Construction System. (#87)

* Construction WiP

* Construction kinda works!

* Lots more construction work.

* It mostly works!

Content.Client/Construction/ConstructionButton.cs

@@ -0,0 +1,56 @@
+using Content.Client.GameObjects.Components.Construction;
+using SS14.Client.UserInterface;
+using SS14.Client.UserInterface.Controls;
+using SS14.Shared.Utility;
+
+namespace Content.Client.Construction
+{
+    public class ConstructionButton : Button
+    {
+        protected override ResourcePath ScenePath => new ResourcePath("/Scenes/Construction/ConstructionButton.tscn");
+
+        public ConstructorComponent Owner
+        {
+            get => Menu.Owner;
+            set => Menu.Owner = value;
+        }
+        ConstructionMenu Menu;
+
+        protected override void Initialize()
+        {
+            base.Initialize();
+
+            OnPressed += IWasPressed;
+            Menu = new ConstructionMenu();
+            Menu.AddToScreen();
+        }
+
+        void IWasPressed(ButtonEventArgs args)
+        {
+            Menu.Open();
+        }
+
+        public void AddToScreen()
+        {
+            UserInterfaceManager.StateRoot.AddChild(this);
+        }
+
+        public void RemoveFromScreen()
+        {
+            if (Parent != null)
+            {
+                Parent.RemoveChild(this);
+            }
+        }
+
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing)
+            {
+                Menu.Dispose();
+            }
+
+            base.Dispose(disposing);
+        }
+    }
+}

Content.Client/Construction/ConstructionMenu.cs

@@ -0,0 +1,344 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Content.Client.GameObjects.Components.Construction;
+using Content.Shared.Construction;
+using SS14.Client.GameObjects;
+using SS14.Client.Graphics;
+using SS14.Client.Interfaces.GameObjects;
+using SS14.Client.Interfaces.Placement;
+using SS14.Client.Interfaces.ResourceManagement;
+using SS14.Client.Placement;
+using SS14.Client.ResourceManagement;
+using SS14.Client.UserInterface;
+using SS14.Client.UserInterface.Controls;
+using SS14.Client.UserInterface.CustomControls;
+using SS14.Client.Utility;
+using SS14.Shared.Enums;
+using SS14.Shared.Interfaces.GameObjects.Components;
+using SS14.Shared.IoC;
+using SS14.Shared.Log;
+using SS14.Shared.Maths;
+using SS14.Shared.Prototypes;
+using SS14.Shared.Utility;
+
+namespace Content.Client.Construction
+{
+    public class ConstructionMenu : SS14Window
+    {
+        protected override ResourcePath ScenePath => new ResourcePath("/Scenes/Construction/ConstructionMenu.tscn");
+
+#pragma warning disable CS0649
+        [Dependency]
+        readonly IPrototypeManager PrototypeManager;
+        [Dependency]
+        readonly IResourceCache ResourceCache;
+#pragma warning restore
+
+        public ConstructorComponent Owner { get; set; }
+        Button BuildButton;
+        Button EraseButton;
+        LineEdit SearchBar;
+        Tree RecipeList;
+        TextureRect InfoIcon;
+        Label InfoLabel;
+        ItemList StepList;
+
+        CategoryNode RootCategory;
+        // This list is flattened in such a way that the top most deepest category is first.
+        List<CategoryNode> FlattenedCategories;
+        PlacementManager Placement;
+
+        protected override void Initialize()
+        {
+            base.Initialize();
+            IoCManager.InjectDependencies(this);
+            Placement = (PlacementManager)IoCManager.Resolve<IPlacementManager>();
+            Placement.PlacementCanceled += OnPlacementCanceled;
+
+            HideOnClose = true;
+            Title = "Construction";
+            Visible = false;
+            var split = Contents.GetChild("HSplitContainer");
+            var rightSide = split.GetChild("Guide");
+            var info = rightSide.GetChild("Info");
+            InfoIcon = info.GetChild<TextureRect>("TextureRect");
+            InfoLabel = info.GetChild<Label>("Label");
+            StepList = rightSide.GetChild<ItemList>("StepsList");
+            var buttons = rightSide.GetChild("Buttons");
+            BuildButton = buttons.GetChild<Button>("BuildButton");
+            BuildButton.OnPressed += OnBuildPressed;
+            EraseButton = buttons.GetChild<Button>("EraseButton");
+            EraseButton.OnToggled += OnEraseToggled;
+
+            var leftSide = split.GetChild("Recipes");
+            SearchBar = leftSide.GetChild<LineEdit>("Search");
+            SearchBar.OnTextChanged += OnTextEntered;
+            RecipeList = leftSide.GetChild<Tree>("Tree");
+            RecipeList.OnItemSelected += OnItemSelected;
+
+            PopulatePrototypeList();
+            PopulateTree();
+        }
+
+        protected override void Dispose(bool disposing)
+        {
+            base.Dispose(disposing);
+
+            if (disposing)
+            {
+                Placement.PlacementCanceled -= OnPlacementCanceled;
+            }
+        }
+
+        void OnItemSelected()
+        {
+            var prototype = (ConstructionPrototype)RecipeList.Selected.Metadata;
+
+            if (prototype == null)
+            {
+                InfoLabel.Text = "";
+                InfoIcon.Texture = null;
+                StepList.Clear();
+                BuildButton.Disabled = true;
+            }
+            else
+            {
+                BuildButton.Disabled = false;
+                InfoLabel.Text = prototype.Description;
+                InfoIcon.Texture = prototype.Icon.Frame0();
+
+                StepList.Clear();
+
+                foreach (var forward in prototype.Stages.Select(a => a.Forward))
+                {
+                    if (forward == null)
+                    {
+                        continue;
+                    }
+                    Texture icon;
+                    string text;
+                    switch (forward)
+                    {
+                        case ConstructionStepMaterial mat:
+                            switch (mat.Material)
+                            {
+                                case ConstructionStepMaterial.MaterialType.Metal:
+                                    icon = ResourceCache.GetResource<TextureResource>("/Textures/Objects/sheet_metal.png");
+                                    text = $"Metal x{mat.Amount}";
+                                    break;
+                                case ConstructionStepMaterial.MaterialType.Glass:
+                                    icon = ResourceCache.GetResource<TextureResource>("/Textures/Objects/sheet_glass.png");
+                                    text = $"Glass x{mat.Amount}";
+                                    break;
+                                case ConstructionStepMaterial.MaterialType.Cable:
+                                    icon = ResourceCache.GetResource<TextureResource>("/Textures/Objects/cable_coil.png");
+                                    text = $"Cable Coil x{mat.Amount}";
+                                    break;
+                                default:
+                                    throw new NotImplementedException();
+                            }
+                            break;
+                        case ConstructionStepTool tool:
+                            switch (tool.Tool)
+                            {
+                                case ConstructionStepTool.ToolType.Wrench:
+                                    icon = ResourceCache.GetResource<TextureResource>("/Textures/Objects/wrench.png");
+                                    text = "Wrench";
+                                    break;
+                                case ConstructionStepTool.ToolType.Crowbar:
+                                    icon = ResourceCache.GetResource<TextureResource>("/Textures/Objects/crowbar.png");
+                                    text = "Crowbar";
+                                    break;
+                                case ConstructionStepTool.ToolType.Screwdriver:
+                                    icon = ResourceCache.GetResource<TextureResource>("/Textures/Objects/screwdriver.png");
+                                    text = "Screwdriver";
+                                    break;
+                                case ConstructionStepTool.ToolType.Welder:
+                                    icon = ResourceCache.GetResource<RSIResource>("/Textures/Objects/tools.rsi").RSI["welder"].Frame0;
+                                    text = $"Welding tool ({tool.Amount} fuel)";
+                                    break;
+                                case ConstructionStepTool.ToolType.Wirecutters:
+                                    icon = ResourceCache.GetResource<TextureResource>("/Textures/Objects/wirecutter.png");
+                                    text = "Wirecutters";
+                                    break;
+                                default:
+                                    throw new NotImplementedException();
+                            }
+                            break;
+                        default:
+                            throw new NotImplementedException();
+                    }
+
+                    StepList.AddItem(text, icon, false);
+                }
+            }
+        }
+
+        void OnTextEntered(LineEdit.LineEditEventArgs args)
+        {
+            var str = args.Text;
+            PopulateTree(string.IsNullOrWhiteSpace(str) ? null : str.ToLowerInvariant());
+        }
+
+        void OnBuildPressed(Button.ButtonEventArgs args)
+        {
+            var prototype = (ConstructionPrototype)RecipeList.Selected.Metadata;
+            if (prototype == null)
+            {
+                return;
+            }
+
+            if (prototype.Type != ConstructionType.Structure)
+            {
+                // In-hand attackby doesn't exist so this is the best alternative.
+                var loc = Owner.Owner.GetComponent<ITransformComponent>().LocalPosition;
+                Owner.SpawnGhost(prototype, loc, Direction.North);
+                return;
+            }
+
+            var hijack = new ConstructionPlacementHijack(prototype, Owner);
+            var info = new PlacementInformation
+            {
+                IsTile = false,
+                PlacementOption = prototype.PlacementMode,
+            };
+
+
+            Placement.BeginHijackedPlacing(info, hijack);
+        }
+
+        private void OnEraseToggled(BaseButton.ButtonToggledEventArgs args)
+        {
+            var hijack = new ConstructionPlacementHijack(null, Owner);
+            Placement.ToggleEraserHijacked(hijack);
+        }
+
+        void PopulatePrototypeList()
+        {
+            RootCategory = new CategoryNode("", null);
+            int count = 1;
+
+            foreach (var prototype in PrototypeManager.EnumeratePrototypes<ConstructionPrototype>())
+            {
+                var currentNode = RootCategory;
+
+                foreach (var category in prototype.CategorySegments)
+                {
+                    if (!currentNode.ChildCategories.TryGetValue(category, out var subNode))
+                    {
+                        count++;
+                        subNode = new CategoryNode(category, currentNode);
+                        currentNode.ChildCategories.Add(category, subNode);
+                    }
+                    currentNode = subNode;
+                }
+
+                currentNode.Prototypes.Add(prototype);
+            }
+
+            // Do a pass to sort the prototype lists and flatten the hierarchy.
+            void Recurse(CategoryNode node)
+            {
+                // I give up we're using recursion to flatten this.
+                // There probably IS a way to do it.
+                // I'm too stupid to think of what that way is.
+                foreach (var child in node.ChildCategories.Values)
+                {
+                    Recurse(child);
+                }
+
+                node.Prototypes.Sort(ComparePrototype);
+                FlattenedCategories.Add(node);
+                node.FlattenedIndex = FlattenedCategories.Count - 1;
+            }
+
+            FlattenedCategories = new List<CategoryNode>(count);
+            Recurse(RootCategory);
+        }
+
+        void PopulateTree(string searchTerm = null)
+        {
+            RecipeList.Clear();
+
+            var categoryItems = new Tree.Item[FlattenedCategories.Count];
+            categoryItems[RootCategory.FlattenedIndex] = RecipeList.CreateItem();
+
+            // Yay more recursion.
+            Tree.Item ItemForNode(CategoryNode node)
+            {
+                if (categoryItems[node.FlattenedIndex] != null)
+                {
+                    return categoryItems[node.FlattenedIndex];
+                }
+
+                var item = RecipeList.CreateItem(ItemForNode(node.Parent));
+                item.SetText(0, node.Name);
+                item.SetSelectable(0, false);
+                categoryItems[node.FlattenedIndex] = item;
+                return item;
+            }
+
+            foreach (var node in FlattenedCategories)
+            {
+                foreach (var prototype in node.Prototypes)
+                {
+                    if (searchTerm != null)
+                    {
+                        var found = false;
+                        // TODO: don't run ToLowerInvariant() constantly.
+                        if (prototype.Name.ToLowerInvariant().IndexOf(searchTerm) != -1)
+                        {
+                            found = true;
+                        }
+                        else
+                        {
+                            foreach (var keyw in prototype.Keywords.Concat(prototype.CategorySegments))
+                            {
+                                // TODO: don't run ToLowerInvariant() constantly.
+                                if (keyw.ToLowerInvariant().IndexOf(searchTerm) != -1)
+                                {
+                                    found = true;
+                                    break;
+                                }
+                            }
+                        }
+
+                        if (!found)
+                        {
+                            continue;
+                        }
+                    }
+                    var subItem = RecipeList.CreateItem(ItemForNode(node));
+                    subItem.SetText(0, prototype.Name);
+                    subItem.Metadata = prototype;
+                }
+            }
+        }
+
+        private void OnPlacementCanceled(object sender, EventArgs e)
+        {
+            EraseButton.Pressed = false;
+        }
+
+        private static int ComparePrototype(ConstructionPrototype x, ConstructionPrototype y)
+        {
+            return x.Name.CompareTo(y.Name);
+        }
+
+        class CategoryNode
+        {
+            public readonly string Name;
+            public readonly CategoryNode Parent;
+            public SortedDictionary<string, CategoryNode> ChildCategories = new SortedDictionary<string, CategoryNode>();
+            public List<ConstructionPrototype> Prototypes = new List<ConstructionPrototype>();
+            public int FlattenedIndex = -1;
+
+            public CategoryNode(string name, CategoryNode parent)
+            {
+                Name = name;
+                Parent = parent;
+            }
+        }
+    }
+}

Content.Client/Construction/ConstructionPlacementHijack.cs

@@ -0,0 +1,62 @@
+using Content.Client.GameObjects.Components.Construction;
+using Content.Shared.Construction;
+using SS14.Client.Graphics;
+using SS14.Client.Interfaces.ResourceManagement;
+using SS14.Client.Placement;
+using SS14.Client.ResourceManagement;
+using SS14.Client.Utility;
+using SS14.Shared.Interfaces.GameObjects;
+using SS14.Shared.IoC;
+using SS14.Shared.Map;
+using SS14.Shared.Maths;
+
+namespace Content.Client.Construction
+{
+    public class ConstructionPlacementHijack : PlacementHijack
+    {
+        private readonly ConstructionPrototype Prototype;
+        private readonly ConstructorComponent Owner;
+
+        public ConstructionPlacementHijack(ConstructionPrototype prototype, ConstructorComponent owner)
+        {
+            Prototype = prototype;
+            Owner = owner;
+        }
+
+        public override bool HijackPlacementRequest(GridLocalCoordinates coords)
+        {
+            if (Prototype != null)
+            {
+                // Stupid god damn Y AXIS.
+                var dir = Manager.Direction;
+                if (dir == Direction.South)
+                {
+                    dir = Direction.North;
+                }
+                else if (dir == Direction.North)
+                {
+                    dir = Direction.South;
+                }
+                Owner.SpawnGhost(Prototype, coords, dir);
+            }
+            return true;
+        }
+
+        public override bool HijackDeletion(IEntity entity)
+        {
+            if (entity.TryGetComponent(out ConstructionGhostComponent ghost))
+            {
+                Owner.ClearGhost(ghost.GhostID);
+            }
+            return true;
+        }
+
+        public override void StartHijack(PlacementManager manager)
+        {
+            base.StartHijack(manager);
+
+            var res = IoCManager.Resolve<IResourceCache>();
+            manager.CurrentBaseSprite = Prototype.Icon.DirFrame0();
+        }
+    }
+}

Content.Client/Content.Client.csproj

@@ -63,6 +63,9 @@
     <Reference Include="YamlDotNet, Version=4.3.1.0, Culture=neutral, processorArchitecture=MSIL">
       <HintPath>$(SolutionDir)packages\YamlDotNet.4.3.1\lib\net45\YamlDotNet.dll</HintPath>
     </Reference>
+    <Reference Include="System.ValueTuple">
+      <HintPath>$(SolutionDir)packages\System.ValueTuple.4.4.0\lib\netstandard1.0\System.ValueTuple.dll</HintPath>
+    </Reference>
   </ItemGroup>
   <ItemGroup>
     <Compile Include="EntryPoint.cs" />
@@ -107,5 +110,10 @@
     <None Include="packages.config" />
     <Compile Include="GameObjects\Components\Power\SmesVisualizer2D.cs" />
     <Compile Include="GameObjects\Components\Power\ApcVisualizer2D.cs" />
+    <Compile Include="Construction\ConstructionMenu.cs" />
+    <Compile Include="Construction\ConstructionButton.cs" />
+    <Compile Include="GameObjects\Components\Construction\ConstructorComponent.cs" />
+    <Compile Include="GameObjects\Components\Construction\ConstructionGhostComponent.cs" />
+    <Compile Include="Construction\ConstructionPlacementHijack.cs" />
   </ItemGroup>
 </Project>

Content.Client/EntryPoint.cs

@@ -1,10 +1,12 @@
 using Content.Client.GameObjects;
+using Content.Client.GameObjects.Components.Construction;
 using Content.Client.GameObjects.Components.Power;
 using Content.Client.GameObjects.Components.Storage;
 using Content.Client.Interfaces.GameObjects;
 using SS14.Shared.ContentPack;
 using SS14.Shared.Interfaces.GameObjects;
 using SS14.Shared.IoC;
+using SS14.Shared.Prototypes;
 
 namespace Content.Client
 {
@@ -13,6 +15,7 @@ namespace Content.Client
         public override void Init()
         {
             var factory = IoCManager.Resolve<IComponentFactory>();
+            var prototypes = IoCManager.Resolve<IPrototypeManager>();
 
             factory.RegisterIgnore("Item");
             factory.RegisterIgnore("Interactable");
@@ -40,11 +43,18 @@ namespace Content.Client
             factory.RegisterIgnore("Storeable");
             factory.RegisterIgnore("Clothing");
 
+            factory.RegisterIgnore("Material");
+            factory.RegisterIgnore("Stack");
+
             factory.Register<HandsComponent>();
             factory.RegisterReference<HandsComponent, IHandsComponent>();
             factory.Register<ClientStorageComponent>();
             factory.Register<ClientInventoryComponent>();
             factory.Register<PowerDebugTool>();
+            factory.Register<ConstructorComponent>();
+            factory.Register<ConstructionGhostComponent>();
+
+            prototypes.RegisterIgnore("material");
         }
     }
 }

Content.Client/GameObjects/Components/Construction/ConstructionGhostComponent.cs

@@ -0,0 +1,28 @@
+using Content.Shared.Construction;
+using SS14.Shared.GameObjects;
+using SS14.Shared.Interfaces.GameObjects;
+using SS14.Shared.Interfaces.Network;
+
+namespace Content.Client.GameObjects.Components.Construction
+{
+    public class ConstructionGhostComponent : Component
+    {
+        public override string Name => "ConstructionGhost";
+
+        public ConstructionPrototype Prototype { get; set; }
+        public ConstructorComponent Master { get; set; }
+        public int GhostID { get; set; }
+
+        public override void HandleMessage(ComponentMessage message, INetChannel netChannel = null, IComponent component = null)
+        {
+            base.HandleMessage(message, netChannel, component);
+
+            switch (message)
+            {
+                case ClientEntityClickMsg clickMsg:
+                    Master.TryStartConstruction(GhostID);
+                    break;
+            }
+        }
+    }
+}

Content.Client/GameObjects/Components/Construction/ConstructorComponent.cs

@@ -0,0 +1,96 @@
+using System.Collections.Generic;
+using Content.Client.Construction;
+using Content.Shared.Construction;
+using Content.Shared.GameObjects.Components.Construction;
+using SS14.Client.GameObjects;
+using SS14.Client.Interfaces.GameObjects;
+using SS14.Shared.GameObjects;
+using SS14.Shared.Interfaces.GameObjects;
+using SS14.Shared.Interfaces.GameObjects.Components;
+using SS14.Shared.Interfaces.Network;
+using SS14.Shared.IoC;
+using SS14.Shared.Log;
+using SS14.Shared.Map;
+using SS14.Shared.Maths;
+
+namespace Content.Client.GameObjects.Components.Construction
+{
+    public class ConstructorComponent : SharedConstructorComponent
+    {
+        int nextId;
+        readonly Dictionary<int, ConstructionGhostComponent> Ghosts = new Dictionary<int, ConstructionGhostComponent>();
+        ConstructionButton Button;
+
+        ITransformComponent Transform;
+
+        public override void Initialize()
+        {
+            base.Initialize();
+
+            Transform = Owner.GetComponent<ITransformComponent>();
+        }
+
+        public override void HandleMessage(ComponentMessage message, INetChannel netChannel = null, IComponent component = null)
+        {
+            base.HandleMessage(message, netChannel, component);
+
+            switch (message)
+            {
+                case PlayerAttachedMsg _:
+                    if (Button == null)
+                    {
+                        Button = new ConstructionButton();
+                        Button.Owner = this;
+                    }
+                    Button.AddToScreen();
+                    break;
+
+                case PlayerDetachedMsg _:
+                    Button.RemoveFromScreen();
+                    break;
+
+                case AckStructureConstructionMessage ackMsg:
+                    ClearGhost(ackMsg.Ack);
+                    break;
+            }
+        }
+
+        public override void OnRemove()
+        {
+            Button?.Dispose();
+        }
+
+        public void SpawnGhost(ConstructionPrototype prototype, GridLocalCoordinates loc, Direction dir)
+        {
+            var entMgr = IoCManager.Resolve<IClientEntityManager>();
+            var ghost = entMgr.ForceSpawnEntityAt("constructionghost", loc);
+            var comp = ghost.GetComponent<ConstructionGhostComponent>();
+            comp.Prototype = prototype;
+            comp.Master = this;
+            comp.GhostID = nextId++;
+            var transform = ghost.GetComponent<ITransformComponent>().LocalRotation = dir.ToAngle();
+            var sprite = ghost.GetComponent<SpriteComponent>();
+            sprite.LayerSetSprite(0, prototype.Icon);
+            sprite.LayerSetShader(0, "unshaded");
+
+            Ghosts.Add(comp.GhostID, comp);
+        }
+
+        public void TryStartConstruction(int ghostId)
+        {
+            var ghost = Ghosts[ghostId];
+            var transform = ghost.Owner.GetComponent<ITransformComponent>();
+            var msg = new TryStartStructureConstructionMessage(transform.LocalPosition, ghost.Prototype.ID, transform.LocalRotation, ghostId);
+            SendNetworkMessage(msg);
+        }
+
+        public void ClearGhost(int ghostId)
+        {
+            if (Ghosts.TryGetValue(ghostId, out var ghost))
+            {
+                ghost.Owner.Delete();
+                Ghosts.Remove(ghostId);
+            }
+        }
+    }
+}

Content.Client/GameObjects/Components/Items/ClientHandsComponent.cs

@@ -60,7 +60,7 @@ namespace Content.Client.GameObjects
 
         public void UseActiveHand()
         {
-            if(GetEntity(ActiveIndex) != null)
+            if (GetEntity(ActiveIndex) != null)
             {
                 SendNetworkMessage(new ActivateInhandMsg());
             }

Content.Client/packages.config

@@ -2,4 +2,4 @@
 <packages>
   <package id="System.ValueTuple" version="4.4.0" targetFramework="net451" />
   <package id="YamlDotNet" version="4.3.1" targetFramework="net451" />
-</packages>
+</packages>

Content.Server/AI/AimShootLifeProcessor.cs

@@ -25,7 +25,7 @@ namespace Content.Server.AI
 
         private readonly List<IEntity> _workList = new List<IEntity>();
 
-        private const float MaxAngSpeed = (float) (Math.PI / 2); // how fast our turret can rotate
+        private const float MaxAngSpeed = (float)(Math.PI / 2); // how fast our turret can rotate
         private const float ScanPeriod = 1.0f; // tweak this for performance and gameplay experience
         private float _lastScan;
 
@@ -56,7 +56,7 @@ namespace Content.Server.AI
             var curTime = _timeMan.CurTime.TotalSeconds;
             if (curTime - _lastScan > ScanPeriod)
             {
-                _lastScan = (float) curTime;
+                _lastScan = (float)curTime;
                 _curTarget = FindBestTarget();
             }
         }
@@ -72,9 +72,10 @@ namespace Content.Server.AI
 
             // point me at the target
             var tarPos = _curTarget.GetComponent<ITransformComponent>().WorldPosition;
-            var myPos = SelfEntity.GetComponent<ITransformComponent>().WorldPosition;
+            var selfTransform = SelfEntity.GetComponent<ITransformComponent>();
+            var myPos = selfTransform.WorldPosition;
 
-            var curDir = SelfEntity.GetComponent<IServerTransformComponent>().LocalRotation.ToVec();
+            var curDir = selfTransform.LocalRotation.ToVec();
             var tarDir = (tarPos - myPos).Normalized;
 
             var fwdAng = Vector2.Dot(curDir, tarDir);
@@ -92,7 +93,7 @@ namespace Content.Server.AI
                 newDir = MoveTowards(curDir, tarDir, MaxAngSpeed, frameTime);
             }
 
-            SelfEntity.GetComponent<IServerTransformComponent>().LocalRotation = new Angle(newDir);
+            selfTransform.LocalRotation = new Angle(newDir);
 
             if (fwdAng > -0.9999)
             {
@@ -105,7 +106,7 @@ namespace Content.Server.AI
             // "best" target is the closest one with LOS
 
             var ents = _entMan.GetEntitiesInRange(SelfEntity, VisionRadius);
-            var myTransform = SelfEntity.GetComponent<IServerTransformComponent>();
+            var myTransform = SelfEntity.GetComponent<ITransformComponent>();
             var maxRayLen = VisionRadius * 2.5f; // circle inscribed in square, square diagonal = 2*r*sqrt(2)
 
             _workList.Clear();
@@ -116,7 +117,7 @@ namespace Content.Server.AI
                     continue;
 
                 // build the ray
-                var dir = entity.GetComponent<TransformComponent>().WorldPosition - myTransform.WorldPosition;
+                var dir = entity.GetComponent<ITransformComponent>().WorldPosition - myTransform.WorldPosition;
                 var ray = new Ray(myTransform.WorldPosition, dir.Normalized);
 
                 // cast the ray

Content.Server/Content.Server.csproj

@@ -59,6 +59,9 @@
     <Reference Include="YamlDotNet, Version=4.3.1.0, Culture=neutral, processorArchitecture=MSIL">
       <HintPath>$(SolutionDir)packages\YamlDotNet.4.3.1\lib\net45\YamlDotNet.dll</HintPath>
     </Reference>
+    <Reference Include="System.ValueTuple">
+      <HintPath>$(SolutionDir)packages\System.ValueTuple.4.4.0\lib\netstandard1.0\System.ValueTuple.dll</HintPath>
+    </Reference>
   </ItemGroup>
   <ItemGroup>
     <Compile Include="AI\AimShootLifeProcessor.cs" />
@@ -146,5 +149,8 @@
     <Compile Include="GameObjects\Components\Power\ApcComponent.cs" />
     <Compile Include="Materials\Material.cs" />
     <Compile Include="GameObjects\Components\Materials\MaterialComponent.cs" />
+    <Compile Include="GameObjects\Components\Stack\StackComponent.cs" />
+    <Compile Include="GameObjects\Components\Construction\ConstructorComponent.cs" />
+    <Compile Include="GameObjects\Components\Construction\ConstructionComponent.cs" />
   </ItemGroup>
 </Project>

Content.Server/EntryPoint.cs

@@ -26,6 +26,8 @@ using Content.Server.GameObjects.Components.Weapon.Ranged.Projectile;
 using Content.Server.GameObjects.Components.Projectiles;
 using Content.Server.GameObjects.Components.Weapon.Melee;
 using Content.Server.GameObjects.Components.Materials;
+using Content.Server.GameObjects.Components.Stack;
+using Content.Server.GameObjects.Components.Construction;
 
 namespace Content.Server
 {
@@ -95,6 +97,11 @@ namespace Content.Server
             factory.Register<SmesComponent>();
             factory.Register<ApcComponent>();
             factory.Register<MaterialComponent>();
+            factory.Register<StackComponent>();
+
+            factory.Register<ConstructionComponent>();
+            factory.Register<ConstructorComponent>();
+            factory.RegisterIgnore("ConstructionGhost");
         }
 
         /// <inheritdoc />

Content.Server/GameObjects/Components/Construction/ConstructionComponent.cs

@@ -0,0 +1,175 @@
+using System;
+using System.Collections.Generic;
+using Content.Server.GameObjects.Components.Interactable.Tools;
+using Content.Server.GameObjects.Components.Stack;
+using Content.Server.GameObjects.EntitySystems;
+using Content.Shared.Construction;
+using SS14.Server.GameObjects;
+using SS14.Server.GameObjects.EntitySystems;
+using SS14.Server.Interfaces.GameObjects;
+using SS14.Shared.GameObjects;
+using SS14.Shared.Interfaces.GameObjects;
+using SS14.Shared.Interfaces.GameObjects.Components;
+using SS14.Shared.IoC;
+using static Content.Shared.Construction.ConstructionStepMaterial;
+using static Content.Shared.Construction.ConstructionStepTool;
+
+namespace Content.Server.GameObjects.Components.Construction
+{
+    public class ConstructionComponent : Component, IAttackby
+    {
+        public override string Name => "Construction";
+
+        public ConstructionPrototype Prototype { get; private set; }
+        public int Stage { get; private set; }
+
+        SpriteComponent Sprite;
+        ITransformComponent Transform;
+        AudioSystem AudioSystem;
+        Random random;
+
+        public override void Initialize()
+        {
+            base.Initialize();
+
+            Sprite = Owner.GetComponent<SpriteComponent>();
+            Transform = Owner.GetComponent<ITransformComponent>();
+            var systemman = IoCManager.Resolve<IEntitySystemManager>();
+            AudioSystem = systemman.GetEntitySystem<AudioSystem>();
+            random = new Random();
+        }
+
+        public bool Attackby(IEntity user, IEntity attackwith)
+        {
+            var stage = Prototype.Stages[Stage];
+
+            if (TryProcessStep(stage.Forward, attackwith))
+            {
+                Stage++;
+                if (Stage == Prototype.Stages.Count - 1)
+                {
+                    // Oh boy we get to finish construction!
+                    var entMgr = IoCManager.Resolve<IServerEntityManager>();
+                    var ent = entMgr.ForceSpawnEntityAt(Prototype.Result, Transform.LocalPosition);
+                    ent.GetComponent<ITransformComponent>().LocalRotation = Transform.LocalRotation;
+                    Owner.Delete();
+                    return true;
+                }
+
+                stage = Prototype.Stages[Stage];
+                if (stage.Icon != null)
+                {
+                    Sprite.LayerSetSprite(0, stage.Icon);
+                }
+            }
+
+            else if (TryProcessStep(stage.Backward, attackwith))
+            {
+                Stage--;
+                if (Stage == 0)
+                {
+                    // Deconstruction complete.
+                    Owner.Delete();
+                    return true;
+                }
+
+                stage = Prototype.Stages[Stage];
+                if (stage.Icon != null)
+                {
+                    Sprite.LayerSetSprite(0, stage.Icon);
+                }
+            }
+
+            return true;
+        }
+
+        public void Init(ConstructionPrototype prototype)
+        {
+            Prototype = prototype;
+            Stage = 1;
+            Sprite.AddLayerWithSprite(prototype.Stages[1].Icon);
+        }
+
+        bool TryProcessStep(ConstructionStep step, IEntity slapped)
+        {
+            switch (step)
+            {
+                case ConstructionStepMaterial matStep:
+                    if (!slapped.TryGetComponent(out StackComponent stack)
+                     || !MaterialStackValidFor(matStep, stack)
+                     || !stack.Use(matStep.Amount))
+                    {
+                        return false;
+                    }
+                    if (matStep.Material == MaterialType.Cable)
+                        AudioSystem.Play("/Audio/items/zip.ogg", Transform.LocalPosition);
+                    else
+                        AudioSystem.Play("/Audio/items/deconstruct.ogg", Transform.LocalPosition);
+                    return true;
+                case ConstructionStepTool toolStep:
+                    switch (toolStep.Tool)
+                    {
+                        case ToolType.Crowbar:
+                            if (slapped.HasComponent<CrowbarComponent>())
+                            {
+                                AudioSystem.Play("/Audio/items/crowbar.ogg", Transform.LocalPosition);
+                                return true;
+                            }
+                            return false;
+                        case ToolType.Welder:
+                            if (slapped.TryGetComponent(out WelderComponent welder) && welder.TryUse(toolStep.Amount))
+                            {
+                                if (random.NextDouble() > 0.5)
+                                    AudioSystem.Play("/Audio/items/welder.ogg", Transform.LocalPosition);
+                                else
+                                    AudioSystem.Play("/Audio/items/welder2.ogg", Transform.LocalPosition);
+                                return true;
+                            }
+                            return false;
+                        case ToolType.Wrench:
+                            if (slapped.HasComponent<WrenchComponent>())
+                            {
+                                AudioSystem.Play("/Audio/items/ratchet.ogg", Transform.LocalPosition);
+                                return true;
+                            }
+                            return false;
+                        case ToolType.Screwdriver:
+                            if (slapped.HasComponent<ScrewdriverComponent>())
+                            {
+                                if (random.NextDouble() > 0.5)
+                                    AudioSystem.Play("/Audio/items/screwdriver.ogg", Transform.LocalPosition);
+                                else
+                                    AudioSystem.Play("/Audio/items/screwdriver2.ogg", Transform.LocalPosition);
+                                return true;
+                            }
+                            return false;
+                        case ToolType.Wirecutters:
+                            if (slapped.HasComponent<WirecutterComponent>())
+                            {
+                                AudioSystem.Play("/Audio/items/wirecutter.ogg", Transform.LocalPosition);
+                                return true;
+                            }
+                            return false;
+                        default:
+                            throw new NotImplementedException();
+                    }
+                default:
+                    throw new NotImplementedException();
+            }
+        }
+
+        private static Dictionary<StackType, ConstructionStepMaterial.MaterialType> StackTypeMap
+        = new Dictionary<StackType, ConstructionStepMaterial.MaterialType>
+        {
+            { StackType.Cable, MaterialType.Cable },
+            { StackType.Glass, MaterialType.Glass },
+            { StackType.Metal, MaterialType.Metal }
+        };
+
+        // Really this should check the actual materials at play..
+        public static bool MaterialStackValidFor(ConstructionStepMaterial step, StackComponent stack)
+        {
+            return StackTypeMap.TryGetValue((StackType)stack.StackType, out var should) && should == step.Material;
+        }
+    }
+}

Content.Server/GameObjects/Components/Construction/ConstructorComponent.cs

@@ -0,0 +1,98 @@
+using System;
+using System.Collections.Generic;
+using Content.Server.GameObjects.Components.Materials;
+using Content.Server.GameObjects.Components.Stack;
+using Content.Server.GameObjects.EntitySystems;
+using Content.Shared.Construction;
+using Content.Shared.GameObjects.Components.Construction;
+using SS14.Server.GameObjects;
+using SS14.Server.GameObjects.EntitySystems;
+using SS14.Server.Interfaces.GameObjects;
+using SS14.Shared.GameObjects;
+using SS14.Shared.Interfaces.GameObjects;
+using SS14.Shared.Interfaces.GameObjects.Components;
+using SS14.Shared.Interfaces.Network;
+using SS14.Shared.IoC;
+using SS14.Shared.Map;
+using SS14.Shared.Maths;
+using SS14.Shared.Prototypes;
+
+namespace Content.Server.GameObjects.Components.Construction
+{
+    public class ConstructorComponent : SharedConstructorComponent
+    {
+        public override void HandleMessage(ComponentMessage message, INetChannel netChannel = null, IComponent component = null)
+        {
+            base.HandleMessage(message, netChannel, component);
+
+            switch (message)
+            {
+                case TryStartStructureConstructionMessage tryStart:
+                    TryStartStructureConstruction(tryStart.Location, tryStart.PrototypeName, tryStart.Angle, tryStart.Ack);
+                    break;
+            }
+        }
+
+        void TryStartStructureConstruction(GridLocalCoordinates loc, string prototypeName, Angle angle, int ack)
+        {
+            var protoMan = IoCManager.Resolve<IPrototypeManager>();
+            var prototype = protoMan.Index<ConstructionPrototype>(prototypeName);
+
+            var transform = Owner.GetComponent<ITransformComponent>();
+            if (!loc.InRange(transform.LocalPosition, InteractionSystem.INTERACTION_RANGE))
+            {
+                return;
+            }
+
+            if (prototype.Stages.Count < 2)
+            {
+                throw new InvalidOperationException($"Prototype '{prototypeName}' does not have enough stages.");
+            }
+
+            var stage0 = prototype.Stages[0];
+            if (!(stage0.Forward is ConstructionStepMaterial matStep))
+            {
+                throw new NotImplementedException();
+            }
+
+            // Try to find the stack with the material in the user's hand.
+            var hands = Owner.GetComponent<HandsComponent>();
+            var activeHand = hands.GetActiveHand?.Owner;
+            if (activeHand == null)
+            {
+                return;
+            }
+
+            if (!activeHand.TryGetComponent(out StackComponent stack) || !ConstructionComponent.MaterialStackValidFor(matStep, stack))
+            {
+                return;
+            }
+
+            if (!stack.Use(matStep.Amount))
+            {
+                return;
+            }
+
+            // OK WE'RE GOOD CONSTRUCTION STARTED.
+            var entMgr = IoCManager.Resolve<IServerEntityManager>();
+            var AudioSystem = IoCManager.Resolve<IEntitySystemManager>().GetEntitySystem<AudioSystem>();
+            AudioSystem.Play("/Audio/items/deconstruct.ogg", loc);
+            if (prototype.Stages.Count == 2)
+            {
+                // Exactly 2 stages, so don't make an intermediate frame.
+                var ent = entMgr.ForceSpawnEntityAt(prototype.Result, loc);
+                ent.GetComponent<ITransformComponent>().LocalRotation = angle;
+            }
+            else
+            {
+                var frame = entMgr.ForceSpawnEntityAt("structureconstructionframe", loc);
+                var construction = frame.GetComponent<ConstructionComponent>();
+                construction.Init(prototype);
+                frame.GetComponent<ITransformComponent>().LocalRotation = angle;
+            }
+
+            var msg = new AckStructureConstructionMessage(ack);
+            SendNetworkMessage(msg);
+        }
+    }
+}

Content.Server/GameObjects/Components/GUI/InventoryComponent.cs

@@ -14,6 +14,7 @@ using SS14.Server.Interfaces.Player;
 using SS14.Shared.ContentPack;
 using System.Linq;
 using SS14.Shared.Serialization;
+using SS14.Shared.Interfaces.GameObjects.Components;
 
 namespace Content.Server.GameObjects
 {
@@ -159,8 +160,8 @@ namespace Content.Server.GameObjects
             item.RemovedFromSlot();
 
             // TODO: The item should be dropped to the container our owner is in, if any.
-            var itemTransform = item.Owner.GetComponent<TransformComponent>();
+            var itemTransform = item.Owner.GetComponent<ITransformComponent>();
-            itemTransform.LocalPosition = Owner.GetComponent<TransformComponent>().LocalPosition;
+            itemTransform.LocalPosition = Owner.GetComponent<ITransformComponent>().LocalPosition;
             return true;
         }
 

Content.Server/GameObjects/Components/GUI/ServerHandsComponent.cs

@@ -10,6 +10,7 @@ using SS14.Server.Interfaces.Player;
 using SS14.Shared.GameObjects;
 using SS14.Shared.Input;
 using SS14.Shared.Interfaces.GameObjects;
+using SS14.Shared.Interfaces.GameObjects.Components;
 using SS14.Shared.Interfaces.Network;
 using SS14.Shared.IoC;
 using SS14.Shared.Serialization;
@@ -162,8 +163,8 @@ namespace Content.Server.GameObjects
             item.RemovedFromSlot();
 
             // TODO: The item should be dropped to the container our owner is in, if any.
-            var itemTransform = item.Owner.GetComponent<TransformComponent>();
+            var itemTransform = item.Owner.GetComponent<ITransformComponent>();
-            itemTransform.LocalPosition = Owner.GetComponent<TransformComponent>().LocalPosition;
+            itemTransform.LocalPosition = Owner.GetComponent<ITransformComponent>().LocalPosition;
             Dirty();
             return true;
         }

Content.Server/GameObjects/Components/Interactable/Tools/WelderComponent.cs

@@ -85,6 +85,17 @@ namespace Content.Server.GameObjects.Components.Interactable.Tools
             }
         }
 
+        public bool TryUse(float value)
+        {
+            if (!Activated || !CanUse(value))
+            {
+                return false;
+            }
+
+            Fuel -= value;
+            return true;
+        }
+
         public bool CanUse(float value)
         {
             return Fuel > value;

Content.Server/GameObjects/Components/Items/Storage/ServerStorageComponent.cs

@@ -8,6 +8,7 @@ using SS14.Server.Player;
 using SS14.Shared.Enums;
 using SS14.Shared.GameObjects;
 using SS14.Shared.Interfaces.GameObjects;
+using SS14.Shared.Interfaces.GameObjects.Components;
 using SS14.Shared.Interfaces.Network;
 using SS14.Shared.IoC;
 using SS14.Shared.Log;
@@ -214,8 +215,8 @@ namespace Content.Server.GameObjects
                     var session = playerMan.GetSessionByChannel(netChannel);
                     var playerentity = session.AttachedEntity;
 
-                    var ourtransform = Owner.GetComponent<TransformComponent>();
+                    var ourtransform = Owner.GetComponent<ITransformComponent>();
-                    var playertransform = playerentity.GetComponent<TransformComponent>();
+                    var playertransform = playerentity.GetComponent<ITransformComponent>();
 
                     if (playertransform.LocalPosition.InRange(ourtransform.LocalPosition, 2)
                         && (ourtransform.IsMapTransform || playertransform.ContainsEntity(ourtransform)))
@@ -233,7 +234,7 @@ namespace Content.Server.GameObjects
                                     return;
                             }
 
-                            entity.GetComponent<TransformComponent>().WorldPosition = Owner.GetComponent<TransformComponent>().WorldPosition;
+                            entity.GetComponent<ITransformComponent>().WorldPosition = ourtransform.WorldPosition;
                         }
                     }
                     break;

Content.Server/GameObjects/Components/Materials/MaterialComponent.cs

@@ -67,8 +67,8 @@ namespace Content.Server.GameObjects.Components.Materials
                 }
 
                 var refl = IoCManager.Resolve<IReflectionManager>();
-                Value = serializer.ReadDataField("mat", "unobtanium");
+                Value = serializer.ReadDataField<string>("mat");
-                var key = serializer.ReadDataField("key", string.Empty);
+                var key = serializer.ReadDataField<string>("key");
                 if (refl.TryParseEnumReference(key, out var @enum))
                 {
                     Key = @enum;
@@ -78,4 +78,9 @@ namespace Content.Server.GameObjects.Components.Materials
             }
         }
     }
+
+    public enum MaterialKeys
+    {
+        Stack,
+    }
 }

Content.Server/GameObjects/Components/Power/PowerDebugTool.cs

@@ -5,6 +5,7 @@ using Content.Shared.GameObjects.Components.Power;
 using SS14.Server.Interfaces.GameObjects;
 using SS14.Shared.GameObjects;
 using SS14.Shared.Interfaces.GameObjects;
+using SS14.Shared.Interfaces.GameObjects.Components;
 using SS14.Shared.Map;
 
 namespace Content.Server.GameObjects.Components.Power
@@ -49,7 +50,7 @@ namespace Content.Server.GameObjects.Components.Power
                     builder.Append("    Providers:\n");
                     foreach (var provider in device.AvailableProviders)
                     {
-                        var providerTransform = provider.Owner.GetComponent<IServerTransformComponent>();
+                        var providerTransform = provider.Owner.GetComponent<ITransformComponent>();
                         builder.AppendFormat("      {0} ({1}) @ {2}", provider.Owner.Name, provider.Owner.Uid, providerTransform.LocalPosition);
                         if (device.Provider == provider)
                         {

Content.Server/GameObjects/Components/Power/PowerDevice.cs

@@ -2,6 +2,7 @@
 using SS14.Server.GameObjects;
 using SS14.Shared.GameObjects;
 using SS14.Shared.Interfaces.GameObjects;
+using SS14.Shared.Interfaces.GameObjects.Components;
 using SS14.Shared.IoC;
 using SS14.Shared.Serialization;
 using SS14.Shared.Utility;
@@ -240,18 +241,18 @@ namespace Content.Server.GameObjects.Components.Power
                 return;
 
             //Get the starting value for our loop
-            var position = Owner.GetComponent<TransformComponent>().WorldPosition;
+            var position = Owner.GetComponent<ITransformComponent>().WorldPosition;
             var bestprovider = AvailableProviders[0];
 
             //If we are already connected to a power provider we need to do a loop to find the nearest one, otherwise skip it and use first entry
             if (Connected == DrawTypes.Provider)
             {
-                var bestdistance = (bestprovider.Owner.GetComponent<TransformComponent>().WorldPosition - position).LengthSquared;
+                var bestdistance = (bestprovider.Owner.GetComponent<ITransformComponent>().WorldPosition - position).LengthSquared;
 
                 foreach (var availprovider in AvailableProviders)
                 {
                     //Find distance to new provider
-                    var distance = (availprovider.Owner.GetComponent<TransformComponent>().WorldPosition - position).LengthSquared;
+                    var distance = (availprovider.Owner.GetComponent<ITransformComponent>().WorldPosition - position).LengthSquared;
 
                     //If new provider distance is shorter it becomes new best possible provider
                     if (distance < bestdistance)

Content.Server/GameObjects/Components/Power/PowerNodeComponent.cs

@@ -1,6 +1,7 @@
 using SS14.Server.GameObjects;
 using SS14.Server.Interfaces.GameObjects;
 using SS14.Shared.GameObjects;
+using SS14.Shared.Interfaces.GameObjects.Components;
 using SS14.Shared.IoC;
 using System;
 using System.Linq;
@@ -56,10 +57,10 @@ namespace Content.Server.GameObjects.Components.Power
                 return;
             }
             var _emanager = IoCManager.Resolve<IServerEntityManager>();
-            var position = Owner.GetComponent<TransformComponent>().WorldPosition;
+            var position = Owner.GetComponent<ITransformComponent>().WorldPosition;
             var wires = _emanager.GetEntitiesIntersecting(Owner)
                         .Where(x => x.HasComponent<PowerTransferComponent>())
-                        .OrderByDescending(x => (x.GetComponent<TransformComponent>().WorldPosition - position).Length);
+                        .OrderByDescending(x => (x.GetComponent<ITransformComponent>().WorldPosition - position).Length);
             var choose = wires.FirstOrDefault();
             if (choose != null)
             {

Content.Server/GameObjects/Components/Power/PowerProviderComponent.cs

@@ -1,6 +1,7 @@
 using SS14.Server.GameObjects;
 using SS14.Server.Interfaces.GameObjects;
 using SS14.Shared.Interfaces.GameObjects;
+using SS14.Shared.Interfaces.GameObjects.Components;
 using SS14.Shared.IoC;
 using SS14.Shared.Log;
 using SS14.Shared.Serialization;
@@ -139,7 +140,7 @@ namespace Content.Server.GameObjects.Components.Power
 
             //Find devices within range to take under our control
             var _emanager = IoCManager.Resolve<IServerEntityManager>();
-            var position = Owner.GetComponent<TransformComponent>().WorldPosition;
+            var position = Owner.GetComponent<ITransformComponent>().WorldPosition;
             var entities = _emanager.GetEntitiesInRange(Owner, PowerRange)
                         .Where(x => x.HasComponent<PowerDeviceComponent>());
 

Content.Server/GameObjects/Components/Power/PowerTransferComponent.cs

@@ -6,6 +6,7 @@ using SS14.Shared.IoC;
 using System.Linq;
 using SS14.Shared.Interfaces.GameObjects;
 using Content.Server.GameObjects.Components.Interactable.Tools;
+using SS14.Shared.Interfaces.GameObjects.Components;
 
 namespace Content.Server.GameObjects.Components.Power
 {
@@ -44,7 +45,7 @@ namespace Content.Server.GameObjects.Components.Power
         public void SpreadPowernet()
         {
             var _emanager = IoCManager.Resolve<IServerEntityManager>();
-            var position = Owner.GetComponent<TransformComponent>().WorldPosition;
+            var position = Owner.GetComponent<ITransformComponent>().WorldPosition;
             var wires = _emanager.GetEntitiesInRange(Owner, 1.1f) //arbitrarily low, just scrape things //wip
                         .Where(x => x.HasComponent<PowerTransferComponent>());
 

Content.Server/GameObjects/Components/Stack/StackComponent.cs

@@ -0,0 +1,122 @@
+using System;
+using Content.Server.GameObjects.EntitySystems;
+using SS14.Shared.GameObjects;
+using SS14.Shared.Interfaces.GameObjects;
+using SS14.Shared.Interfaces.Reflection;
+using SS14.Shared.IoC;
+using SS14.Shared.Serialization;
+
+namespace Content.Server.GameObjects.Components.Stack
+{
+    // TODO: Naming and presentation and such could use some improvement.
+    public class StackComponent : Component, IAttackby, IExamine
+    {
+        private const string SerializationCache = "stack";
+        private int _count = 50;
+        private int _maxCount = 50;
+
+        public override string Name => "Stack";
+
+        public int Count
+        {
+            get => _count;
+            private set
+            {
+                _count = value;
+                if (_count <= 0)
+                {
+                    Owner.Delete();
+                }
+            }
+        }
+        public int MaxCount { get => _maxCount; private set => _maxCount = value; }
+        public int AvailableSpace => MaxCount - Count;
+
+        public object StackType { get; private set; }
+
+        public void Add(int amount)
+        {
+            Count += amount;
+        }
+
+        /// <summary>
+        ///     Try to use an amount of items on this stack.
+        /// </summary>
+        /// <param name="amount"></param>
+        /// <returns>True if there were enough items to remove, false if not in which case nothing was changed.</returns>
+        public bool Use(int amount)
+        {
+            if (Count >= amount)
+            {
+                Count -= amount;
+                return true;
+            }
+            return false;
+        }
+
+        public override void ExposeData(ObjectSerializer serializer)
+        {
+            serializer.DataFieldCached(ref _maxCount, "max", 50);
+            serializer.DataFieldCached(ref _count, "count", MaxCount);
+
+            if (!serializer.Reading)
+            {
+                return;
+            }
+
+            if (serializer.TryGetCacheData(SerializationCache, out object stackType))
+            {
+                StackType = stackType;
+                return;
+            }
+
+            if (serializer.TryReadDataFieldCached("stacktype", out string raw))
+            {
+                var refl = IoCManager.Resolve<IReflectionManager>();
+                if (refl.TryParseEnumReference(raw, out var @enum))
+                {
+                    stackType = @enum;
+                }
+                else
+                {
+                    stackType = raw;
+                }
+            }
+            else
+            {
+                stackType = Owner.Prototype.ID;
+            }
+            serializer.SetCacheData(SerializationCache, stackType);
+            StackType = stackType;
+        }
+
+        public bool Attackby(IEntity user, IEntity attackwith)
+        {
+            if (attackwith.TryGetComponent<StackComponent>(out var stack))
+            {
+                if (!stack.StackType.Equals(StackType))
+                {
+                    return false;
+                }
+
+                var toTransfer = Math.Min(Count, stack.AvailableSpace);
+                Count -= toTransfer;
+                stack.Add(toTransfer);
+            }
+
+            return false;
+        }
+
+        public string Examine()
+        {
+            return $"There are {Count} things in the stack.";
+        }
+    }
+
+    public enum StackType
+    {
+        Metal,
+        Glass,
+        Cable,
+    }
+}

Content.Server/GameObjects/Components/Weapon/Melee/MeleeWeaponComponent.cs

@@ -10,6 +10,7 @@ using SS14.Server.Interfaces.GameObjects;
 using SS14.Shared.Interfaces.Timing;
 using SS14.Shared.GameObjects.EntitySystemMessages;
 using SS14.Shared.Serialization;
+using SS14.Shared.Interfaces.GameObjects.Components;
 
 namespace Content.Server.GameObjects.Components.Weapon.Melee
 {
@@ -32,13 +33,13 @@ namespace Content.Server.GameObjects.Components.Weapon.Melee
 
         void IAfterAttack.Afterattack(IEntity user, GridLocalCoordinates clicklocation, IEntity attacked)
         {
-            var location = user.GetComponent<TransformComponent>().LocalPosition;
+            var location = user.GetComponent<ITransformComponent>().LocalPosition;
             var angle = new Angle(clicklocation.ToWorld().Position - location.ToWorld().Position);
-            var entities = IoCManager.Resolve<IServerEntityManager>().GetEntitiesInArc(user.GetComponent<TransformComponent>().LocalPosition, Range, angle, ArcWidth);
+            var entities = IoCManager.Resolve<IServerEntityManager>().GetEntitiesInArc(user.GetComponent<ITransformComponent>().LocalPosition, Range, angle, ArcWidth);
 
             foreach (var entity in entities)
             {
-                if (!entity.GetComponent<TransformComponent>().IsMapTransform || entity == user)
+                if (!entity.GetComponent<ITransformComponent>().IsMapTransform || entity == user)
                     continue;
 
                 if (entity.TryGetComponent(out DamageableComponent damagecomponent))

Content.Server/GameObjects/Components/Weapon/Ranged/Hitscan/HitscanWeaponComponent.cs

@@ -4,6 +4,7 @@ using SS14.Shared.Audio;
 using SS14.Shared.GameObjects;
 using SS14.Shared.GameObjects.EntitySystemMessages;
 using SS14.Shared.Interfaces.GameObjects;
+using SS14.Shared.Interfaces.GameObjects.Components;
 using SS14.Shared.Interfaces.Physics;
 using SS14.Shared.Interfaces.Timing;
 using SS14.Shared.IoC;
@@ -22,11 +23,11 @@ namespace Content.Server.GameObjects.Components.Weapon.Ranged.Hitscan
 
         protected override void Fire(IEntity user, GridLocalCoordinates clicklocation)
         {
-            var userposition = user.GetComponent<TransformComponent>().WorldPosition; //Remember world positions are ephemeral and can only be used instantaneously
+            var userposition = user.GetComponent<ITransformComponent>().WorldPosition; //Remember world positions are ephemeral and can only be used instantaneously
             var angle = new Angle(clicklocation.Position - userposition);
 
             var ray = new Ray(userposition, angle.ToVec());
-            var raycastresults = IoCManager.Resolve<ICollisionManager>().IntersectRay(ray, 20, Owner.GetComponent<TransformComponent>().GetMapTransform().Owner);
+            var raycastresults = IoCManager.Resolve<ICollisionManager>().IntersectRay(ray, 20, Owner.GetComponent<ITransformComponent>().GetMapTransform().Owner);
 
             Hit(raycastresults);
             AfterEffects(user, raycastresults, angle);
@@ -51,7 +52,7 @@ namespace Content.Server.GameObjects.Components.Weapon.Ranged.Hitscan
                 Born = time,
                 DeathTime = time + TimeSpan.FromSeconds(1),
                 Size = new Vector2(ray.Distance, 1f),
-                Coordinates = user.GetComponent<TransformComponent>().LocalPosition.Translated(offset),
+                Coordinates = user.GetComponent<ITransformComponent>().LocalPosition.Translated(offset),
                 //Rotated from east facing
                 Rotation = (float)angle.Theta,
                 ColorDelta = new Vector4(0, 0, 0, -1500f),

Content.Server/GameObjects/Components/Weapon/Ranged/Projectile/ProjectileWeapon.cs

@@ -3,6 +3,7 @@ using SS14.Server.GameObjects;
 using SS14.Server.GameObjects.EntitySystems;
 using SS14.Server.Interfaces.GameObjects;
 using SS14.Shared.Interfaces.GameObjects;
+using SS14.Shared.Interfaces.GameObjects.Components;
 using SS14.Shared.IoC;
 using SS14.Shared.Map;
 using SS14.Shared.Maths;
@@ -19,7 +20,7 @@ namespace Content.Server.GameObjects.Components.Weapon.Ranged.Projectile
 
         protected override void Fire(IEntity user, GridLocalCoordinates clicklocation)
         {
-            var userposition = user.GetComponent<TransformComponent>().LocalPosition; //Remember world positions are ephemeral and can only be used instantaneously
+            var userposition = user.GetComponent<ITransformComponent>().LocalPosition; //Remember world positions are ephemeral and can only be used instantaneously
             var angle = new Angle(clicklocation.Position - userposition.Position);
 
             var theta = angle.Theta;
@@ -34,7 +35,7 @@ namespace Content.Server.GameObjects.Components.Weapon.Ranged.Projectile
             projectile.GetComponent<PhysicsComponent>().LinearVelocity = angle.ToVec() * _velocity;
 
             //Rotate the bullets sprite to the correct direction, from north facing I guess
-            projectile.GetComponent<TransformComponent>().LocalRotation = angle.Theta;
+            projectile.GetComponent<ITransformComponent>().LocalRotation = angle.Theta;
 
             // Sound!
             IoCManager.Resolve<IEntitySystemManager>().GetEntitySystem<AudioSystem>().Play("/Audio/gunshot_c20.ogg");

Content.Server/GameObjects/EntitySystems/Click/ClickParser.cs

@@ -1,7 +1,7 @@
 using System;
 using SS14.Server.Interfaces.Player;
 using SS14.Shared.GameObjects;
-using SS14.Shared.GameObjects.System;
+using SS14.Shared.GameObjects.Systems;
 using SS14.Shared.Input;
 using SS14.Shared.Interfaces.GameObjects;
 using SS14.Shared.Interfaces.Network;

Content.Server/GameObjects/EntitySystems/Click/ExamineSystem.cs

@@ -1,8 +1,9 @@
 using SS14.Server.Interfaces.Chat;
 using SS14.Server.Interfaces.GameObjects;
 using SS14.Shared.GameObjects;
-using SS14.Shared.GameObjects.System;
+using SS14.Shared.GameObjects.Systems;
 using SS14.Shared.Interfaces.GameObjects;
+using SS14.Shared.Interfaces.GameObjects.Components;
 using SS14.Shared.IoC;
 using SS14.Shared.Log;
 using System;
@@ -33,7 +34,7 @@ namespace Content.Server.GameObjects.EntitySystems
                 return;
 
             //Verify player has a transform component
-            if (!player.TryGetComponent<IServerTransformComponent>(out var playerTransform))
+            if (!player.TryGetComponent<ITransformComponent>(out var playerTransform))
             {
                 return;
             }

Content.Server/GameObjects/EntitySystems/Click/InteractionSystem.cs

@@ -1,7 +1,7 @@
 using Content.Server.Interfaces.GameObjects;
 using SS14.Server.Interfaces.GameObjects;
 using SS14.Shared.GameObjects;
-using SS14.Shared.GameObjects.System;
+using SS14.Shared.GameObjects.Systems;
 using SS14.Shared.Interfaces.GameObjects;
 using System.Collections.Generic;
 using System.Linq;
@@ -9,6 +9,8 @@ using SS14.Shared.Input;
 using SS14.Shared.Log;
 using SS14.Shared.Map;
 using SS14.Server.GameObjects;
+using SS14.Shared.Interfaces.GameObjects.Components;
+using SS14.Shared.GameObjects.Components.BoundingBox;
 
 namespace Content.Server.GameObjects.EntitySystems
 {
@@ -87,8 +89,8 @@ namespace Content.Server.GameObjects.EntitySystems
     /// </summary>
     public class InteractionSystem : EntitySystem
     {
-        private const float INTERACTION_RANGE = 2;
+        public const float INTERACTION_RANGE = 2;
-        private const float INTERACTION_RANGE_SQUARED = INTERACTION_RANGE * INTERACTION_RANGE;
+        public const float INTERACTION_RANGE_SQUARED = INTERACTION_RANGE * INTERACTION_RANGE;
 
         public void UserInteraction(ClickEventMessage msg, IEntity player)
         {
@@ -98,7 +100,7 @@ namespace Content.Server.GameObjects.EntitySystems
                 attacked = EntityManager.GetEntity(msg.Uid);
 
             //Verify player has a transform component
-            if (!player.TryGetComponent<IServerTransformComponent>(out var playerTransform))
+            if (!player.TryGetComponent<ITransformComponent>(out var playerTransform))
             {
                 return;
             }
@@ -136,7 +138,7 @@ namespace Content.Server.GameObjects.EntitySystems
             }
 
             //Verify attacked object is on the map if we managed to click on it somehow
-            if (!attacked.GetComponent<TransformComponent>().IsMapTransform)
+            if (!attacked.GetComponent<ITransformComponent>().IsMapTransform)
             {
                 Logger.Warning(string.Format("Player named {0} clicked on object {1} that isn't currently on the map somehow", player.Name, attacked.Name));
                 return;
@@ -154,7 +156,7 @@ namespace Content.Server.GameObjects.EntitySystems
 
             //RANGEDATTACK/AFTERATTACK: Check distance between user and clicked item, if too large parse it in the ranged function
             //TODO: have range based upon the item being used? or base it upon some variables of the player himself?
-            var distance = (playerTransform.WorldPosition - attacked.GetComponent<IServerTransformComponent>().WorldPosition).LengthSquared;
+            var distance = (playerTransform.WorldPosition - attacked.GetComponent<ITransformComponent>().WorldPosition).LengthSquared;
             if (distance > INTERACTION_RANGE_SQUARED)
             {
                 if (item != null)

Content.Server/GameObjects/EntitySystems/DoorSystem.cs

@@ -1,5 +1,5 @@
 using SS14.Shared.GameObjects;
-using SS14.Shared.GameObjects.System;
+using SS14.Shared.GameObjects.Systems;
 
 namespace Content.Server.GameObjects.EntitySystems
 {

Content.Server/GameObjects/EntitySystems/PowerApcSystem.cs

@@ -1,6 +1,6 @@
 using Content.Server.GameObjects.Components.Power;
 using SS14.Shared.GameObjects;
-using SS14.Shared.GameObjects.System;
+using SS14.Shared.GameObjects.Systems;
 
 namespace Content.Server.GameObjects.EntitySystems
 {

Content.Server/GameObjects/EntitySystems/PowerSmesSystem.cs

@@ -1,6 +1,6 @@
 using Content.Server.GameObjects.Components.Power;
 using SS14.Shared.GameObjects;
-using SS14.Shared.GameObjects.System;
+using SS14.Shared.GameObjects.Systems;
 
 namespace Content.Server.GameObjects.EntitySystems
 {
@@ -10,7 +10,7 @@ namespace Content.Server.GameObjects.EntitySystems
         {
             EntityQuery = new TypeEntityQuery(typeof(SmesComponent));
         }
-        
+
         public override void Update(float frameTime)
         {
             foreach (var entity in RelevantEntities)

Content.Server/GameObjects/EntitySystems/PowerSystem.cs

@@ -1,5 +1,5 @@
 using Content.Server.GameObjects.Components.Power;
-using SS14.Shared.GameObjects.System;
+using SS14.Shared.GameObjects.Systems;
 using SS14.Shared.Interfaces.GameObjects;
 using SS14.Shared.IoC;
 using System.Collections.Generic;

Content.Server/GameObjects/EntitySystems/WelderSystem.cs

@@ -1,6 +1,6 @@
 using Content.Server.GameObjects.Components.Interactable.Tools;
 using SS14.Shared.GameObjects;
-using SS14.Shared.GameObjects.System;
+using SS14.Shared.GameObjects.Systems;
 
 namespace Content.Server.GameObjects.EntitySystems
 {

Content.Server/GameObjects/TemperatureSystem.cs

@@ -1,5 +1,5 @@
 using SS14.Shared.GameObjects;
-using SS14.Shared.GameObjects.System;
+using SS14.Shared.GameObjects.Systems;
 
 namespace Content.Server.GameObjects
 {

Content.Server/Placement/SpawnHelpers.cs

@@ -1,4 +1,5 @@
 using SS14.Server.Interfaces.GameObjects;
+using SS14.Shared.Interfaces.GameObjects.Components;
 using SS14.Shared.Interfaces.Map;
 using SS14.Shared.IoC;
 using SS14.Shared.Map;
@@ -20,11 +21,12 @@ namespace Content.Server.Placement
         {
             var entMan = IoCManager.Resolve<IServerEntityManager>();
             var tBase = entMan.SpawnEntity("TurretBase");
-            tBase.GetComponent<IServerTransformComponent>().LocalPosition = new GridLocalCoordinates(localPosition, grid);
+            tBase.GetComponent<ITransformComponent>().LocalPosition = new GridLocalCoordinates(localPosition, grid);
 
             var tTop = entMan.SpawnEntity("TurretTopLight");
-            tTop.GetComponent<IServerTransformComponent>().LocalPosition = new GridLocalCoordinates(localPosition, grid);
+            var topTransform = tTop.GetComponent<ITransformComponent>();
-            tTop.GetComponent<IServerTransformComponent>().AttachParent(tBase);
+            topTransform.LocalPosition = new GridLocalCoordinates(localPosition, grid);
+            topTransform.AttachParent(tBase);
         }
     }
 }

Content.Shared/Construction/ConstructionPrototype.cs

@@ -0,0 +1,221 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using SS14.Shared.Prototypes;
+using SS14.Shared.Serialization;
+using SS14.Shared.Utility;
+using YamlDotNet.RepresentationModel;
+
+namespace Content.Shared.Construction
+{
+    [Prototype("construction")]
+    public class ConstructionPrototype : IPrototype, IIndexedPrototype
+    {
+        private string _name;
+        private string _description;
+        private SpriteSpecifier _icon;
+        private List<string> _keywords;
+        private List<string> _categorySegments;
+        private List<ConstructionStage> _stages = new List<ConstructionStage>();
+        private ConstructionType _type;
+        private string _id;
+        private string _result;
+        private string _placementMode;
+
+        /// <summary>
+        ///     Friendly name displayed in the construction GUI.
+        /// </summary>
+        public string Name => _name;
+
+        /// <summary>
+        ///     "Useful" description displayed in the construction GUI.
+        /// </summary>
+        public string Description => _description;
+
+        /// <summary>
+        ///     Texture path inside the construction GUI.
+        /// </summary>
+        public SpriteSpecifier Icon => _icon;
+
+        /// <summary>
+        ///     A list of keywords that are used for searching.
+        /// </summary>
+        public IReadOnlyList<string> Keywords => _keywords;
+
+        /// <summary>
+        ///     The split up segments of the category.
+        /// </summary>
+        public IReadOnlyList<string> CategorySegments => _categorySegments;
+
+        /// <summary>
+        ///     The list of stages of construction.
+        ///     Construction is separated into "stages" which is basically a state in a linear FSM.
+        ///     The stage has forward and optionally backwards "steps" which are the criteria to move around in the FSM.
+        ///     NOTE that the stages are mapped differently than they appear in the prototype.
+        ///     In the prototype, the forward step is displayed as "to move into this stage" and reverse "to move out of"
+        ///     Stage 0 is considered "construction not started" and last stage is considered "construction is finished".
+        ///     As such, neither last or 0 stage have actual stage DATA, only backward/forward steps respectively.
+        ///     This would be akward for a YAML prototype because it's always jagged.
+        /// </summary>
+        public IReadOnlyList<ConstructionStage> Stages => _stages;
+
+        public ConstructionType Type => _type;
+
+        public string ID => _id;
+
+        /// <summary>
+        ///     The prototype name of the entity prototype when construction is done.
+        /// </summary>
+        public string Result => _result;
+
+        public string PlacementMode => _placementMode;
+
+        public void LoadFrom(YamlMappingNode mapping)
+        {
+            var ser = YamlObjectSerializer.NewReader(mapping);
+            _name = ser.ReadDataField<string>("name");
+
+            ser.DataField(ref _id, "id", string.Empty);
+            ser.DataField(ref _description, "description", string.Empty);
+            ser.DataField(ref _icon, "icon", SpriteSpecifier.Invalid);
+            ser.DataField(ref _type, "objecttype", ConstructionType.Structure);
+            ser.DataField(ref _result, "result", null);
+            ser.DataField(ref _placementMode, "placementmode", "PlaceFree");
+
+            _keywords = ser.ReadDataField<List<string>>("keywords", new List<string>());
+            {
+                var cat = ser.ReadDataField<string>("category");
+                var split = cat.Split(new char[] { '/' }, StringSplitOptions.RemoveEmptyEntries);
+                _categorySegments = split.ToList();
+            }
+
+            {
+                SpriteSpecifier nextIcon = null;
+                ConstructionStep nextBackward = null;
+
+                foreach (var stepMap in mapping.GetNode<YamlSequenceNode>("steps").Cast<YamlMappingNode>())
+                {
+                    var step = ReadStepPrototype(stepMap);
+                    _stages.Add(new ConstructionStage(step, nextIcon, nextBackward));
+                    if (stepMap.TryGetNode("icon", out var node))
+                    {
+                        nextIcon = SpriteSpecifier.FromYaml(node);
+                    }
+
+                    if (stepMap.TryGetNode("reverse", out YamlMappingNode revMap))
+                    {
+                        nextBackward = ReadStepPrototype(revMap);
+                    }
+                }
+
+                _stages.Add(new ConstructionStage(null, nextIcon, nextBackward));
+            }
+        }
+
+        ConstructionStep ReadStepPrototype(YamlMappingNode step)
+        {
+            int amount = 1;
+
+            if (step.TryGetNode("amount", out var node))
+            {
+                amount = node.AsInt();
+            }
+            if (step.TryGetNode("material", out node))
+            {
+                return new ConstructionStepMaterial(
+                    node.AsEnum<ConstructionStepMaterial.MaterialType>(),
+                    amount
+                );
+            }
+
+            if (step.TryGetNode("tool", out node))
+            {
+                return new ConstructionStepTool(
+                    node.AsEnum<ConstructionStepTool.ToolType>(),
+                    amount
+                );
+            }
+
+            throw new InvalidOperationException("Not enough data specified to determine step.");
+        }
+    }
+
+    public sealed class ConstructionStage
+    {
+        /// <summary>
+        ///     The icon of the construction frame at this stage.
+        /// </summary>
+        public readonly SpriteSpecifier Icon;
+
+        /// <summary>
+        ///     The step that should be completed to move away from this stage to the next one.
+        /// </summary>
+        public readonly ConstructionStep Forward;
+
+        /// <summary>
+        ///     The optional step that can be completed to move away from this stage to the previous one.
+        /// </summary>
+        public readonly ConstructionStep Backward;
+
+        public ConstructionStage(ConstructionStep forward, SpriteSpecifier icon = null, ConstructionStep backward = null)
+        {
+            Icon = icon;
+            Forward = forward;
+            Backward = backward;
+        }
+    }
+
+    public enum ConstructionType
+    {
+        Structure,
+        Item,
+    }
+
+    public abstract class ConstructionStep
+    {
+        public readonly int Amount = 1;
+
+        protected ConstructionStep(int amount)
+        {
+            Amount = amount;
+        }
+    }
+
+    public class ConstructionStepTool : ConstructionStep
+    {
+        public readonly ToolType Tool;
+
+        public ConstructionStepTool(ToolType tool, int amount) : base(amount)
+        {
+            Tool = tool;
+        }
+
+        public enum ToolType
+        {
+            Wrench,
+            Welder,
+            Screwdriver,
+            Crowbar,
+            Wirecutters,
+        }
+    }
+
+    public class ConstructionStepMaterial : ConstructionStep
+    {
+        public readonly MaterialType Material;
+
+        public ConstructionStepMaterial(MaterialType material, int amount) : base(amount)
+        {
+            Material = material;
+        }
+
+
+        public enum MaterialType
+        {
+            Metal,
+            Glass,
+            Cable,
+        }
+    }
+}
+

Content.Shared/Content.Shared.csproj

@@ -58,6 +58,9 @@
     <Reference Include="YamlDotNet, Version=4.3.1.0, Culture=neutral, processorArchitecture=MSIL">
       <HintPath>$(SolutionDir)packages\YamlDotNet.4.3.1\lib\net45\YamlDotNet.dll</HintPath>
     </Reference>
+    <Reference Include="System.ValueTuple">
+      <HintPath>$(SolutionDir)packages\System.ValueTuple.4.4.0\lib\netstandard1.0\System.ValueTuple.dll</HintPath>
+    </Reference>
   </ItemGroup>
   <ItemGroup>
     <Compile Include="EntryPoint.cs" />
@@ -101,6 +104,8 @@
     <Compile Include="Utility\ContentHelpers.cs" />
     <Compile Include="GameObjects\Components\Power\SharedSmesComponent.cs" />
     <Compile Include="GameObjects\Components\Power\SharedApcComponent.cs" />
+    <Compile Include="GameObjects\Components\Construction\SharedConstructorComponent.cs" />
+    <Compile Include="Construction\ConstructionPrototype.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
-</Project>
+</Project>

Content.Shared/GameObjects/Components/Construction/SharedConstructorComponent.cs

@@ -0,0 +1,63 @@
+using System;
+using SS14.Shared.GameObjects;
+using SS14.Shared.Map;
+using SS14.Shared.Maths;
+using SS14.Shared.Serialization;
+
+namespace Content.Shared.GameObjects.Components.Construction
+{
+    /// <summary>
+    ///     Basically handles the logic of "this mob can do construction".
+    /// </summary>
+    public abstract class SharedConstructorComponent : Component
+    {
+        public override string Name => "Constructor";
+        public override uint? NetID => ContentNetIDs.CONSTRUCTOR;
+
+        /// <summary>
+        ///     Sent client -> server to to tell the server that we started building
+        ///     a structure-construction.
+        /// </summary>
+        [Serializable, NetSerializable]
+        protected class TryStartStructureConstructionMessage : ComponentMessage
+        {
+            /// <summary>
+            ///     Position to start building.
+            /// </summary>
+            public readonly GridLocalCoordinates Location;
+
+            /// <summary>
+            ///     The construction prototype to start building.
+            /// </summary>
+            public readonly string PrototypeName;
+
+            public readonly Angle Angle;
+
+            /// <summary>
+            ///     Identifier to be sent back in the acknowledgement so that the client can clean up its ghost.
+            /// </summary>
+            public readonly int Ack;
+
+            public TryStartStructureConstructionMessage(GridLocalCoordinates loc, string prototypeName, Angle angle, int ack)
+            {
+                Directed = true;
+                Location = loc;
+                PrototypeName = prototypeName;
+                Angle = angle;
+                Ack = ack;
+            }
+        }
+
+        [Serializable, NetSerializable]
+        protected class AckStructureConstructionMessage : ComponentMessage
+        {
+            public readonly int Ack;
+
+            public AckStructureConstructionMessage(int ack)
+            {
+                Directed = true;
+                Ack = ack;
+            }
+        }
+    }
+}

Content.Shared/GameObjects/ContentNetIDs.cs

@@ -10,5 +10,6 @@
         public const uint STORAGE = 1005;
         public const uint INVENTORY = 1006;
         public const uint POWER_DEBUG_TOOL = 1007;
+        public const uint CONSTRUCTOR = 1008;
     }
 }

Resources/Prototypes/Construction/machines.yml

@@ -0,0 +1,27 @@
+- type: construction
+  name: Wall Light
+  id: wall_light
+  keywords: [fixture, lamp]
+  category: Machines
+  description: A simple wall-mounted light fixture.
+  placementmode: SnapgridBorder
+  icon:
+    sprite: Objects/lighting.rsi
+    state: on
+
+  result: poweredlight
+  steps:
+  - material: Metal
+    amount: 1
+    icon:
+      sprite: Objects/lighting.rsi
+      state: construct
+
+  - material: Cable
+    amount: 1
+    icon:
+      sprite: Objects/lighting.rsi
+      state: empty
+
+  - material: Glass
+    amount: 1

Resources/Prototypes/Construction/power.yml

@@ -0,0 +1,57 @@
+- type: construction
+  name: SMES
+  id: smes
+  category: Machines/Power
+  keywords: [battery, cell, storage]
+  placementmode: SnapgridCenter
+  description: A SMES is a large battery capable of connecting directly to a power grid.
+  icon:
+    sprite: Buildings/smes.rsi
+    state: smes
+  result: SMES
+  steps:
+  - material: Metal
+    amount: 2
+    icon:
+      sprite: Buildings/smes.rsi
+      state: smes
+
+  - material: Cable
+    amount: 2
+
+- type: construction
+  name: Generator
+  id: generator
+  category: Machines/Power
+  placementmode: SnapgridCenter
+  description: A portable generator capable of producing power from thin air.
+  icon: Objects/generator.png
+  result: Generator
+  steps:
+  - material: Metal
+    amount: 2
+    icon: Objects/generator.png
+
+  - material: Cable
+    amount: 2
+
+- type: construction
+  name: APC
+  id: apc
+  category: Machines/Power
+  placementmode: SnapgridCenter
+  description: Provides power from the grid wirelessly to other machines in the area.
+  icon:
+    sprite: Buildings/apc.rsi
+    state: apc0
+  result: APC
+  steps:
+  - material: Metal
+    amount: 2
+    icon:
+      sprite: Buildings/apc.rsi
+      state: apcmaint
+
+  - material: Cable
+    amount: 2
+

Resources/Prototypes/Construction/structures.yml

@@ -0,0 +1,31 @@
+- type: construction
+  name: Wall
+  id: wall
+  category: Structures
+  description: Keeps the air in and the greytide out.
+  icon: Tiles/wall_texture.png
+  objecttype: Structure
+  result: __engine_wall
+  placementmode: SnapgridBorder
+  steps:
+  - material: Metal
+    amount: 2
+    icon: Buildings/wall_girder.png
+    reverse:
+      tool: Wrench
+
+  - material: Metal
+    amount: 2
+    reverse:
+      tool: Welder
+
+- type: construction
+  name: Table
+  id: table
+  category: Structures
+  icon: Objects/worktop_single.png
+  result: __engine_worktop
+  placementmode: SnapgridCenter
+  steps:
+  - material: Metal
+    amount: 2

Resources/Prototypes/Construction/weapons.yml

@@ -0,0 +1,18 @@
+- type: construction
+  name: Crude Spear
+  id: spear
+  category: Items/Weapons
+  keywords: [melee]
+  description: A crude spear for when you need to put holes in somebody.
+  icon: Objects/spear.png
+  objecttype: Item
+  steps:
+  - material: Metal
+    amount: 1
+
+  - material: Cable
+    amount: 3
+
+  # Should probably use a shard but y'know.
+  - material: Glass
+    amount: 1

Resources/Prototypes/Entities/Construction.yml

@@ -0,0 +1,22 @@
+- type: entity
+  name: spooky ghost
+  id: constructionghost
+  components:
+  - type: Transform
+  - type: Sprite
+    color: '#3F38'
+  - type: ConstructionGhost
+  - type: BoundingBox
+  - type: Clickable
+    baseshader: unshaded
+    selectionshader: selection_outline_unshaded
+
+- type: entity
+  name: somebody-messed-up frame
+  id: structureconstructionframe
+  components:
+  - type: Transform
+  - type: Sprite
+  - type: Construction
+  - type: BoundingBox
+  - type: Clickable

Resources/Prototypes/Entities/Materials.yml

@@ -0,0 +1,60 @@
+- type: entity
+  name: Material Stack
+  id: MaterialStack
+  parent: BaseItem
+  components:
+  - type: Stack
+  - type: Material
+
+- type: entity
+  name: Steel Sheet
+  id: MetalStack
+  parent: MaterialStack
+  components:
+  - type: Material
+    materials:
+    - key: enum.MaterialKeys.Stack
+      mat: steel
+  - type: Stack
+    stacktype: enum.StackType.Metal
+  - type: Sprite
+    texture: Objects/sheet_metal.png
+  - type: Icon
+    texture: Objects/sheet_metal.png
+
+- type: entity
+  id: SteelSheet1
+  name: Steel Sheet 1
+  parent: MetalStack
+  components:
+  - type: Stack
+    count: 1
+
+- type: entity
+  name: Glass Sheet
+  id: GlassStack
+  parent: MaterialStack
+  components:
+  - type: Material
+    materials:
+    - key: enum.MaterialKeys.Stack
+      mat: glass
+  - type: Stack
+    stacktype: enum.StackType.Glass
+  - type: Sprite
+    texture: Objects/sheet_glass.png
+  - type: Icon
+    texture: Objects/sheet_glass.png
+
+- type: entity
+  name: Cable Coil
+  id: CableStack
+  parent: BaseItem
+  components:
+  - type: Stack
+    stacktype: enum.StackType.Cable
+  - type: Sprite
+    texture: Objects/cable_coil.png
+    color: red
+  - type: Icon
+    texture: Objects/cable_coil.png

Resources/Prototypes/Entities/Mobs.yml

@@ -10,6 +10,7 @@
     - left
     - right
   - type: Inventory
+  - type: Constructor
 
 - type: entity
   id: MobObserver

Resources/Prototypes/Entities/Power.yml

@@ -114,6 +114,13 @@
     visuals:
     - type: SmesVisualizer2D
 
+- type: entity
+  id: smes_dry
+  parent: SMES
+  components:
+  - type: PowerStorage
+    charge: 0
+
 - type: entity
   id: WiredMachine
   name: WiredMachine

Resources/Prototypes/Entities/Weapons.yml

@@ -26,3 +26,15 @@
   - type: Item
     Size: 24
 
+- type: entity
+  name: Spear
+  parent: BaseItem
+  id: Spear
+  components:
+  - type: Sprite
+    texture: Objects/spear.png
+  - type: Icon
+    texture: Objects/spear.png
+  - type: MeleeWeapon
+  - type: Item
+    Size: 24

Resources/Scenes/Construction/ConstructionButton.tscn

@@ -0,0 +1,26 @@
+[gd_scene format=2]
+
+[node name="Control" type="Button"]
+anchor_left = 1.0
+anchor_top = 1.0
+anchor_right = 1.0
+anchor_bottom = 1.0
+margin_left = -110.0
+margin_top = -70.0
+margin_right = -50.0
+margin_bottom = -50.0
+rect_pivot_offset = Vector2( 0, 0 )
+rect_clip_content = false
+focus_mode = 2
+mouse_filter = 0
+mouse_default_cursor_shape = 0
+size_flags_horizontal = 1
+size_flags_vertical = 1
+toggle_mode = false
+enabled_focus_mode = 2
+shortcut = null
+group = null
+text = "Crafting"
+flat = false
+align = 1
+

Resources/Scenes/Construction/ConstructionMenu.tscn

@@ -0,0 +1,273 @@
+[gd_scene load_steps=2 format=2]
+
+[ext_resource path="res://Scenes/SS14Window/SS14Window.tscn" type="PackedScene" id=1]
+
+[node name="SS14Window" index="0" instance=ExtResource( 1 )]
+margin_left = 99.0
+margin_right = 583.0
+margin_bottom = 357.0
+rect_clip_content = false
+
+[node name="Contents" parent="." index="0"]
+rect_clip_content = false
+
+[node name="HSplitContainer" type="HSplitContainer" parent="Contents" index="0"]
+anchor_left = 0.0
+anchor_top = 0.0
+anchor_right = 1.0
+anchor_bottom = 1.0
+rect_pivot_offset = Vector2( 0, 0 )
+rect_clip_content = false
+mouse_filter = 1
+mouse_default_cursor_shape = 0
+size_flags_horizontal = 1
+size_flags_vertical = 0
+split_offset = 15
+collapsed = false
+dragger_visibility = 0
+
+[node name="Recipes" type="VBoxContainer" parent="Contents/HSplitContainer" index="0"]
+anchor_left = 0.0
+anchor_top = 0.0
+anchor_right = 0.0
+anchor_bottom = 0.0
+margin_right = 163.0
+margin_bottom = 269.0
+rect_pivot_offset = Vector2( 0, 0 )
+rect_clip_content = false
+mouse_filter = 2
+mouse_default_cursor_shape = 0
+size_flags_horizontal = 3
+size_flags_vertical = 1
+size_flags_stretch_ratio = 0.5
+alignment = 0
+_sections_unfolded = [ "Grow Direction", "Size Flags" ]
+
+[node name="Search" type="LineEdit" parent="Contents/HSplitContainer/Recipes" index="0"]
+anchor_left = 0.0
+anchor_top = 0.0
+anchor_right = 0.0
+anchor_bottom = 0.0
+margin_right = 163.0
+margin_bottom = 24.0
+rect_pivot_offset = Vector2( 0, 0 )
+rect_clip_content = false
+focus_mode = 2
+mouse_filter = 0
+mouse_default_cursor_shape = 1
+size_flags_horizontal = 1
+size_flags_vertical = 1
+secret_character = "*"
+focus_mode = 2
+context_menu_enabled = true
+placeholder_text = "Search"
+placeholder_alpha = 0.6
+caret_blink = false
+caret_blink_speed = 0.65
+caret_position = 0
+
+[node name="Tree" type="Tree" parent="Contents/HSplitContainer/Recipes" index="1"]
+anchor_left = 0.0
+anchor_top = 0.0
+anchor_right = 0.0
+anchor_bottom = 0.0
+margin_top = 28.0
+margin_right = 163.0
+margin_bottom = 269.0
+rect_pivot_offset = Vector2( 0, 0 )
+rect_clip_content = true
+focus_mode = 2
+mouse_filter = 0
+mouse_default_cursor_shape = 0
+size_flags_horizontal = 1
+size_flags_vertical = 3
+columns = 1
+allow_reselect = false
+allow_rmb_select = false
+hide_folding = false
+hide_root = true
+drop_mode_flags = 0
+select_mode = 0
+_sections_unfolded = [ "Mouse" ]
+
+[node name="Guide" type="VBoxContainer" parent="Contents/HSplitContainer" index="1"]
+anchor_left = 0.0
+anchor_top = 0.0
+anchor_right = 0.0
+anchor_bottom = 0.0
+margin_left = 175.0
+margin_right = 464.0
+margin_bottom = 269.0
+rect_pivot_offset = Vector2( 0, 0 )
+rect_clip_content = false
+mouse_filter = 2
+mouse_default_cursor_shape = 0
+size_flags_horizontal = 3
+size_flags_vertical = 3
+alignment = 0
+
+[node name="Info" type="HBoxContainer" parent="Contents/HSplitContainer/Guide" index="0"]
+editor/display_folded = true
+anchor_left = 0.0
+anchor_top = 0.0
+anchor_right = 0.0
+anchor_bottom = 0.0
+margin_right = 289.0
+margin_bottom = 14.0
+rect_pivot_offset = Vector2( 0, 0 )
+rect_clip_content = false
+mouse_filter = 2
+mouse_default_cursor_shape = 0
+size_flags_horizontal = 1
+size_flags_vertical = 1
+alignment = 0
+
+[node name="TextureRect" type="TextureRect" parent="Contents/HSplitContainer/Guide/Info" index="0"]
+anchor_left = 0.0
+anchor_top = 0.0
+anchor_right = 0.0
+anchor_bottom = 0.0
+margin_bottom = 14.0
+rect_pivot_offset = Vector2( 0, 0 )
+rect_clip_content = false
+mouse_filter = 2
+mouse_default_cursor_shape = 0
+size_flags_horizontal = 1
+size_flags_vertical = 1
+stretch_mode = 0
+
+[node name="Label" type="Label" parent="Contents/HSplitContainer/Guide/Info" index="1"]
+anchor_left = 0.0
+anchor_top = 0.0
+anchor_right = 0.0
+anchor_bottom = 0.0
+margin_left = 4.0
+margin_right = 289.0
+margin_bottom = 14.0
+rect_pivot_offset = Vector2( 0, 0 )
+rect_clip_content = false
+mouse_filter = 2
+mouse_default_cursor_shape = 0
+size_flags_horizontal = 3
+size_flags_vertical = 4
+autowrap = true
+percent_visible = 1.0
+lines_skipped = 0
+max_lines_visible = -1
+_sections_unfolded = [ "Size Flags" ]
+
+[node name="Label" type="Label" parent="Contents/HSplitContainer/Guide" index="1"]
+anchor_left = 0.0
+anchor_top = 0.0
+anchor_right = 0.0
+anchor_bottom = 0.0
+margin_left = 127.0
+margin_top = 18.0
+margin_right = 162.0
+margin_bottom = 32.0
+rect_pivot_offset = Vector2( 0, 0 )
+rect_clip_content = false
+mouse_filter = 2
+mouse_default_cursor_shape = 0
+size_flags_horizontal = 4
+size_flags_vertical = 4
+custom_colors/font_color = Color( 0.505882, 0.505882, 0.505882, 1 )
+text = "Steps"
+percent_visible = 1.0
+lines_skipped = 0
+max_lines_visible = -1
+
+[node name="StepsList" type="ItemList" parent="Contents/HSplitContainer/Guide" index="2"]
+anchor_left = 0.0
+anchor_top = 0.0
+anchor_right = 0.0
+anchor_bottom = 0.0
+margin_top = 36.0
+margin_right = 289.0
+margin_bottom = 245.0
+rect_pivot_offset = Vector2( 0, 0 )
+rect_clip_content = true
+focus_mode = 2
+mouse_filter = 0
+mouse_default_cursor_shape = 0
+size_flags_horizontal = 1
+size_flags_vertical = 3
+items = [  ]
+select_mode = 0
+allow_reselect = false
+icon_mode = 1
+fixed_icon_size = Vector2( 0, 0 )
+_sections_unfolded = [ "Icon", "Size Flags" ]
+
+[node name="Buttons" type="HBoxContainer" parent="Contents/HSplitContainer/Guide" index="3"]
+anchor_left = 0.0
+anchor_top = 0.0
+anchor_right = 0.0
+anchor_bottom = 0.0
+margin_top = 249.0
+margin_right = 289.0
+margin_bottom = 269.0
+rect_pivot_offset = Vector2( 0, 0 )
+rect_clip_content = false
+mouse_filter = 1
+mouse_default_cursor_shape = 0
+size_flags_horizontal = 1
+size_flags_vertical = 1
+alignment = 0
+
+[node name="BuildButton" type="Button" parent="Contents/HSplitContainer/Guide/Buttons" index="0"]
+anchor_left = 0.0
+anchor_top = 0.0
+anchor_right = 0.0
+anchor_bottom = 0.0
+margin_right = 192.0
+margin_bottom = 20.0
+rect_pivot_offset = Vector2( 0, 0 )
+rect_clip_content = false
+focus_mode = 2
+mouse_filter = 0
+mouse_default_cursor_shape = 0
+size_flags_horizontal = 3
+size_flags_vertical = 1
+disabled = true
+toggle_mode = false
+enabled_focus_mode = 2
+shortcut = null
+group = null
+text = "Build!"
+flat = false
+align = 1
+_sections_unfolded = [ "Size Flags" ]
+
+[node name="EraseButton" type="Button" parent="Contents/HSplitContainer/Guide/Buttons" index="1"]
+anchor_left = 0.0
+anchor_top = 0.0
+anchor_right = 0.0
+anchor_bottom = 0.0
+margin_left = 196.0
+margin_right = 289.0
+margin_bottom = 20.0
+rect_pivot_offset = Vector2( 0, 0 )
+rect_clip_content = false
+focus_mode = 2
+mouse_filter = 0
+mouse_default_cursor_shape = 0
+size_flags_horizontal = 1
+size_flags_vertical = 1
+toggle_mode = true
+enabled_focus_mode = 2
+shortcut = null
+group = null
+text = "Clear Ghosts"
+flat = false
+align = 1
+
+[node name="Header" parent="." index="1"]
+rect_clip_content = false
+
+[node name="Header Text" parent="Header" index="0"]
+rect_clip_content = false
+
+[node name="CloseButton" parent="Header" index="1"]
+rect_clip_content = false
+

Resources/Textures/Buildings/smes.rsi/meta.json

@@ -1,170 +1 @@
-{
+{"version":1,"license":"CC-BY-SA-3.0","copyright":"Taken from https://github.com/discordia-space/CEV-Eris/blob/d1e0161af146835f4fb79d21a6200caa9cc842d0/icons/obj/power.dmi and modified.","size":{"x":32,"y":32},"states":[{"name":"smes","select":[],"flags":{},"directions":1},{"name":"smes-display","select":[],"flags":{},"directions":1,"delays":[[0.2,0.2,0.2,0.2,0.2]]},{"name":"smes-crit","select":[],"flags":{},"directions":1,"delays":[[0.2,0.2,0.2,0.2]]},{"name":"smes-oc0","select":[],"flags":{},"directions":1,"delays":[[1]]},{"name":"smes-oc1","select":[],"flags":{},"directions":1,"delays":[[0.5,0.5]]},{"name":"smes-oc2","select":[],"flags":{},"directions":1,"delays":[[0.5,0.5]]},{"name":"smes-og1","select":[],"flags":{},"directions":1,"delays":[[1]]},{"name":"smes-og2","select":[],"flags":{},"directions":1,"delays":[[1]]},{"name":"smes-og3","select":[],"flags":{},"directions":1,"delays":[[1]]},{"name":"smes-og4","select":[],"flags":{},"directions":1,"delays":[[1]]},{"name":"smes-og5","select":[],"flags":{},"directions":1,"delays":[[1]]},{"name":"smes-op0","select":[],"flags":{},"directions":1,"delays":[[1]]},{"name":"smes-op1","select":[],"flags":{},"directions":1,"delays":[[1,1]]},{"name":"smes-op2","select":[],"flags":{},"directions":1,"delays":[[1]]}]}
-    "version": 1,
-    "license": "CC-BY-SA-3.0",
-    "copyright": "Taken from https://github.com/discordia-space/CEV-Eris/blob/d1e0161af146835f4fb79d21a6200caa9cc842d0/icons/obj/power.dmi and modified.",
-    "size": {
-        "x": 32,
-        "y": 32
-    },
-    "states": [
-        {
-            "name": "smes",
-            "select": [],
-            "flags": {},
-            "directions": 1
-        },
-        {
-            "name": "smes-display",
-            "select": [],
-            "flags": {},
-            "directions": 1,
-            "delays": [
-                [
-                    0.2,
-                    0.2,
-                    0.2,
-                    0.2,
-                    0.2
-                ]
-            ]
-        },
-        {
-            "name": "smes-crit",
-            "select": [],
-            "flags": {},
-            "directions": 1,
-            "delays": [
-                [
-                    0.2,
-                    0.2,
-                    0.2,
-                    0.2
-                ]
-            ]
-        },
-        {
-            "name": "smes-oc0",
-            "select": [],
-            "flags": {},
-            "directions": 1,
-            "delays": [
-                [
-                    1.0
-                ]
-            ]
-        },
-        {
-            "name": "smes-oc1",
-            "select": [],
-            "flags": {},
-            "directions": 1,
-            "delays": [
-                [
-                    0.5,
-                    0.5
-                ]
-            ]
-        },
-        {
-            "name": "smes-oc2",
-            "select": [],
-            "flags": {},
-            "directions": 1,
-            "delays": [
-                [
-                    0.5,
-                    0.5
-                ]
-            ]
-        },
-        {
-            "name": "smes-og1",
-            "select": [],
-            "flags": {},
-            "directions": 1,
-            "delays": [
-                [
-                    1.0
-                ]
-            ]
-        },
-        {
-            "name": "smes-og2",
-            "select": [],
-            "flags": {},
-            "directions": 1,
-            "delays": [
-                [
-                    1.0
-                ]
-            ]
-        },
-        {
-            "name": "smes-og3",
-            "select": [],
-            "flags": {},
-            "directions": 1,
-            "delays": [
-                [
-                    1.0
-                ]
-            ]
-        },
-        {
-            "name": "smes-og4",
-            "select": [],
-            "flags": {},
-            "directions": 1,
-            "delays": [
-                [
-                    1.0
-                ]
-            ]
-        },
-        {
-            "name": "smes-og5",
-            "select": [],
-            "flags": {},
-            "directions": 1,
-            "delays": [
-                [
-                    1.0
-                ]
-            ]
-        },
-        {
-            "name": "smes-op0",
-            "select": [],
-            "flags": {},
-            "directions": 1,
-            "delays": [
-                [
-                    1.0
-                ]
-            ]
-        },
-        {
-            "name": "smes-op1",
-            "select": [],
-            "flags": {},
-            "directions": 1,
-            "delays": [
-                [
-                    1.0,
-                    1.0
-                ]
-            ]
-        },
-        {
-            "name": "smes-op2",
-            "select": [],
-            "flags": {},
-            "directions": 1,
-            "delays": [
-                [
-                    1.0
-                ]
-            ]
-        }
-    ]
-}

Resources/Textures/Objects/lighting.rsi/meta.json

@@ -1,21 +1 @@
-{
+{"version":1,"size":{"x":32,"y":32},"states":[{"name":"on","select":[],"flags":{},"directions":4},{"name":"off","select":[],"flags":{},"directions":4},{"name":"construct","select":[],"flags":{},"directions":4},{"name":"empty","select":[],"flags":{},"directions":4}]}
-    "version": 1,
-    "size": {
-        "x": 32,
-        "y": 32
-    },
-    "states": [
-        {
-            "name": "on",
-            "select": [],
-            "flags": {},
-            "directions": 4
-        },
-        {
-            "name": "off",
-            "select": [],
-            "flags": {},
-            "directions": 4
-        }
-    ]
-}