feat(rendering): frustum-cull chunk draws and log render counts

Core/Game.cs

@@ -29,6 +29,7 @@ public sealed class Game : GameWindow
     private WorldGenerator _generator = null!;
     private ChunkStreamer _streamer = null!;
     private Player _player = null!;
+    private double _logAccumSeconds;
 
     public Game(Configuration cfg, GameWindowSettings gameSettings, NativeWindowSettings nativeSettings)
         : base(gameSettings, nativeSettings)
@@ -127,13 +128,31 @@ public sealed class Game : GameWindow
         this._shader.SetVector3("u_skyColor", this._cfg.SkyColor);
         this._texture.Use(TextureUnit.Texture0);
 
-        this._streamer.DrawAll((pos, renderer) =>
+        Matrix4 viewProj = this._player.Camera.GetViewMatrix() * this._player.Camera.GetProjectionMatrix();
+        Frustum frustum = Frustum.FromViewProjection(viewProj);
+
+        int drawn = this._streamer.DrawVisible(
+            pos =>
+            {
+                Vector3 min = new(pos.X * Chunk.Size, pos.Y * Chunk.Size, pos.Z * Chunk.Size);
+                Vector3 max = min + new Vector3(Chunk.Size);
+                return frustum.Intersects(min, max);
+            },
+            (pos, renderer) =>
             {
                 this._shader.SetMatrix4("model", Matrix4.CreateTranslation(
                     pos.X * Chunk.Size, pos.Y * Chunk.Size, pos.Z * Chunk.Size));
                 renderer.Draw();
             });
 
+        this._logAccumSeconds += args.Time;
+        if (this._logAccumSeconds >= 1.0)
+        {
+            this._logAccumSeconds = 0;
+            Log.Information("Rendered {Drawn} / {Renderers} chunks ({Tracked} loaded)",
+                drawn, this._streamer.RendererCount, this._streamer.TrackedCount);
+        }
+
         this.SwapBuffers();
     }
 

VoxelEngine.Tests/Streaming/ChunkStreamerTests.cs

@@ -1,3 +1,4 @@
+using System.Linq;
 using OpenTK.Mathematics;
 using VoxelEngine.Core;
 using VoxelEngine.World;
@@ -445,4 +446,25 @@ public class ChunkStreamerTests
         Assert.Null(world.GetChunk(new Vector3i(0, 3, 0)));    // air above surface — not loaded
         Assert.Null(world.GetChunk(new Vector3i(0, 5, 0)));    // air above surface — not loaded
     }
+
+    [Fact]
+    public void DrawVisible_DrawsOnlyChunksPassingPredicate_AndReturnsCount()
+    {
+        var cfg = new Configuration
+        {
+            RenderDistanceHorizontal = 1,
+            RenderDistanceVertical = 0,
+            MaxGenerateJobsInFlight = 100,
+            MaxMeshUploadsPerFrame = 100,
+        };
+        var (streamer, _, created) = CreateStreamer(cfg);
+        streamer.Tick(new Vector3i(0, 0, 0));   // 9 columns, all chunk Y 0, non-empty meshes
+
+        int drawn = streamer.DrawVisible(
+            pos => pos == new Vector3i(0, 0, 0),  // only the centre chunk "visible"
+            (_, r) => r.Draw());
+
+        Assert.Equal(1, drawn);
+        Assert.Equal(1, created.Sum(r => r.DrawCount));
+    }
 }

World/Streaming/ChunkStreamer.cs

@@ -39,6 +39,7 @@ public sealed class ChunkStreamer : IDisposable
     private Vector3i _spawnAnchor;
 
     public int RendererCount => this._renderers.Count;
+    public int TrackedCount => this._tracked.Count;
     public bool IsReady(Vector3i pos) => this._ready.Contains(pos);
     public bool SpawnReady => this._spawnReady;
 
@@ -88,9 +89,20 @@ public sealed class ChunkStreamer : IDisposable
         this.UpdateSpawnReady();
     }
 
-    public void DrawAll(Action<Vector3i, IChunkRenderer> drawCallback)
+    // Draws every loaded chunk for which `isChunkVisible` returns true. Returns
+    // the number of chunks actually drawn (passed the visibility test). The
+    // visibility predicate lives with the caller so the streamer stays free of
+    // any rendering/Frustum dependency.
+    public int DrawVisible(Func<Vector3i, bool> isChunkVisible, Action<Vector3i, IChunkRenderer> draw)
     {
-        foreach (var kvp in this._renderers) drawCallback(kvp.Key, kvp.Value);
+        int drawn = 0;
+        foreach (var kvp in this._renderers)
+        {
+            if (!isChunkVisible(kvp.Key)) continue;
+            draw(kvp.Key, kvp.Value);
+            drawn++;
+        }
+        return drawn;
     }
 
     public void Dispose()
@@ -258,7 +270,7 @@ public sealed class ChunkStreamer : IDisposable
         }
         // Skip renderer allocation for empty meshes (pure-air chunks above
         // terrain, or chunks whose every face culls). The chunk still counts
-        // as ready — DrawAll's iteration over _renderers naturally no-ops.
+        // as ready — DrawVisible's iteration over _renderers naturally no-ops.
         if (result.Mesh.Length > 0)
         {
             this._renderers[result.Pos] = this._rendererFactory(result.Mesh);