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Source/Engine/Level/SceneQuery.h

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+// Copyright (c) 2012-2020 Wojciech Figat. All rights reserved.
+
+#pragma once
+
+// Enables locking scenes during scene query execution can provide some safety when using scene queries from other threads but may provide stalls on a main thread
+#define SCENE_QUERIES_WITH_LOCK 0
+
+#include "Scene/Scene.h"
+#include "Level.h"
+#if SCENE_QUERIES_WITH_LOCK
+#include "Engine/Threading/Threading.h"
+#endif
+
+/// <summary>
+/// Helper class to perform scene actions and queries
+/// </summary>
+class FLAXENGINE_API SceneQuery
+{
+public:
+
+    /// <summary>
+    /// Try to find actor hit by the given ray
+    /// </summary>
+    /// <param name="ray">Ray to test</param>
+    /// <returns>Hit actor or nothing</returns>
+    static Actor* RaycastScene(const Ray& ray);
+
+public:
+
+    /// <summary>
+    /// Gets all scene objects from the actor into linear list. Appends them (without the given actor).
+    /// </summary>
+    /// <param name="root">The root actor.</param>
+    /// <param name="objects">The objects output.</param>
+    static void GetAllSceneObjects(Actor* root, Array<SceneObject*>& objects);
+
+    /// <summary>
+    /// Gets all scene objects (for serialization) from the actor into linear list. Appends them (including the given actor).
+    /// </summary>
+    /// <param name="root">The root actor.</param>
+    /// <param name="objects">The objects output.</param>
+    static void GetAllSerializableSceneObjects(Actor* root, Array<SceneObject*>& objects);
+
+    /// <summary>
+    /// Gets all actors from the actor into linear list. Appends them (without the given actor).
+    /// </summary>
+    /// <param name="root">The root actor.</param>
+    /// <param name="actors">The actors output.</param>
+    static void GetAllActors(Actor* root, Array<Actor*>& actors);
+
+    /// <summary>
+    /// Gets all actors from the loaded scenes into linear list (without scene actors).
+    /// </summary>
+    /// <param name="actors">The actors output.</param>
+    static void GetAllActors(Array<Actor*>& actors);
+
+public:
+
+    /// <summary>
+    /// Execute custom action on actors tree.
+    /// Action should returns false to stop calling deeper.
+    /// First action argument is current actor object.
+    /// </summary>
+    /// <param name="action">Actor to call on every actor in the tree. Returns true if keep calling deeper.</param>
+    /// <param name="args">Custom arguments for the function</param>
+    template<typename... Params>
+    static void TreeExecute(Function<bool(Actor*, Params ...)>& action, Params ... args)
+    {
+#if SCENE_QUERIES_WITH_LOCK
+		ScopeLock lock(Level::ScenesLock);
+#endif
+
+        for (int32 i = 0; i < Level::Scenes.Count(); i++)
+            Level::Scenes[i]->TreeExecute<Params...>(action, args...);
+    }
+};