finished untested packing algorithm for texture atlas as well as added some documentation.

RecrownedAthenaeum.ConsoleTools/TextureAtlasTools/TexturePacker.cs

@@ -11,69 +11,206 @@ using SixLabors.ImageSharp.PixelFormats;
 namespace RecrownedAthenaeum.ConsoleTools.TextureAtlasTools
 {
 
-    internal class TexturePacker
+    internal class TexturePacker : IDisposable
     {
         private enum SupportedExtensions
         {
             jpeg, jpg, png
         }
 
+        int powLimit;
+
         Rectangle theoreticalSpace;
         Node masterNode;
+        ImageHandler[] imageHandlers;
+        Queue<ImageHandler> imageHandlerQueue;
+        int textureLength;
 
-        internal TexturePacker(string rootDirectoryPath)
+        /// <summary>
+        /// Machine to pack multiple textures into one large texture.
+        /// </summary>
+        /// <param name="rootDirectoryPath">Path to textures.</param>
+        /// <param name="powLimit">Power of two limit for auto expanding texture. Default is 12 which is a 4096x4096 texture.</param>
+        /// <param name="startingPower">What power to start at and build up from. Default is 8 which is a 256x256 texture.</param>
+        internal TexturePacker(string rootDirectoryPath, int powLimit = 12, int startingPower = 8)
         {
+            this.powLimit = powLimit;
             string[] paths = Directory.GetFiles(rootDirectoryPath);
-
+            int currentPoT = startingPower;
-            int minArea = 0;
+            List<ImageHandler> imageHandlers = new List<ImageHandler>();
-            int currentPoTArea = 2 * 2;
-            List<TheoreticalImage> theoreticalImages = new List<TheoreticalImage>();
             for (int pathID = 0; pathID < paths.Length; pathID++)
             {
                 SupportedExtensions extension;
                 if (Enum.TryParse(Path.GetExtension(paths[pathID]), out extension))
                 {
-                    using (FileStream stream = new FileStream(paths[pathID], FileMode.Open))
+                    ImageHandler image = new ImageHandler(paths[pathID]);
-                    {
+                    imageHandlers.Add(image);
-                        IImageInfo info = Image.Identify(stream);
-                        TheoreticalImage ti = new TheoreticalImage(info.Width, info.Height, paths[pathID]);
-                        theoreticalImages.Add(ti);
-
-                        minArea += ti.Area;
-                        while (currentPoTArea < minArea)
-                        {
-                            currentPoTArea *= 2 * 2;
-                        }
-                    }
                 }
             }
+            imageHandlers.Sort();
+            this.imageHandlers = imageHandlers.ToArray();
+            imageHandlerQueue = new Queue<ImageHandler>(imageHandlers);
+            textureLength = currentPoT;
+        }
 
+        /// <summary>
+        /// Builds a texture atlas.
+        /// </summary>
+        /// <param name="AutoCorrectAtlasSize">Whether or not to automatically upscale atlas' texture in the case it is too small. Goes up to 4096 by default.</param>
+        public void Build(bool AutoCorrectAtlasSize = true)
+        {
+            masterNode = new Node();
+            masterNode.region.Width = textureLength;
+            masterNode.region.Height = textureLength;
+
+            ImageHandler imageHandler;
+            while (imageHandlerQueue.TryDequeue(out imageHandler))
+            {
+                try
+                {
+                    masterNode.InsertImageHandler(imageHandler);
+                }
+                catch (InvalidOperationException)
+                {
+                    textureLength *= 2;
+                    if (!AutoCorrectAtlasSize || textureLength > Math.Pow(2, powLimit))
+                    {
+                        throw new InvalidOperationException("Dimensions of texture goes past limit amount of " + powLimit + " which is " + Math.Pow(2, powLimit) + ". New texture size would be " + textureLength + "x" + textureLength + ".");
+                    }
+                    Build();
+                }
+            }
+        }
+
+        /// <summary>
+        /// Renders the build into a PNG file and generates the respective <see cref="TextureAtlasData"/> meant for serialization and later to be loaded.
+        /// </summary>
+        public void Save()
+        {
+
+        }
+
+        public void Dispose()
+        {
+            foreach (ImageHandler imageHandler in imageHandlers)
+            {
+                imageHandler.Dispose();
+            }
         }
 
         private class Node
         {
             public Node parent;
-            public Node[] branches = new Node[2];
+            private Node a, b;
-            public readonly TheoreticalImage theoreticalImage;
+            public Node childA { get { if (a == null) a = new Node(this); return a; } set { value.parent = this; a = value; } }
+            public Node childB { get { if (b == null) { b = new Node(this); } return b; } set { value.parent = this; b = value; } }
+            public Rectangle region;
+            public ImageHandler imageHandler;
+            public bool Filled { get { return (imageHandler != null) || (a != null && b != null && a.Filled && b.Filled); } }
 
-            public Node(TheoreticalImage theoreticalImage)
+            public Node(Node parent = null)
             {
-                this.theoreticalImage = theoreticalImage;
+                this.parent = parent;
+                region = parent.region;
+            }
+
+            public void SetNodeRegion(int x, int y, int width, int height, ImageHandler imageHandler)
+            {
+                region.X = x;
+                region.Y = y;
+                region.Width = width;
+                region.Height = height;
+                this.imageHandler = imageHandler;
+            }
+
+            public void SetNodeRegion(ImageHandler imageHandler)
+            {
+                SetNodeRegion(imageHandler.x, imageHandler.y, imageHandler.Width, imageHandler.Height, imageHandler);
+            }
+
+
+            public Node InsertImageHandler(ImageHandler imageHandler)
+            {
+                if (imageHandler.Width != region.Width)
+                {
+                    if (imageHandler.Width < region.Width)
+                    {
+                        if (a == null)
+                        {
+                            childA.region.Width = imageHandler.Width;
+                            childB.region.Width = region.Width - childA.region.Width;
+                        }
+                        if (!childA.Filled && imageHandler.Width <= childA.region.Width)
+                        {
+                            return childA.InsertImageHandler(imageHandler);
+                        }
+
+                        if (!childB.Filled)
+                        {
+                            return childB.InsertImageHandler(imageHandler);
+                        }
+                    }
+                }
+                else if (imageHandler.Height != region.Height)
+                {
+                    if (imageHandler.Height < region.Height)
+                    {
+                        if (a == null)
+                        {
+                            childA.region.Height = imageHandler.Height;
+                            childB.region.Height = region.Height - childA.region.Height;
+                        }
+
+                        if (!childA.Filled && imageHandler.Width <= childA.region.Width)
+                        {
+                            return childA.InsertImageHandler(imageHandler);
+                        }
+
+                        if (!childB.Filled)
+                        {
+                            return childB.InsertImageHandler(imageHandler);
+                        }
+                    }
+                }
+                else
+                {
+                    imageHandler.x = region.X;
+                    imageHandler.y = region.Y;
+                    this.imageHandler = imageHandler;
+                    return this;
+                }
+
+                throw new ArgumentException();
             }
         }
 
-        private struct TheoreticalImage
+        private class ImageHandler : IComparable<ImageHandler>, IDisposable
         {
-            public Rectangle bounds;
             public readonly string path;
-            public int Area { get { return bounds.Width * bounds.Height; } }
+            public readonly Image<Rgba32> image;
+            public int Area { get { return image.Width * image.Height; } }
+            public string Name { get { return Path.GetFileName(path); } }
+            public int Width { get { return image.Width; } }
+            public int Height { get { return image.Height; } }
+            public int x, y;
 
-            public TheoreticalImage(int width, int height, string path)
+            internal ImageHandler(String path)
             {
-                bounds = new Rectangle();
-                bounds.Width = width;
-                bounds.Height = height;
                 this.path = path;
+                using (FileStream stream = new FileStream(path, FileMode.Open))
+                {
+                    image = Image.Load(stream);
+                }
+            }
+
+            public int CompareTo(ImageHandler tImage)
+            {
+                return Area - tImage.Area;
+            }
+
+            public void Dispose()
+            {
+                image.Dispose();
             }
         }
     }