merge: P28 民居第二变体强化 + 512 沿河加密（青灰挑檐B/竖长格栅窗/绿院门，2/3/4 宽分层 16 座外环）— Hermes 复验通过

2 files changed, 68 insertions, 0 deletions

diff --git a/src/LivingVillage.Desktop.Tests/MapGenTests.fs b/src/LivingVillage.Desktop.Tests/MapGenTests.fs
index 6486dd7..b737707 100644
--- a/src/LivingVillage.Desktop.Tests/MapGenTests.fs
+++ b/src/LivingVillage.Desktop.Tests/MapGenTests.fs
@@ -256,6 +256,21 @@ type MapGenTests () =
         Assert.IsTrue(a.Buildings = b.Buildings)
         Assert.AreEqual<string>(MapGen.serialize a, MapGen.serialize b)
 
+    /// P28：512 沿河民居由 10 -> 16 增密（+6），并出现 2/3/4 三档宽度（附属小筑/民居/大宅），
+    /// 形成聚落层次；默认图仍为 0，不消耗 RNG，故 64/256 checksum 锁定不变。
+    [<TestMethod>]
+    member _.LargeMapHouseDensityHierarchyOnlyGrowsLargeMaps () =
+        Assert.AreEqual<int>(16, (MapGen.paramsForSize 512 384 (uint64 1)).ExtraRiversideHouses)
+        Assert.AreEqual<int>(0, (MapGen.paramsForSize 64 48 (uint64 1)).ExtraRiversideHouses)
+        Assert.AreEqual<int>(0, (MapGen.paramsForSize 256 192 (uint64 1)).ExtraRiversideHouses)
+        let map = MapGen.generateWithSize 512 384 (uint64 4242)
+        Assert.IsTrue(map.Buildings.Length >= 22, sprintf "P28 512 must place >=22 houses, saw %d" map.Buildings.Length)
+        let widths = map.Buildings |> List.map (fun b -> b.Width) |> Set.ofList
+        Assert.IsTrue(widths.Contains 2, "outbuilding width 2 must appear")
+        Assert.IsTrue(widths.Contains 3, "house width 3 must appear")
+        Assert.IsTrue(widths.Contains 4, "hall width 4 must appear")
+        Assert.AreEqual<int>(24, map.Buildings.Length)
+
     [<TestMethod>]
     member _.DefaultSizeHouseCountUnchanged () =
         Assert.AreEqual<int>(4, (MapGen.generateWithSize 64 48 (uint64 4242)).Buildings.Length)
diff --git a/src/LivingVillage.Desktop.Tests/PrototypeTests.fs b/src/LivingVillage.Desktop.Tests/PrototypeTests.fs
index bc3425a..7f67280 100644
--- a/src/LivingVillage.Desktop.Tests/PrototypeTests.fs
+++ b/src/LivingVillage.Desktop.Tests/PrototypeTests.fs
@@ -1171,6 +1171,59 @@ type PrototypeTests () =
         Assert.IsTrue((atlasWidth = VillageArt.worldAtlasWidth), "world atlas width must match 32 x 32px slots")
         Assert.IsTrue((atlasHeight = VillageArt.worldAtlasHeight), "world atlas height must stay 32px")
 
+    /// P28：防复发。第二变体（P26）在 512 整图 ~2px/tile 下不可辨，根因是挑檐与第一变体同为
+    /// 近黑黛瓦。此回归直接解码 world 图集，断言变体 B 的挑檐（slot 28）平均亮度显著高于
+    /// 变体 A 的屋脊（slot 8），保证「配色差异」不会在后续编辑中被悄悄抹平。
+    [<TestMethod>]
+    member _.VariantBRoofPaletteIsClearlyLighterThanVariantA () =
+        let worldPath = Path.Combine(AppContext.BaseDirectory, "Assets/jiangnan-world.png")
+        let bytes = File.ReadAllBytes worldPath
+        let be32 offset =
+            (int bytes.[offset] <<< 24)
+            ||| (int bytes.[offset + 1] <<< 16)
+            ||| (int bytes.[offset + 2] <<< 8)
+            ||| int bytes.[offset + 3]
+        Assert.AreEqual<int>(0x89504E47, be32 0)
+        let width = be32 16
+        let height = be32 20
+        Assert.AreEqual<int>(VillageArt.worldAtlasWidth, width)
+        Assert.AreEqual<int>(VillageArt.worldAtlasHeight, height)
+        // Collect IDAT and inflate; the baked atlas is 8-bit RGBA, non-interlaced, filter 0.
+        let mutable offset = 8
+        use idat = new MemoryStream()
+        while offset < bytes.Length do
+            let length = be32 offset
+            let tag = System.Text.Encoding.ASCII.GetString(bytes, offset + 4, 4)
+            if tag = "IDAT" then idat.Write(bytes, offset + 8, length)
+            offset <- offset + 12 + length
+        idat.Position <- 0L
+        use inflater = new System.IO.Compression.ZLibStream(idat, System.IO.Compression.CompressionMode.Decompress)
+        use raw = new MemoryStream()
+        inflater.CopyTo raw
+        let data = raw.ToArray()
+        let stride = width * 4 + 1
+        let pixel (x: int) (y: int) =
+            let rowStart = y * stride
+            Assert.AreEqual<byte>(0uy, data.[rowStart])
+            let p = rowStart + 1 + x * 4
+            (int data.[p], int data.[p + 1], int data.[p + 2], int data.[p + 3])
+        let slotMeanBrightness (slot: int) =
+            let mutable sum = 0.0
+            let mutable count = 0
+            for y in 0 .. height - 1 do
+                for x in slot * 32 .. slot * 32 + 31 do
+                    let (r, g, b, a) = pixel x y
+                    if a > 0 then
+                        sum <- sum + float (r + g + b) / 3.0
+                        count <- count + 1
+            Assert.IsTrue(count > 0, sprintf "slot %d must have opaque pixels" slot)
+            sum / float count
+        let roofA = slotMeanBrightness 8   // RoofRidgeSprite: variant A near-black 黛瓦
+        let roofB = slotMeanBrightness 28  // RoofEaveOverhangSprite: variant B light blue-grey 瓦
+        Assert.IsTrue(
+            roofB > roofA + 15.0,
+            sprintf "variant B roof must be clearly lighter than variant A (A=%.1f B=%.1f)" roofA roofB)
+
     [<TestMethod>]
     member _.CjkGlyphManifestIsUniqueAndMatchesAtlasGrid () =
         // 防复发：图集用字增长时，清单必须非空、每行恰 1 个字符、字符唯一，