Urist's damage and health thing. (#10)

* Add prototype for temperature testing entity.

* Add Damageable, Destructible, Temperature. Add a prototype based on those.

* Works and cleaned up.

* Nerf

Content.Client/EntryPoint.cs

@@ -15,6 +15,9 @@ namespace Content.Client
             factory.RegisterIgnore("Inventory");
             factory.RegisterIgnore("Item");
             factory.RegisterIgnore("Interactable");
+            factory.RegisterIgnore("Damageable");
+            factory.RegisterIgnore("Destructible");
+            factory.RegisterIgnore("Temperature");
 
             factory.Register<HandsComponent>();
             factory.RegisterReference<HandsComponent, IHandsComponent>();

Content.Server/Content.Server.csproj

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
+  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')"/>
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
     <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
@@ -39,14 +39,14 @@
     <PlatformTarget>x64</PlatformTarget>
   </PropertyGroup>
   <ItemGroup>
-    <Reference Include="System" />
+    <Reference Include="System"/>
-    <Reference Include="System.Core" />
+    <Reference Include="System.Core"/>
-    <Reference Include="System.Xml.Linq" />
+    <Reference Include="System.Xml.Linq"/>
-    <Reference Include="System.Data.DataSetExtensions" />
+    <Reference Include="System.Data.DataSetExtensions"/>
-    <Reference Include="Microsoft.CSharp" />
+    <Reference Include="Microsoft.CSharp"/>
-    <Reference Include="System.Data" />
+    <Reference Include="System.Data"/>
-    <Reference Include="System.Net.Http" />
+    <Reference Include="System.Net.Http"/>
-    <Reference Include="System.Xml" />
+    <Reference Include="System.Xml"/>
     <Reference Include="YamlDotNet">
       <HintPath>$(SolutionDir)packages\YamlDotNet.4.2.1\lib\net35\YamlDotNet.dll</HintPath>
     </Reference>
@@ -55,16 +55,23 @@
     </Reference>
   </ItemGroup>
   <ItemGroup>
-    <Compile Include="EntryPoint.cs" />
+    <Compile Include="EntryPoint.cs"/>
     <Compile Include="GameObjects\Components\Interactable\InteractableComponent.cs" />
     <Compile Include="Interfaces\GameObjects\Components\Interactable\IInteractableComponent.cs" />
-    <Compile Include="Interfaces\GameObjects\Components\Items\IHandsComponent.cs" />
+    <Compile Include="Interfaces\GameObjects\Components\Items\IHandsComponent.cs"/>
-    <Compile Include="Interfaces\GameObjects\Components\Items\IInventoryComponent.cs" />
+    <Compile Include="Interfaces\GameObjects\Components\Items\IInventoryComponent.cs"/>
-    <Compile Include="Interfaces\GameObjects\Components\Items\IItemComponent.cs" />
+    <Compile Include="Interfaces\GameObjects\Components\Items\IItemComponent.cs"/>
-    <Compile Include="GameObjects\Components\Items\ServerHandsComponent.cs" />
+    <Compile Include="GameObjects\Components\Items\ServerHandsComponent.cs"/>
-    <Compile Include="GameObjects\Components\Items\InventoryComponent.cs" />
+    <Compile Include="GameObjects\Components\Items\InventoryComponent.cs"/>
-    <Compile Include="GameObjects\Components\Items\ItemComponent.cs" />
+    <Compile Include="GameObjects\Components\Items\ItemComponent.cs"/>
-    <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="GameObjects\Components\Damage\DamageableComponent.cs"/>
+    <Compile Include="GameObjects\Components\Damage\DestructibleComponent.cs"/>
+    <Compile Include="GameObjects\Components\Damage\ResistanceSet.cs"/>
+    <Compile Include="GameObjects\Components\Temperature\TemperatureComponent.cs"/>
+    <Compile Include="Interfaces\GameObjects\IOnDamageBehavior.cs"/>
+    <Compile Include="Properties\AssemblyInfo.cs"/>
+    <Compile Include="Interfaces\GameObjects\Components\Temperature\ITemperatureComponent.cs" />
+    <Compile Include="Interfaces\GameObjects\Components\Damage\IDamageableComponent.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\Content.Shared\Content.Shared.csproj">
@@ -84,13 +91,13 @@
       <Name>SS14.Shared</Name>
     </ProjectReference>
   </ItemGroup>
-  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets"/>
-  <Import Project="..\SS14.Content.targets" />
+  <Import Project="..\SS14.Content.targets"/>
-  <Target Name="AfterBuild" DependsOnTargets="CopyContentAssemblies" />
+  <Target Name="AfterBuild" DependsOnTargets="CopyContentAssemblies"/>
   <ItemGroup>
-    <ContentAssemblies Include="$(OutputPath)Content.Server.dll" />
+    <ContentAssemblies Include="$(OutputPath)Content.Server.dll"/>
-    <ContentAssemblies Include="$(OutputPath)Content.Shared.dll" />
+    <ContentAssemblies Include="$(OutputPath)Content.Shared.dll"/>
-    <ContentAssemblies Include="$(OutputPath)Content.Server.pdb" Condition="'$(Configuration)' == 'Debug'" />
+    <ContentAssemblies Include="$(OutputPath)Content.Server.pdb" Condition="'$(Configuration)' == 'Debug'"/>
-    <ContentAssemblies Include="$(OutputPath)Content.Shared.pdb" Condition="'$(Configuration)' == 'Debug'" />
+    <ContentAssemblies Include="$(OutputPath)Content.Shared.pdb" Condition="'$(Configuration)' == 'Debug'"/>
   </ItemGroup>
 </Project>

Content.Server/EntryPoint.cs

@@ -23,6 +23,10 @@ namespace Content.Server
 
             factory.Register<InteractableComponent>();
             factory.RegisterReference<InteractableComponent, IInteractableComponent>();
+
+            factory.Register<DamageableComponent>();
+            factory.Register<DestructibleComponent>();
+            factory.Register<TemperatureComponent>();
         }
     }
 }

Content.Server/GameObjects/Components/Damage/DamageableComponent.cs

@@ -0,0 +1,197 @@
+using Content.Server.Interfaces.GameObjects;
+using System;
+using System.Collections.Generic;
+using OpenTK;
+using SS14.Shared.GameObjects;
+using SS14.Shared.Utility;
+using YamlDotNet.RepresentationModel;
+using Content.Server.Interfaces;
+using Content.Shared.GameObjects;
+
+namespace Content.Server.GameObjects
+{
+    //TODO: add support for component add/remove
+
+    /// <summary>
+    /// A component that handles receiving damage and healing,
+    /// as well as informing other components of it.
+    /// </summary>
+    public class DamageableComponent : Component, IDamageableComponent
+    {
+        /// <inheritdoc />
+        public override string Name => "Damageable";
+
+        /// <inheritdoc />
+        public override uint? NetID => ContentNetIDs.DAMAGEABLE;
+
+        /// <summary>
+        /// The resistance set of this object.
+        /// Affects receiving damage of various types.
+        /// </summary>
+        public ResistanceSet Resistances { get; private set; }
+
+        Dictionary<DamageType, int> CurrentDamage = new Dictionary<DamageType, int>();
+        Dictionary<DamageType, List<int>> Thresholds = new Dictionary<DamageType, List<int>>();
+
+        public event EventHandler<DamageThresholdPassedEventArgs> DamageThresholdPassed;
+
+        /// <inheritdoc />
+        public override void LoadParameters(YamlMappingNode mapping)
+        {
+            if (mapping.TryGetNode("resistanceset", out YamlNode node))
+            {
+                Resistances = ResistanceSet.GetResistanceSet(node.AsString());
+            }
+        }
+
+        /// <inheritdoc />
+        public override void Initialize()
+        {
+            base.Initialize();
+            InitializeDamageType(DamageType.Total);
+            if (Owner is IOnDamageBehavior damageBehavior)
+            {
+                AddThresholdsFrom(damageBehavior);
+            }
+
+            RecalculateComponentThresholds();
+        }
+
+        /// <inheritdoc />
+        public void TakeDamage(DamageType damageType, int amount)
+        {
+            if (damageType == DamageType.Total)
+            {
+                throw new ArgumentException("Cannot take damage for DamageType.Total");
+            }
+            InitializeDamageType(damageType);
+
+            int oldValue = CurrentDamage[damageType];
+            int oldTotalValue = -1;
+
+            if (amount == 0)
+            {
+                return;
+            }
+
+            amount = Resistances.CalculateDamage(damageType, amount);
+            CurrentDamage[damageType] = Math.Max(0, CurrentDamage[damageType] + amount);
+            UpdateForDamageType(damageType, oldValue);
+
+            if (Resistances.AppliesToTotal(damageType))
+            {
+                oldTotalValue = CurrentDamage[DamageType.Total];
+                CurrentDamage[DamageType.Total] = Math.Max(0, CurrentDamage[DamageType.Total] + amount);
+                UpdateForDamageType(DamageType.Total, oldTotalValue);
+            }
+        }
+
+        /// <inheritdoc />
+        public void TakeHealing(DamageType damageType, int amount)
+        {
+            if (damageType == DamageType.Total)
+            {
+                throw new ArgumentException("Cannot heal for DamageType.Total");
+            }
+            TakeDamage(damageType, -amount);
+        }
+
+        void UpdateForDamageType(DamageType damageType, int oldValue)
+        {
+            int change = CurrentDamage[damageType] - oldValue;
+
+            if (change == 0)
+            {
+                return;
+            }
+
+            int changeSign = Math.Sign(change);
+
+            foreach (int value in Thresholds[damageType])
+            {
+                if (((value * changeSign) > (oldValue * changeSign)) && ((value * changeSign) <= (CurrentDamage[damageType] * changeSign)))
+                {
+                    var args = new DamageThresholdPassedEventArgs(new DamageThreshold(damageType, value), (changeSign > 0));
+                    DamageThresholdPassed?.Invoke(this, args);
+                }
+            }
+        }
+
+        void RecalculateComponentThresholds()
+        {
+            foreach (IOnDamageBehavior onDamageBehaviorComponent in Owner.GetComponents<IOnDamageBehavior>())
+            {
+                AddThresholdsFrom(onDamageBehaviorComponent);
+            }
+        }
+
+        void AddThresholdsFrom(IOnDamageBehavior onDamageBehavior)
+        {
+            if (onDamageBehavior == null)
+            {
+                throw new ArgumentNullException(nameof(onDamageBehavior));
+            }
+
+            List<DamageThreshold> thresholds = onDamageBehavior.GetAllDamageThresholds();
+
+            foreach (DamageThreshold threshold in thresholds)
+            {
+                if (!Thresholds[threshold.DamageType].Contains(threshold.Value))
+                {
+                    Thresholds[threshold.DamageType].Add(threshold.Value);
+                }
+            }
+        }
+
+        void InitializeDamageType(DamageType damageType)
+        {
+            if (!CurrentDamage.ContainsKey(damageType))
+            {
+                CurrentDamage.Add(damageType, 0);
+                Thresholds.Add(damageType, new List<int>());
+            }
+        }
+    }
+
+    public struct DamageThreshold
+    {
+        public DamageType DamageType { get; }
+        public int Value { get; }
+
+        public DamageThreshold(DamageType damageType, int value)
+        {
+            DamageType = damageType;
+            Value = value;
+        }
+
+        public override bool Equals(Object obj)
+        {
+            return obj is DamageThreshold && this == (DamageThreshold)obj;
+        }
+        public override int GetHashCode()
+        {
+            return DamageType.GetHashCode() ^ Value.GetHashCode();
+        }
+        public static bool operator ==(DamageThreshold x, DamageThreshold y)
+        {
+            return x.DamageType == y.DamageType && x.Value == y.Value;
+        }
+        public static bool operator !=(DamageThreshold x, DamageThreshold y)
+        {
+            return !(x == y);
+        }
+    }
+
+    public class DamageThresholdPassedEventArgs : EventArgs
+    {
+        public DamageThreshold DamageThreshold { get; }
+        public bool Passed { get; }
+
+        public DamageThresholdPassedEventArgs(DamageThreshold threshold, bool passed)
+        {
+            DamageThreshold = threshold;
+            Passed = passed;
+        }
+    }
+}
+

Content.Server/GameObjects/Components/Damage/DestructibleComponent.cs

@@ -0,0 +1,78 @@
+using System;
+using System.Collections.Generic;
+using SS14.Shared.GameObjects;
+using SS14.Shared.Log;
+using SS14.Shared.Utility;
+using YamlDotNet.RepresentationModel;
+using Content.Server.Interfaces;
+using Content.Shared.GameObjects;
+
+
+namespace Content.Server.GameObjects
+{
+    /// <summary>
+    /// Deletes the entity once a certain damage threshold has been reached.
+    /// </summary>
+    public class DestructibleComponent : Component, IOnDamageBehavior
+    {
+        /// <inheritdoc />
+        public override string Name => "Destructible";
+
+        /// <inheritdoc />
+        public override uint? NetID => ContentNetIDs.DESTRUCTIBLE;
+
+        /// <summary>
+        /// Damage threshold calculated from the values
+        /// given in the prototype declaration.
+        /// </summary>
+        public DamageThreshold Threshold { get; private set; }
+
+        /// <inheritdoc />
+        public override void LoadParameters(YamlMappingNode mapping)
+        {
+            //TODO currently only supports one threshold pair; gotta figure out YAML better
+
+            YamlNode node;
+
+            DamageType damageType = DamageType.Total;
+            int damageValue = 0;
+
+            if (mapping.TryGetNode("thresholdtype", out node))
+            {
+                damageType = node.AsEnum<DamageType>();
+            }
+            if (mapping.TryGetNode("thresholdvalue", out node))
+            {
+                damageValue = node.AsInt();
+            }
+
+            Threshold = new DamageThreshold(damageType, damageValue);
+        }
+
+        /// <inheritdoc />
+        public override void Initialize()
+        {
+            base.Initialize();
+
+            if (Owner.TryGetComponent<DamageableComponent>(out DamageableComponent damageable))
+            {
+                damageable.DamageThresholdPassed += OnDamageThresholdPassed;
+            }
+        }
+
+        /// <inheritdoc />
+        public List<DamageThreshold> GetAllDamageThresholds()
+        {
+            return new List<DamageThreshold>() { Threshold };
+        }
+
+        /// <inheritdoc />
+        public void OnDamageThresholdPassed(object obj, DamageThresholdPassedEventArgs e)
+        {
+            if (e.Passed && e.DamageThreshold == Threshold)
+            {
+                Owner.EntityManager.DeleteEntity(Owner);
+            }
+        }
+    }
+}

Content.Server/GameObjects/Components/Damage/ResistanceSet.cs

@@ -0,0 +1,115 @@
+using System;
+using System.Collections.Generic;
+
+namespace Content.Server.GameObjects
+{
+    /// <summary>
+    /// Damage types used in-game.
+    /// Total should never be used directly - it's a derived value.
+    /// </summary>
+    public enum DamageType
+    {
+        Total,
+        Brute,
+        Heat,
+        Cold,
+        Acid,
+        Toxic,
+        Electric
+    }
+
+    /// <summary>
+    /// Resistance set used by damageable objects.
+    /// For each damage type, has a coefficient, damage reduction and "included in total" value.
+    /// </summary>
+    public class ResistanceSet
+    {
+        Dictionary<DamageType, ResistanceSetSettings> _resistances = new Dictionary<DamageType, ResistanceSetSettings>();
+        static Dictionary<string, ResistanceSet> _resistanceSets = new Dictionary<string, ResistanceSet>();
+
+        //TODO: make it load from YAML instead of hardcoded like this
+        public ResistanceSet()
+        {
+            _resistances.Add(DamageType.Total, new ResistanceSetSettings(1f, 0, true));
+            _resistances.Add(DamageType.Acid, new ResistanceSetSettings(1f, 0, true));
+            _resistances.Add(DamageType.Brute, new ResistanceSetSettings(1f, 0, true));
+            _resistances.Add(DamageType.Heat, new ResistanceSetSettings(1f, 0, true));
+            _resistances.Add(DamageType.Cold, new ResistanceSetSettings(1f, 0, true));
+            _resistances.Add(DamageType.Toxic, new ResistanceSetSettings(1f, 0, true));
+            _resistances.Add(DamageType.Electric, new ResistanceSetSettings(1f, 0, true));
+        }
+
+        /// <summary>
+        /// Loads a resistance set with the given name.
+        /// </summary>
+        /// <param name="setName">Name of the resistance set.</param>
+        /// <returns>Resistance set by given name</returns>
+        public static ResistanceSet GetResistanceSet(string setName)
+        {
+            ResistanceSet resistanceSet = null;
+
+            if (!_resistanceSets.TryGetValue(setName, out resistanceSet))
+            {
+                resistanceSet = Load(setName);
+            }
+
+            return resistanceSet;
+        }
+
+        static ResistanceSet Load(string setName)
+        {
+            //TODO: only creates a standard set RN, should be YAMLed
+
+            ResistanceSet resistanceSet = new ResistanceSet();
+
+            _resistanceSets.Add(setName, resistanceSet);
+
+            return resistanceSet;
+        }
+
+        /// <summary>
+        /// Adjusts input damage with the resistance set values.
+        /// </summary>
+        /// <param name="damageType">Type of the damage.</param>
+        /// <param name="amount">Incoming amount of the damage.</param>
+        /// <returns>Damage adjusted by the resistance set.</returns>
+        public int CalculateDamage(DamageType damageType, int amount)
+        {
+            if (amount > 0) //if it's damage, reduction applies
+            {
+                amount -= _resistances[damageType].DamageReduction;
+
+                if (amount <= 0)
+                    return 0;
+            }
+
+            amount = (int)Math.Floor(amount * _resistances[damageType].Coefficient);
+
+            return amount;
+        }
+
+        public bool AppliesToTotal(DamageType damageType)
+        {
+            //Damage that goes straight to total (for whatever reason) never applies twice
+
+            return damageType == DamageType.Total ? false : _resistances[damageType].AppliesToTotal;
+        }
+
+        /// <summary>
+        /// Settings for a specific damage type in a resistance set.
+        /// </summary>
+        struct ResistanceSetSettings
+        {
+            public float Coefficient { get; private set; }
+            public int DamageReduction { get; private set; }
+            public bool AppliesToTotal { get; private set; }
+
+            public ResistanceSetSettings(float coefficient, int damageReduction, bool appliesInTotal)
+            {
+                Coefficient = coefficient;
+                DamageReduction = damageReduction;
+                AppliesToTotal = appliesInTotal;
+            }
+        }
+    }
+}

Content.Server/GameObjects/Components/Temperature/TemperatureComponent.cs

@@ -0,0 +1,65 @@
+using Content.Server.Interfaces.GameObjects;
+using Content.Shared.Maths;
+using System;
+using SS14.Shared.GameObjects;
+using SS14.Shared.Utility;
+using YamlDotNet.RepresentationModel;
+using Content.Shared.GameObjects;
+
+namespace Content.Server.GameObjects
+{
+    /// <summary>
+    /// Handles changing temperature,
+    /// informing others of the current temperature,
+    /// and taking fire damage from high temperature.
+    /// </summary>
+    public class TemperatureComponent : Component, ITemperatureComponent
+    {
+        /// <inheritdoc />
+        public override string Name => "Temperature";
+
+        /// <inheritdoc />
+        public override uint? NetID => ContentNetIDs.TEMPERATURE;
+
+        //TODO: should be programmatic instead of how it currently is
+        public float CurrentTemperature { get; private set; } = PhysicalConstants.ZERO_CELCIUS;
+
+        float _fireDamageThreshold = 0;
+        float _fireDamageCoefficient = 1;
+
+        float _secondsSinceLastDamageUpdate = 0;
+
+        /// <inheritdoc />
+        public override void LoadParameters(YamlMappingNode mapping)
+        {
+            YamlNode node;
+
+            if (mapping.TryGetNode("firedamagethreshold", out node))
+            {
+                _fireDamageThreshold = node.AsFloat();
+            }
+            if (mapping.TryGetNode("firedamagecoefficient", out node))
+            {
+                _fireDamageCoefficient = node.AsFloat();
+            }
+        }
+
+        /// <inheritdoc />
+        public override void Update(float frameTime)
+        {
+            base.Update(frameTime);
+
+            int fireDamage = (int)Math.Floor(Math.Max(0, CurrentTemperature - _fireDamageThreshold) / _fireDamageCoefficient);
+
+            _secondsSinceLastDamageUpdate += frameTime;
+
+            Owner.TryGetComponent<DamageableComponent>(out DamageableComponent component);
+
+            while (_secondsSinceLastDamageUpdate >= 1)
+            {
+                component?.TakeDamage(DamageType.Heat, fireDamage);
+                _secondsSinceLastDamageUpdate -= 1;
+            }
+        }
+    }
+}

Content.Server/Interfaces/GameObjects/Components/Damage/IDamageableComponent.cs

@@ -0,0 +1,30 @@
+using Content.Server.GameObjects;
+using SS14.Shared.Interfaces.GameObjects;
+using System;
+
+namespace Content.Server.Interfaces.GameObjects
+{
+    public interface IDamageableComponent : IComponent
+    {
+        event EventHandler<DamageThresholdPassedEventArgs> DamageThresholdPassed;
+        ResistanceSet Resistances { get; }
+
+        /// <summary>
+        /// The function that handles receiving damage.
+        /// Converts damage via the resistance set then applies it
+        /// and informs components of thresholds passed as necessary.
+        /// </summary>
+        /// <param name="damageType">Type of damage being received.</param>
+        /// <param name="amount">Amount of damage being received.</param>
+        void TakeDamage(DamageType damageType, int amount);
+
+        /// <summary>
+        /// Handles receiving healing.
+        /// Converts healing via the resistance set then applies it
+        /// and informs components of thresholds passed as necessary.
+        /// </summary>
+        /// <param name="damageType">Type of damage being received.</param>
+        /// <param name="amount">Amount of damage being received.</param>
+        void TakeHealing(DamageType damageType, int amount);
+    }
+}

Content.Server/Interfaces/GameObjects/Components/Temperature/ITemperatureComponent.cs

@@ -0,0 +1,9 @@
+using SS14.Shared.Interfaces.GameObjects;
+
+namespace Content.Server.Interfaces.GameObjects
+{
+    public interface ITemperatureComponent : IComponent
+    {
+        float CurrentTemperature { get; }
+    }
+}

Content.Server/Interfaces/GameObjects/IOnDamageBehavior.cs

@@ -0,0 +1,27 @@
+using System.Collections.Generic;
+using Content.Server.GameObjects;
+
+namespace Content.Server.Interfaces
+{
+    /// <summary>
+    /// Any component/entity that has behaviour linked to taking damage should implement this interface.
+    /// TODO: Don't know how to work around this currently, but due to how events work
+    /// you need to hook it up to the DamageableComponent via Initialize().
+    /// See DestructibleComponent.Initialize() for an example.
+    /// </summary>
+    interface IOnDamageBehavior
+    {
+        /// <summary>
+        /// Gets a list of all DamageThresholds this component/entity are interested in.
+        /// </summary>
+        /// <returns>List of DamageThresholds to be added to DamageableComponent for watching.</returns>
+        List<DamageThreshold> GetAllDamageThresholds();
+
+        /// <summary>
+        /// Damage threshold passed event hookup.
+        /// </summary>
+        /// <param name="obj">Damageable component.</param>
+        /// <param name="e">Damage threshold and whether it's passed in one way or another.</param>
+        void OnDamageThresholdPassed(object obj, DamageThresholdPassedEventArgs e);
+    }
+}

Content.Shared/Content.Shared.csproj

@@ -55,9 +55,11 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="EntryPoint.cs" />
+    <Compile Include="GameObjects\ContentNetIDs.cs" />
+    <Compile Include="GameObjects\PhysicalConstants.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="GameObjects\Components\Items\SharedHandsComponent.cs" />
-    <Compile Include="GameObjects\Components\NetIDs.cs" />
+    <Compile Include="Maths\PhysicalConstants.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\engine\Lidgren.Network\Lidgren.Network.csproj">

Content.Shared/GameObjects/Components/NetIDs.cs

@@ -1,7 +0,0 @@
-namespace Content.Shared.GameObjects
-{
-    public static class ContentNetIDs
-    {
-        public const uint HANDS = 1000;
-    }
-}

Content.Shared/GameObjects/ContentNetIDs.cs

@@ -0,0 +1,11 @@
+namespace Content.Shared.GameObjects
+{
+    // Starting from 1000 to avoid crossover with engine.
+    public static class ContentNetIDs
+    {
+        public const uint DAMAGEABLE = 1000;
+        public const uint DESTRUCTIBLE = 1001;
+        public const uint TEMPERATURE = 1002;
+        public const uint HANDS = 1003;
+    }
+}

Content.Shared/GameObjects/PhysicalConstants.cs

@@ -0,0 +1,10 @@
+namespace Content.Shared.GameObjects
+{
+    /// <summary>
+    /// Contains physical constants used in calculations.
+    /// </summary>
+    class PhysicalConstants
+    {
+        public const float ZERO_CELCIUS = 273.15f;
+    }
+}

Content.Shared/Maths/PhysicalConstants.cs

@@ -0,0 +1,10 @@
+namespace Content.Shared.Maths
+{
+    /// <summary>
+    ///     Contains physical constants used in calculations.
+    /// </summary>
+    public static class PhysicalConstants
+    {
+        public const float ZERO_CELCIUS = 273.15f;
+    }
+}

Resources/Prototypes/1_Temperature.yml

@@ -0,0 +1,23 @@
+- type: entity
+  id: thing_that_heats_up_on_its_own_and_dies
+  name: Thing that heats up on its own and dies
+  components:
+  - type: Transform
+  - type: Clickable
+  - type: Sprite
+    sprites:
+    - shoes
+
+  - type: Icon
+    icon: shoes
+
+  - type: Damageable
+    resistanceset: Standard
+
+  - type: Destructible
+    thresholdtype: Total
+    thresholdvalue: 100
+
+  - type: Temperature
+    firedamagethreshold: 200
+    firedamagecoefficient: 20