Move ImageConfig into GenConfig file

Author: a-maurice

firebaseai/src/GenerationConfig.cs

@@ -328,5 +328,81 @@ internal Dictionary<string, object> ToJson()
     }
   }
 
+  /// <summary>
+  /// Configuration options for generating images with Gemini models.
+  /// </summary>
+  public readonly struct ImageConfig
+  {
+    /// <summary>
+    /// The aspect ratio of generated images.
+    /// </summary>
+    public readonly struct AspectRatio
+    {
+      public string Value { get; }
+
+      /// <summary>
+      /// Constructs a custom AspectRatio, instead of one of the presets.
+      /// Note that the backend model needs to support the requested ratio.
+      /// </summary>
+      public AspectRatio(string value) { Value = value; }
+
+      public static readonly AspectRatio Square1x1 = new("1:1");
+      public static readonly AspectRatio Portrait9x16 = new("9:16");
+      public static readonly AspectRatio Landscape16x9 = new("16:9");
+      public static readonly AspectRatio Portrait3x4 = new("3:4");
+      public static readonly AspectRatio Landscape4x3 = new("4:3");
+      public static readonly AspectRatio Portrait2x3 = new("2:3");
+      public static readonly AspectRatio Landscape3x2 = new("3:2");
+      public static readonly AspectRatio Portrait4x5 = new("4:5");
+      public static readonly AspectRatio Landscape5x4 = new("5:4");
+      public static readonly AspectRatio Portrait1x4 = new("1:4");
+      public static readonly AspectRatio Landscape4x1 = new("4:1");
+      public static readonly AspectRatio Portrait1x8 = new("1:8");
+      public static readonly AspectRatio Landscape8x1 = new("8:1");
+      public static readonly AspectRatio Ultrawide21x9 = new("21:9");
+
+      public override string ToString() => Value;
+    }
+
+    /// <summary>
+    /// The size of images to generate.
+    /// </summary>
+    public readonly struct ImageSize
+    {
+      public string Value { get; }
+
+      /// <summary>
+      /// Constructs a custom ImageSize, instead of one of the presets.
+      /// Note that the backend model needs to support the requested size.
+      /// </summary>
+      public ImageSize(string value) { Value = value; }
+
+      public static readonly ImageSize Size512 = new("512");
+      public static readonly ImageSize Size1K = new("1K");
+      public static readonly ImageSize Size2K = new("2K");
+      public static readonly ImageSize Size4K = new("4K");
+
+      public override string ToString() => Value;
+    }
 
+    public AspectRatio? Ratio { get; }
+    public ImageSize? Size { get; }
+
+    /// <summary>
+    /// Creates a new `ImageConfig` with the given settings.
+    /// </summary>
+    public ImageConfig(AspectRatio? aspectRatio = null, ImageSize? imageSize = null)
+    {
+      Ratio = aspectRatio;
+      Size = imageSize;
+    }
+
+    internal Dictionary<string, object> ToJson()
+    {
+      Dictionary<string, object> jsonDict = new();
+      if (Ratio?.Value is string aspectRatio) jsonDict["aspectRatio"] = aspectRatio;
+      if (Size?.Value is string imageSize) jsonDict["imageSize"] = imageSize;
+      return jsonDict;
+    }
+  }
 }