riversong code showcase

Source/Riversong/Game/EditTools/Validation/EditToolValidatorSystem.cs

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+using Unity.Mathematics;
+
+namespace DanieleMarotta.RiversongCodeShowcase
+{
+    [Service(typeof(IEditToolValidatorService))]
+    public class EditToolValidatorSystem : GameSystem, IEditToolValidatorService
+    {
+        [InjectService]
+        private GameConfig _config;
+
+        [InjectService]
+        private World _world;
+
+        public EditToolValidatorSystem(IServiceLocator serviceLocator) : base(serviceLocator)
+        {
+        }
+
+        public EditToolValidationResult DoCommonValidation(TileRect rect, BlockReason blockReason)
+        {
+            foreach (var tile in TileRange.From(rect))
+                if (!DoCommonTileValidation(tile, blockReason))
+                    return EditToolValidationResult.BlockedTile;
+
+            return EditToolValidationResult.Success;
+        }
+
+        private bool DoCommonTileValidation(int2 tile, BlockReason blockReason)
+        {
+            return _world.Contains(tile) && !_world.BlockMap.IsBlocked(tile, blockReason);
+        }
+
+        public EditToolValidationResult ValidateBuildingPlacementRules(TileRect rect, BuildingDefinition buildingDefinition)
+        {
+            if (buildingDefinition.NearWater)
+            {
+                var waterMap = _world.WaterMap;
+                foreach (var tile in TileRange.From(rect))
+                    if (!waterMap.IsNearWater(tile))
+                        return EditToolValidationResult.CanOnlyBePlacedNearWater;
+            }
+
+            if (buildingDefinition.RequiresFertileTile)
+            {
+                foreach (var tile in TileRange.From(rect))
+                {
+                    var fertility = _world.Fertility.GetValue(tile);
+                    if (fertility.MaxFertility > 0) return EditToolValidationResult.Success;
+                }
+
+                return EditToolValidationResult.CanOnlyBePlacedOnFertileGround;
+            }
+
+            return EditToolValidationResult.Success;
+        }
+    }
+}