riversong code showcase

Source/Riversong/Game/EditTools/BuildTool/BuildToolValidator.cs

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+using System.Collections.Generic;
+using Unity.Mathematics;
+
+namespace DanieleMarotta.RiversongCodeShowcase
+{
+    public class BuildToolValidator
+    {
+        private readonly World _world;
+
+        private readonly int _baseElevation;
+
+        public BuildToolValidator(World world, int baseElevation)
+        {
+            _world = world;
+            _baseElevation = baseElevation;
+        }
+
+        public bool ValidatePlacement(List<int2> affectedTiles)
+        {
+            foreach (var tile in affectedTiles)
+            {
+                if (_world.Heightmap.GetValue(tile) != _baseElevation) return false;
+
+                if (_world.BlockMap.IsBlocked(tile)) return false;
+            }
+
+            return true;
+        }
+    }
+}