then "-" else p57PendingName) p57HighlightDisabled frame
+            (fmt main) (fmt hl) (fmt mainPhase) (fmt hlPhase)
+
+    /// P57 证据：Splash 阶段按帧表拍「高光层关 / 开」两帧。
+    member private this.PrepareP57Splash () =
+        if not p57Pending then
+            match p57Step with
+            | 0 ->
+                p57HighlightDisabled <- true
+                p57PendingName <- P57ShotScript.splashBaseName
+                p57Pending <- true
+            | 1 ->
+                p57HighlightDisabled <- false
+                p57PendingName <- P57ShotScript.splashHighlightName
+                p57Pending <- true
+            | _ -> ()
+
+    /// P57 证据：菜单阶段拍「高光层关 / 开」两帧后收尾。
+    member private this.PrepareP57Shot () =
+        if p57Step >= 4 then
+            printfn "p57-shot=done"
+            this.Exit()
+        elif not p57Pending then
+            match p57Step with
+            | 2 ->
+                menuEntranceFrame <- P57ShotScript.menuFrame
+                p57HighlightDisabled <- true
+                p57PendingName <- P57ShotScript.menuBaseName
+                p57Pending <- true
+            | 3 ->
+                menuEntranceFrame <- P57ShotScript.menuFrame
+                p57HighlightDisabled <- false
+                p57PendingName <- P57ShotScript.menuHighlightName
+                p57Pending <- true
+            | _ -> ()
+
+    /// P57 证据：Draw 末尾落盘并打印逐列数字。
+    member private this.CaptureP57Shot () =
+        if p57Pending then
+            p57Pending <- false
+            System.IO.Directory.CreateDirectory recordDirectory |> ignore
+            this.SaveBackBuffer(sprintf "%s/%s.png" recordDirectory p57PendingName)
+            this.LogP57Columns p57PendingName
+            p57Step <- p57Step + 1
+
     /// P47 证据：真实生成器世界里拍「白天河道 / 夜晚河道 / 近景」三帧，含 P47 场景细节。
     member private this.PrepareP47Shot () =
         let setHour (hour: float) =
@@ -1829,6 +1893,9 @@ type LivingVillageGame() as this =
                 match target with
                 | Some t -> splashFrame <- t
                 | None -> ()
+            if p57ShotMode && splashFrame >= 10L && p57Step < 2 then
+                splashFrame <- P57ShotScript.splashFrame
+                this.PrepareP57Splash()
             let skip = LaunchScreen.skipRequested (pressed Keys.Escape) (pressed Keys.Space)
             if skip || LaunchScreen.isComplete splashFrame then
                 splashActive <- false
@@ -1886,6 +1953,9 @@ type LivingVillageGame() as this =
             elif p46ShotMode then
                 if menu.Page = MainMenu then
                     this.PrepareP46Shot()
+            elif p57ShotMode then
+                if menu.Page = MainMenu then
+                    this.PrepareP57Shot()
             elif p47ShotMode then
                 if menu.Page = MainMenu then
                     this.DispatchMenuInput Confirm
@@ -1940,6 +2010,9 @@ type LivingVillageGame() as this =
                 this.UpdateMenu pressed
             if menu.Page <> Playing then
                 menuEntranceFrame <- menuEntranceFrame + 1L
+                // P57 取证：钉住菜单水面帧，令「高光层关/开」两帧渲染同一帧号（差即高光层）。
+                if p57ShotMode && menu.Page = MainMenu && p57Step <= 3 then
+                    menuEntranceFrame <- P57ShotScript.menuFrame + 1L
         match pauseHelpControl with
         | Some original when menu.Page = Playing ->
             let _, restoredControl = MenuState.exitPauseHelp original menu
@@ -2343,6 +2416,8 @@ type LivingVillageGame() as this =
                 this.CaptureP45Shot()
             if p46ShotMode then
                 this.CaptureP46Shot()
+            if p57ShotMode then
+                this.CaptureP57Shot()
             if p47ShotMode && menu.Page = Playing then
                 this.CaptureP47Shot()
             if p52ShotMode && menu.Page = Playing then
@@ -2406,6 +2481,17 @@ type LivingVillageGame() as this =
                 spriteBatch.Draw(artTextures.TileAtlas, Rectangle(x, row + lift, Sim.tilePixels, Sim.tilePixels), VillageArt.atlasTileRectangle TitleScreen.waterSlot, crestColor)
                 if MenuAmbience.waterColumnCrest splashFrame column rowIndex then
                     spriteBatch.Draw(pixel, Rectangle(x, row + lift, Sim.tilePixels, 3), Color(225, 240, 245, waterAlpha))
+                // P57 第二层高光波光：同列相位错开、更亮更窄的细高光条（昼/夜由 light 衰减）。
+                if not p57HighlightDisabled && MenuAmbience.highlightVisible splashFrame column rowIndex then
+                    let hr, hg, hb = MenuAmbience.highlightRgb
+                    let ha =
+                        MenuAmbience.highlightAlpha MenuAmbience.highlightDayLight splashFrame column rowIndex
+                        * waterAlpha / 255
+                    let barX = x + (Sim.tilePixels - MenuAmbience.highlightBarWidth) / 2
+                    spriteBatch.Draw(
+                        pixel,
+                        Rectangle(barX, row + lift + MenuAmbience.highlightRowDelta, MenuAmbience.highlightBarWidth, MenuAmbience.highlightThickness),
+                        Color(hr, hg, hb, ha))
 
         // P42 屋檐灯笼呼吸光晕：复用 P14 预乘 alpha 径向路径，随帧与灯序号呼吸。
         let lanternColor, _ = TitleScreen.lanternColors
@@ -2516,6 +2602,17 @@ type LivingVillageGame() as this =
                 spriteBatch.Draw(artTextures.TileAtlas, Rectangle(x, row + lift, Sim.tilePixels, Sim.tilePixels), VillageArt.atlasTileRectangle TitleScreen.waterSlot, crestColor)
                 if MenuAmbience.waterColumnCrest menuEntranceFrame column rowIndex then
                     spriteBatch.Draw(pixel, Rectangle(x, row + lift, Sim.tilePixels, 3), Color(225, 240, 245, waterAlpha))
+                // P57 第二层高光波光（menu）。
+                if not p57HighlightDisabled && MenuAmbience.highlightVisible menuEntranceFrame column rowIndex then
+                    let hr, hg, hb = MenuAmbience.highlightRgb
+                    let ha =
+                        MenuAmbience.highlightAlpha MenuAmbience.highlightDayLight menuEntranceFrame column rowIndex
+                        * waterAlpha / 255
+                    let barX = x + (Sim.tilePixels - MenuAmbience.highlightBarWidth) / 2
+                    spriteBatch.Draw(
+                        pixel,
+                        Rectangle(barX, row + lift + MenuAmbience.highlightRowDelta, MenuAmbience.highlightBarWidth, MenuAmbience.highlightThickness),
+                        Color(hr, hg, hb, ha))
 
         // P42 bank lanterns breathe through the shared P14 premultiplied-alpha radial path.
         let lanternColor, _ = TitleScreen.lanternColors
diff --git a/src/LivingVillage.Desktop/MenuAmbience.fs b/src/LivingVillage.Desktop/MenuAmbience.fs
index 74fefeb..6d258c5 100644
--- a/src/LivingVillage.Desktop/MenuAmbience.fs
+++ b/src/LivingVillage.Desktop/MenuAmbience.fs
@@ -41,6 +41,49 @@ module MenuAmbience =
     let waterColumnCrest (frame: int64) (column: int) (rowIndex: int) : bool =
         waterWave frame column rowIndex > 0.7f
 
+    // ---------------- ①.5 第二层高光波光（P57） ----------------
+    // P46 验收遗留：主水带波光层次偏弱。在**主水带之上**再叠一层细高光条：
+    //   * 更快/更细：周期 80 tick（主水带连续相位 96 tick），故推进速度略不同；
+    //   * 逐列相位错开：相邻列固定差 highlightColumnStep（=2.4 rad，非零且异于主水带的 120°）；
+    //   * 更亮：纯白 (255,255,255)，亮于主水带波峰色 (225,240,245)；
+    //   * 更窄：条高 2px（主波峰 3px）、段宽 20px（满格 32px），且亮列阈值更高（0.86 > 0.7）。
+    // 全为帧计数纯函数：无随机、无时钟；`light` 参数用于昼夜 tint 衰减（日场 1.0，夜场 <1）。
+
+    let highlightPeriodTicks = 80.0f
+    let highlightColumnStep = 2.4f
+    let highlightRowStep = 0.9f
+    let highlightCrestThreshold = 0.86f
+    let highlightThickness = 2
+    let highlightBarWidth = 20
+    let highlightRowDelta = 1
+    let highlightRgb : int * int * int = (255, 255, 255)
+    let highlightMaxAlpha = 220
+    let highlightDayLight = 1.0f
+    let highlightNightLight = 0.42f
+
+    /// 高光层相位（弧度）。帧推进用 highlightPeriodTicks（与主水带的 96 tick 不同），
+    /// 逐列差 highlightColumnStep、逐行差 highlightRowStep；帧号取模保持有界、无浮点漂移。
+    let highlightPhase (frame: int64) (column: int) (rowIndex: int) : float32 =
+        let t = float32 (frame % 100000L)
+        (t / highlightPeriodTicks) * (2.0f * float32 Math.PI)
+        + float32 column * highlightColumnStep
+        + float32 rowIndex * highlightRowStep
+
+    /// 高光层正弦波值，范围 [-1, 1]。
+    let highlightWave (frame: int64) (column: int) (rowIndex: int) : float32 =
+        sin (highlightPhase frame column rowIndex)
+
+    /// 该列是否出现细高光条（阈值比主水带高 → 更稀疏）。
+    let highlightVisible (frame: int64) (column: int) (rowIndex: int) : bool =
+        highlightWave frame column rowIndex > highlightCrestThreshold
+
+    /// 高光条 alpha：波峰处最亮，随 `light`（昼夜 tint）线性衰减，钳 [0,255]。
+    let highlightAlpha (light: float32) (frame: int64) (column: int) (rowIndex: int) : int =
+        let wave = highlightWave frame column rowIndex
+        let raw = float32 highlightMaxAlpha * light * (0.6f + 0.4f * wave)
+        let rounded = int (Math.Round(float raw, MidpointRounding.AwayFromZero))
+        max 0 (min 255 rounded)
+
     // ---------------- ② 灯笼呼吸光晕 ----------------
 
     /// 灯笼呼吸 alpha，界于 [40, 96]；相位随帧与灯序号推进，邻灯不同步。
@@ -115,3 +158,17 @@ module P46ShotScript =
     // menuEntranceFrame 在 Update 末尾 +1，故设置值取目标相位帧的前一帧。
     let menuPeakFrame = 172L
     let menuTroughFrame = 241L
+
+/// P57 取证：第二层高光波光证据帧表（60Hz 帧号纯数据，Game 与回归测试共用）。
+/// 对同一帧各拍「高光层关 / 开」两帧，像素差即高光层贡献；splash 与 menu 各一组。
+module P57ShotScript =
+
+    let splashBaseName = "p57-splash-base"
+    let splashHighlightName = "p57-splash-highlight"
+    let menuBaseName = "p57-menu-base"
+    let menuHighlightName = "p57-menu-highlight"
+
+    /// splash 水面仍可见（reveal<1）。
+    let splashFrame = 16L
+    /// menu 入场完成后的稳定帧（>=120）。
+    let menuFrame = 180L