feat: ChunkStreamer load path with target-set, dispatch, and diff application

VoxelEngine.Tests/Streaming/ChunkStreamerTests.cs

@@ -0,0 +1,173 @@
+using OpenTK.Mathematics;
+using VoxelEngine.Core;
+using VoxelEngine.World;
+using VoxelEngine.World.Blocks;
+using VoxelEngine.World.Chunk;
+using VoxelEngine.World.Persistence;
+using VoxelEngine.World.Streaming;
+using Xunit;
+using VoxelChunk = VoxelEngine.World.Chunk.Chunk;
+
+namespace VoxelEngine.Tests.Streaming;
+
+// Synchronous executor: runs the submitted action on the calling thread.
+internal sealed class SynchronousJobExecutor : IJobExecutor
+{
+    public void Submit(Action work) => work();
+}
+
+// Fake renderer: never touches GL. Just records lifecycle.
+internal sealed class FakeRenderer : IChunkRenderer
+{
+    public bool Disposed { get; private set; }
+    public int DrawCount { get; private set; }
+    public float[] Mesh { get; }
+
+    public FakeRenderer(float[] mesh) { this.Mesh = mesh; }
+    public void Draw() => this.DrawCount++;
+    public void Dispose() => this.Disposed = true;
+}
+
+// Minimal mesher returning a fixed-length non-empty mesh.
+internal sealed class FakeMesher : IChunkMesher
+{
+    public float[] Build(VoxelChunk chunk, BlockRegistry registry, Func<int, int, int, bool>? neighborOpaqueOutside = null)
+        => new float[6]; // one vertex worth
+}
+
+public class ChunkStreamerTests
+{
+    private static (ChunkStreamer streamer, World.World world, List<FakeRenderer> created) CreateStreamer(Configuration cfg)
+    {
+        var registry = new BlockRegistry();
+        var store = new InMemoryChunkModificationStore();
+        var world = new World.World(registry, store);
+        var mesher = new FakeMesher();
+        var executor = new SynchronousJobExecutor();
+        var created = new List<FakeRenderer>();
+        Func<float[], IChunkRenderer> factory = m =>
+        {
+            var r = new FakeRenderer(m);
+            created.Add(r);
+            return r;
+        };
+        Func<Vector3i, VoxelChunk> generate = _ => new VoxelChunk();
+        var streamer = new ChunkStreamer(cfg, world, generate, mesher, registry, executor, factory);
+        return (streamer, world, created);
+    }
+
+    [Fact]
+    public void Tick_FirstCall_LoadsAllChunksInLoadBox()
+    {
+        var cfg = new Configuration
+        {
+            RenderDistanceHorizontal = 1,
+            RenderDistanceVertical = 0,
+            MaxGenerateJobsInFlight = 100,
+            MaxMeshUploadsPerFrame = 100,
+        };
+        var (streamer, world, created) = CreateStreamer(cfg);
+
+        streamer.Tick(new Vector3i(0, 0, 0));
+
+        // Load box H=1, V=0 → 3 × 1 × 3 = 9 chunks
+        Assert.Equal(9, created.Count);
+        for (int x = -1; x <= 1; x++)
+        for (int z = -1; z <= 1; z++)
+        {
+            var pos = new Vector3i(x, 0, z);
+            Assert.NotNull(world.GetChunk(pos));
+            Assert.True(streamer.IsReady(pos));
+        }
+    }
+
+    [Fact]
+    public void Tick_PlayerMoves_LoadsNewChunksOnly()
+    {
+        var cfg = new Configuration
+        {
+            RenderDistanceHorizontal = 1,
+            RenderDistanceVertical = 0,
+            MaxGenerateJobsInFlight = 100,
+            MaxMeshUploadsPerFrame = 100,
+        };
+        var (streamer, world, created) = CreateStreamer(cfg);
+
+        streamer.Tick(new Vector3i(0, 0, 0));     // loads 9
+        int firstWave = created.Count;
+        streamer.Tick(new Vector3i(1, 0, 0));     // loads only the 3 new column to +x
+
+        Assert.Equal(firstWave + 3, created.Count);
+    }
+
+    [Fact]
+    public void Tick_RespectsMaxMeshUploadsPerFrame()
+    {
+        var cfg = new Configuration
+        {
+            RenderDistanceHorizontal = 1,
+            RenderDistanceVertical = 0,
+            MaxGenerateJobsInFlight = 100,
+            MaxMeshUploadsPerFrame = 2,   // cap drains per tick
+        };
+        var (streamer, _, created) = CreateStreamer(cfg);
+
+        // With sync executor every submitted job completes immediately and
+        // posts into _completed. The cap throttles how many drain per Tick().
+        streamer.Tick(new Vector3i(0, 0, 0));   // dispatch fills the queue; drain ≤ 2
+        Assert.Equal(2, created.Count);
+
+        streamer.Tick(new Vector3i(0, 0, 0));   // same player chunk, drains 2 more
+        Assert.Equal(4, created.Count);
+    }
+
+    [Fact]
+    public void Tick_ClampsYToWorldBounds()
+    {
+        var cfg = new Configuration
+        {
+            RenderDistanceHorizontal = 0,
+            RenderDistanceVertical = 2,
+            MaxGenerateJobsInFlight = 100,
+            MaxMeshUploadsPerFrame = 100,
+        };
+        var (streamer, world, created) = CreateStreamer(cfg);
+
+        // 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)));
+        Assert.NotNull(world.GetChunk(new Vector3i(0, 1, 0)));
+        Assert.NotNull(world.GetChunk(new Vector3i(0, 2, 0)));
+    }
+
+    [Fact]
+    public void Tick_AppliesModificationDiffOnLoad()
+    {
+        var cfg = new Configuration
+        {
+            RenderDistanceHorizontal = 0,
+            RenderDistanceVertical = 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();  // all air
+
+        // Pre-record an edit before the chunk loads.
+        var pos = new Vector3i(0, 0, 0);
+        int localIndex = (5 * VoxelChunk.Size + 6) * VoxelChunk.Size + 7;
+        store.RecordEdit(pos, localIndex, registry.Stone.Id);
+
+        var streamer = new ChunkStreamer(cfg, world, generate, mesher, registry, executor, factory);
+        streamer.Tick(pos);
+
+        Assert.Equal(registry.Stone.Id, world.GetBlock(5, 6, 7).Id);
+    }
+}