Store a RuntimeTexturePacker packed texture region's source region

CHANGELOG.md

@@ -76,6 +76,7 @@ Improvements
 - Made RuntimeTexturePacker restore texture region name and pivot when packing
 - Multi-target net452, making MLEM compatible with MonoGame for consoles
 - Added trimming and AOT annotations and made MLEM.Data trimmable
+- Store a RuntimeTexturePacker packed texture region's source region
 
 Fixes
 - Fixed data texture atlases not allowing most characters in their region names

MLEM.Data/RuntimeTexturePacker.cs

@@ -203,7 +203,8 @@ namespace MLEM.Data {
                 var packedArea = request.PackedArea.Shrink(new Point(request.Padding, request.Padding));
                 request.Result.Invoke(new TextureRegion(this.PackedTexture, packedArea) {
                     Pivot = request.Texture.Pivot,
-                    Name = request.Texture.Name
+                    Name = request.Texture.Name,
+                    Source = request.Texture
                 });
                 if (this.disposeTextures)
                     request.Texture.Texture.Dispose();

MLEM/Textures/TextureRegion.cs

@@ -58,6 +58,11 @@ namespace MLEM.Textures {
         /// The name of this texture region. By default, this name is <see cref="string.Empty"/>.
         /// </summary>
         public string Name = string.Empty;
+        /// <summary>
+        /// A <see cref="TextureRegion"/> that this texture region was created from.
+        /// This value is set in the various constructors that accept another <see cref="TextureRegion"/> to create sub-regions from, as well as by MLEM.Data's <c>RuntimeTexturePacker</c>.
+        /// </summary>
+        public TextureRegion Source;
 
         /// <summary>
         /// Creates a new texture region from a texture and a rectangle which defines the region's area
@@ -116,7 +121,9 @@ namespace MLEM.Textures {
         /// <param name="region">The texture region to create a sub-region of</param>
         /// <param name="uv">The top left corner of this area</param>
         /// <param name="size">The size of this area</param>
-        public TextureRegion(TextureRegion region, Point uv, Point size) : this(region.Texture, region.Position + uv, size) {}
+        public TextureRegion(TextureRegion region, Point uv, Point size) : this(region.Texture, region.Position + uv, size) {
+            this.Source = region;
+        }
 
         /// <summary>
         /// Returns a new <see cref="TextureRegion"/> that has the same <see cref="Texture"/>, <see cref="Pivot"/> and <see cref="Size"/> as this texture, but the returned region's <see cref="Position"/> will be offset by <paramref name="offset"/>.