add audio volume and muted in game panel tab rmb menu

Source/Editor/Windows/GameWindow.cs

@@ -23,6 +23,8 @@ namespace FlaxEditor.Windows
         private readonly GameRoot _guiRoot;
         private bool _showGUI = true;
         private bool _showDebugDraw = false;
+        private bool _audioMuted = false;
+        private float _audioVolume = 1;
         private bool _isMaximized = false, _isUnlockingMouse = false;
         private bool _isFloating = false, _isBorderless = false;
         private bool _cursorVisible = true;
@@ -69,6 +71,35 @@ namespace FlaxEditor.Windows
             set => _showDebugDraw = value;
         }
 
+
+        /// <summary>
+        /// Gets or set a value indicating whether Audio is muted.
+        /// </summary>
+        public bool AudioMuted
+        {
+            get => _audioMuted;
+            set
+            {
+                Audio.MasterVolume = value ? 0 : AudioVolume;
+                _audioMuted = value;
+            }
+        }
+
+        /// <summary>
+        /// Gets or sets a value that set the audio volume.
+        /// </summary>
+        public float AudioVolume
+        {
+            get => _audioVolume;
+            set
+            {
+                if (!AudioMuted)
+                    Audio.MasterVolume = value;
+
+                _audioVolume = value;
+            }
+        }
+
         /// <summary>
         /// Gets or sets a value indicating whether the game window is maximized (only in play mode).
         /// </summary>
@@ -596,6 +627,24 @@ namespace FlaxEditor.Windows
                 checkbox.StateChanged += x => ShowDebugDraw = x.Checked;
             }
 
+            menu.AddSeparator();
+
+            // Mute Audio
+            {
+                var button = menu.AddButton("Mute Audio");
+                button.CloseMenuOnClick = false;
+                var checkbox = new CheckBox(140, 2, AudioMuted) { Parent = button };
+                checkbox.StateChanged += x => AudioMuted = x.Checked;
+            }
+
+            // Audio Volume
+            {
+                var button = menu.AddButton("Audio Volume");
+                button.CloseMenuOnClick = false;
+                var slider = new FloatValueBox(1, 140, 2, 50, 0, 1) { Parent = button };
+                slider.ValueChanged += () => AudioVolume = slider.Value;
+            }
+
             menu.MinimumWidth = 200;
             menu.AddSeparator();
         }