【Unity3D】【NGUI】Atlas的动态创建

1、参见SZUIAtlasMakerRuntimeTest设置相应的值以上值需要提前设置好
2、没有检查是否atlas能够正确创建，自己可以改，加入返回值
3、代码都是在NGUI里面拷贝出来的，只是进行改动，没有新代码
4、适用与那种从网上下图片，之后还不想用UITexture的人，但是还是建议用UITexture如果drawcall不是问题的话
5、自己以后更新按我的方式改改就可以
6、动态创建速度较慢，建议在游戏启动的时候运行
7、游戏时可以将创建的atlas保存到可写目录，避免每次都新创建

SZUIAtlasMakerRuntimeTest.cs

 using UnityEngine;
 using System.Collections;

 public class SZUIAtlasMakerRuntimeTest : MonoBehaviour {

     public Texture2D[] texs;
     public UISprite sprite;
     private UIAtlas atlas;

     void Start () {

         SZUIAtlasMakerRuntime.atlasTrimming = true;
         SZUIAtlasMakerRuntime.atlasPMA = atlas != null ? atlas.premultipliedAlpha : false;
         SZUIAtlasMakerRuntime.unityPacking = false;
         SZUIAtlasMakerRuntime.atlasPadding = 1;
         SZUIAtlasMakerRuntime.allow4096 = true;
         SZUIAtlasMakerRuntime.UITexturePacker.forceSquareAtlas = true;

         if (atlas == null)
         {
             atlas = this.gameObject.AddComponent();
         }
         string lastName = string.Empty;
         foreach (var tex in texs)
         {
             SZUIAtlasMakerRuntime.AddOrUpdate(atlas, tex);
             lastName = tex.name;
         }
         sprite.atlas = atlas;
         sprite.spriteName = lastName;
     }

 }

SZUIAtlasMakerRuntime.cs

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;

 public class SZUIAtlasMakerRuntime {

     public static bool atlasTrimming = true;
     public static bool atlasPMA = false;
     public static bool unityPacking = false;
     public static int atlasPadding = 1;
     public static bool allow4096 = true;

     public class SpriteEntry : UISpriteData
     {
         // Sprite texture -- original texture or a temporary texture
         public Texture2D tex;

         // Whether the texture is temporary and should be deleted
         public bool temporaryTexture = false;
     }

     ///
     /// Used to sort the sprites by pixels used
     ///

     static int Compare (SpriteEntry a, SpriteEntry b)
     {
         // A is null b is not b is greater so put it at the front of the list
         if (a == null && b != null) return 1;

         // A is not null b is null a is greater so put it at the front of the list
         if (a != null && b == null) return -1;

         // Get the total pixels used for each sprite
         int aPixels = a.width * a.height;
         int bPixels = b.width * b.height;

         if (aPixels > bPixels) return -1;
         else if (aPixels < bPixels) return 1;
         return 0;
     }

     ///
     /// Pack all of the specified sprites into a single texture, updating the outer and inner rects of the sprites as needed.
     ///

     static bool PackTextures (Texture2D tex, List sprites)
     {
         Texture2D[] textures = new Texture2D[sprites.Count];
         Rect[] rects;

         #if UNITY_3_5 || UNITY_4_0
         int maxSize = 4096;
         #else
         int maxSize = SystemInfo.maxTextureSize;
         #endif

         #if UNITY_ANDROID || UNITY_IPHONE
         maxSize = Mathf.Min(maxSize, allow4096 ? 4096 : 2048);
         #endif
         if (unityPacking)
         {
             for (int i = 0; i < sprites.Count; ++i) textures[i] = sprites[i].tex;
             rects = tex.PackTextures(textures, atlasPadding, maxSize);
         }
         else
         {
             sprites.Sort(Compare);
             for (int i = 0; i < sprites.Count; ++i) textures[i] = sprites[i].tex;
             rects = UITexturePacker.PackTextures(tex, textures, 4, 4, atlasPadding, maxSize);
         }

         for (int i = 0; i < sprites.Count; ++i)
         {
             Rect rect = NGUIMath.ConvertToPixels(rects[i], tex.width, tex.height, true);

             // Make sure that we don't shrink the textures
             if (Mathf.RoundToInt(rect.width) != textures[i].width) return false;

             SpriteEntry se = sprites[i];
             se.x = Mathf.RoundToInt(rect.x);
             se.y = Mathf.RoundToInt(rect.y);
             se.width = Mathf.RoundToInt(rect.width);
             se.height = Mathf.RoundToInt(rect.height);
         }
         return true;
     }

     static public void AddOrUpdate (UIAtlas atlas, Texture2D tex)
     {
         if (atlas != null && tex != null)
         {
             List textures = new List();
             textures.Add(tex);
             List sprites = CreateSprites(textures);
             ExtractSprites(atlas, sprites);
             UpdateAtlas(atlas, sprites);
         }
     }

     ///
     /// Update the sprite atlas, keeping only the sprites that are on the specified list.
     ///

     static public void UpdateAtlas (UIAtlas atlas, List sprites)
     {
         if (sprites.Count > 0)
         {
             // Combine all sprites into a single texture and save it
             if (UpdateTexture(atlas, sprites))
             {
                 // Replace the sprites within the atlas
                 ReplaceSprites(atlas, sprites);
             }

             // Release the temporary textures
             ReleaseSprites(sprites);
             return;
         }
         else
         {
             atlas.spriteList.Clear();
             NGUITools.Destroy(atlas.spriteMaterial.mainTexture);
             atlas.spriteMaterial.mainTexture = null;
         }

         atlas.MarkAsChanged();
     }

     ///
     /// Add a new sprite to the atlas, given the texture it's coming from and the packed rect within the atlas.
     ///

     static public UISpriteData AddSprite (List sprites, SpriteEntry se)
     {
         // See if this sprite already exists
         foreach (UISpriteData sp in sprites)
         {
             if (sp.name == se.name)
             {
                 sp.CopyFrom(se);
                 return sp;
             }
         }

         UISpriteData sprite = new UISpriteData();
         sprite.CopyFrom(se);
         sprites.Add(sprite);
         return sprite;
     }

     ///
     /// Create a list of sprites using the specified list of textures.
     ///
     ///
     static public List CreateSprites (List textures)
     {
         List list = new List();

         foreach (Texture tex in textures)
         {
             Texture2D oldTex = tex as Texture2D;

             // If we aren't doing trimming, just use the texture as-is
             if (!atlasTrimming && !atlasPMA)
             {
                 SpriteEntry sprite = new SpriteEntry();
                 sprite.SetRect(0, 0, oldTex.width, oldTex.height);
                 sprite.tex = oldTex;
                 sprite.name = oldTex.name;
                 sprite.temporaryTexture = false;
                 list.Add(sprite);
                 continue;
             }

             // If we want to trim transparent pixels, there is more work to be done
             Color32[] pixels = oldTex.GetPixels32();

             int xmin = oldTex.width;
             int xmax = 0;
             int ymin = oldTex.height;
             int ymax = 0;
             int oldWidth = oldTex.width;
             int oldHeight = oldTex.height;

             // Find solid pixels
             if (atlasTrimming)
             {
                 for (int y = 0, yw = oldHeight; y < yw; ++y)
                 {
                     for (int x = 0, xw = oldWidth; x < xw; ++x)
                     {
                         Color32 c = pixels[y * xw + x];

                         if (c.a != 0)
                         {
                             if (y < ymin) ymin = y;
                             if (y > ymax) ymax = y;
                             if (x < xmin) xmin = x;
                             if (x > xmax) xmax = x;
                         }
                     }
                 }
             }
             else
             {
                 xmin = 0;
                 xmax = oldWidth - 1;
                 ymin = 0;
                 ymax = oldHeight - 1;
             }

             int newWidth  = (xmax - xmin) + 1;
             int newHeight = (ymax - ymin) + 1;

             if (newWidth > 0 && newHeight > 0)
             {
                 SpriteEntry sprite = new SpriteEntry();
                 sprite.x = 0;
                 sprite.y = 0;
                 sprite.width = oldTex.width;
                 sprite.height = oldTex.height;

                 // If the dimensions match, then nothing was actually trimmed
                 if (!atlasPMA && (newWidth == oldWidth && newHeight == oldHeight))
                 {
                     sprite.tex = oldTex;
                     sprite.name = oldTex.name;
                     sprite.temporaryTexture = false;
                 }
                 else
                 {
                     // Copy the non-trimmed texture data into a temporary buffer
                     Color32[] newPixels = new Color32[newWidth * newHeight];

                     for (int y = 0; y < newHeight; ++y)
                     {
                         for (int x = 0; x < newWidth; ++x)
                         {
                             int newIndex = y * newWidth + x;
                             int oldIndex = (ymin + y) * oldWidth + (xmin + x);
                             if (atlasPMA) newPixels[newIndex] = NGUITools.ApplyPMA(pixels[oldIndex]);
                             else newPixels[newIndex] = pixels[oldIndex];
                         }
                     }

                     // Create a new texture
                     sprite.temporaryTexture = true;
                     sprite.name = oldTex.name;
                     sprite.tex = new Texture2D(newWidth, newHeight);
                     sprite.tex.SetPixels32(newPixels);
                     sprite.tex.Apply();

                     // Remember the padding offset
                     sprite.SetPadding(xmin, ymin, oldWidth - newWidth - xmin, oldHeight - newHeight - ymin);
                 }
                 list.Add(sprite);
             }
         }
         return list;
     }

     ///
     /// Release all temporary textures created for the sprites.
     ///

     static public void ReleaseSprites (List sprites)
     {
         foreach (SpriteEntry se in sprites)
         {
             if (se.temporaryTexture)
             {
                 NGUITools.Destroy(se.tex);
                 se.tex = null;
             }
         }
         Resources.UnloadUnusedAssets();
     }

     ///
     /// Replace the sprites within the atlas.
     ///

     static public void ReplaceSprites (UIAtlas atlas, List sprites)
     {
         // Get the list of sprites we'll be updating
         List spriteList = atlas.spriteList;
         List kept = new List();

         // Run through all the textures we added and add them as sprites to the atlas
         for (int i = 0; i < sprites.Count; ++i)
         {
             SpriteEntry se = sprites[i];
             UISpriteData sprite = AddSprite(spriteList, se);
             kept.Add(sprite);
         }

         // Remove unused sprites
         for (int i = spriteList.Count; i > 0; )
         {
             UISpriteData sp = spriteList[--i];
             if (!kept.Contains(sp)) spriteList.RemoveAt(i);
         }

         // Sort the sprites so that they are alphabetical within the atlas
         atlas.SortAlphabetically();
         atlas.MarkAsChanged();
     }

     ///
     /// Extract the specified sprite from the atlas.
     ///
     ///
     static public SpriteEntry ExtractSprite (UIAtlas atlas, string spriteName)
     {
         if (atlas.texture == null) return null;
         UISpriteData sd = atlas.GetSprite(spriteName);
         if (sd == null) return null;

         Texture2D tex = atlas.texture as Texture2D;
         SpriteEntry se = ExtractSprite(sd, tex);
         return se;
     }

     ///
     /// Extract the specified sprite from the atlas texture.
     ///

     static SpriteEntry ExtractSprite (UISpriteData es, Texture2D tex)
     {
         return (tex != null) ? ExtractSprite(es, tex.GetPixels32(), tex.width, tex.height) : null;
     }

     ///
     /// Extract the specified sprite from the atlas texture.
     ///

     static SpriteEntry ExtractSprite (UISpriteData es, Color32[] oldPixels, int oldWidth, int oldHeight)
     {
         int xmin = Mathf.Clamp(es.x, 0, oldWidth);
         int ymin = Mathf.Clamp(es.y, 0, oldHeight);
         int xmax = Mathf.Min(xmin + es.width, oldWidth - 1);
         int ymax = Mathf.Min(ymin + es.height, oldHeight - 1);
         int newWidth = Mathf.Clamp(es.width, 0, oldWidth);
         int newHeight = Mathf.Clamp(es.height, 0, oldHeight);

         if (newWidth == 0 || newHeight == 0) return null;

         Color32[] newPixels = new Color32[newWidth * newHeight];

         for (int y = 0; y < newHeight; ++y)
         {
             int cy = ymin + y;
             if (cy > ymax) cy = ymax;

             for (int x = 0; x < newWidth; ++x)
             {
                 int cx = xmin + x;
                 if (cx > xmax) cx = xmax;

                 int newIndex = (newHeight - 1 - y) * newWidth + x;
                 int oldIndex = (oldHeight - 1 - cy) * oldWidth + cx;

                 newPixels[newIndex] = oldPixels[oldIndex];
             }
         }

         // Create a new sprite
         SpriteEntry sprite = new SpriteEntry();
         sprite.CopyFrom(es);
         sprite.SetRect(0, 0, newWidth, newHeight);
         sprite.temporaryTexture = true;
         sprite.tex = new Texture2D(newWidth, newHeight);
         sprite.tex.SetPixels32(newPixels);
         sprite.tex.Apply();
         return sprite;
     }

     ///
     /// Extract sprites from the atlas, adding them to the list.
     ///

     static public void ExtractSprites (UIAtlas atlas, List finalSprites)
     {
         Texture2D tex = atlas.texture as Texture2D;

         if (tex != null)
         {
             Color32[] pixels = null;
             int width = tex.width;
             int height = tex.height;
             List sprites = atlas.spriteList;
             float count = sprites.Count;
             int index = 0;

             foreach (UISpriteData es in sprites)
             {
                 bool found = false;

                 foreach (SpriteEntry fs in finalSprites)
                 {
                     if (es.name == fs.name)
                     {
                         fs.CopyBorderFrom(es);
                         found = true;
                         break;
                     }
                 }

                 if (!found)
                 {
                     if (pixels == null) pixels = tex.GetPixels32();
                     SpriteEntry sprite = ExtractSprite(es, pixels, width, height);
                     if (sprite != null) finalSprites.Add(sprite);
                 }
             }
         }
     }

     static public bool UpdateTexture (UIAtlas atlas, List sprites)
     {
         // Get the texture for the atlas
         Texture2D tex = atlas.texture as Texture2D;

         bool newTexture = tex == null;

         if (newTexture)
         {
             // Create a new texture for the atlas
             tex = new Texture2D(1, 1, TextureFormat.ARGB32, false);
         }

         // Pack the sprites into this texture
         if (PackTextures(tex, sprites) && tex != null)
         {
             // Update the atlas texture
             if (newTexture)
             {
                 if (atlas.spriteMaterial == null)
                 {
                     Shader shader = Shader.Find(atlasPMA ? "Unlit/Premultiplied Colored" : "Unlit/Transparent Colored");
                     atlas.spriteMaterial = new Material(shader);
                 }
                 atlas.spriteMaterial.mainTexture = tex;
                 ReleaseSprites(sprites);
             }
             return true;
         }
         else
         {
             return false;
         }
     }

     // save as ngui's
     public class UITexturePacker
     {
         // sz modify
         public static bool forceSquareAtlas = true;
         public int binWidth = 0;
         public int binHeight = 0;
         public bool allowRotations;

         public List usedRectangles = new List();
         public List freeRectangles = new List();

         public enum FreeRectChoiceHeuristic
         {
             RectBestShortSideFit, //< -BSSF: Positions the rectangle against the short side of a free rectangle into which it fits the best.
             RectBestLongSideFit, //< -BLSF: Positions the rectangle against the long side of a free rectangle into which it fits the best.
             RectBestAreaFit, //< -BAF: Positions the rectangle into the smallest free rect into which it fits.
             RectBottomLeftRule, //< -BL: Does the Tetris placement.
             RectContactPointRule //< -CP: Choosest the placement where the rectangle touches other rects as much as possible.
         };

         public UITexturePacker (int width, int height, bool rotations)
         {
             Init(width, height, rotations);
         }

         public void Init (int width, int height, bool rotations)
         {
             binWidth = width;
             binHeight = height;
             allowRotations = rotations;

             Rect n = new Rect();
             n.x = 0;
             n.y = 0;
             n.width = width;
             n.height = height;

             usedRectangles.Clear();

             freeRectangles.Clear();
             freeRectangles.Add(n);
         }

         private struct Storage
         {
             public Rect rect;
             public bool paddingX;
             public bool paddingY;
         }

         public static Rect[] PackTextures (Texture2D texture, Texture2D[] textures, int width, int height, int padding, int maxSize)
         {
             if (width > maxSize && height > maxSize) return null;
             if (width > maxSize || height > maxSize) { int temp = width; width = height; height = temp; }

             // Force square by sizing up
             // sz modify
             //if (NGUISettings.forceSquareAtlas)
             if (forceSquareAtlas)
             {
                 if (width > height)
                     height = width;
                 else if (height > width)
                     width = height;
             }
             UITexturePacker bp = new UITexturePacker(width, height, false);
             Storage[] storage = new Storage[textures.Length];

             for (int i = 0; i < textures.Length; i++)
             {
                 Texture2D tex = textures[i];
                 if (!tex) continue;

                 Rect rect = new Rect();

                 int xPadding = 1;
                 int yPadding = 1;

                 for (xPadding = 1; xPadding >= 0; --xPadding)
                 {
                     for (yPadding = 1; yPadding >= 0; --yPadding)
                     {
                         rect = bp.Insert(tex.width + (xPadding * padding), tex.height + (yPadding * padding),
                                          UITexturePacker.FreeRectChoiceHeuristic.RectBestAreaFit);
                         if (rect.width != 0 && rect.height != 0) break;

                         // After having no padding if it still doesn't fit -- increase texture size.
                         else if (xPadding == 0 && yPadding == 0)
                         {
                             return PackTextures(texture, textures, width * (width <= height ? 2 : 1),
                                                 height * (height < width ? 2 : 1), padding, maxSize);
                         }
                     }
                     if (rect.width != 0 && rect.height != 0) break;
                 }

                 storage[i] = new Storage();
                 storage[i].rect = rect;
                 storage[i].paddingX = (xPadding != 0);
                 storage[i].paddingY = (yPadding != 0);
             }

             texture.Resize(width, height);
             texture.SetPixels(new Color[width * height]);

             // The returned rects
             Rect[] rects = new Rect[textures.Length];

             for (int i = 0; i < textures.Length; i++)
             {
                 Texture2D tex = textures[i];
                 if (!tex) continue;

                 Rect rect = storage[i].rect;
                 int xPadding = (storage[i].paddingX ? padding : 0);
                 int yPadding = (storage[i].paddingY ? padding : 0);
                 Color[] colors = tex.GetPixels();

                 // Would be used to rotate the texture if need be.
                 if (rect.width != tex.width + xPadding)
                 {
                     Color[] newColors = tex.GetPixels();

                     for (int x = 0; x < rect.width; x++)
                     {
                         for (int y = 0; y < rect.height; y++)
                         {
                             int prevIndex = ((int)rect.height - (y + 1)) + x * (int)tex.width;
                             newColors[x + y * (int)rect.width] = colors[prevIndex];
                         }
                     }

                     colors = newColors;
                 }

                 texture.SetPixels((int)rect.x, (int)rect.y, (int)rect.width - xPadding, (int)rect.height - yPadding, colors);
                 rect.x /= width;
                 rect.y /= height;
                 rect.width = (rect.width - xPadding) / width;
                 rect.height = (rect.height - yPadding) / height;
                 rects[i] = rect;
             }
             texture.Apply();
             return rects;
         }

         public Rect Insert (int width, int height, FreeRectChoiceHeuristic method)
         {
             Rect newNode = new Rect();
             int score1 = 0; // Unused in this function. We don't need to know the score after finding the position.
             int score2 = 0;
             switch (method)
             {
             case FreeRectChoiceHeuristic.RectBestShortSideFit: newNode = FindPositionForNewNodeBestShortSideFit(width, height, ref score1, ref score2); break;
             case FreeRectChoiceHeuristic.RectBottomLeftRule: newNode = FindPositionForNewNodeBottomLeft(width, height, ref score1, ref score2); break;
             case FreeRectChoiceHeuristic.RectContactPointRule: newNode = FindPositionForNewNodeContactPoint(width, height, ref score1); break;
             case FreeRectChoiceHeuristic.RectBestLongSideFit: newNode = FindPositionForNewNodeBestLongSideFit(width, height, ref score2, ref score1); break;
             case FreeRectChoiceHeuristic.RectBestAreaFit: newNode = FindPositionForNewNodeBestAreaFit(width, height, ref score1, ref score2); break;
             }

             if (newNode.height == 0)
                 return newNode;

             int numRectanglesToProcess = freeRectangles.Count;
             for (int i = 0; i < numRectanglesToProcess; ++i)
             {
                 if (SplitFreeNode(freeRectangles[i], ref newNode))
                 {
                     freeRectangles.RemoveAt(i);
                     --i;
                     --numRectanglesToProcess;
                 }
             }

             PruneFreeList();

             usedRectangles.Add(newNode);
             return newNode;
         }

         public void Insert (List rects, List dst, FreeRectChoiceHeuristic method)
         {
             dst.Clear();

             while (rects.Count > 0)
             {
                 int bestScore1 = int.MaxValue;
                 int bestScore2 = int.MaxValue;
                 int bestRectIndex = -1;
                 Rect bestNode = new Rect();

                 for (int i = 0; i < rects.Count; ++i)
                 {
                     int score1 = 0;
                     int score2 = 0;
                     Rect newNode = ScoreRect((int)rects[i].width, (int)rects[i].height, method, ref score1, ref score2);

                     if (score1 < bestScore1 || (score1 == bestScore1 && score2 < bestScore2))
                     {
                         bestScore1 = score1;
                         bestScore2 = score2;
                         bestNode = newNode;
                         bestRectIndex = i;
                     }
                 }

                 if (bestRectIndex == -1)
                     return;

                 PlaceRect(bestNode);
                 rects.RemoveAt(bestRectIndex);
             }
         }

         void PlaceRect (Rect node)
         {
             int numRectanglesToProcess = freeRectangles.Count;
             for (int i = 0; i < numRectanglesToProcess; ++i)
             {
                 if (SplitFreeNode(freeRectangles[i], ref node))
                 {
                     freeRectangles.RemoveAt(i);
                     --i;
                     --numRectanglesToProcess;
                 }
             }

             PruneFreeList();

             usedRectangles.Add(node);
         }

         Rect ScoreRect (int width, int height, FreeRectChoiceHeuristic method, ref int score1, ref int score2)
         {
             Rect newNode = new Rect();
             score1 = int.MaxValue;
             score2 = int.MaxValue;
             switch (method)
             {
             case FreeRectChoiceHeuristic.RectBestShortSideFit: newNode = FindPositionForNewNodeBestShortSideFit(width, height, ref score1, ref score2); break;
             case FreeRectChoiceHeuristic.RectBottomLeftRule: newNode = FindPositionForNewNodeBottomLeft(width, height, ref score1, ref score2); break;
             case FreeRectChoiceHeuristic.RectContactPointRule: newNode = FindPositionForNewNodeContactPoint(width, height, ref score1);
                 score1 = -score1; // Reverse since we are minimizing, but for contact point score bigger is better.
                 break;
             case FreeRectChoiceHeuristic.RectBestLongSideFit: newNode = FindPositionForNewNodeBestLongSideFit(width, height, ref score2, ref score1); break;
             case FreeRectChoiceHeuristic.RectBestAreaFit: newNode = FindPositionForNewNodeBestAreaFit(width, height, ref score1, ref score2); break;
             }

             // Cannot fit the current rectangle.
             if (newNode.height == 0)
             {
                 score1 = int.MaxValue;
                 score2 = int.MaxValue;
             }

             return newNode;
         }

         /// Computes the ratio of used surface area.
         public float Occupancy ()
         {
             ulong usedSurfaceArea = 0;
             for (int i = 0; i < usedRectangles.Count; ++i)
                 usedSurfaceArea += (uint)usedRectangles[i].width * (uint)usedRectangles[i].height;

             return (float)usedSurfaceArea / (binWidth * binHeight);
         }

         Rect FindPositionForNewNodeBottomLeft (int width, int height, ref int bestY, ref int bestX)
         {
             Rect bestNode = new Rect();
             //memset(bestNode, 0, sizeof(Rect));

             bestY = int.MaxValue;

             for (int i = 0; i < freeRectangles.Count; ++i)
             {
                 // Try to place the rectangle in upright (non-flipped) orientation.
                 if (freeRectangles[i].width >= width && freeRectangles[i].height >= height)
                 {
                     int topSideY = (int)freeRectangles[i].y + height;
                     if (topSideY < bestY || (topSideY == bestY && freeRectangles[i].x < bestX))
                     {
                         bestNode.x = freeRectangles[i].x;
                         bestNode.y = freeRectangles[i].y;
                         bestNode.width = width;
                         bestNode.height = height;
                         bestY = topSideY;
                         bestX = (int)freeRectangles[i].x;
                     }
                 }
                 if (allowRotations && freeRectangles[i].width >= height && freeRectangles[i].height >= width)
                 {
                     int topSideY = (int)freeRectangles[i].y + width;
                     if (topSideY < bestY || (topSideY == bestY && freeRectangles[i].x < bestX))
                     {
                         bestNode.x = freeRectangles[i].x;
                         bestNode.y = freeRectangles[i].y;
                         bestNode.width = height;
                         bestNode.height = width;
                         bestY = topSideY;
                         bestX = (int)freeRectangles[i].x;
                     }
                 }
             }
             return bestNode;
         }

         Rect FindPositionForNewNodeBestShortSideFit (int width, int height, ref int bestShortSideFit, ref int bestLongSideFit)
         {
             Rect bestNode = new Rect();
             //memset(&bestNode, 0, sizeof(Rect));

             bestShortSideFit = int.MaxValue;

             for (int i = 0; i < freeRectangles.Count; ++i)
             {
                 // Try to place the rectangle in upright (non-flipped) orientation.
                 if (freeRectangles[i].width >= width && freeRectangles[i].height >= height)
                 {
                     int leftoverHoriz = Mathf.Abs((int)freeRectangles[i].width - width);
                     int leftoverVert = Mathf.Abs((int)freeRectangles[i].height - height);
                     int shortSideFit = Mathf.Min(leftoverHoriz, leftoverVert);
                     int longSideFit = Mathf.Max(leftoverHoriz, leftoverVert);

                     if (shortSideFit < bestShortSideFit || (shortSideFit == bestShortSideFit && longSideFit < bestLongSideFit))
                     {
                         bestNode.x = freeRectangles[i].x;
                         bestNode.y = freeRectangles[i].y;
                         bestNode.width = width;
                         bestNode.height = height;
                         bestShortSideFit = shortSideFit;
                         bestLongSideFit = longSideFit;
                     }
                 }

                 if (allowRotations && freeRectangles[i].width >= height && freeRectangles[i].height >= width)
                 {
                     int flippedLeftoverHoriz = Mathf.Abs((int)freeRectangles[i].width - height);
                     int flippedLeftoverVert = Mathf.Abs((int)freeRectangles[i].height - width);
                     int flippedShortSideFit = Mathf.Min(flippedLeftoverHoriz, flippedLeftoverVert);
                     int flippedLongSideFit = Mathf.Max(flippedLeftoverHoriz, flippedLeftoverVert);

                     if (flippedShortSideFit < bestShortSideFit || (flippedShortSideFit == bestShortSideFit && flippedLongSideFit < bestLongSideFit))
                     {
                         bestNode.x = freeRectangles[i].x;
                         bestNode.y = freeRectangles[i].y;
                         bestNode.width = height;
                         bestNode.height = width;
                         bestShortSideFit = flippedShortSideFit;
                         bestLongSideFit = flippedLongSideFit;
                     }
                 }
             }
             return bestNode;
         }

         Rect FindPositionForNewNodeBestLongSideFit (int width, int height, ref int bestShortSideFit, ref int bestLongSideFit)
         {
             Rect bestNode = new Rect();
             //memset(&bestNode, 0, sizeof(Rect));

             bestLongSideFit = int.MaxValue;

             for (int i = 0; i < freeRectangles.Count; ++i)
             {
                 // Try to place the rectangle in upright (non-flipped) orientation.
                 if (freeRectangles[i].width >= width && freeRectangles[i].height >= height)
                 {
                     int leftoverHoriz = Mathf.Abs((int)freeRectangles[i].width - width);
                     int leftoverVert = Mathf.Abs((int)freeRectangles[i].height - height);
                     int shortSideFit = Mathf.Min(leftoverHoriz, leftoverVert);
                     int longSideFit = Mathf.Max(leftoverHoriz, leftoverVert);

                     if (longSideFit < bestLongSideFit || (longSideFit == bestLongSideFit && shortSideFit < bestShortSideFit))
                     {
                         bestNode.x = freeRectangles[i].x;
                         bestNode.y = freeRectangles[i].y;
                         bestNode.width = width;
                         bestNode.height = height;
                         bestShortSideFit = shortSideFit;
                         bestLongSideFit = longSideFit;
                     }
                 }

                 if (allowRotations && freeRectangles[i].width >= height && freeRectangles[i].height >= width)
                 {
                     int leftoverHoriz = Mathf.Abs((int)freeRectangles[i].width - height);
                     int leftoverVert = Mathf.Abs((int)freeRectangles[i].height - width);
                     int shortSideFit = Mathf.Min(leftoverHoriz, leftoverVert);
                     int longSideFit = Mathf.Max(leftoverHoriz, leftoverVert);

                     if (longSideFit < bestLongSideFit || (longSideFit == bestLongSideFit && shortSideFit < bestShortSideFit))
                     {
                         bestNode.x = freeRectangles[i].x;
                         bestNode.y = freeRectangles[i].y;
                         bestNode.width = height;
                         bestNode.height = width;
                         bestShortSideFit = shortSideFit;
                         bestLongSideFit = longSideFit;
                     }
                 }
             }
             return bestNode;
         }

         Rect FindPositionForNewNodeBestAreaFit (int width, int height, ref int bestAreaFit, ref int bestShortSideFit)
         {
             Rect bestNode = new Rect();
             //memset(&bestNode, 0, sizeof(Rect));

             bestAreaFit = int.MaxValue;

             for (int i = 0; i < freeRectangles.Count; ++i)
             {
                 int areaFit = (int)freeRectangles[i].width * (int)freeRectangles[i].height - width * height;

                 // Try to place the rectangle in upright (non-flipped) orientation.
                 if (freeRectangles[i].width >= width && freeRectangles[i].height >= height)
                 {
                     int leftoverHoriz = Mathf.Abs((int)freeRectangles[i].width - width);
                     int leftoverVert = Mathf.Abs((int)freeRectangles[i].height - height);
                     int shortSideFit = Mathf.Min(leftoverHoriz, leftoverVert);

                     if (areaFit < bestAreaFit || (areaFit == bestAreaFit && shortSideFit < bestShortSideFit))
                     {
                         bestNode.x = freeRectangles[i].x;
                         bestNode.y = freeRectangles[i].y;
                         bestNode.width = width;
                         bestNode.height = height;
                         bestShortSideFit = shortSideFit;
                         bestAreaFit = areaFit;
                     }
                 }

                 if (allowRotations && freeRectangles[i].width >= height && freeRectangles[i].height >= width)
                 {
                     int leftoverHoriz = Mathf.Abs((int)freeRectangles[i].width - height);
                     int leftoverVert = Mathf.Abs((int)freeRectangles[i].height - width);
                     int shortSideFit = Mathf.Min(leftoverHoriz, leftoverVert);

                     if (areaFit < bestAreaFit || (areaFit == bestAreaFit && shortSideFit < bestShortSideFit))
                     {
                         bestNode.x = freeRectangles[i].x;
                         bestNode.y = freeRectangles[i].y;
                         bestNode.width = height;
                         bestNode.height = width;
                         bestShortSideFit = shortSideFit;
                         bestAreaFit = areaFit;
                     }
                 }
             }
             return bestNode;
         }

         /// Returns 0 if the two intervals i1 and i2 are disjoint, or the length of their overlap otherwise.
         int CommonIntervalLength (int i1start, int i1end, int i2start, int i2end)
         {
             if (i1end < i2start || i2end < i1start)
                 return 0;
             return Mathf.Min(i1end, i2end) - Mathf.Max(i1start, i2start);
         }

         int ContactPointScoreNode (int x, int y, int width, int height)
         {
             int score = 0;

             if (x == 0 || x + width == binWidth)
                 score += height;
             if (y == 0 || y + height == binHeight)
                 score += width;

             for (int i = 0; i < usedRectangles.Count; ++i)
             {
                 if (usedRectangles[i].x == x + width || usedRectangles[i].x + usedRectangles[i].width == x)
                     score += CommonIntervalLength((int)usedRectangles[i].y, (int)usedRectangles[i].y + (int)usedRectangles[i].height, y, y + height);
                 if (usedRectangles[i].y == y + height || usedRectangles[i].y + usedRectangles[i].height == y)
                     score += CommonIntervalLength((int)usedRectangles[i].x, (int)usedRectangles[i].x + (int)usedRectangles[i].width, x, x + width);
             }
             return score;
         }

         Rect FindPositionForNewNodeContactPoint (int width, int height, ref int bestContactScore)
         {
             Rect bestNode = new Rect();
             //memset(&bestNode, 0, sizeof(Rect));

             bestContactScore = -1;

             for (int i = 0; i < freeRectangles.Count; ++i)
             {
                 // Try to place the rectangle in upright (non-flipped) orientation.
                 if (freeRectangles[i].width >= width && freeRectangles[i].height >= height)
                 {
                     int score = ContactPointScoreNode((int)freeRectangles[i].x, (int)freeRectangles[i].y, width, height);
                     if (score > bestContactScore)
                     {
                         bestNode.x = (int)freeRectangles[i].x;
                         bestNode.y = (int)freeRectangles[i].y;
                         bestNode.width = width;
                         bestNode.height = height;
                         bestContactScore = score;
                     }
                 }
                 if (allowRotations && freeRectangles[i].width >= height && freeRectangles[i].height >= width)
                 {
                     int score = ContactPointScoreNode((int)freeRectangles[i].x, (int)freeRectangles[i].y, height, width);
                     if (score > bestContactScore)
                     {
                         bestNode.x = (int)freeRectangles[i].x;
                         bestNode.y = (int)freeRectangles[i].y;
                         bestNode.width = height;
                         bestNode.height = width;
                         bestContactScore = score;
                     }
                 }
             }
             return bestNode;
         }

         bool SplitFreeNode (Rect freeNode, ref Rect usedNode)
         {
             // Test with SAT if the rectangles even intersect.
             if (usedNode.x >= freeNode.x + freeNode.width || usedNode.x + usedNode.width <= freeNode.x ||
                 usedNode.y >= freeNode.y + freeNode.height || usedNode.y + usedNode.height <= freeNode.y)
                 return false;

             if (usedNode.x < freeNode.x + freeNode.width && usedNode.x + usedNode.width > freeNode.x)
             {
                 // New node at the top side of the used node.
                 if (usedNode.y > freeNode.y && usedNode.y < freeNode.y + freeNode.height)
                 {
                     Rect newNode = freeNode;
                     newNode.height = usedNode.y - newNode.y;
                     freeRectangles.Add(newNode);
                 }

                 // New node at the bottom side of the used node.
                 if (usedNode.y + usedNode.height < freeNode.y + freeNode.height)
                 {
                     Rect newNode = freeNode;
                     newNode.y = usedNode.y + usedNode.height;
                     newNode.height = freeNode.y + freeNode.height - (usedNode.y + usedNode.height);
                     freeRectangles.Add(newNode);
                 }
             }

             if (usedNode.y < freeNode.y + freeNode.height && usedNode.y + usedNode.height > freeNode.y)
             {
                 // New node at the left side of the used node.
                 if (usedNode.x > freeNode.x && usedNode.x < freeNode.x + freeNode.width)
                 {
                     Rect newNode = freeNode;
                     newNode.width = usedNode.x - newNode.x;
                     freeRectangles.Add(newNode);
                 }

                 // New node at the right side of the used node.
                 if (usedNode.x + usedNode.width < freeNode.x + freeNode.width)
                 {
                     Rect newNode = freeNode;
                     newNode.x = usedNode.x + usedNode.width;
                     newNode.width = freeNode.x + freeNode.width - (usedNode.x + usedNode.width);
                     freeRectangles.Add(newNode);
                 }
             }

             return true;
         }

         void PruneFreeList ()
         {
             for (int i = 0; i < freeRectangles.Count; ++i)
                 for (int j = i + 1; j < freeRectangles.Count; ++j)
             {
                 if (IsContainedIn(freeRectangles[i], freeRectangles[j]))
                 {
                     freeRectangles.RemoveAt(i);
                     --i;
                     break;
                 }
                 if (IsContainedIn(freeRectangles[j], freeRectangles[i]))
                 {
                     freeRectangles.RemoveAt(j);
                     --j;
                 }
             }
         }

         bool IsContainedIn (Rect a, Rect b)
         {
             return a.x >= b.x && a.y >= b.y
                 && a.x + a.width <= b.x + b.width
                     && a.y + a.height <= b.y + b.height;
         }
     }

 }