riversong code showcase

Source/Riversong/Game/World/Terrain/GrassLodGameSystem.cs

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+
+namespace DanieleMarotta.RiversongCodeShowcase
+{
+    public class GrassLodGameSystem : GameSystem, IUpdatable
+    {
+        [InjectService]
+        private GameConfig _config;
+
+        [InjectService]
+        private IScene _scene;
+
+        [InjectService]
+        private WorldRenderingState _renderingState;
+
+        public GrassLodGameSystem(IServiceLocator serviceLocator) : base(serviceLocator)
+        {
+        }
+
+        public void Update()
+        {
+            var grassConfig = _config.Terrain.GrassLODs;
+            var cropsConfig = _config.Terrain.CropsLODs;
+
+            foreach (var chunk in _renderingState.TerrainChunks)
+            {
+                SelectLOD(chunk.GrassLODs, grassConfig);
+                SelectLOD(chunk.CropsLODs, cropsConfig);
+            }
+        }
+
+        private void SelectLOD(TerrainChunk.RenderData[] lods, GameConfig.TerrainConfig.GrassLOD[] config)
+        {
+            // We can assume all LODs have almost the same center, so we just use the center of the first one
+            var position = lods[0].Renderer.bounds.center;
+
+            var viewSpacePosition = _scene.CinemachineCamera.transform.InverseTransformPoint(position);
+
+            var selectedLod = int.MaxValue;
+            for (var lod = 0; lod < config.Length; lod++)
+                if (viewSpacePosition.z < config[lod].Threshold)
+                {
+                    selectedLod = lod;
+                    break;
+                }
+
+            for (var lod = 0; lod < lods.Length; lod++) lods[lod].Renderer.enabled = lod == selectedLod;
+        }
+    }
+}