Add Customizable Output Filename Formatting

Core/Data/GlobalSettings.cs

@@ -17,6 +17,11 @@ internal class GlobalConfig
     /// GlobalSettings.DefaultOutputDirectory. Ignored while the directory does not exist (see EffectiveOutputDirectory).
     /// </summary>
     public string? OutputDirectory { get; set; }
+    /// <summary>
+    /// File name format template chosen in the render configuration window; null or empty selects
+    /// GlobalSettings.DefaultFileNameFormat ("{date} {time}").
+    /// </summary>
+    public string? FileNameFormat { get; set; }
     /// <summary>Name of the preset last selected or saved in the render configuration window; selected again when it opens.</summary>
     public string? LastPresetName { get; set; }
     /// <summary>
@@ -72,6 +77,18 @@ internal static class GlobalSettings
         }
     }
 
+    /// <summary>Default file name format template: "{date} {time}".</summary>
+    public const string DefaultFileNameFormat = "{date} {time}";
+
+    /// <summary>
+    /// File name format used for renders without an explicit output path: Current.FileNameFormat when it is set,
+    /// otherwise <see cref="DefaultFileNameFormat"/>.
+    /// </summary>
+    public static string EffectiveFileNameFormat =>
+        string.IsNullOrWhiteSpace(Current.FileNameFormat)
+            ? DefaultFileNameFormat
+            : Current.FileNameFormat;
+
     static GlobalSettings()
     {
         Load();