项目结构调整

2026-03-19 16:06:35 +08:00 · 2023-04-16 20:11:40 +08:00
parent cbfbf96033
commit 81f91f3f35
2124 changed files with 218 additions and 5516 deletions
--- a/Others/WpfAnimatedGif/Decoding/GifFile.cs
+++ b/Others/WpfAnimatedGif/Decoding/GifFile.cs
@@ -0,0 +1,86 @@
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+
+namespace WpfAnimatedGif.Decoding
+{
+    internal class GifFile
+    {
+        public GifHeader Header { get; private set; }
+        public GifColor[] GlobalColorTable { get; set; }
+        public IList<GifFrame> Frames { get; set; }
+        public IList<GifExtension> Extensions { get; set; }
+        public ushort RepeatCount { get; set; }
+
+        private GifFile()
+        {
+        }
+
+        internal static GifFile ReadGifFile(Stream stream, bool metadataOnly)
+        {
+            var file = new GifFile();
+            file.Read(stream, metadataOnly);
+            return file;
+        }
+
+        private void Read(Stream stream, bool metadataOnly)
+        {
+            Header = GifHeader.ReadHeader(stream);
+
+            if (Header.LogicalScreenDescriptor.HasGlobalColorTable)
+            {
+                GlobalColorTable = GifHelpers.ReadColorTable(stream, Header.LogicalScreenDescriptor.GlobalColorTableSize);
+            }
+            ReadFrames(stream, metadataOnly);
+
+            var netscapeExtension =
+                            Extensions
+                                .OfType<GifApplicationExtension>()
+                                .FirstOrDefault(GifHelpers.IsNetscapeExtension);
+
+            if (netscapeExtension != null)
+                RepeatCount = GifHelpers.GetRepeatCount(netscapeExtension);
+            else
+                RepeatCount = 1;
+        }
+
+        private void ReadFrames(Stream stream, bool metadataOnly)
+        {
+            List<GifFrame> frames = new List<GifFrame>();
+            List<GifExtension> controlExtensions = new List<GifExtension>();
+            List<GifExtension> specialExtensions = new List<GifExtension>();
+            while (true)
+            {
+                var block = GifBlock.ReadBlock(stream, controlExtensions, metadataOnly);
+
+                if (block.Kind == GifBlockKind.GraphicRendering)
+                    controlExtensions = new List<GifExtension>();
+
+                if (block is GifFrame)
+                {
+                    frames.Add((GifFrame)block);
+                }
+                else if (block is GifExtension)
+                {
+                    var extension = (GifExtension)block;
+                    switch (extension.Kind)
+                    {
+                        case GifBlockKind.Control:
+                            controlExtensions.Add(extension);
+                            break;
+                        case GifBlockKind.SpecialPurpose:
+                            specialExtensions.Add(extension);
+                            break;
+                    }
+                }
+                else if (block is GifTrailer)
+                {
+                    break;
+                }
+            }
+
+            this.Frames = frames.AsReadOnly();
+            this.Extensions = specialExtensions.AsReadOnly();
+        }
+    }
+}