Add support for sprites with alpha mask

- Sprites with alpha mask can now be viewed and exported with transparency
- Added hotkeys to control display of an alpha mask  on the preview tab
- Added an option to the export settings to enable/disable export with alpha mask as well
- Prevented texture2D preview options from being changed with hotkeys outside of texture preview (e.g. when some other asset is selected)

AssetStudioGUI/Properties/Settings.Designer.cs

@@ -1,10 +1,10 @@
 //------------------------------------------------------------------------------
 // <auto-generated>
-//     此代码由工具生成。
-//     运行时版本:4.0.30319.42000
+//     This code was generated by a tool.
+//     Runtime Version:4.0.30319.42000
 //
-//     对此文件的更改可能会导致不正确的行为，并且如果
-//     重新生成代码，这些更改将会丢失。
+//     Changes to this file may cause incorrect behavior and will be lost if
+//     the code is regenerated.
 // </auto-generated>
 //------------------------------------------------------------------------------
 
@@ -12,7 +12,7 @@ namespace AssetStudioGUI.Properties {
     
     
     [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]
-    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.VisualStudio.Editors.SettingsDesigner.SettingsSingleFileGenerator", "16.10.0.0")]
+    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.VisualStudio.Editors.SettingsDesigner.SettingsSingleFileGenerator", "17.1.0.0")]
     internal sealed partial class Settings : global::System.Configuration.ApplicationSettingsBase {
         
         private static Settings defaultInstance = ((Settings)(global::System.Configuration.ApplicationSettingsBase.Synchronized(new Settings())));
@@ -274,5 +274,17 @@ namespace AssetStudioGUI.Properties {
                 this["exportAllUvsAsDiffuseMaps"] = value;
             }
         }
+        
+        [global::System.Configuration.UserScopedSettingAttribute()]
+        [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
+        [global::System.Configuration.DefaultSettingValueAttribute("True")]
+        public bool exportSpriteWithMask {
+            get {
+                return ((bool)(this["exportSpriteWithMask"]));
+            }
+            set {
+                this["exportSpriteWithMask"] = value;
+            }
+        }
     }
 }

AssetStudioGUI/Properties/Settings.settings

@@ -65,5 +65,8 @@
     <Setting Name="exportAllUvsAsDiffuseMaps" Type="System.Boolean" Scope="User">
       <Value Profile="(Default)">False</Value>
     </Setting>
+    <Setting Name="exportSpriteWithMask" Type="System.Boolean" Scope="User">
+      <Value Profile="(Default)">True</Value>
+    </Setting>
   </Settings>
 </SettingsFile>