Re-organised the repo

.gitignore

@@ -1,7 +1,5 @@
 DoxyGen/DoxyWarnLogfile.txt
 .vscode/settings.json
-test/bin
-test/obj
-/bin
-/obj
+**bin
+**obj
 **.meta

.vscode/launch.json

@@ -0,0 +1,14 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "C#: BB2B Debug",
+            "type": "dotnet",
+            "request": "launch",
+            "projectPath": "${workspaceFolder}/Examples/BB2B/BB2B.csproj"
+        }
+    ]
+}

Examples/BB2B/BB2B.csproj

@@ -0,0 +1,11 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net5.0</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\RoboidControl.csproj" />
+  </ItemGroup>
+</Project>

Examples/BB2B/Program.cs

@@ -0,0 +1,35 @@
+using System;
+using System.Diagnostics;
+using System.Threading;
+using RoboidControl;
+
+class BB2B {
+    static void Main() {
+        // The robot's propulsion is a differential drive
+        DifferentialDrive bb2b = new DifferentialDrive();
+        // Is has a touch sensor at the front left of the roboid
+        TouchSensor touchLeft = new TouchSensor(bb2b);
+        // and other one on the right
+        TouchSensor touchRight = new TouchSensor(bb2b);
+
+        // Do forever:
+        while (true) {
+            Console.Write("A");
+            // The left wheel turns forward when nothing is touched on the right side
+            // and turn backward when the roboid hits something on the right
+            float leftWheelSpeed = (touchRight.touchedSomething) ? -600.0f : 600.0f;
+            // The right wheel does the same, but instead is controlled by
+            // touches on the left side
+            float rightWheelSpeed = (touchLeft.touchedSomething) ? -600.0f : 600.0f;
+            // When both sides are touching something, both wheels will turn backward
+            // and the roboid will move backwards
+            bb2b.SetWheelVelocity(leftWheelSpeed, rightWheelSpeed);
+
+            // Update the roboid state
+            bb2b.Update(true);
+
+            // and sleep for 100ms
+            Thread.Sleep(100);
+        }
+    }
+}

LinearAlgebra/Angle.cs.meta

@@ -1,2 +0,0 @@
-fileFormatVersion: 2
-guid: ee99a6777ed47f743be8068c6ede98c8

LinearAlgebra/Direction.cs.meta

@@ -1,11 +0,0 @@
-fileFormatVersion: 2
-guid: 9975e4702de32624e8d3deaf84669f2f
-MonoImporter:
-  externalObjects: {}
-  serializedVersion: 2
-  defaultReferences: []
-  executionOrder: 0
-  icon: {instanceID: 0}
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: 

LinearAlgebra/Quat32.cs.meta

@@ -1,11 +0,0 @@
-fileFormatVersion: 2
-guid: 96aa3cf18eaeb574d9265704d68000da
-MonoImporter:
-  externalObjects: {}
-  serializedVersion: 2
-  defaultReferences: []
-  executionOrder: 0
-  icon: {instanceID: 0}
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: 

LinearAlgebra/Spherical.cs.meta

@@ -1,11 +0,0 @@
-fileFormatVersion: 2
-guid: 33f05ee51ff6f7042b3e22723bcfc4f5
-MonoImporter:
-  externalObjects: {}
-  serializedVersion: 2
-  defaultReferences: []
-  executionOrder: 0
-  icon: {instanceID: 0}
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: 

LinearAlgebra/SwingTwist.cs.meta

@@ -1,11 +0,0 @@
-fileFormatVersion: 2
-guid: 003a6ec763b101642b0589486f087aef
-MonoImporter:
-  externalObjects: {}
-  serializedVersion: 2
-  defaultReferences: []
-  executionOrder: 0
-  icon: {instanceID: 0}
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: 

RoboidControl.sln

@@ -0,0 +1,39 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.0.31903.59
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "test", "test\test.csproj", "{B65BB41E-5A93-46FC-BA68-B865F50D57BD}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Examples", "Examples", "{D6086F71-404B-4D18-BBE9-45947ED33DB2}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "BB2B", "Examples\BB2B\BB2B.csproj", "{488F28B2-A2CC-4E32-8D3B-7DB4EB1485F9}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "RoboidControl", "src\RoboidControl.csproj", "{72BFCD03-FA78-4D0B-8B36-32301D60D6DD}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{B65BB41E-5A93-46FC-BA68-B865F50D57BD}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{B65BB41E-5A93-46FC-BA68-B865F50D57BD}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{B65BB41E-5A93-46FC-BA68-B865F50D57BD}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{B65BB41E-5A93-46FC-BA68-B865F50D57BD}.Release|Any CPU.Build.0 = Release|Any CPU
+		{488F28B2-A2CC-4E32-8D3B-7DB4EB1485F9}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{488F28B2-A2CC-4E32-8D3B-7DB4EB1485F9}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{488F28B2-A2CC-4E32-8D3B-7DB4EB1485F9}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{488F28B2-A2CC-4E32-8D3B-7DB4EB1485F9}.Release|Any CPU.Build.0 = Release|Any CPU
+		{72BFCD03-FA78-4D0B-8B36-32301D60D6DD}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{72BFCD03-FA78-4D0B-8B36-32301D60D6DD}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{72BFCD03-FA78-4D0B-8B36-32301D60D6DD}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{72BFCD03-FA78-4D0B-8B36-32301D60D6DD}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(NestedProjects) = preSolution
+		{488F28B2-A2CC-4E32-8D3B-7DB4EB1485F9} = {D6086F71-404B-4D18-BBE9-45947ED33DB2}
+	EndGlobalSection
+EndGlobal

src/LocalParticipant.cs

@@ -9,7 +9,7 @@ namespace RoboidControl {
     /// <summary>
     /// A participant is used for communcation between things
     /// </summary>
-    public class Participant : RemoteParticipant {
+    public class LocalParticipant : Participant {
         public byte[] buffer = new byte[1024];
         public ulong publishInterval = 3000; // = 3 seconds
 
@@ -26,7 +26,7 @@ namespace RoboidControl {
         /// <summary>
         /// Create a porticiapnt
         /// </summary>
-        public Participant() {
+        public LocalParticipant() {
             //senders.Add(this);
         }
 
@@ -34,16 +34,16 @@ namespace RoboidControl {
         /// Create a participant with the give UDP port
         /// </summary>
         /// <param name="port">The port number on which to communicate</param>
-        // public Participant(int port) : this() {
-        //     this.port = port;
-        // }
+        public LocalParticipant(int port) : this() {
+            this.port = port;
+        }
 
         /// <summary>
         /// Create a new participant for a site at the given address and port
         /// </summary>
         /// <param name="ipAddress">The ip address of the site server</param>
         /// <param name="port">The port number of the site server</param>
-        public Participant(string ipAddress = "0.0.0.0", int port = 7681) : this() {
+        public LocalParticipant(string ipAddress = "0.0.0.0", int port = 7681) : this() {
             this.ipAddress = ipAddress;
             this.port = port;
 
@@ -61,35 +61,42 @@ namespace RoboidControl {
         /// </summary>
         /// <param name="udpClient">UDP client to use for communication</param>
         /// <param name="port">The port number on which to communicate</param>
-        public Participant(UdpClient udpClient, int port) : this() {
+        public LocalParticipant(UdpClient udpClient, int port) : this() {
             this.udpClient = udpClient;
             this.port = port;
         }
 
-        public List<RemoteParticipant> owners = new List<RemoteParticipant>();
+        private static LocalParticipant isolatedParticipant = null;
+        public static LocalParticipant Isolated() {
+            if (isolatedParticipant == null)
+                isolatedParticipant = new LocalParticipant(0);
+            return isolatedParticipant;
+        }
 
-        public RemoteParticipant GetParticipant(string ipAddress, int port) {
+        public List<Participant> owners = new List<Participant>();
+
+        public Participant GetParticipant(string ipAddress, int port) {
             //Console.WriteLine($"Get Participant {ipAddress}:{port}");
-            foreach (RemoteParticipant sender in owners) {
+            foreach (Participant sender in owners) {
                 if (sender.ipAddress == ipAddress && sender.port == port)
                     return sender;
             }
             return null;
         }
-        public RemoteParticipant AddParticipant(string ipAddress, int port) {
+        public Participant AddParticipant(string ipAddress, int port) {
             Console.WriteLine($"New Participant {ipAddress}:{port}");
-            RemoteParticipant participant = new(ipAddress, port) {
+            Participant participant = new(ipAddress, port) {
                 networkId = (byte)(this.owners.Count + 1)
             };
             owners.Add(participant);
             return participant;
         }
 
-        protected readonly Dictionary<byte, Func<RemoteParticipant, byte, byte, Thing>> thingMsgProcessors = new();
+        protected readonly Dictionary<byte, Func<Participant, byte, byte, Thing>> thingMsgProcessors = new();
 
-        public delegate Thing ThingConstructor(RemoteParticipant sender, byte networkId, byte thingId);
+        public delegate Thing ThingConstructor(Participant sender, byte networkId, byte thingId);
         public void Register(byte thingType, ThingConstructor constr) {
-            thingMsgProcessors[thingType] = new Func<RemoteParticipant, byte, byte, Thing>(constr);
+            thingMsgProcessors[thingType] = new Func<Participant, byte, byte, Thing>(constr);
         }
 
         public void Register<ThingClass>(Thing.Type thingType) where ThingClass : Thing {
@@ -118,7 +125,7 @@ namespace RoboidControl {
             // We can receive our own publish (broadcast) packages. How do we recognize them????
             // It is hard to determine our source port
             string ipAddress = this.endPoint.Address.ToString();
-            RemoteParticipant remoteParticipant = GetParticipant(ipAddress, this.endPoint.Port);
+            Participant remoteParticipant = GetParticipant(ipAddress, this.endPoint.Port);
             remoteParticipant ??= AddParticipant(ipAddress, this.endPoint.Port);
 
             ReceiveData(data, remoteParticipant);
@@ -161,7 +168,7 @@ namespace RoboidControl {
 
         #region Send
 
-        public void SendThingInfo(RemoteParticipant remoteParticipant, Thing thing) {
+        public void SendThingInfo(Participant remoteParticipant, Thing thing) {
             Console.WriteLine("Send thing info");
             this.Send(remoteParticipant, new ThingMsg(this.networkId, thing));
             this.Send(remoteParticipant, new NameMsg(this.networkId, thing));
@@ -169,7 +176,7 @@ namespace RoboidControl {
             this.Send(remoteParticipant, new BinaryMsg(this.networkId, thing));
         }
 
-        public bool Send(RemoteParticipant remoteParticipant, IMessage msg) {
+        public bool Send(Participant remoteParticipant, IMessage msg) {
             int bufferSize = msg.Serialize(ref this.buffer);
             if (bufferSize <= 0)
                 return true;
@@ -220,7 +227,7 @@ namespace RoboidControl {
 
         #region Receive
 
-        public void ReceiveData(byte[] data, RemoteParticipant remoteParticipant) {
+        public void ReceiveData(byte[] data, Participant remoteParticipant) {
             byte msgId = data[0];
             if (msgId == 0xFF) {
                 // Timeout
@@ -268,9 +275,9 @@ namespace RoboidControl {
 
         #region Process
 
-        protected virtual void Process(RemoteParticipant sender, ParticipantMsg msg) { }
+        protected virtual void Process(Participant sender, ParticipantMsg msg) { }
 
-        protected virtual void Process(RemoteParticipant sender, NetworkIdMsg msg) {
+        protected virtual void Process(Participant sender, NetworkIdMsg msg) {
             Console.WriteLine($"{this.name} receive network id {this.networkId} {msg.networkId}");
             if (this.networkId != msg.networkId) {
                 this.networkId = msg.networkId;
@@ -279,27 +286,27 @@ namespace RoboidControl {
             }
         }
 
-        protected virtual void Process(RemoteParticipant sender, InvestigateMsg msg) { }
+        protected virtual void Process(Participant sender, InvestigateMsg msg) { }
 
-        protected virtual void Process(RemoteParticipant sender, ThingMsg msg) {
+        protected virtual void Process(Participant sender, ThingMsg msg) {
             //Console.WriteLine($"Participant: Process thing [{msg.networkId}/{msg.thingId}]");
         }
 
-        protected virtual void Process(RemoteParticipant sender, NameMsg msg) {
+        protected virtual void Process(Participant sender, NameMsg msg) {
             //Console.WriteLine($"Participant: Process name [{msg.networkId}/{msg.thingId}] {msg.name}");
             Thing thing = sender.Get(msg.networkId, msg.thingId);
             if (thing != null)
                 thing.name = msg.name;
         }
 
-        protected virtual void Process(RemoteParticipant sender, ModelUrlMsg msg) {
+        protected virtual void Process(Participant sender, ModelUrlMsg msg) {
             //Console.WriteLine($"Participant: Process model [{msg.networkId}/{msg.thingId}] {msg.url}");
             Thing thing = sender.Get(msg.networkId, msg.thingId);
             if (thing != null)
                 thing.modelUrl = msg.url;
         }
 
-        protected virtual void Process(RemoteParticipant sender, PoseMsg msg) {
+        protected virtual void Process(Participant sender, PoseMsg msg) {
             //Console.WriteLine($"Participant: Process pose [{msg.networkId}/{msg.thingId}] {msg.poseType}");
             Thing thing = sender.Get(msg.networkId, msg.thingId);
             if (thing != null) {
@@ -320,15 +327,15 @@ namespace RoboidControl {
             }
         }
 
-        protected virtual void Process(RemoteParticipant sender, BinaryMsg msg) {
+        protected virtual void Process(Participant sender, BinaryMsg msg) {
             // Console.WriteLine($"Participant: Process binary [{msg.networkId}/{msg.thingId}]");
             Thing thing = sender.Get(msg.networkId, msg.thingId);
             thing?.ProcessBinary(msg.bytes);
         }
 
-        protected virtual void Process(RemoteParticipant sender, TextMsg temsgxt) { }
+        protected virtual void Process(Participant sender, TextMsg temsgxt) { }
 
-        protected virtual void Process(RemoteParticipant sender, DestroyMsg msg) { }
+        protected virtual void Process(Participant sender, DestroyMsg msg) { }
 
         private void ForwardMessage(IMessage msg) {
             // foreach (Participant client in senders) {

src/Participant.cs

@@ -6,7 +6,7 @@ namespace RoboidControl {
     /// <summary>
     /// A reference to a participant, possibly on a remote location
     /// </summary>
-    public class RemoteParticipant {
+    public class Participant {
         /// <summary>
         /// The internet address of the participant
         /// </summary>
@@ -24,13 +24,13 @@ namespace RoboidControl {
         /// <summary>
         /// Default constructor
         /// </summary>
-        public RemoteParticipant() {}
+        public Participant() { }
         /// <summary>
         /// Create a new remote participant
         /// </summary>
         /// <param name="ipAddress">The IP address of the participant</param>
         /// <param name="port">The UDP port of the participant</param>
-        public RemoteParticipant(string ipAddress, int port) {
+        public Participant(string ipAddress, int port) {
             this.ipAddress = ipAddress;
             this.port = port;
         }
@@ -68,7 +68,8 @@ namespace RoboidControl {
                 if (invokeEvent)
                     Thing.InvokeNewThing(thing);
                 // Console.Write($"Add thing {ipAddress}:{port}[{networkId}/{thing.id}]");
-            } else {
+            }
+            else {
                 if (thing != foundThing) {
                     // should be: find first non-existing id...
                     thing.id = (byte)this.things.Count;

src/SiteServer.cs

@@ -7,7 +7,7 @@ namespace RoboidControl {
     /// <summary>
     /// A site server is a participant which provides a shared simulated environment 
     /// </summary>
-    public class SiteServer : Participant {
+    public class SiteServer : LocalParticipant {
 
         public SiteServer(int port = 7681) : this("0.0.0.0", port) { }
 
@@ -42,21 +42,21 @@ namespace RoboidControl {
         public override void Publish() {
         }
 
-        protected override void Process(RemoteParticipant remoteParticipant, ParticipantMsg msg) {
+        protected override void Process(Participant remoteParticipant, ParticipantMsg msg) {
             if (msg.networkId == 0) {
                 Console.WriteLine($"{this.name} received New Client -> {remoteParticipant.networkId}");
                 this.Send(remoteParticipant, new NetworkIdMsg(remoteParticipant.networkId));
             }
         }
 
-        protected override void Process(RemoteParticipant sender, NetworkIdMsg msg) { }
+        protected override void Process(Participant sender, NetworkIdMsg msg) { }
 
-        protected override void Process(RemoteParticipant sender, ThingMsg msg) {
+        protected override void Process(Participant sender, ThingMsg msg) {
             //Console.WriteLine($"SiteServer: Process thing [{msg.networkId}/{msg.thingId}]");
             Thing thing = sender.Get(msg.networkId, msg.thingId);
             if (thing == null) {
                 Thing newThing = null;
-                if (thingMsgProcessors.TryGetValue(msg.thingType, out Func<RemoteParticipant, byte, byte, Thing> msgProcessor)) {
+                if (thingMsgProcessors.TryGetValue(msg.thingType, out Func<Participant, byte, byte, Thing> msgProcessor)) {
                     //Console.WriteLine("Found thing message processor");
                     if (msgProcessor != null)
                         newThing = msgProcessor(sender, msg.networkId, msg.thingId);

src/Thing.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using Passer.LinearAlgebra;
 
 namespace RoboidControl {
@@ -12,28 +13,6 @@ namespace RoboidControl {
 
         #region Types
 
-        #endregion Types
-
-        #region Properties
-
-        public delegate void ChangeHandler();
-        public delegate void SphericalHandler(Spherical v);
-        public delegate void ThingHandler(Thing t);
-
-        /// <summary>
-        /// The participant to which this thing belongs
-        /// </summary>
-        public RemoteParticipant owner;
-
-        /// <summary>
-        /// The network ID of this thing.
-        /// </summary>
-        public byte networkId;
-        /// <summary>
-        /// The ID of this thing
-        /// </summary>
-        public byte id;
-
         /// <summary>
         /// Predefined thing types
         /// </summary>
@@ -54,6 +33,81 @@ namespace RoboidControl {
             Humanoid,
             ExternalSensor
         };
+
+        #endregion Types
+
+        #region Init
+
+        public Thing(byte thingType = (byte)Type.Undetermined) : this(LocalParticipant.Isolated(), thingType) {
+        }
+
+        public Thing(Participant owner, byte thingType = (byte)Type.Undetermined) {
+            this.owner = owner;
+            this.type = thingType;
+        }
+
+        public Thing(Thing parent, byte thingType = (byte)Type.Undetermined) : this(parent.owner, thingType) {
+            this.parent = parent;
+        }
+
+        /// <summary>
+        /// Create a new thing for the given participant
+        /// </summary>
+        /// <param name="owner">The participant for which this thing is created</param>
+        /// <param name="invokeEvent">True when a new thing event should be triggered</param>
+        public Thing(Participant owner, bool invokeEvent = false) {
+            this.owner = owner;
+            //owner.Add(this);
+            if (invokeEvent)
+                InvokeNewThing(this);
+        }
+        /// <summary>
+        /// Create a new thing for the given participant
+        /// </summary>
+        /// <param name="participant">The participant for which this thing is created</param>
+        /// <param name="networkId">The network ID of the thing</param>
+        /// <param name="thingId">The ID of the thing</param>
+        /// <param name="thingType">The type of thing</param>
+        public Thing(Participant participant, byte networkId, byte thingId, byte thingType = 0) {
+            this.owner = participant;
+            this.id = thingId;
+            this.type = thingType;
+            this.networkId = networkId;
+        }
+
+        /// <summary>
+        /// Function which can be used to create components in external engines.
+        /// </summary>
+        /// Currently this is used to create GameObjects in Unity
+        public virtual void CreateComponent() {
+#if UNITY_5_3_OR_NEWER            
+            this.component = Unity.Thing.Create(this);
+            this.component.core = this;
+#endif            
+        }
+
+        #endregion Init
+
+        #region Properties
+
+        public delegate void ChangeHandler();
+        public delegate void SphericalHandler(Spherical v);
+        public delegate void ThingHandler(Thing t);
+
+        /// <summary>
+        /// The participant to which this thing belongs
+        /// </summary>
+        public Participant owner;
+
+        /// <summary>
+        /// The network ID of this thing.
+        /// </summary>
+        public byte networkId;
+        /// <summary>
+        /// The ID of this thing
+        /// </summary>
+        public byte id;
+
         /// <summary>
         /// The type of this thing. This can be either a Thing::Type (needs casting)
         /// or a byte value for custom types.
@@ -201,62 +255,30 @@ namespace RoboidControl {
 
         #endregion Properties
 
-        #region Init
-
-        /// <summary>
-        /// Create a new thing for the given participant
-        /// </summary>
-        /// <param name="owner">The participant for which this thing is created</param>
-        /// <param name="invokeEvent">True when a new thing event should be triggered</param>
-        public Thing(RemoteParticipant owner, bool invokeEvent = false) {
-            this.owner = owner;
-            //owner.Add(this);
-            if (invokeEvent)
-                InvokeNewThing(this);
-        }
-        /// <summary>
-        /// Create a new thing for the given participant
-        /// </summary>
-        /// <param name="participant">The participant for which this thing is created</param>
-        /// <param name="networkId">The network ID of the thing</param>
-        /// <param name="thingId">The ID of the thing</param>
-        /// <param name="thingType">The type of thing</param>
-        public Thing(RemoteParticipant participant, byte networkId, byte thingId, byte thingType = 0) {
-            this.owner = participant;
-            this.id = thingId;
-            this.type = thingType;
-            this.networkId = networkId;
-        }
-
-        /// <summary>
-        /// Function which can be used to create components in external engines.
-        /// </summary>
-        /// Currently this is used to create GameObjects in Unity
-        public virtual void CreateComponent() {
-#if UNITY_5_3_OR_NEWER            
-            this.component = Unity.Thing.Create(this);
-            this.component.core = this;
-#endif            
-        }
-
-        #endregion Init
-
         #region Update
 
-#if UNITY_5_3_OR_NEWER
+        // #if UNITY_5_3_OR_NEWER
         /// <summary>
         /// Convience function for use in Unity which removes the need for a currentTime argument
         /// </summary>
-        public void Update() {
-            Update((ulong)UnityEngine.Time.time * 1000);
+        public void Update(bool recursive = false) {
+            Update(TimeManager.GetCurrentTimeMilliseconds(), recursive);
         }
-#endif
+        // #endif
         /// <summary>
         /// Update this thing
         /// </summary>
         /// <param name="currentTime">The current time in milliseconds</param>
-        public virtual void Update(ulong currentTime) {
+        public virtual void Update(ulong currentTimeMs, bool recursive = false) {
             // should recurse over children...
+            if (recursive) {
+                for (byte childIx = 0; childIx < this.children.Count; childIx++) {
+                    Thing child = this.children[childIx];
+                    if (child == null)
+                        continue;
+                    child.Update(currentTimeMs, recursive);
+                }
+            }
         }
 
         /// <summary>

src/Things/DifferentialDrive.cs

@@ -0,0 +1,51 @@
+namespace RoboidControl {
+
+    /// @brief A thing which can move itself using a differential drive system
+    ///
+    /// @sa @link https://en.wikipedia.org/wiki/Differential_wheeled_robot @endlink
+    public class DifferentialDrive : Thing {
+        /// @brief Create a differential drive without networking support
+        public DifferentialDrive() { }
+        /// @brief Create a differential drive with networking support
+        /// @param participant The local participant
+        public DifferentialDrive(LocalParticipant participant) : base(participant, false) { }
+
+        /// @brief Configures the dimensions of the drive
+        /// @param wheelDiameter The diameter of the wheels in meters
+        /// @param wheelSeparation The distance between the wheels in meters
+        ///
+        /// These values are used to compute the desired wheel speed from the set
+        /// linear and angular velocity.
+        /// @sa SetLinearVelocity SetAngularVelocity
+        public void SetDriveDimensions(float wheelDiameter, float wheelSeparation) { }
+        /// @brief Congures the motors for the wheels
+        /// @param leftWheel The motor for the left wheel
+        /// @param rightWheel The motor for the right wheel
+        public void SetMotors(Thing leftWheel, Thing rightWheel) { }
+
+        /// @brief Directly specify the speeds of the motors
+        /// @param speedLeft The speed of the left wheel in degrees per second.
+        /// Positive moves the robot in the forward direction.
+        /// @param speedRight The speed of the right wheel in degrees per second.
+        /// Positive moves the robot in the forward direction.
+
+        public void SetWheelVelocity(float speedLeft, float speedRight) { }
+
+        /// @copydoc RoboidControl::Thing::Update(unsigned long)
+        public override void Update(ulong currentMs, bool recursive = true) { }
+
+        /// @brief The radius of a wheel in meters
+        protected float wheelRadius = 1.0f;
+        /// @brief The distance between the wheels in meters
+        protected float wheelSeparation = 1.0f;
+
+        /// @brief Convert revolutions per second to meters per second
+        protected float rpsToMs = 1.0f;
+
+        /// @brief The left wheel
+        protected Thing leftWheel = null;
+        /// @brief The right wheel
+        protected Thing rightWheel = null;
+    };
+
+}  // namespace RoboidControl

src/Things/DistanceSensor.cs

@@ -13,14 +13,14 @@ namespace RoboidControl {
         /// Constructor for a new distance sensor
         /// </summary>
         /// <param name="participant">The participant for which the sensor is needed</param>
-        public DistanceSensor(RemoteParticipant participant) : base(participant, true) { }
+        public DistanceSensor(Participant participant) : base(participant, true) { }
         /// <summary>
         /// Create a distance sensor with the given ID
         /// </summary>
         /// <param name="participant">The participant for with the sensor is needed</param>
         /// <param name="networkId">The network ID of the sensor</param>
         /// <param name="thingId">The ID of the thing</param>
-        public DistanceSensor(RemoteParticipant participant, byte networkId, byte thingId) : base(participant, networkId, thingId, (byte)Type.TemperatureSensor) {
+        public DistanceSensor(Participant participant, byte networkId, byte thingId) : base(participant, networkId, thingId, (byte)Type.TemperatureSensor) {
         }
 
 #if UNITY_5_3_OR_NEWER

src/Things/TemperatureSensor.cs

@@ -17,7 +17,7 @@ namespace RoboidControl {
         /// <param name="participant">The participant for with the sensor is needed</param>
         /// <param name="networkId">The network ID of the sensor</param>
         /// <param name="thingId">The ID of the thing</param>
-        public TemperatureSensor(Participant participant, byte networkId, byte thingId) : base(participant, networkId, thingId, (byte)Type.TemperatureSensor) {}
+        public TemperatureSensor(LocalParticipant participant, byte networkId, byte thingId) : base(participant, networkId, thingId, (byte)Type.TemperatureSensor) { }
 
         /// <summary>
         /// Function to extract the temperature received in the binary message

src/Things/TouchSensor.cs

@@ -7,7 +7,25 @@ namespace RoboidControl {
     /// </summary>
     public class TouchSensor : Thing {
 
-        public Participant thisParticipant;
+        /// <summary>
+        /// Create a touch sensor
+        /// </summary>
+        /// <param name="owner">The participant for with the sensor is needed</param>
+        /// <param name="invokeEvent">True when the creation should trigger an event</param>
+        public TouchSensor(Participant owner, bool invokeEvent = true) : base(owner, invokeEvent) {
+            //touchedSomething = false;
+            //thisParticipant = owner;
+        }
+
+        public TouchSensor(Participant owner, byte networkId, byte thingId) : base(owner, networkId, thingId) {
+            Console.Write("TouchSensor constructor");
+            //touchedSomething = false;
+            //thisParticipant = participant;
+        }
+
+        public TouchSensor(Thing parent) : base(parent) { }
+
+        public LocalParticipant thisParticipant;
 
         /// <summary>
         /// Value which is true when the sensor is touching something, false otherwise
@@ -20,28 +38,12 @@ namespace RoboidControl {
                 _touchedSomething = value;
                 if (thisParticipant != null && this.owner != thisParticipant) {
                     BinaryMsg msg = new(networkId, this);
-                    foreach (RemoteParticipant remoteParticipant in thisParticipant.owners)
+                    foreach (Participant remoteParticipant in thisParticipant.owners)
                         thisParticipant.Send(remoteParticipant, msg);
                 }
             }
         }
 
-        /// <summary>
-        /// Create a touch sensor
-        /// </summary>
-        /// <param name="owner">The participant for with the sensor is needed</param>
-        /// <param name="invokeEvent">True when the creation should trigger an event</param>
-        public TouchSensor(RemoteParticipant owner, bool invokeEvent = true) : base(owner, invokeEvent) {
-            //touchedSomething = false;
-            //thisParticipant = owner;
-        }
-
-        public TouchSensor(RemoteParticipant owner, byte networkId, byte thingId) : base(owner, networkId, thingId) {
-            Console.Write("TouchSensor constructor");
-            //touchedSomething = false;
-            //thisParticipant = participant;
-        }
-
 #if UNITY_5_3_OR_NEWER
         /// @copydoc Passer::RoboidControl::Thing::CreateComponent 
         public override void CreateComponent() {

src/TimeManger.cs

@@ -0,0 +1,22 @@
+using System.Diagnostics;
+
+namespace RoboidControl {
+    public static class TimeManager {
+        private static readonly Stopwatch _stopwatch = new Stopwatch();
+
+        /// <summary>
+        /// Static constructor to start the stopwatch
+        /// </summary>
+        static TimeManager() {
+            _stopwatch.Start();
+        }
+
+        /// <summary>
+        /// Method to get the current time in milliseconds
+        /// </summary>
+        /// <returns>The current time in milliseconds</returns>
+        public static ulong GetCurrentTimeMilliseconds() {
+            return (ulong)_stopwatch.ElapsedMilliseconds;
+        }
+    }
+}

test.meta

@@ -1,8 +0,0 @@
-fileFormatVersion: 2
-guid: 239400f5314a5aa4bac98db5861f77a7
-folderAsset: yes
-DefaultImporter:
-  externalObjects: {}
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: 

test.sln

@@ -1,36 +0,0 @@
-
-Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio Version 17
-VisualStudioVersion = 17.0.31903.59
-MinimumVisualStudioVersion = 10.0.40219.1
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ControlCore", "ControlCore.csproj", "{F2DEE6B0-AF41-454E-AAC8-9E1E3ACC769F}"
-EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "test", "test\test.csproj", "{2C350E2B-9DDA-4037-BAE5-E12AB7A52398}"
-EndProject
-Global
-	GlobalSection(SolutionConfigurationPlatforms) = preSolution
-		Debug|Any CPU = Debug|Any CPU
-		Release|Any CPU = Release|Any CPU
-	EndGlobalSection
-	GlobalSection(SolutionProperties) = preSolution
-		HideSolutionNode = FALSE
-	EndGlobalSection
-	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{6601071A-9E9C-42E1-95EA-0A36C5D718E4}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{6601071A-9E9C-42E1-95EA-0A36C5D718E4}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{6601071A-9E9C-42E1-95EA-0A36C5D718E4}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{6601071A-9E9C-42E1-95EA-0A36C5D718E4}.Release|Any CPU.Build.0 = Release|Any CPU
-		{DD7238DA-DBEF-4D6A-98DB-6FE28BBDB75D}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{DD7238DA-DBEF-4D6A-98DB-6FE28BBDB75D}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{DD7238DA-DBEF-4D6A-98DB-6FE28BBDB75D}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{DD7238DA-DBEF-4D6A-98DB-6FE28BBDB75D}.Release|Any CPU.Build.0 = Release|Any CPU
-		{F2DEE6B0-AF41-454E-AAC8-9E1E3ACC769F}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{F2DEE6B0-AF41-454E-AAC8-9E1E3ACC769F}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{F2DEE6B0-AF41-454E-AAC8-9E1E3ACC769F}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{F2DEE6B0-AF41-454E-AAC8-9E1E3ACC769F}.Release|Any CPU.Build.0 = Release|Any CPU
-		{2C350E2B-9DDA-4037-BAE5-E12AB7A52398}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{2C350E2B-9DDA-4037-BAE5-E12AB7A52398}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{2C350E2B-9DDA-4037-BAE5-E12AB7A52398}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{2C350E2B-9DDA-4037-BAE5-E12AB7A52398}.Release|Any CPU.Build.0 = Release|Any CPU
-	EndGlobalSection
-EndGlobal

test/UnitTest1.cs

@@ -5,7 +5,7 @@ using NUnit.Framework;
 
 using RoboidControl;
 
-namespace ControlCore.test {
+namespace RoboidControl.test {
     public class Tests {
         [SetUp]
         public void Setup() {
@@ -13,7 +13,7 @@ namespace ControlCore.test {
 
         [Test]
         public void Test_Participant() {
-            Participant participant = new Participant("127.0.0.1", 7682);
+            LocalParticipant participant = new LocalParticipant("127.0.0.1", 7682);
 
             ulong milliseconds = (ulong)DateTimeOffset.UtcNow.ToUnixTimeMilliseconds();
             ulong startTime = milliseconds;
@@ -46,7 +46,7 @@ namespace ControlCore.test {
         [Test]
         public void Test_SiteParticipant() {
             SiteServer siteServer = new SiteServer(7681);
-            Participant participant = new Participant("127.0.0.1", 7681);
+            LocalParticipant participant = new LocalParticipant("127.0.0.1", 7681);
 
             ulong milliseconds = (ulong)DateTimeOffset.UtcNow.ToUnixTimeMilliseconds();
             ulong startTime = milliseconds;
@@ -64,8 +64,8 @@ namespace ControlCore.test {
         [Test]
         public void Test_ThingMsg() {
             SiteServer siteServer = new SiteServer(7681);
-            Participant participant = new Participant("127.0.0.1");
-            Thing thing = new Thing(participant) {
+            LocalParticipant participant = new LocalParticipant("127.0.0.1");
+            Thing thing = new Thing(participant, false) {
                 name = "First Thing",
                 modelUrl = "https://passer.life/extras/ant.jpg"
             };

test/test.csproj

@@ -13,7 +13,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <ProjectReference Include="..\ControlCore.csproj" />
+    <ProjectReference Include="..\src\RoboidControl.csproj" />
   </ItemGroup>
 
 </Project>