riversong code showcase

Source/Riversong/Game/WorldGen/ChunkGenerators/ChunkMeshGenerator.cs

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+using System.Collections.Generic;
+using Cysharp.Threading.Tasks;
+using Unity.Collections;
+using Unity.Jobs;
+using Unity.Mathematics;
+using UnityEngine;
+
+namespace DanieleMarotta.RiversongCodeShowcase
+{
+    public abstract class ChunkMeshGenerator
+    {
+        private readonly List<ChunkGenerationJobState> _pendingJobs = new();
+
+        private JobHandle _dependency;
+
+        protected ChunkMeshGenerator(World world, GameConfig config)
+        {
+            World = world;
+            Config = config;
+        }
+
+        protected World World { get; }
+
+        protected GameConfig Config { get; }
+
+        public void InitializeChunk(TerrainChunk chunk)
+        {
+            for (var lod = 0; lod < GetLodCount(); lod++) InitializeChunk(chunk, lod);
+        }
+
+        private void InitializeChunk(TerrainChunk chunk, int lod)
+        {
+            var childName = GetGameObjectName(chunk.Root.name, chunk.Coords, lod);
+
+            var child = new GameObject(childName);
+            child.transform.SetParent(chunk.Root.transform);
+
+            var mesh = new Mesh { name = childName };
+            mesh.MarkDynamic();
+
+            var meshFilter = child.AddComponent<MeshFilter>();
+            meshFilter.sharedMesh = mesh;
+
+            var renderer = child.AddComponent<MeshRenderer>();
+
+            InitializeChunk(chunk, lod, child, mesh, renderer);
+        }
+
+        protected abstract int GetLodCount();
+
+        protected abstract string GetGameObjectName(string chunkName, int2 chunkCoords, int lod);
+
+        protected abstract void InitializeChunk(TerrainChunk chunk, int lod, GameObject gameObject, Mesh mesh, Renderer renderer);
+
+        public void BeginGeneratingChunks(List<TerrainChunk> chunks)
+        {
+            var chunkCoords = new NativeArray<int2>(chunks.Count, Allocator.Persistent, NativeArrayOptions.UninitializedMemory);
+            for (var i = 0; i < chunks.Count; i++) chunkCoords[i] = chunks[i].Coords;
+
+            for (var lod = 0; lod < GetLodCount(); lod++)
+            {
+                var jobState = CreateJobState(lod, chunks);
+                _pendingJobs.Add(jobState);
+
+                var jobHandle = ScheduleJob(jobState, chunkCoords);
+                _dependency = JobHandle.CombineDependencies(_dependency, jobHandle);
+            }
+
+            chunkCoords.Dispose(_dependency);
+        }
+
+        private ChunkGenerationJobState CreateJobState(int lod, List<TerrainChunk> chunks)
+        {
+            var jobState = new ChunkGenerationJobState { Lod = lod };
+
+            jobState.Chunks.AddRange(chunks);
+
+            foreach (var chunk in chunks)
+            {
+                var mesh = GetMesh(chunk, lod);
+                jobState.Meshes.Add(mesh);
+            }
+
+            jobState.MeshDataArray = Mesh.AllocateWritableMeshData(jobState.Meshes);
+
+            return jobState;
+        }
+
+        protected abstract Mesh GetMesh(TerrainChunk chunk, int lod);
+
+        protected abstract JobHandle ScheduleJob(ChunkGenerationJobState jobState, NativeArray<int2> chunkCoords);
+
+        public async UniTask Wait()
+        {
+            while (!_dependency.IsCompleted) await UniTask.NextFrame();
+
+            _dependency.Complete();
+            _dependency = default;
+        }
+
+        public void EndGeneratingChunks()
+        {
+            foreach (var jobState in _pendingJobs) OnCompleted(jobState);
+            _pendingJobs.Clear();
+        }
+
+        private void OnCompleted(ChunkGenerationJobState jobState)
+        {
+            Mesh.ApplyAndDisposeWritableMeshData(jobState.MeshDataArray, jobState.Meshes);
+
+            foreach (var mesh in jobState.Meshes)
+            {
+                mesh.RecalculateBounds();
+                mesh.UploadMeshData(false);
+            }
+
+            OnCompleted(jobState.Lod, jobState.Chunks);
+
+            jobState.Clear();
+        }
+
+        protected abstract void OnCompleted(int lod, List<TerrainChunk> chunks);
+    }
+}