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

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);