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Source/Editor/States/PlayingState.cs

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+// Copyright (c) 2012-2020 Wojciech Figat. All rights reserved.
+
+using System;
+using System.Collections.Generic;
+using FlaxEditor.Content.Settings;
+using FlaxEditor.SceneGraph;
+using FlaxEditor.Utilities;
+using FlaxEngine;
+using FlaxEngine.Utilities;
+
+namespace FlaxEditor.States
+{
+    /// <summary>
+    /// In this state editor is simulating game.
+    /// </summary>
+    /// <seealso cref="FlaxEditor.States.EditorState" />
+    [HideInEditor]
+    public sealed class PlayingState : EditorState
+    {
+        private readonly DuplicateScenes _duplicateScenes = new DuplicateScenes();
+        private readonly List<Guid> _selectedObjects = new List<Guid>();
+
+        /// <summary>
+        /// Gets a value indicating whether any scene was dirty before entering the play mode.
+        /// </summary>
+        public bool WasDirty => _duplicateScenes.WasDirty;
+
+        /// <inheritdoc />
+        public override bool CanEditScene => true;
+
+        /// <inheritdoc />
+        public override bool CanEnterPlayMode => true;
+
+        /// <summary>
+        /// Occurs when play mode is starting (before scene duplicating).
+        /// </summary>
+        public event Action SceneDuplicating;
+
+        /// <summary>
+        /// Occurs when play mode is starting (after scene duplicating).
+        /// </summary>
+        public event Action SceneDuplicated;
+
+        /// <summary>
+        /// Occurs when play mode is applying game settings. Can be used to cache the editor local state of some settings.
+        /// </summary>
+        public event Action GameSettingsApplying;
+
+        /// <summary>
+        /// Occurs when play mode applied game settings. Can be used to preserve the editor local state of some settings.
+        /// </summary>
+        public event Action GameSettingsApplied;
+
+        /// <summary>
+        /// Occurs when play mode is ending (before scene restoring).
+        /// </summary>
+        public event Action SceneRestoring;
+
+        /// <summary>
+        /// Occurs when play mode is ending (after scene restoring).
+        /// </summary>
+        public event Action SceneRestored;
+
+        /// <summary>
+        /// Gets or sets a value indicating whether game logic is paused.
+        /// </summary>
+        public bool IsPaused
+        {
+            get => Time.GamePaused;
+            set
+            {
+                if (!IsActive)
+                    throw new InvalidOperationException();
+
+                Time.GamePaused = value;
+            }
+        }
+
+        internal PlayingState(Editor editor)
+        : base(editor)
+        {
+            SetupEditorEnvOptions();
+        }
+
+        private void CacheSelection()
+        {
+            _selectedObjects.Clear();
+            for (int i = 0; i < Editor.SceneEditing.Selection.Count; i++)
+            {
+                _selectedObjects.Add(Editor.SceneEditing.Selection[i].ID);
+            }
+        }
+
+        private void RestoreSelection()
+        {
+            var count = Editor.SceneEditing.Selection.Count;
+            Editor.SceneEditing.Selection.Clear();
+            for (int i = 0; i < _selectedObjects.Count; i++)
+            {
+                var node = SceneGraphFactory.FindNode(_selectedObjects[i]);
+                if (node != null)
+                    Editor.SceneEditing.Selection.Add(node);
+            }
+            if (Editor.SceneEditing.Selection.Count != count)
+                Editor.SceneEditing.OnSelectionChanged();
+        }
+
+        /// <inheritdoc />
+        public override string Status => "Play Mode!";
+
+        /// <inheritdoc />
+        public override void OnEnter()
+        {
+            Editor.OnPlayBeginning();
+
+            CacheSelection();
+
+            // Remove references to the scene objects
+            Editor.Scene.ClearRefsToSceneObjects(true);
+
+            // Apply game settings (user may modify them before the gameplay)
+            GameSettingsApplying?.Invoke();
+            GameSettings.Apply();
+            GameSettingsApplied?.Invoke();
+
+            // Duplicate editor scene for simulation
+            SceneDuplicating?.Invoke();
+            _duplicateScenes.GatherSceneData();
+            Editor.Internal_SetPlayMode(true);
+            IsPaused = false;
+            _duplicateScenes.CreateScenes();
+            SceneDuplicated?.Invoke();
+            RestoreSelection();
+
+            Editor.OnPlayBegin();
+        }
+
+        private void SetupEditorEnvOptions()
+        {
+            Time.TimeScale = 1.0f;
+            Physics.AutoSimulation = true;
+            Screen.CursorVisible = true;
+            Screen.CursorLock = CursorLockMode.None;
+        }
+
+        /// <inheritdoc />
+        public override void UpdateFPS()
+        {
+            // Game drives the Time settings
+        }
+
+        /// <inheritdoc />
+        public override void OnExit(State nextState)
+        {
+            IsPaused = true;
+
+            // Remove references to the scene objects
+            Editor.Scene.ClearRefsToSceneObjects(true);
+
+            // Restore editor scene
+            SceneRestoring?.Invoke();
+            _duplicateScenes.DeletedScenes();
+            Editor.Internal_SetPlayMode(false);
+            _duplicateScenes.RestoreSceneData();
+            SceneRestored?.Invoke();
+
+            // Restore game settings and state for editor environment
+            SetupEditorEnvOptions();
+            var win = Editor.Windows.GameWin?.Root;
+            if (win != null)
+                win.Cursor = CursorType.Default;
+            IsPaused = true;
+            RestoreSelection();
+
+            Editor.OnPlayEnd();
+        }
+    }
+}