p72: 角色行走四向动画帧提升（6 走 + 2 待机）

CharacterArt 运行时点阵图集从 4 走 + 2 待机扩为 6 走（新增左右低过渡步 4/5，由 1/2 镜像）+ 2 待机，格数 *8、图集 5120x48；VillageArt 帧循环 %6、characterSourceRectangle *8、characterAtlasWidth 5120。同步 P45/Prototype 帧断言、新增 P72 帧表完整性回归、脚本与素材重新生成、维护说明动画语义。白天正午村庄行走实跑证据落 docs/evidence/p72-*。Desktop 343/343、Kernel 120/120、digest 与 p70 一致。

8 files changed, 119 insertions, 42 deletions

diff --git a/src/LivingVillage.Desktop.Tests/LivingVillage.Desktop.Tests.fsproj b/src/LivingVillage.Desktop.Tests/LivingVillage.Desktop.Tests.fsproj
index a736a83..432cd03 100644
--- a/src/LivingVillage.Desktop.Tests/LivingVillage.Desktop.Tests.fsproj
+++ b/src/LivingVillage.Desktop.Tests/LivingVillage.Desktop.Tests.fsproj
@@ -43,6 +43,7 @@
     <Compile Include="P68MapSnapshotTests.fs" />
     <Compile Include="P69CopyAuditTests.fs" />
     <Compile Include="P71ApiDocsTests.fs" />
+    <Compile Include="P72CharacterWalkTests.fs" />
     <Compile Include="SampleTests.fs" />
   </ItemGroup>
 
diff --git a/src/LivingVillage.Desktop.Tests/P45CharacterAnimTests.fs b/src/LivingVillage.Desktop.Tests/P45CharacterAnimTests.fs
index eba03aa..b9241ad 100644
--- a/src/LivingVillage.Desktop.Tests/P45CharacterAnimTests.fs
+++ b/src/LivingVillage.Desktop.Tests/P45CharacterAnimTests.fs
@@ -5,7 +5,7 @@ open LivingVillage.Kernel
 open LivingVillage.Kernel.Sim
 open LivingVillage.Desktop
 
-/// P45 角色动画帧升级回归：四向 x 6 帧原创点阵、帧序列确定性、行走推进、停止回 idle。
+/// P45 角色动画帧升级回归：四向 x 8 帧（6 走 + 2 待机）原创点阵、帧序列确定性、行走推进、停止回 idle。
 [<TestClass>]
 type P45CharacterAnimTests () =
 
@@ -76,16 +76,18 @@ type P45CharacterAnimTests () =
             [ VillageArt.NorthFacing; VillageArt.SouthFacing; VillageArt.WestFacing; VillageArt.EastFacing ]
             |> List.map (fun d -> (rect VillageArt.IndigoRobe d (VillageArt.WalkFrame VillageArt.FrameOne)).X)
         assertEqualMsg 4 (xs |> List.distinct |> List.length) "四向必须落在不同源格"
-        // 同向 6 帧源格逐一不同且按序排列。
+        // 同向 8 帧源格逐一不同且按序排列。
         let frameXs =
             [ VillageArt.WalkFrame VillageArt.FrameOne
               VillageArt.WalkFrame VillageArt.FrameTwo
               VillageArt.WalkFrame VillageArt.FrameThree
               VillageArt.WalkFrame VillageArt.FrameFour
+              VillageArt.WalkFrame VillageArt.FrameFive
+              VillageArt.WalkFrame VillageArt.FrameSix
               VillageArt.IdleFrame VillageArt.IdleOne
               VillageArt.IdleFrame VillageArt.IdleTwo ]
             |> List.map (fun f -> (rect VillageArt.IndigoRobe VillageArt.SouthFacing f).X)
-        assertEqualMsg 6 (frameXs |> List.distinct |> List.length) "同向 6 帧源格须互不同"
+        assertEqualMsg 8 (frameXs |> List.distinct |> List.length) "同向 8 帧源格须互不同"
         assertEqualMsg frameXs (List.sort frameXs) "帧源格须按帧序递增"
 
     [<TestMethod>]
@@ -95,18 +97,22 @@ type P45CharacterAnimTests () =
         assertEqualMsg (VillageArt.WalkFrame VillageArt.FrameTwo) (VillageArt.characterFrame true 4L) "走 4"
         assertEqualMsg (VillageArt.WalkFrame VillageArt.FrameThree) (VillageArt.characterFrame true 8L) "走 8"
         assertEqualMsg (VillageArt.WalkFrame VillageArt.FrameFour) (VillageArt.characterFrame true 12L) "走 12"
-        assertEqualMsg (VillageArt.WalkFrame VillageArt.FrameOne) (VillageArt.characterFrame true 16L) "走 16 循环"
+        assertEqualMsg (VillageArt.WalkFrame VillageArt.FrameFive) (VillageArt.characterFrame true 16L) "走 16"
+        assertEqualMsg (VillageArt.WalkFrame VillageArt.FrameSix) (VillageArt.characterFrame true 20L) "走 20"
+        assertEqualMsg (VillageArt.WalkFrame VillageArt.FrameOne) (VillageArt.characterFrame true 24L) "走 24 循环"
         // 停止：无论 tick，回 idle 两帧呼吸循环。
         assertEqualMsg (VillageArt.IdleFrame VillageArt.IdleOne) (VillageArt.characterFrame false 0L) "停 0"
         assertEqualMsg (VillageArt.IdleFrame VillageArt.IdleTwo) (VillageArt.characterFrame false 24L) "停 24"
         assertEqualMsg (VillageArt.IdleFrame VillageArt.IdleOne) (VillageArt.characterFrame false 9999L) "停任意 tick 仍在 idle"
         // 玩家行走规格：方向 + 是否移动 + tick 决定帧，四向共享同一帧序（方向只换源格）。
         let framesFor direction =
-            [ 0L; 4L; 8L; 12L ] |> List.map (fun t -> (VillageArt.avatarSpriteSpec direction true t).Frame)
+            [ 0L; 4L; 8L; 12L; 16L; 20L ] |> List.map (fun t -> (VillageArt.avatarSpriteSpec direction true t).Frame)
         let north = framesFor VillageArt.NorthFacing
         assertEqualMsg [ VillageArt.WalkFrame VillageArt.FrameOne
                          VillageArt.WalkFrame VillageArt.FrameTwo
                          VillageArt.WalkFrame VillageArt.FrameThree
-                         VillageArt.WalkFrame VillageArt.FrameFour ] north "方向->帧序确定"
+                         VillageArt.WalkFrame VillageArt.FrameFour
+                         VillageArt.WalkFrame VillageArt.FrameFive
+                         VillageArt.WalkFrame VillageArt.FrameSix ] north "方向->帧序确定"
         for direction in [ VillageArt.SouthFacing; VillageArt.WestFacing; VillageArt.EastFacing ] do
             assertEqualMsg north (framesFor direction) "四向帧序一致"
diff --git a/src/LivingVillage.Desktop.Tests/P72CharacterWalkTests.fs b/src/LivingVillage.Desktop.Tests/P72CharacterWalkTests.fs
new file mode 100644
index 0000000..781d22c
--- /dev/null
+++ b/src/LivingVillage.Desktop.Tests/P72CharacterWalkTests.fs
@@ -0,0 +1,40 @@
+namespace LivingVillage.Desktop.Tests
+
+open Microsoft.VisualStudio.TestTools.UnitTesting
+open LivingVillage.Desktop
+
+/// P72 回归：角色行走帧表完整性——四向各 8 格（6 走 + 2 待机），
+/// 六张行走帧两两可见区分（含左右过渡步），且与待机帧不同。
+[<TestClass>]
+type P72CharacterWalkTests () =
+
+    let letters variant direction frame = CharacterArt.frameLetters variant direction frame
+
+    let cellDiff (a: string list) (b: string list) : int =
+        List.zip a b
+        |> List.sumBy (fun (ra, rb) -> Seq.zip ra rb |> Seq.filter (fun (x, y) -> x <> y) |> Seq.length)
+
+    [<TestMethod>]
+    member _.WalkFrameTableHasSixDistinctPosesPerDirection () =
+        Assert.AreEqual<int>(8, CharacterArt.frameCount)
+        Assert.AreEqual<int>(6, CharacterArt.walkFrameCount)
+        Assert.AreEqual<int>(2, CharacterArt.idleFrameCount)
+        for variant in 0 .. CharacterArt.variantCount - 1 do
+            for direction in 0 .. CharacterArt.directionCount - 1 do
+                let walk = [ 0 .. CharacterArt.walkFrameCount - 1 ] |> List.map (letters variant direction)
+                // 6 张行走帧两两必须有可见差异（不允许重复姿态）。
+                for i in 0 .. walk.Length - 1 do
+                    for j in i + 1 .. walk.Length - 1 do
+                        Assert.IsTrue(
+                            cellDiff walk.[i] walk.[j] >= 4,
+                            sprintf "v%d d%d 走帧 %d 与 %d 姿态重复" variant direction i j)
+                // 行走与待机必须不同。
+                let idle = letters variant direction CharacterArt.walkFrameCount
+                Assert.IsTrue(cellDiff walk.[0] idle >= 4, "行走帧与待机帧相同")
+
+    [<TestMethod>]
+    member _.AtlasStridePlacesSixWalkThenTwoIdleCells () =
+        Assert.AreEqual<int>(5120, CharacterArt.atlasWidth)
+        Assert.AreEqual<int>(5120, VillageArt.characterAtlasWidth)
+        let stride = VillageArt.characterAtlasWidth / 32 / (5 * 4)
+        Assert.AreEqual<int>(8, stride)
diff --git a/src/LivingVillage.Desktop.Tests/PrototypeTests.fs b/src/LivingVillage.Desktop.Tests/PrototypeTests.fs
index 61fda7d..68e5b93 100644
--- a/src/LivingVillage.Desktop.Tests/PrototypeTests.fs
+++ b/src/LivingVillage.Desktop.Tests/PrototypeTests.fs
@@ -326,7 +326,7 @@ type PrototypeTests () =
         Assert.IsTrue(first.PanelY + first.PanelHeight <= 720)
 
     [<TestMethod>]
-    member _.NpcVariantsAreStableAndAnimationCoversFourDirectionsAndFourFrames () =
+    member _.NpcVariantsAreStableAndAnimationCoversFourDirectionsAndSixFrames () =
         let sameNpc = npcVisualVariant (NpcId 7)
         let repeatedNpc = npcVisualVariant (NpcId 7)
         let otherNpc = npcVisualVariant (NpcId 8)
@@ -345,7 +345,9 @@ type PrototypeTests () =
         Assert.AreEqual<AnimationFrame>(FrameTwo, (VillageArt.animationFrame 4L))
         Assert.AreEqual<AnimationFrame>(FrameThree, (VillageArt.animationFrame 8L))
         Assert.AreEqual<AnimationFrame>(FrameFour, (VillageArt.animationFrame 12L))
-        Assert.AreEqual<AnimationFrame>(FrameOne, (VillageArt.animationFrame 16L))
+        Assert.AreEqual<AnimationFrame>(FrameFive, (VillageArt.animationFrame 16L))
+        Assert.AreEqual<AnimationFrame>(FrameSix, (VillageArt.animationFrame 20L))
+        Assert.AreEqual<AnimationFrame>(FrameOne, (VillageArt.animationFrame 24L))
 
     [<TestMethod>]
     member _.VillagersUseFourDistinctVariantsDistinctFromTheAvatar () =
@@ -363,28 +365,27 @@ type PrototypeTests () =
                 rect.X)
             |> Set.ofList
         Assert.AreEqual<int>(4, variantXes.Count)
-        Assert.AreEqual<int>(3840, VillageArt.characterAtlasWidth)
+        Assert.AreEqual<int>(5120, VillageArt.characterAtlasWidth)
 
     [<TestMethod>]
-    member _.WalkAnimationCoversFourFramesDeterministically () =
-        // 16-tick cycle, new frame every 4 sim ticks, no wall-clock dependency.
+    member _.WalkAnimationCoversSixFramesDeterministically () =
+        // 24-tick cycle, new frame every 4 sim ticks, no wall-clock dependency.
         let frames = [ 0L; 4L; 8L; 12L; 16L; 20L ] |> List.map VillageArt.animationFrame
-        Assert.AreEqual<AnimationFrame list>([ FrameOne; FrameTwo; FrameThree; FrameFour; FrameOne; FrameTwo ], frames)
+        Assert.AreEqual<AnimationFrame list>([ FrameOne; FrameTwo; FrameThree; FrameFour; FrameFive; FrameSix ], frames)
 
         let cycleFrames =
-            [ 0L; 4L; 8L; 12L ]
+            [ 0L; 4L; 8L; 12L; 16L; 20L ]
             |> List.map VillageArt.animationFrame
             |> List.distinct
-        Assert.AreEqual<AnimationFrame list>([ FrameOne; FrameTwo; FrameThree; FrameFour ], cycleFrames)
+        Assert.AreEqual<AnimationFrame list>([ FrameOne; FrameTwo; FrameThree; FrameFour; FrameFive; FrameSix ], cycleFrames)
 
         // Every frame maps to a distinct atlas cell column across the five variants.
-        // Every frame maps to a distinct atlas cell column across the five variants.
         let perFrameX =
-            [ FrameOne; FrameTwo; FrameThree; FrameFour ]
+            [ FrameOne; FrameTwo; FrameThree; FrameFour; FrameFive; FrameSix ]
             |> List.map (fun frame ->
                 let rect = characterSourceRectangle { Variant = IndigoRobe; Direction = NorthFacing; Frame = WalkFrame frame }
                 rect.X / 32)
-        Assert.AreEqual<int list>([ 0; 1; 2; 3 ], perFrameX)
+        Assert.AreEqual<int list>([ 0; 1; 2; 3; 4; 5 ], perFrameX)
 
         // Idle breath poses occupy the two cells after the walk cycle for each (variant, direction).
         let idleXes =
@@ -392,7 +393,7 @@ type PrototypeTests () =
             |> List.map (fun frame ->
                 let rect = characterSourceRectangle { Variant = IndigoRobe; Direction = NorthFacing; Frame = IdleFrame frame }
                 rect.X / 32)
-        Assert.AreEqual<int list>([ 4; 5 ], idleXes)
+        Assert.AreEqual<int list>([ 6; 7 ], idleXes)
 
     [<TestMethod>]
     member _.ChineseCopyProvidesFormalSceneTimeMenuAndStatusLabels () =
@@ -533,6 +534,9 @@ type PrototypeTests () =
         Assert.AreEqual<CharacterFrame>(IdleFrame IdleTwo, VillageArt.characterFrame false 24L)
         Assert.AreEqual<CharacterFrame>(WalkFrame FrameOne, VillageArt.characterFrame true 0L)
         Assert.AreEqual<CharacterFrame>(WalkFrame FrameTwo, VillageArt.characterFrame true 4L)
+        Assert.AreEqual<CharacterFrame>(WalkFrame FrameFive, VillageArt.characterFrame true 16L)
+        Assert.AreEqual<CharacterFrame>(WalkFrame FrameSix, VillageArt.characterFrame true 20L)
+        Assert.AreEqual<CharacterFrame>(WalkFrame FrameOne, VillageArt.characterFrame true 24L)
         Assert.AreEqual<CharacterFrame>(VillageArt.characterFrame true 12L, VillageArt.characterFrame true 12L)
 
     [<TestMethod>]
@@ -550,18 +554,18 @@ type PrototypeTests () =
         Assert.IsTrue(peddler.WalkWindow < farmer.WalkWindow && farmer.WalkWindow < scholar.WalkWindow)
         Assert.IsTrue(peddler.IdleWindow < farmer.IdleWindow && farmer.IdleWindow < scholar.IdleWindow)
 
-        // Same tick, three trade-specific frames (at 12 ticks: Farmer IV, Peddler II, Scholar I).
+        // Same tick, three trade-specific frames (at 12 ticks: Farmer IV, Peddler VI, Scholar V).
         let frameAt trade tick = VillageArt.animationFrameFor (VillageArt.rhythmFor trade) tick
         let frames =
             [ VillageArt.Farmer; VillageArt.Peddler; VillageArt.Scholar ]
             |> List.map (fun trade -> frameAt trade 12L)
-        Assert.AreEqual<AnimationFrame list>([ FrameFour; FrameTwo; FrameOne ], frames)
+        Assert.AreEqual<AnimationFrame list>([ FrameFour; FrameSix; FrameFive ], frames)
         Assert.AreEqual<VillageArt.WalkRhythm>(VillageArt.rhythmFor VillageArt.Scholar, VillageArt.rhythmFor VillageArt.Scholar)
 
         // npcSpriteSpec now follows the NPC's own trade cadence.
         Assert.AreEqual<CharacterFrame>(WalkFrame FrameFour, (VillageArt.npcSpriteSpec (NpcId 0) VillageArt.SouthFacing true 12L).Frame)
-        Assert.AreEqual<CharacterFrame>(WalkFrame FrameTwo, (VillageArt.npcSpriteSpec (NpcId 1) VillageArt.SouthFacing true 12L).Frame)
-        Assert.AreEqual<CharacterFrame>(WalkFrame FrameOne, (VillageArt.npcSpriteSpec (NpcId 2) VillageArt.SouthFacing true 12L).Frame)
+        Assert.AreEqual<CharacterFrame>(WalkFrame FrameSix, (VillageArt.npcSpriteSpec (NpcId 1) VillageArt.SouthFacing true 12L).Frame)
+        Assert.AreEqual<CharacterFrame>(WalkFrame FrameFive, (VillageArt.npcSpriteSpec (NpcId 2) VillageArt.SouthFacing true 12L).Frame)
 
     [<TestMethod>]
     member _.ChimneySmokeFramesAreDeterministicAndThreePhase () =
diff --git a/src/LivingVillage.Desktop/Assets/jiangnan-characters.png b/src/LivingVillage.Desktop/Assets/jiangnan-characters.png
index dd96e60..8698b39 100644
--- a/src/LivingVillage.Desktop/Assets/jiangnan-characters.png
+++ b/src/LivingVillage.Desktop/Assets/jiangnan-characters.png
diff --git a/src/LivingVillage.Desktop/CharacterArt.fs b/src/LivingVillage.Desktop/CharacterArt.fs
index 9d02baf..bfe86ad 100644
--- a/src/LivingVillage.Desktop/CharacterArt.fs
+++ b/src/LivingVillage.Desktop/CharacterArt.fs
@@ -5,8 +5,9 @@ open Microsoft.Xna.Framework.Graphics
 
 /// P45 角色动画帧：全部原创手绘点阵，用像素代码内嵌生成图集，不依赖任何外部素材。
 /// 布局与既有 `characterSourceRectangle` 完全一致：cell 32x48，
-/// cellIndex = (variant*4 + direction)*6 + frame，共 5 变体 x 4 向 x 6 帧。
-/// direction 顺序 North/South/West/East（0..3），frame 顺序 走1/走2/走3/走4/待机1/待机2（0..5）。
+/// cellIndex = (variant*4 + direction)*8 + frame，共 5 变体 x 4 向 x 8 帧。
+/// direction 顺序 North/South/West/East（0..3），
+/// frame 顺序 走1..走6/待机1/待机2（0..7）；P72 将行走由 4 帧提升为 6 帧（含左右过渡步）。
 module CharacterArt =
 
     let sourceWidth = 16
@@ -16,8 +17,8 @@ module CharacterArt =
     let cellHeight = sourceHeight * pixelScale
     let variantCount = 5
     let directionCount = 4
-    let frameCount = 6
-    let walkFrameCount = 4
+    let frameCount = 8
+    let walkFrameCount = 6
     let idleFrameCount = 2
     let atlasWidth = cellWidth * variantCount * directionCount * frameCount
 
@@ -102,6 +103,13 @@ module CharacterArt =
           "....BBBBBBBB...."
           "....RRRRRRRR...." ]
 
+    let private mirrorRow (row: string) : string =
+        System.String(row.ToCharArray() |> Array.rev)
+
+    /// P72 过渡步：走 5/6 为走 2/3 的左右镜像，形成「左-右」对称的六帧循环。
+    let private torsoWalk4 : string list = torsoWalk1 |> List.map mirrorRow
+    let private torsoWalk5 : string list = torsoWalk2 |> List.map mirrorRow
+
     let private torsoIdle1 : string list =
         [ "...SRRRRRRRRS..."
           "...SRRRRRRRRS..."
@@ -123,7 +131,8 @@ module CharacterArt =
           "....RRRRRRRR...."
           "....RRRRRRRR...." ]
 
-    /// 腿（6 行，行 18..23）：四帧行走跨步姿态各不相同，待机两帧双脚并拢。
+    /// 腿（6 行，行 18..23）：六帧行走跨步姿态各不相同，待机两帧双脚并拢。
+    /// 走 5/6 为走 2/3 的左右镜像（P72 过渡步），使左右跨步对称。
     let private legsWalk0 : string list =
         [ "....RRRRRRRR...."
           "...RRRRRRRRRR..."
@@ -154,7 +163,10 @@ module CharacterArt =
           ".....RRRRRR....."
           ".....RRR.RR....."
           ".....RRR.FF....."
-          ".....FFF........" ]
+          ".......FFFF....." ]
+
+    let private legsWalk4 : string list = legsWalk1 |> List.map mirrorRow
+    let private legsWalk5 : string list = legsWalk2 |> List.map mirrorRow
 
     let private legsIdle : string list =
         [ "....RRRRRRRR...."
@@ -165,13 +177,10 @@ module CharacterArt =
           ".....FFF.FF....." ]
 
     let private torsoByFrame : string list list =
-        [ torsoWalk0; torsoWalk1; torsoWalk2; torsoWalk3; torsoIdle1; torsoIdle2 ]
+        [ torsoWalk0; torsoWalk1; torsoWalk2; torsoWalk3; torsoWalk4; torsoWalk5; torsoIdle1; torsoIdle2 ]
 
     let private legsByFrame : string list list =
-        [ legsWalk0; legsWalk1; legsWalk2; legsWalk3; legsIdle; legsIdle ]
-
-    let private mirrorRow (row: string) : string =
-        System.String(row.ToCharArray() |> Array.rev)
+        [ legsWalk0; legsWalk1; legsWalk2; legsWalk3; legsWalk4; legsWalk5; legsIdle; legsIdle ]
 
     let private headByDirection : string list list =
         [ headNorth; headSouth; headWest; headWest |> List.map mirrorRow ]
diff --git a/src/LivingVillage.Desktop/Game.fs b/src/LivingVillage.Desktop/Game.fs
index ff1dfe0..6252117 100644
--- a/src/LivingVillage.Desktop/Game.fs
+++ b/src/LivingVillage.Desktop/Game.fs
@@ -99,6 +99,9 @@ type LivingVillageGame() as this =
     // P36 证据钩子：复用 sample 脚本的走位/互动序列，但按状态抓 4 帧关键帧
     // （靠近→提示出现→对话层打开且世界交互被隔离→关闭离开提示消失）后退出。
     let p36ShotMode = Environment.GetEnvironmentVariable("LV_P36_SHOT") = "1"
+    // P72 evidence hook: with sample recording on, log each saved frame's per-NPC walk
+    // frame so the PNGs can be correlated with the deterministic 6-frame cycle.
+    let p72Log = Environment.GetEnvironmentVariable("LV_P72_LOG") = "1"
     let sampleMode = Environment.GetEnvironmentVariable("LV_AUTOPLAY_SAMPLE") = "1" || p36ShotMode
     let menuShotMode = Environment.GetEnvironmentVariable("LV_AUTOPLAY_MENU_SHOT") = "1"
     let daylightAutoplay = Environment.GetEnvironmentVariable("LV_AUTOPLAY_DAYLIGHT") = "1"
@@ -2812,7 +2815,13 @@ type LivingVillageGame() as this =
                 recordIndex <- recordIndex + 1
                 if recordIndex % recordEvery = 0 then
                     System.IO.Directory.CreateDirectory recordDirectory |> ignore
-                    this.SaveBackBuffer(sprintf "%s/%s%04d.png" recordDirectory recordName recordIndex)
+                    let name = sprintf "%s/%s%04d.png" recordDirectory recordName recordIndex
+                    this.SaveBackBuffer(name)
+                    if p72Log then
+                        printfn "p72-frame %s tick=%d" name world.Tick
+                        for npc in world.Npcs do
+                            let spec = VillageArt.npcSpriteSpecAtTarget npc.Id npc.Pos npc.Mind.Target world.Tick
+                            printfn "  npc=%A pos=(%.1f,%.1f) frame=%A moving=%b" npc.Id npc.Pos.X npc.Pos.Y spec.Frame (npc.Mind.Target <> npc.Pos)
             if menuShotMode then
                 this.CaptureMenuShot()
             if p42ShotMode then
diff --git a/src/LivingVillage.Desktop/VillageArt.fs b/src/LivingVillage.Desktop/VillageArt.fs
index 76abc4a..db594d2 100644
--- a/src/LivingVillage.Desktop/VillageArt.fs
+++ b/src/LivingVillage.Desktop/VillageArt.fs
@@ -108,13 +108,16 @@ module VillageArt =
         | FrameTwo
         | FrameThree
         | FrameFour
+        | FrameFive
+        | FrameSix
 
     /// Two-pose standing breath cycle used whenever a character is not moving.
     type IdleFrame =
         | IdleOne
         | IdleTwo
 
-    /// A character either walks (four-pose cycle) or breathes in place (two-pose cycle).
+    /// A character either walks (six-pose cycle, incl. left/right transition steps) or
+    /// breathes in place (two-pose cycle).
     type CharacterFrame =
         | WalkFrame of AnimationFrame
         | IdleFrame of IdleFrame
@@ -363,13 +366,16 @@ module VillageArt =
         | Peddler -> { WalkWindow = 3L; IdleWindow = 20L; PhaseOffset = 1L }
         | Scholar -> { WalkWindow = 6L; IdleWindow = 36L; PhaseOffset = 2L }
 
-    /// Four-pose walk cycle at a rhythm's window (one pose per WalkWindow sim ticks).
+    /// Six-pose walk cycle at a rhythm's window (one pose per WalkWindow sim ticks).
+    /// P72: four strides became six by adding left/right transition steps.
     let animationFrameFor (rhythm: WalkRhythm) (tick: int64) : AnimationFrame =
-        match positiveModulo64 4L (tick / rhythm.WalkWindow + rhythm.PhaseOffset) with
+        match positiveModulo64 6L (tick / rhythm.WalkWindow + rhythm.PhaseOffset) with
         | 0L -> FrameOne
         | 1L -> FrameTwo
         | 2L -> FrameThree
-        | _ -> FrameFour
+        | 3L -> FrameFour
+        | 4L -> FrameFive
+        | _ -> FrameSix
 
     /// Two-pose standing breath cycle at a rhythm's IdleWindow, fully deterministic.
     let idleFrameFor (rhythm: WalkRhythm) (tick: int64) : IdleFrame =
@@ -454,9 +460,11 @@ module VillageArt =
             | WalkFrame FrameTwo -> 1
             | WalkFrame FrameThree -> 2
             | WalkFrame FrameFour -> 3
-            | IdleFrame IdleOne -> 4
-            | IdleFrame IdleTwo -> 5
-        let cellIndex = (variantIndex * 4 + directionIndex) * 6 + frameIndex
+            | WalkFrame FrameFive -> 4
+            | WalkFrame FrameSix -> 5
+            | IdleFrame IdleOne -> 6
+            | IdleFrame IdleTwo -> 7
+        let cellIndex = (variantIndex * 4 + directionIndex) * 8 + frameIndex
         Microsoft.Xna.Framework.Rectangle(cellIndex * 32, 0, 32, 48)
 
     let private rgba (r: int) (g: int) (b: int) (a: int) : XnaColor = XnaColor(r, g, b, a)
@@ -566,7 +574,7 @@ module VillageArt =
     let worldTileCount = 32
     let worldAtlasWidth = Sim.tilePixels * worldTileCount
     let worldAtlasHeight = Sim.tilePixels
-    let characterAtlasWidth = 32 * 5 * 4 * 6
+    let characterAtlasWidth = 32 * 5 * 4 * 8
     let characterAtlasHeight = 48
     let interiorAtlasWidth = 392
     let interiorAtlasHeight = 96