Refactor Output() slightly and document more stuff

This is in preparation for a GUI.

SpritePacker/SpritePacker.cs

@@ -17,8 +17,16 @@ namespace SpritePacker
 		/// </summary>
 		private List<Sprite> sprites = new List<Sprite>();
 
+		/// <summary>
+		/// Whether debug information should be outputted to the console.
+		/// </summary>
+		/// <value><c>true</c> if verbose; <c>false</c> otherwise.</value>
 		public bool Verbose { get; private set; }
 
+		/// <summary>
+		/// Initializes a new SpritePacker.
+		/// </summary>
+		/// <param name="inVerbose">Whether to output debug information to the console.</param>
 		public SpritePacker(bool inVerbose = false)
 		{
 			Verbose = inVerbose;
@@ -176,7 +184,12 @@ namespace SpritePacker
 			// because Sprite is a class and classes are passed by _reference_.
 		}
 
-		public void Output(string outputFilename)
+		/// <summary>
+		/// Generates an image that contains all the currently added sprites.
+		/// You probably want to call Arrage() before calling this method.
+		/// </summary>
+		/// <returns>The generated image.</returns>
+		public Bitmap GenerateImage()
 		{
 			// Calculate the size of the image we are about to output
 			Point imageSize = new Point(0, 0);
@@ -190,17 +203,35 @@ namespace SpritePacker
 
 			Bitmap finalImage = new Bitmap(imageSize.X, imageSize.Y, PixelFormat.Format32bppArgb);
 			finalImage.MakeTransparent();
-			Graphics context = Graphics.FromImage(finalImage);
-			foreach(Sprite spr in sprites)
+			using (Graphics context = Graphics.FromImage(finalImage))
 			{
-				context.DrawImage(spr.Image, spr.Location);
+				foreach(Sprite spr in sprites)
+				{
+					context.DrawImage(spr.Image, spr.Location);
+				}
 			}
-			finalImage.Save(outputFilename);
 
-			context.Dispose();
-			finalImage.Dispose();
+			return finalImage;
 		}
 
+		/// <summary>
+		/// Output the packed sprite as an image to the specified filename.
+		/// You probably want to call Arrage() before calling this method.
+		/// </summary>
+		/// <param name="outputFilename">The filename to save the generated image to.</param>
+		public void Output(string outputFilename)
+		{
+			using (Bitmap finalImage = GenerateImage())
+			{
+				finalImage.Save(outputFilename);
+			}
+		}
+
+		/// <summary>
+		/// Gets a the details of the currently added sprites as a string of CSV.
+		/// </summary>
+		/// <returns>Details of the current sprites as a string of CSV.</returns>
+		/// <param name="header">Whether to include a header in the generated CSV.</param>
 		public string GetSpritePositionsCSV(bool header = true)
 		{
 			StringWriter result = new StringWriter();