Add UnitTest

src/ImageSharp/Formats/Png/PngChunkType.cs

@@ -9,22 +9,7 @@ namespace SixLabors.ImageSharp.Formats.Png;
 internal enum PngChunkType : uint
 {
     /// <summary>
-    /// </summary>
-    /// <remarks>acTL (Single)</remarks>
-    AnimationControl = 0x6163544cU,
-
-    /// <summary>
-    /// </summary>
-    /// <remarks>fcTL (Multiple)</remarks>
-    FrameControl = 0x6663544cU,
-
-    /// <summary>
-    /// </summary>
-    /// <remarks>fdAT (Multiple)</remarks>
-    FrameData = 0x66644154U,
-
-    /// <summary>
-    /// The IDAT chunk contains the actual image data. The image can contains more
+    /// This chunk contains the actual image data. The image can contains more
     /// than one chunk of this type. All chunks together are the whole image.
     /// </summary>
     /// <remarks>IDAT (Multiple)</remarks>
@@ -155,6 +140,27 @@ internal enum PngChunkType : uint
     /// <remarks>cHRM (Single)</remarks>
     Chroma = 0x6348524d,
 
+    /// <summary>
+    /// This chunk is an ancillary chunk as defined in the PNG Specification.
+    /// It must appear before the first IDAT chunk within a valid PNG stream.
+    /// </summary>
+    /// <remarks>acTL (Single, APNG)</remarks>
+    AnimationControl = 0x6163544cU,
+
+    /// <summary>
+    /// This chunk is an ancillary chunk as defined in the PNG Specification.
+    /// It must appear before the IDAT or fdAT chunks of the frame to which it applies.
+    /// </summary>
+    /// <remarks>fcTL (Multiple, APNG)</remarks>
+    FrameControl = 0x6663544cU,
+
+    /// <summary>
+    /// This chunk has the same purpose as an IDAT chunk.
+    /// It has the same structure as an IDAT chunk, except preceded by a sequence number.
+    /// </summary>
+    /// <remarks>fdAT (Multiple, APNG)</remarks>
+    FrameData = 0x66644154U,
+
     /// <summary>
     /// Malformed chunk named CgBI produced by apple, which is not conform to the specification.
     /// Related issue is here https://github.com/SixLabors/ImageSharp/issues/410

src/ImageSharp/Formats/Png/PngEncoderCore.cs

@@ -168,7 +168,8 @@ internal sealed class PngEncoderCore : IImageEncoderInternals, IDisposable
         this.WriteXmpChunk(stream, metadata);
         this.WriteTextChunks(stream, pngMetadata);
 
-        if (this.encoder.IsSimplePng is not true && targetImage.Frames.Count > 1)
+        if ((this.encoder.IsSimplePng is null && targetImage.Frames.Count > 1)
+            || this.encoder.IsSimplePng is false)
         {
             this.WriteAnimationControlChunk(stream, targetImage.Frames.Count, pngMetadata.NumberPlays);
 
@@ -642,7 +643,7 @@ internal sealed class PngEncoderCore : IImageEncoderInternals, IDisposable
         ref Rgba32 rgbaPaletteRef = ref MemoryMarshal.GetReference(rgbaPaletteSpan);
 
         // Loop, assign, and extract alpha values from the palette.
-        for (int i = 0; i < paletteLength; i++)
+        for (int i = 0; i < paletteLength; ++i)
         {
             Rgba32 rgba = Unsafe.Add(ref rgbaPaletteRef, (uint)i);
             byte alpha = rgba.A;
@@ -674,7 +675,7 @@ internal sealed class PngEncoderCore : IImageEncoderInternals, IDisposable
     /// <param name="meta">The image metadata.</param>
     private void WritePhysicalChunk(Stream stream, ImageMetadata meta)
     {
-        if ((this.chunkFilter & PngChunkFilter.ExcludePhysicalChunk) == PngChunkFilter.ExcludePhysicalChunk)
+        if (this.chunkFilter.HasFlag(PngChunkFilter.ExcludePhysicalChunk))
         {
             return;
         }

tests/ImageSharp.Tests/Formats/Png/PngDecoderTests.cs

@@ -111,20 +111,7 @@ public partial class PngDecoderTests
     public void Decode_APng<TPixel>(TestImageProvider<TPixel> provider)
         where TPixel : unmanaged, IPixel<TPixel>
     {
-        using Image<TPixel> image = provider.GetImage(PngDecoder.Instance);
-        image.SaveAsPng("C:\\WorkSpace\\1.png");
-        image.DebugSave(provider);
-        image.CompareToOriginal(provider, ImageComparer.Exact);
-        // TODO test
-    }
-
-    [Theory]
-    [WithFile("C:\\WorkSpace\\Fuck.png", PixelTypes.Rgba32)]
-    public void Decode_APng2<TPixel>(TestImageProvider<TPixel> provider)
-        where TPixel : unmanaged, IPixel<TPixel>
-    {
-        using Image<TPixel> image = provider.GetImage(PngDecoder.Instance);
-        image.SaveAsPng("C:\\WorkSpace\\1.png");
+        using Image<TPixel> image = provider.GetImage(PngDecoder.Instance); // MagickReferenceDecoder cannot decode APNGs
     }
 
     [Theory]

tests/ImageSharp.Tests/Formats/Png/PngEncoderTests.cs

@@ -439,6 +439,19 @@ public partial class PngEncoderTests
         });
     }
 
+    [Theory]
+    [WithFile(TestImages.Png.APng, PixelTypes.Rgba32)]
+    public void Encode_APng<TPixel>(TestImageProvider<TPixel> provider)
+        where TPixel : unmanaged, IPixel<TPixel>
+    {
+        using Image<TPixel> image = provider.GetImage(PngDecoder.Instance);
+        using MemoryStream memStream = new();
+        image.Save(memStream, PngEncoder);
+        memStream.Position = 0;
+        using Image<Rgba32> output = Image.Load<Rgba32>(memStream);
+        ImageComparer.Exact.VerifySimilarity(output, image);
+    }
+
     [Theory]
     [MemberData(nameof(PngTrnsFiles))]
     public void Encode_PreserveTrns(string imagePath, PngBitDepth pngBitDepth, PngColorType pngColorType)

tests/ImageSharp.Tests/TestUtilities/ImagingTestCaseUtility.cs

@@ -208,7 +208,7 @@ public class ImagingTestCaseUtility
         bool appendPixelTypeToFileName = true)
         where TPixel : unmanaged, IPixel<TPixel>
     {
-        encoder = encoder ?? TestEnvironment.GetReferenceEncoder($"foo.{extension}");
+        encoder ??= TestEnvironment.GetReferenceEncoder($"foo.{extension}");
 
         string[] files = this.GetTestOutputFileNamesMultiFrame(
             image.Frames.Count,
@@ -218,14 +218,10 @@ public class ImagingTestCaseUtility
 
         for (int i = 0; i < image.Frames.Count; i++)
         {
-            using (Image<TPixel> frameImage = image.Frames.CloneFrame(i))
-            {
-                string filePath = files[i];
-                using (FileStream stream = File.OpenWrite(filePath))
-                {
-                    frameImage.Save(stream, encoder);
-                }
-            }
+            using Image<TPixel> frameImage = image.Frames.CloneFrame(i);
+            string filePath = files[i];
+            using FileStream stream = File.OpenWrite(filePath);
+            frameImage.Save(stream, encoder);
         }
 
         return files;

tests/ImageSharp.Tests/TestUtilities/TestImageExtensions.cs

@@ -534,10 +534,8 @@ public static class TestImageExtensions
         referenceDecoder ??= TestEnvironment.GetReferenceDecoder(path);
 
         using MemoryStream stream = new(testFile.Bytes);
-        using (Image<TPixel> original = referenceDecoder.Decode<TPixel>(referenceDecoderOptions ?? DecoderOptions.Default, stream))
-        {
-            comparer.VerifySimilarity(original, image);
-        }
+        using Image<TPixel> original = referenceDecoder.Decode<TPixel>(referenceDecoderOptions ?? DecoderOptions.Default, stream);
+        comparer.VerifySimilarity(original, image);
 
         return image;
     }
@@ -560,10 +558,8 @@ public static class TestImageExtensions
         referenceDecoder ??= TestEnvironment.GetReferenceDecoder(path);
 
         using MemoryStream stream = new(testFile.Bytes);
-        using (Image<TPixel> original = referenceDecoder.Decode<TPixel>(DecoderOptions.Default, stream))
-        {
-            comparer.VerifySimilarity(original, image);
-        }
+        using Image<TPixel> original = referenceDecoder.Decode<TPixel>(DecoderOptions.Default, stream);
+        comparer.VerifySimilarity(original, image);
 
         return image;
     }

tests/Images/Input/Png/apng.png

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:f6b0e5a904e269a9108b32c0f5cc98cda4240a60db421f560f45d2e36ead32a9
-size 212
+oid sha256:7c15e4670da1826d1cc25555bd6cbe287ecc70327cd029a7613334a39a283021
+size 2508