Fix torch placement and prevent overwriting blocks

Fixes #50

TrueCraft.Core/Logic/BlockProvider.cs

@@ -6,6 +6,8 @@ using TrueCraft.API.Networking;
 using TrueCraft.Core.Entities;
 using TrueCraft.API.Entities;
 using TrueCraft.API.Server;
+using TrueCraft.Core.Logic.Blocks;
+using System.Linq;
 
 namespace TrueCraft.Core.Logic
 {
@@ -75,7 +77,10 @@ namespace TrueCraft.Core.Logic
 
         protected virtual ItemStack[] GetDrop(BlockDescriptor descriptor) // TODO: Include tools
         {
-            return new[] { new ItemStack(descriptor.ID, 1, descriptor.Metadata) };
+            short meta = 0;
+            if (this is ICraftingRecipe)
+                meta = (short)((this as ICraftingRecipe).SignificantMetadata ? descriptor.Metadata : 0);
+            return new[] { new ItemStack(descriptor.ID, 1, meta) };
         }
 
         public virtual void ItemUsedOnEntity(ItemStack item, IEntity usedOn, IWorld world, IRemoteClient user)
@@ -91,11 +96,30 @@ namespace TrueCraft.Core.Logic
         public virtual void ItemUsedOnBlock(Coordinates3D coordinates, ItemStack item, BlockFace face, IWorld world, IRemoteClient user)
         {
             coordinates += MathHelper.BlockFaceToCoordinates(face);
+            var old = world.GetBlockData(coordinates);
+            byte[] overwritable =
+                {
+                AirBlock.BlockID,
+                WaterBlock.BlockID,
+                StationaryWaterBlock.BlockID,
+                LavaBlock.BlockID,
+                StationaryLavaBlock.BlockID
+            };
+            if (overwritable.Any(b => b == old.ID))
+            {
                 world.SetBlockID(coordinates, (byte)item.ID);
                 world.SetMetadata(coordinates, (byte)item.Metadata);
+
+                BlockPlaced(world.GetBlockData(coordinates), face, world, user);
+
+                if (!IsSupported(world.GetBlockData(coordinates), user.Server, world))
+                    world.SetBlockData(coordinates, old);
+                else
+                {
                     item.Count--;
                     user.Inventory[user.SelectedSlot] = item;
-            BlockPlaced(world.GetBlockData(coordinates), face, world, user);
+                }
+            }
         }
 
         short IItemProvider.ID

TrueCraft.Core/Logic/Blocks/TorchBlock.cs

@@ -11,10 +11,10 @@ namespace TrueCraft.Core.Logic.Blocks
     {
         public enum TorchDirection
         {
-            South = 0x01, // Positive Z
+            West = 0x01, // West
-            North = 0x02,
+            East = 0x02, // East
-            West = 0x03,
+            South = 0x03, // South
-            East = 0x04,
+            North = 0x04, // North
             Ground = 0x05
         }
 
@@ -34,28 +34,59 @@ namespace TrueCraft.Core.Logic.Blocks
 
         public override void BlockPlaced(BlockDescriptor descriptor, BlockFace face, IWorld world, IRemoteClient user)
         {
+            TorchDirection[] preferredDirections =
+            {
+                TorchDirection.West, TorchDirection.East,
+                TorchDirection.North, TorchDirection.South,
+                TorchDirection.Ground
+            };
             TorchDirection direction;
             switch (face)
             {
                 case BlockFace.PositiveZ:
-                    direction = TorchDirection.West;
-                    break;
-                case BlockFace.NegativeZ:
-                    direction = TorchDirection.East;
-                    break;
-                case BlockFace.PositiveX:
                     direction = TorchDirection.South;
                     break;
-                case BlockFace.NegativeX:
+                case BlockFace.NegativeZ:
                     direction = TorchDirection.North;
                     break;
+                case BlockFace.PositiveX:
+                    direction = TorchDirection.East;
+                    break;
+                case BlockFace.NegativeX:
+                    direction = TorchDirection.West;
+                    break;
                 default:
                     direction = TorchDirection.Ground;
                     break;
             }
+            int i = 0;
+            descriptor.Metadata = (byte)direction;
+            while (!IsSupported(descriptor, user.Server, world) && i < preferredDirections.Length)
+            {
+                direction = preferredDirections[i++];
+                descriptor.Metadata = (byte)direction;
+            }
             world.SetMetadata(descriptor.Coordinates, (byte)direction);
         }
 
+        public override Coordinates3D GetSupportDirection(BlockDescriptor descriptor)
+        {
+            switch ((TorchDirection)descriptor.Metadata)
+            {
+                case TorchDirection.Ground:
+                    return Coordinates3D.Down;
+                case TorchDirection.East:
+                    return Coordinates3D.West;
+                case TorchDirection.West:
+                    return Coordinates3D.East;
+                case TorchDirection.North:
+                    return Coordinates3D.South;
+                case TorchDirection.South:
+                    return Coordinates3D.North;
+            }
+            return Coordinates3D.Zero;
+        }
+
         public override Tuple<int, int> GetTextureMap(byte metadata)
         {
             return new Tuple<int, int>(0, 5);

TrueCraft.Core/World/Chunk.cs

@@ -229,9 +229,11 @@ namespace TrueCraft.Core.World
 
         public NbtTag Serialize(string tagName)
         {
-            var chunk = (NbtCompound)Serializer.Serialize(this, tagName, true);
+            var chunk = new NbtCompound(tagName);
             var entities = new NbtList("Entities", NbtTagType.Compound);
             chunk.Add(entities);
+            chunk.Add(new NbtInt("X", X));
+            chunk.Add(new NbtInt("Z", Z));
             chunk.Add(new NbtByteArray("Blocks", Blocks));
             chunk.Add(new NbtByteArray("Data", Metadata.Data));
             chunk.Add(new NbtByteArray("SkyLight", SkyLight.Data));
@@ -257,7 +259,7 @@ namespace TrueCraft.Core.World
 
         public void Deserialize(NbtTag value)
         {
-            var chunk = (Chunk)Serializer.Deserialize(value, true);
+            var chunk = new Chunk();
             var tag = (NbtCompound)value;
 
             Biomes = chunk.Biomes;