feat(streaming): load full column bedrock->surface to fix terrain holes

Core/Configuration.cs

@@ -5,17 +5,6 @@ using OpenTK.Mathematics;
 public sealed class Configuration
 {
     public int RenderDistanceHorizontal { get; set; } = 8;
-    // Player-slab half-height in chunks. NOTE: repurposed by the visibility
-    // rework — this is no longer a global vertical load-box. It is how many
-    // chunks load above and below the player's chunk across the whole
-    // horizontal region, so caves at the player's depth render to the full
-    // horizontal distance.
-    public int RenderDistanceVertical { get; set; } = 2;
-
-    // Chunks loaded below the lowest surface chunk of each column. Gives the
-    // surface chunk a solid neighbor below (so its buried bottom faces cull)
-    // and covers cave mouths just under the surface.
-    public int SurfaceShellSkirtBelow { get; set; } = 1;
 
     // Distance fog begins at this fraction of the fog-end distance (fog end is
     // derived from RenderDistanceHorizontal). 0.7 → fog starts at 70% of the edge.

Core/Game.cs

@@ -41,8 +41,8 @@ public sealed class Game : GameWindow
     {
         base.OnLoad();
 
-        Log.Information("Game starting with seed={Seed} renderDistanceH={H} renderDistanceV={V}",
+        Log.Information("Game starting with seed={Seed} renderDistanceH={H}",
-            this._cfg.Seed, this._cfg.RenderDistanceHorizontal, this._cfg.RenderDistanceVertical);
+            this._cfg.Seed, this._cfg.RenderDistanceHorizontal);
 
         GL.ClearColor(this._cfg.SkyColor.X, this._cfg.SkyColor.Y, this._cfg.SkyColor.Z, 1.0f);
         GL.Enable(EnableCap.DepthTest);

VoxelEngine.Tests/ConfigurationTests.cs

@@ -10,7 +10,6 @@ public class ConfigurationTests
     {
         var c = new Configuration();
         Assert.True(c.RenderDistanceHorizontal >= 1);
-        Assert.True(c.RenderDistanceVertical >= 1);
         Assert.True(c.SpawnReadyRadiusHorizontal >= 0);
         Assert.True(c.MaxGenerateJobsInFlight >= 1);
         Assert.True(c.MaxMeshUploadsPerFrame >= 1);
@@ -32,7 +31,6 @@ public class ConfigurationTests
 
         var c2 = new Configuration
         {
-            RenderDistanceVertical     = 2,
             SpawnReadyRadiusHorizontal = 0,
             MaxGenerateJobsInFlight    = 2,
             MaxMeshUploadsPerFrame     = 1,
@@ -43,7 +41,6 @@ public class ConfigurationTests
             WindowWidth                = 800,
             WindowHeight               = 600,
         };
-        Assert.Equal(2,    c2.RenderDistanceVertical);
         Assert.Equal(0,    c2.SpawnReadyRadiusHorizontal);
         Assert.Equal(2,    c2.MaxGenerateJobsInFlight);
         Assert.Equal(1,    c2.MaxMeshUploadsPerFrame);
@@ -80,7 +77,6 @@ public class ConfigurationTests
     {
         var c = new Configuration();
 
-        Assert.Equal(1, c.SurfaceShellSkirtBelow);
         Assert.Equal(0.7f, c.FogStartFraction);
         Assert.Equal(new OpenTK.Mathematics.Vector3(0.45f, 0.65f, 0.95f), c.SkyColor);
         Assert.Equal(256, c.MinCaveY);

VoxelEngine.Tests/Streaming/ChunkStreamerTests.cs

@@ -6,6 +6,7 @@ using VoxelEngine.World.Blocks;
 using VoxelEngine.World.Chunk;
 using VoxelEngine.World.Persistence;
 using VoxelEngine.World.Streaming;
+using VoxelEngine.World.WorldGen;
 using Xunit;
 using VoxelChunk = VoxelEngine.World.Chunk.Chunk;
 
@@ -72,7 +73,6 @@ public class ChunkStreamerTests
         var cfg = new Configuration
         {
             RenderDistanceHorizontal = 1,
-            RenderDistanceVertical = 0,
             MaxGenerateJobsInFlight = 100,
             MaxMeshUploadsPerFrame = 100,
         };
@@ -97,7 +97,6 @@ public class ChunkStreamerTests
         var cfg = new Configuration
         {
             RenderDistanceHorizontal = 1,
-            RenderDistanceVertical = 0,
             MaxGenerateJobsInFlight = 100,
             MaxMeshUploadsPerFrame = 100,
         };
@@ -130,7 +129,6 @@ public class ChunkStreamerTests
         var cfg = new Configuration
         {
             RenderDistanceHorizontal = 1,
-            RenderDistanceVertical = 0,
             MaxGenerateJobsInFlight = 100,
             MaxMeshUploadsPerFrame = 2,   // cap drains per tick
         };
@@ -151,19 +149,21 @@ public class ChunkStreamerTests
         var cfg = new Configuration
         {
             RenderDistanceHorizontal = 0,
-            RenderDistanceVertical = 2,
             MaxGenerateJobsInFlight = 100,
             MaxMeshUploadsPerFrame = 100,
         };
-        var (streamer, world, created) = CreateStreamer(cfg);
+        // Surface far above the world ceiling -> top chunk clamps to
+        // WorldHeightChunks-1 (31). Full column loads cy 0..31 and nothing above.
+        var (streamer, world, _) = CreateStreamer(cfg, surfaceHeightAt: (_, _) => 100_000);
 
-        // Player at y=0 (chunk Y = 0). V=2 wants Y ∈ [-2, 2], but valid Y is [0, 8).
-        // So only Y ∈ {0, 1, 2} qualifies → 1 × 3 × 1 = 3 chunks.
         streamer.Tick(new Vector3i(0, 0, 0));
-        Assert.Equal(3, created.Count);
+
-        Assert.NotNull(world.GetChunk(new Vector3i(0, 0, 0)));
+        for (int cy = 0; cy < WorldConstants.WorldHeightChunks; cy++)
-        Assert.NotNull(world.GetChunk(new Vector3i(0, 1, 0)));
+        {
-        Assert.NotNull(world.GetChunk(new Vector3i(0, 2, 0)));
+            var pos = new Vector3i(0, cy, 0);
+            Assert.NotNull(world.GetChunk(pos));
+            Assert.True(streamer.IsReady(pos));
+        }
     }
 
     [Fact]
@@ -172,7 +172,6 @@ public class ChunkStreamerTests
         var cfg = new Configuration
         {
             RenderDistanceHorizontal = 0,
-            RenderDistanceVertical = 0,
             MaxGenerateJobsInFlight = 100,
             MaxMeshUploadsPerFrame = 100,
         };
@@ -201,7 +200,6 @@ public class ChunkStreamerTests
         var cfg = new Configuration
         {
             RenderDistanceHorizontal = 0,
-            RenderDistanceVertical = 0,
             MaxGenerateJobsInFlight = 100,
             MaxMeshUploadsPerFrame = 100,
         };
@@ -224,7 +222,6 @@ public class ChunkStreamerTests
         var cfg = new Configuration
         {
             RenderDistanceHorizontal = 0,
-            RenderDistanceVertical = 0,
             MaxGenerateJobsInFlight = 100,
             MaxMeshUploadsPerFrame = 100,
         };
@@ -251,7 +248,6 @@ public class ChunkStreamerTests
         var cfg = new Configuration
         {
             RenderDistanceHorizontal = 1,
-            RenderDistanceVertical = 0,
             SpawnReadyRadiusHorizontal = 1,
             MaxGenerateJobsInFlight = 100,
             MaxMeshUploadsPerFrame = 1,         // throttle to expose progression
@@ -271,7 +267,6 @@ public class ChunkStreamerTests
         var cfg = new Configuration
         {
             RenderDistanceHorizontal = 0,
-            RenderDistanceVertical = 0,
             MaxGenerateJobsInFlight = 100,
             MaxMeshUploadsPerFrame = 100,
         };
@@ -296,7 +291,6 @@ public class ChunkStreamerTests
         var cfg = new Configuration
         {
             RenderDistanceHorizontal = 1,
-            RenderDistanceVertical = 0,
             MaxGenerateJobsInFlight = 100,
             MaxMeshUploadsPerFrame = 100,
         };
@@ -318,7 +312,7 @@ public class ChunkStreamerTests
     [Fact]
     public void MarkDirty_OnUntrackedChunk_IsNoOp()
     {
-        var cfg = new Configuration { RenderDistanceHorizontal = 0, RenderDistanceVertical = 0 };
+        var cfg = new Configuration { RenderDistanceHorizontal = 0 };
         var (streamer, _, created) = CreateStreamer(cfg);
 
         streamer.MarkDirty(new Vector3i(99, 0, 99));
@@ -334,7 +328,6 @@ public class ChunkStreamerTests
         var cfg = new Configuration
         {
             RenderDistanceHorizontal = 0,
-            RenderDistanceVertical = 0,
             MaxGenerateJobsInFlight = 100,
             MaxMeshUploadsPerFrame = 100,
         };
@@ -368,7 +361,6 @@ public class ChunkStreamerTests
         var cfg = new Configuration
         {
             RenderDistanceHorizontal = 0,
-            RenderDistanceVertical = 0,
             MaxGenerateJobsInFlight = 100,
             MaxMeshUploadsPerFrame = 100,
         };
@@ -400,20 +392,20 @@ public class ChunkStreamerTests
         var cfg = new Configuration
         {
             RenderDistanceHorizontal = 1,
-            RenderDistanceVertical = 1,
             MaxGenerateJobsInFlight = 100,
             MaxMeshUploadsPerFrame = 5,  // player's chunk + 4 horizontal cardinals
             VerticalPriorityWeight = 4,
         };
-        var (streamer, world, _) = CreateStreamer(cfg);
+        // Surface at worldY 48 -> top chunk 3, so a full column is cy 0..3 and
+        // the player at Y=2 has in-column vertical neighbours at Y=1 and Y=3.
+        var (streamer, world, _) = CreateStreamer(cfg, surfaceHeightAt: (_, _) => 48);
 
-        // Player chunk at Y=2 so vertical neighbors Y=1 and Y=3 are valid.
         var playerPos = new Vector3i(0, 2, 0);
         streamer.Tick(playerPos);
 
         // Drain budget = 5 = priority 0 (player) + 4 priority-1 (horizontal
         // cardinals). With VerticalPriorityWeight=4, vertical cardinals
-        // (Y=1, Y=3) have priority 4 — they should NOT be among the first 5.
+        // (Y=1, Y=3) have priority 4 -- they must NOT be among the first 5.
         Assert.NotNull(world.GetChunk(playerPos));
         Assert.NotNull(world.GetChunk(new Vector3i( 1, 2,  0)));
         Assert.NotNull(world.GetChunk(new Vector3i(-1, 2,  0)));
@@ -424,27 +416,55 @@ public class ChunkStreamerTests
     }
 
     [Fact]
-    public void Tick_LoadsSurfaceShell_AndExcludesAirAboveSurface()
+    public void Tick_LoadsFullColumn_FromBedrockToSurface()
     {
         var cfg = new Configuration
         {
             RenderDistanceHorizontal = 0,   // single column at the player
-            RenderDistanceVertical = 0,     // slab is just the player's chunk
-            SurfaceShellSkirtBelow = 1,
             MaxGenerateJobsInFlight = 100,
             MaxMeshUploadsPerFrame = 100,
         };
-        // Surface at worldY 40 → chunk Y 2. Shell = [2-1, 2] = {1, 2}. Slab at
+        // Surface at worldY 40 -> top chunk floor(40/16) = 2. Full column loads
-        // player Y=0 = {0}. Union = {0, 1, 2}. Chunk Y 3+ is air above surface.
+        // cy 0,1,2; chunk Y 3+ is air above the surface and must NOT load.
         var (streamer, world, _) = CreateStreamer(cfg, surfaceHeightAt: (_, _) => 40);
 
         streamer.Tick(new Vector3i(0, 0, 0));
 
-        Assert.NotNull(world.GetChunk(new Vector3i(0, 0, 0))); // slab
+        Assert.NotNull(world.GetChunk(new Vector3i(0, 0, 0)));  // bedrock
-        Assert.NotNull(world.GetChunk(new Vector3i(0, 1, 0))); // shell skirt
+        Assert.NotNull(world.GetChunk(new Vector3i(0, 1, 0)));  // mid
-        Assert.NotNull(world.GetChunk(new Vector3i(0, 2, 0))); // shell surface
+        Assert.NotNull(world.GetChunk(new Vector3i(0, 2, 0)));  // surface
-        Assert.Null(world.GetChunk(new Vector3i(0, 3, 0)));    // air above surface — not loaded
+        Assert.Null(world.GetChunk(new Vector3i(0, 3, 0)));     // air above surface
-        Assert.Null(world.GetChunk(new Vector3i(0, 5, 0)));    // air above surface — not loaded
+        Assert.Null(world.GetChunk(new Vector3i(0, 5, 0)));     // air above surface
+    }
+
+    [Fact]
+    public void Tick_LoadsEditedSectionAboveSurface()
+    {
+        var cfg = new Configuration
+        {
+            RenderDistanceHorizontal = 0,
+            MaxGenerateJobsInFlight = 100,
+            MaxMeshUploadsPerFrame = 100,
+        };
+        var registry = new BlockRegistry();
+        var store = new InMemoryChunkModificationStore();
+        var world = new World.World(registry, store);
+        var mesher = new FakeMesher();
+        var executor = new SynchronousJobExecutor();
+        Func<float[], IChunkRenderer> factory = m => new FakeRenderer(m);
+        Func<Vector3i, VoxelChunk> generate = _ => new VoxelChunk();
+
+        // Surface at worldY 8 -> top chunk 0. A player edit sits in chunk Y 5,
+        // far above the surface; that edited section must still load.
+        var edited = new Vector3i(0, 5, 0);
+        store.RecordEdit(edited, 0, registry.Stone.Id);
+
+        var streamer = new ChunkStreamer(cfg, world, generate, (_, _) => 8, mesher, registry, executor, factory);
+        streamer.Tick(new Vector3i(0, 0, 0));
+
+        Assert.NotNull(world.GetChunk(new Vector3i(0, 0, 0)));  // surface column
+        Assert.NotNull(world.GetChunk(edited));                 // edited air section above surface
+        Assert.Null(world.GetChunk(new Vector3i(0, 3, 0)));     // unedited air -- not loaded
     }
 
     [Fact]
@@ -453,7 +473,6 @@ public class ChunkStreamerTests
         var cfg = new Configuration
         {
             RenderDistanceHorizontal = 1,
-            RenderDistanceVertical = 0,
             SpawnReadyRadiusHorizontal = 1,
             MaxGenerateJobsInFlight = 100,
             MaxMeshUploadsPerFrame = 100,
@@ -476,7 +495,6 @@ public class ChunkStreamerTests
         var cfg = new Configuration
         {
             RenderDistanceHorizontal = 1,
-            RenderDistanceVertical = 0,
             MaxGenerateJobsInFlight = 100,
             MaxMeshUploadsPerFrame = 100,
         };

VoxelEngine.Tests/Streaming/StreamingIntegrationTests.cs

@@ -32,7 +32,6 @@ public class StreamingIntegrationTests
         var cfg = new Configuration
         {
             RenderDistanceHorizontal = 1,
-            RenderDistanceVertical = 0,
             MaxGenerateJobsInFlight = 100,
             MaxMeshUploadsPerFrame = 100,
         };
@@ -58,7 +57,6 @@ public class StreamingIntegrationTests
         var cfg = new Configuration
         {
             RenderDistanceHorizontal = 0,
-            RenderDistanceVertical = 0,
             MaxGenerateJobsInFlight = 100,
             MaxMeshUploadsPerFrame = 100,
         };

World/Streaming/ChunkStreamer.cs

@@ -18,10 +18,11 @@ public sealed class ChunkStreamer : IDisposable
     private readonly IWorld _world;
     private readonly Func<Vector3i, VoxelChunk> _generate;
     private readonly Func<int, int, int> _surfaceHeightAt;
-    // Per chunk-column (cx,cz) surface (min,max) height range, memoized so each
+    // Per chunk-column (cx,cz) surface-TOP height, memoized so each column's
-    // column's samples are taken once and reused across ticks. Pruned to the
+    // samples are taken once and reused across ticks. Pruned to the horizontal
-    // horizontal window each recompute so it stays bounded.
+    // window each recompute so it stays bounded. Full-column loading only needs
-    private readonly Dictionary<(int cx, int cz), (int min, int max)> _surfaceRangeCache = new();
+    // the top; the bottom is always bedrock (cy 0).
+    private readonly Dictionary<(int cx, int cz), int> _surfaceTopCache = new();
     private readonly IChunkMesher _mesher;
     private readonly BlockRegistry _registry;
     private readonly IJobExecutor _executor;
@@ -156,42 +157,43 @@ public sealed class ChunkStreamer : IDisposable
         this.PruneSurfaceCache(p);
     }
 
-    // Drop cached surface ranges for columns outside the current horizontal
+    // Drop cached surface tops for columns outside the current horizontal
     // window so the cache stays bounded as the player explores.
     private void PruneSurfaceCache(Vector3i p)
     {
         int keep = this._cfg.RenderDistanceHorizontal + 1;
         List<(int cx, int cz)>? stale = null;
-        foreach (var key in this._surfaceRangeCache.Keys)
+        foreach (var key in this._surfaceTopCache.Keys)
         {
             if (Math.Abs(key.cx - p.X) > keep || Math.Abs(key.cz - p.Z) > keep)
                 (stale ??= new()).Add(key);
         }
         if (stale != null)
-            foreach (var key in stale) this._surfaceRangeCache.Remove(key);
+            foreach (var key in stale) this._surfaceTopCache.Remove(key);
     }
 
     // Fills `into` with the chunk positions to load for a viewer at chunk
     // `center`, over a square horizontal region of Chebyshev radius `radiusH`.
-    // Per column the loaded Y-range is the union of the surface shell and the
+    // Per column the full vertical stack from bedrock (cy 0) up to the
-    // player slab, clamped to the world's vertical bounds.
+    // surface-top chunk is loaded, plus any section above the surface holding
+    // player edits (e.g. a built tower).
     private void CollectTargets(Vector3i center, int radiusH, HashSet<Vector3i> into)
     {
-        int v = this._cfg.RenderDistanceVertical;
-        int skirt = this._cfg.SurfaceShellSkirtBelow;
-
         for (int dx = -radiusH; dx <= radiusH; dx++)
         for (int dz = -radiusH; dz <= radiusH; dz++)
         {
             int cx = center.X + dx;
             int cz = center.Z + dz;
 
-            (int minH, int maxH) = this.SurfaceHeightRange(cx, cz);
+            int surfaceTop = ChunkMath.FloorDiv(this.SurfaceTopHeight(cx, cz), VoxelChunk.Size);
-            int shellBot = ChunkMath.FloorDiv(minH, VoxelChunk.Size) - skirt;
+            ChunkStreamer.AddColumn(into, cx, cz, 0, surfaceTop);
-            int shellTop = ChunkMath.FloorDiv(maxH, VoxelChunk.Size);
-            ChunkStreamer.AddColumn(into, cx, cz, shellBot, shellTop);
 
-            ChunkStreamer.AddColumn(into, cx, cz, center.Y - v, center.Y + v);
+            int clampedTop = Math.Min(WorldConstants.WorldHeightChunks - 1, surfaceTop);
+            for (int cy = clampedTop + 1; cy < WorldConstants.WorldHeightChunks; cy++)
+            {
+                var pos = new Vector3i(cx, cy, cz);
+                if (this._world.ModificationStore.HasDiff(pos)) into.Add(pos);
+            }
         }
     }
 
@@ -203,11 +205,13 @@ public sealed class ChunkStreamer : IDisposable
             into.Add(new Vector3i(cx, cy, cz));
     }
 
-    // Min/max terrain surface height across a chunk column's 16×16 footprint,
+    // Max terrain surface height across a chunk column's 16x16 footprint,
-    // sampled at the four corners and the centre (catches slope spread cheaply).
+    // sampled at the four corners and the centre (cheap bound on the column's
-    private (int min, int max) SurfaceHeightRange(int cx, int cz)
+    // top). Cached per column. The bottom of the loaded stack is always bedrock,
+    // so only the top is needed.
+    private int SurfaceTopHeight(int cx, int cz)
     {
-        if (this._surfaceRangeCache.TryGetValue((cx, cz), out (int min, int max) cached))
+        if (this._surfaceTopCache.TryGetValue((cx, cz), out int cached))
             return cached;
 
         int x0 = cx * VoxelChunk.Size;
@@ -217,18 +221,13 @@ public sealed class ChunkStreamer : IDisposable
         int xm = x0 + VoxelChunk.Size / 2;
         int zm = z0 + VoxelChunk.Size / 2;
 
-        int h0 = this._surfaceHeightAt(x0, z0);
+        int max = Math.Max(
-        int h1 = this._surfaceHeightAt(x1, z0);
+            Math.Max(this._surfaceHeightAt(x0, z0), this._surfaceHeightAt(x1, z0)),
-        int h2 = this._surfaceHeightAt(x0, z1);
+            Math.Max(Math.Max(this._surfaceHeightAt(x0, z1), this._surfaceHeightAt(x1, z1)),
-        int h3 = this._surfaceHeightAt(x1, z1);
+                     this._surfaceHeightAt(xm, zm)));
-        int h4 = this._surfaceHeightAt(xm, zm);
 
-        int min = Math.Min(Math.Min(h0, h1), Math.Min(Math.Min(h2, h3), h4));
+        this._surfaceTopCache[(cx, cz)] = max;
-        int max = Math.Max(Math.Max(h0, h1), Math.Max(Math.Max(h2, h3), h4));
+        return max;
-
-        (int min, int max) range = (min, max);
-        this._surfaceRangeCache[(cx, cz)] = range;
-        return range;
     }
 
     private void DrainCompleted()