Added an ExampleEntity entity baked into a snapshot

Includes entity template, prefab, snapshot containing entity and customized Unity Editor menu to provide an easy way of programmatically determining the contents of a snapshot

Author: samc-improbable

snapshots/initial_world.snapshot

@@ -0,0 +1,41 @@
+using System.Collections.Generic;
+using System.IO;
+using Assets.EntityTemplates;
+using Improbable;
+using Improbable.Worker;
+using UnityEngine;
+using JetBrains.Annotations;
+using UnityEditor;
+
+public class SnapshotMenu : MonoBehaviour
+{
+    private static readonly string InitialWorldSnapshotPath = Application.dataPath +
+                                                              "/../../../snapshots/initial_world.snapshot";
+
+    [MenuItem("Improbable/Snapshots/Generate Snapshot Programmatically")]
+    [UsedImplicitly]
+    private static void GenerateSnapshotProgrammatically()
+    {
+        var snapshotEntities = new Dictionary<EntityId, SnapshotEntity>();
+        var currentEntityId = 0;
+
+        snapshotEntities.Add(new EntityId(currentEntityId++), ExampleEntityTemplate.GenerateExampleSnapshotEntityTemplate());
+
+        SaveSnapshot(snapshotEntities);
+    }
+
+    private static void SaveSnapshot(IDictionary<EntityId, SnapshotEntity> snapshotEntities)
+    {
+        File.Delete(InitialWorldSnapshotPath);
+        var maybeError = Snapshot.Save(InitialWorldSnapshotPath, snapshotEntities);
+
+        if (maybeError.HasValue)
+        {
+            Debug.LogErrorFormat("Failed to generate initial world snapshot: {0}", maybeError.Value);
+        }
+        else
+        {
+            Debug.LogFormat("Successfully generated initial world snapshot at {0}", InitialWorldSnapshotPath);
+        }
+    }
+}

workers/unity/Assets/Editor.meta

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+using Improbable.General;
+using Improbable.Worker;
+using Improbable.Math;
+using Improbable.Unity.Core.Acls;
+using UnityEngine;
+
+namespace Assets.EntityTemplates
+{
+    public class ExampleEntityTemplate : MonoBehaviour
+    {
+        // Template definition for a Example entity
+        public static SnapshotEntity GenerateExampleSnapshotEntityTemplate()
+        {
+            // Set name of Unity prefab associated with this entity
+            var exampleEntity = new SnapshotEntity { Prefab = "ExampleEntity" };
+
+            // Define components attached to snapshot entity
+            exampleEntity.Add(new WorldTransform.Data(new WorldTransformData(new Coordinates(-5, 10, 0))));
+
+            // Grant FSim (server-side) workers write-access over all of this entity's components, read-access for visual (e.g. client) workers
+            var acl = Acl.GenerateServerAuthoritativeAcl(exampleEntity);
+            exampleEntity.SetAcl(acl);
+
+            return exampleEntity;
+        }
+    }
+}