Fix simple issues in review

src/ImageSharp/Configuration.cs

@@ -43,7 +43,7 @@ public sealed class Configuration
     /// Initializes a new instance of the <see cref="Configuration" /> class.
     /// </summary>
     /// <param name="configurationModules">A collection of configuration modules to register.</param>
-    public Configuration(params IImageFormatConfigurationModule[]? configurationModules)
+    public Configuration(params IImageFormatConfigurationModule[] configurationModules)
     {
         if (configurationModules != null)
         {

src/ImageSharp/Formats/Png/Chunks/APngAnimationControl.cs → src/ImageSharp/Formats/Png/Chunks/AnimationControl.cs

@@ -5,7 +5,7 @@ using System.Buffers.Binary;
 
 namespace SixLabors.ImageSharp.Formats.Png.Chunks;
 
-internal record APngAnimationControl(
+internal record AnimationControl(
     int NumberFrames,
     int NumberPlays)
 {
@@ -36,7 +36,7 @@ internal record APngAnimationControl(
     /// </summary>
     /// <param name="data">The data to parse.</param>
     /// <returns>The parsed acTL.</returns>
-    public static APngAnimationControl Parse(ReadOnlySpan<byte> data)
+    public static AnimationControl Parse(ReadOnlySpan<byte> data)
         => new(
             NumberFrames: BinaryPrimitives.ReadInt32BigEndian(data[..4]),
             NumberPlays: BinaryPrimitives.ReadInt32BigEndian(data[4..8]));

src/ImageSharp/Formats/Png/Chunks/APngFrameControl.cs → src/ImageSharp/Formats/Png/Chunks/FrameControl.cs

@@ -5,11 +5,11 @@ using System.Buffers.Binary;
 
 namespace SixLabors.ImageSharp.Formats.Png.Chunks;
 
-internal readonly struct APngFrameControl
+internal readonly struct FrameControl
 {
     public const int Size = 26;
 
-    public APngFrameControl(
+    public FrameControl(
         int sequenceNumber,
         int width,
         int height,
@@ -17,8 +17,8 @@ internal readonly struct APngFrameControl
         int yOffset,
         short delayNumber,
         short delayDenominator,
-        APngDisposeOperation disposeOperation,
-        APngBlendOperation blendOperation)
+        PngDisposeOperation disposeOperation,
+        PngBlendOperation blendOperation)
     {
         this.SequenceNumber = sequenceNumber;
         this.Width = width;
@@ -69,12 +69,12 @@ internal readonly struct APngFrameControl
     /// <summary>
     /// Gets the type of frame area disposal to be done after rendering this frame
     /// </summary>
-    public APngDisposeOperation DisposeOperation { get; }
+    public PngDisposeOperation DisposeOperation { get; }
 
     /// <summary>
     /// Gets the type of frame area rendering for this frame
     /// </summary>
-    public APngBlendOperation BlendOperation { get; }
+    public PngBlendOperation BlendOperation { get; }
 
     /// <summary>
     /// Validates the APng fcTL.
@@ -120,9 +120,9 @@ internal readonly struct APngFrameControl
     /// </summary>
     /// <param name="frameMetadata">The metadata to parse.</param>
     /// <param name="sequenceNumber">Sequence number.</param>
-    public static APngFrameControl FromMetadata(APngFrameMetadata frameMetadata, int sequenceNumber)
+    public static FrameControl FromMetadata(PngFrameMetadata frameMetadata, int sequenceNumber)
     {
-        APngFrameControl fcTL = new(
+        FrameControl fcTL = new(
             sequenceNumber,
             frameMetadata.Width,
             frameMetadata.Height,
@@ -158,7 +158,7 @@ internal readonly struct APngFrameControl
     /// </summary>
     /// <param name="data">The data to parse.</param>
     /// <returns>The parsed fcTL.</returns>
-    public static APngFrameControl Parse(ReadOnlySpan<byte> data)
+    public static FrameControl Parse(ReadOnlySpan<byte> data)
         => new(
             sequenceNumber: BinaryPrimitives.ReadInt32BigEndian(data[..4]),
             width: BinaryPrimitives.ReadInt32BigEndian(data[4..8]),
@@ -167,6 +167,6 @@ internal readonly struct APngFrameControl
             yOffset: BinaryPrimitives.ReadInt32BigEndian(data[16..20]),
             delayNumber: BinaryPrimitives.ReadInt16BigEndian(data[20..22]),
             delayDenominator: BinaryPrimitives.ReadInt16BigEndian(data[22..24]),
-            disposeOperation: (APngDisposeOperation)data[24],
-            blendOperation: (APngBlendOperation)data[25]);
+            disposeOperation: (PngDisposeOperation)data[24],
+            blendOperation: (PngBlendOperation)data[25]);
 }

src/ImageSharp/Formats/Png/MetadataExtensions.cs

@@ -23,15 +23,14 @@ public static partial class MetadataExtensions
     /// Gets the aPng format specific metadata for the image frame.
     /// </summary>
     /// <param name="source">The metadata this method extends.</param>
-    /// <returns>The <see cref="APngFrameMetadata"/>.</returns>
-    public static APngFrameMetadata GetAPngFrameMetadata(this ImageFrameMetadata source) => source.GetFormatMetadata(PngFormat.Instance);
+    /// <returns>The <see cref="PngFrameMetadata"/>.</returns>
+    public static PngFrameMetadata GetPngFrameMetadata(this ImageFrameMetadata source) => source.GetFormatMetadata(PngFormat.Instance);
 
     /// <summary>
     /// Gets the aPng format specific metadata for the image frame.
     /// </summary>
     /// <param name="source">The metadata this method extends.</param>
     /// <param name="metadata">The metadata.</param>
-    /// <returns>The <see cref="APngFrameMetadata"/>.</returns>
-    public static bool TryGetAPngFrameMetadata(this ImageFrameMetadata source, [NotNullWhen(true)] out APngFrameMetadata? metadata) => source.TryGetFormatMetadata(PngFormat.Instance, out metadata);
-
+    /// <returns>The <see cref="PngFrameMetadata"/>.</returns>
+    public static bool TryGetPngFrameMetadata(this ImageFrameMetadata source, [NotNullWhen(true)] out PngFrameMetadata? metadata) => source.TryGetFormatMetadata(PngFormat.Instance, out metadata);
 }

src/ImageSharp/Formats/Png/APngBlendOperation.cs → src/ImageSharp/Formats/Png/PngBlendOperation.cs

@@ -6,7 +6,7 @@ namespace SixLabors.ImageSharp.Formats.Png;
 /// <summary>
 /// Specifies whether the frame is to be alpha blended into the current output buffer content, or whether it should completely replace its region in the output buffer.
 /// </summary>
-public enum APngBlendOperation
+public enum PngBlendOperation
 {
     /// <summary>
     /// All color components of the frame, including alpha, overwrite the current contents of the frame's output buffer region.

src/ImageSharp/Formats/Png/PngConstants.cs

@@ -80,5 +80,24 @@ internal static class PngConstants
     /// <summary>
     /// Gets the keyword of the XMP metadata, encoded in an iTXT chunk.
     /// </summary>
-    public static ReadOnlySpan<byte> XmpKeyword => "XML:com.adobe.xmp"u8;
+    public static ReadOnlySpan<byte> XmpKeyword => new[]
+    {
+        (byte)'X',
+        (byte)'M',
+        (byte)'L',
+        (byte)':',
+        (byte)'c',
+        (byte)'o',
+        (byte)'m',
+        (byte)'.',
+        (byte)'a',
+        (byte)'d',
+        (byte)'o',
+        (byte)'b',
+        (byte)'e',
+        (byte)'.',
+        (byte)'x',
+        (byte)'m',
+        (byte)'p'
+    };
 }

src/ImageSharp/Formats/Png/PngDecoderCore.cs

@@ -28,11 +28,6 @@ namespace SixLabors.ImageSharp.Formats.Png;
 /// </summary>
 internal sealed class PngDecoderCore : IImageDecoderInternals
 {
-    /// <summary>
-    /// Indicate whether the file is a simple PNG.
-    /// </summary>
-    private bool isSimplePng;
-
     /// <summary>
     /// The general decoder options.
     /// </summary>
@@ -66,7 +61,7 @@ internal sealed class PngDecoderCore : IImageDecoderInternals
     /// <summary>
     /// The png animation control.
     /// </summary>
-    private APngAnimationControl? animationControl;
+    private AnimationControl? animationControl;
 
     /// <summary>
     /// The number of bytes per pixel.
@@ -149,7 +144,7 @@ internal sealed class PngDecoderCore : IImageDecoderInternals
         this.currentStream = stream;
         this.currentStream.Skip(8);
         Image<TPixel>? image = null;
-        APngFrameControl? lastFrameControl = null;
+        FrameControl? lastFrameControl = null;
         ImageFrame<TPixel>? currentFrame = null;
         Span<byte> buffer = stackalloc byte[20];
 
@@ -170,11 +165,6 @@ internal sealed class PngDecoderCore : IImageDecoderInternals
                             this.ReadHeaderChunk(pngMetadata, chunk.Data.GetSpan());
                             break;
                         case PngChunkType.AnimationControl:
-                            if (this.isSimplePng || this.animationControl is not null)
-                            {
-                                PngThrowHelper.ThrowInvalidAnimationControl();
-                            }
-
                             this.ReadAnimationControlChunk(pngMetadata, chunk.Data.GetSpan());
                             break;
                         case PngChunkType.Physical:
@@ -184,11 +174,6 @@ internal sealed class PngDecoderCore : IImageDecoderInternals
                             ReadGammaChunk(pngMetadata, chunk.Data.GetSpan());
                             break;
                         case PngChunkType.FrameControl:
-                            if (this.isSimplePng)
-                            {
-                                continue;
-                            }
-
                             currentFrame = null;
                             lastFrameControl = this.ReadFrameControlChunk(chunk.Data.GetSpan());
                             break;
@@ -228,11 +213,6 @@ internal sealed class PngDecoderCore : IImageDecoderInternals
                             lastFrameControl = null;
                             break;
                         case PngChunkType.Data:
-                            if (this.animationControl is null)
-                            {
-                                this.isSimplePng = true;
-                            }
-
                             if (image is null)
                             {
                                 this.InitializeImage(metadata, lastFrameControl, out image);
@@ -313,7 +293,7 @@ internal sealed class PngDecoderCore : IImageDecoderInternals
         ImageMetadata metadata = new();
         PngMetadata pngMetadata = metadata.GetPngMetadata();
         this.currentStream = stream;
-        APngFrameControl? lastFrameControl = null;
+        FrameControl? lastFrameControl = null;
         Span<byte> buffer = stackalloc byte[20];
 
         this.currentStream.Skip(8);
@@ -330,11 +310,6 @@ internal sealed class PngDecoderCore : IImageDecoderInternals
                             this.ReadHeaderChunk(pngMetadata, chunk.Data.GetSpan());
                             break;
                         case PngChunkType.AnimationControl:
-                            if (this.isSimplePng || this.animationControl is not null)
-                            {
-                                PngThrowHelper.ThrowInvalidAnimationControl();
-                            }
-
                             this.ReadAnimationControlChunk(pngMetadata, chunk.Data.GetSpan());
                             break;
                         case PngChunkType.Physical:
@@ -356,11 +331,6 @@ internal sealed class PngDecoderCore : IImageDecoderInternals
                             ReadGammaChunk(pngMetadata, chunk.Data.GetSpan());
                             break;
                         case PngChunkType.FrameControl:
-                            if (this.isSimplePng)
-                            {
-                                continue;
-                            }
-
                             lastFrameControl = this.ReadFrameControlChunk(chunk.Data.GetSpan());
                             break;
                         case PngChunkType.FrameData:
@@ -379,11 +349,6 @@ internal sealed class PngDecoderCore : IImageDecoderInternals
                             this.SkipChunkDataAndCrc(chunk);
                             break;
                         case PngChunkType.Data:
-                            if (this.animationControl is null)
-                            {
-                                this.isSimplePng = true;
-                            }
-
                             // Spec says tRNS must be before IDAT so safe to exit.
                             if (this.colorMetadataOnly)
                             {
@@ -465,7 +430,7 @@ internal sealed class PngDecoderCore : IImageDecoderInternals
             }
 
             EOF:
-            if (this.header is { Width: 0, Height: 0 })
+            if (this.header.Width == 0 && this.header.Height == 0)
             {
                 PngThrowHelper.ThrowInvalidHeader();
             }
@@ -568,7 +533,7 @@ internal sealed class PngDecoderCore : IImageDecoderInternals
     /// <param name="metadata">The metadata information for the image</param>
     /// <param name="frameControl">The frame control information for the frame</param>
     /// <param name="image">The image that we will populate</param>
-    private void InitializeImage<TPixel>(ImageMetadata metadata, APngFrameControl? frameControl, out Image<TPixel> image)
+    private void InitializeImage<TPixel>(ImageMetadata metadata, FrameControl? frameControl, out Image<TPixel> image)
         where TPixel : unmanaged, IPixel<TPixel>
     {
         image = Image.CreateUninitialized<TPixel>(
@@ -579,7 +544,7 @@ internal sealed class PngDecoderCore : IImageDecoderInternals
 
         if (frameControl is { } control)
         {
-            APngFrameMetadata frameMetadata = image.Frames.RootFrame.Metadata.GetAPngFrameMetadata();
+            PngFrameMetadata frameMetadata = image.Frames.RootFrame.Metadata.GetPngFrameMetadata();
             frameMetadata.FromChunk(control);
         }
 
@@ -603,12 +568,13 @@ internal sealed class PngDecoderCore : IImageDecoderInternals
     /// <typeparam name="TPixel">The type the pixels will be</typeparam>
     /// <param name="frameControl">The frame control information for the frame</param>
     /// <param name="image">The image that we will populate</param>
-    private void InitializeFrame<TPixel>(APngFrameControl frameControl, Image<TPixel> image, out ImageFrame<TPixel> frame)
+    /// <param name="frame">The created frame</param>
+    private void InitializeFrame<TPixel>(FrameControl frameControl, Image<TPixel> image, out ImageFrame<TPixel> frame)
         where TPixel : unmanaged, IPixel<TPixel>
     {
         frame = image.Frames.CreateFrame();
 
-        APngFrameMetadata frameMetadata = frame.Metadata.GetAPngFrameMetadata();
+        PngFrameMetadata frameMetadata = frame.Metadata.GetPngFrameMetadata();
 
         frameMetadata.FromChunk(frameControl);
 
@@ -716,7 +682,7 @@ internal sealed class PngDecoderCore : IImageDecoderInternals
     {
         int currentRow = Adam7.FirstRow[0];
         int currentRowBytesRead = 0;
-        int height = image.Metadata.TryGetAPngFrameMetadata(out APngFrameMetadata? frameMetadata) ? frameMetadata.Height : this.header.Height;
+        int height = image.Metadata.TryGetPngFrameMetadata(out PngFrameMetadata? frameMetadata) ? frameMetadata.Height : this.header.Height;
         while (currentRow < height)
         {
             cancellationToken.ThrowIfCancellationRequested();
@@ -763,7 +729,7 @@ internal sealed class PngDecoderCore : IImageDecoderInternals
             this.ProcessDefilteredScanline(currentRow, scanlineSpan, image, pngMetadata);
 
             this.SwapScanlineBuffers();
-            ++currentRow;
+            currentRow++;
         }
     }
 
@@ -784,7 +750,7 @@ internal sealed class PngDecoderCore : IImageDecoderInternals
         int pass = 0;
         int width = this.header.Width;
         int height = this.header.Height;
-        if (image.Metadata.TryGetAPngFrameMetadata(out APngFrameMetadata? frameMetadata))
+        if (image.Metadata.TryGetPngFrameMetadata(out PngFrameMetadata? frameMetadata))
         {
             width = frameMetadata.Width;
             height = frameMetadata.Height;
@@ -797,7 +763,7 @@ internal sealed class PngDecoderCore : IImageDecoderInternals
 
             if (numColumns == 0)
             {
-                ++pass;
+                pass++;
 
                 // This pass contains no data; skip to next pass
                 continue;
@@ -1124,7 +1090,7 @@ internal sealed class PngDecoderCore : IImageDecoderInternals
     /// <param name="data">The <see cref="T:ReadOnlySpan{byte}"/> containing data.</param>
     private void ReadAnimationControlChunk(PngMetadata pngMetadata, ReadOnlySpan<byte> data)
     {
-        this.animationControl = APngAnimationControl.Parse(data);
+        this.animationControl = AnimationControl.Parse(data);
 
         pngMetadata.NumberPlays = this.animationControl.NumberPlays;
     }
@@ -1133,9 +1099,9 @@ internal sealed class PngDecoderCore : IImageDecoderInternals
     /// Reads a header chunk from the data.
     /// </summary>
     /// <param name="data">The <see cref="T:ReadOnlySpan{byte}"/> containing data.</param>
-    private APngFrameControl ReadFrameControlChunk(ReadOnlySpan<byte> data)
+    private FrameControl ReadFrameControlChunk(ReadOnlySpan<byte> data)
     {
-        APngFrameControl fcTL = APngFrameControl.Parse(data);
+        FrameControl fcTL = FrameControl.Parse(data);
 
         fcTL.Validate(this.header);
 

src/ImageSharp/Formats/Png/APngDisposeOperation.cs → src/ImageSharp/Formats/Png/PngDisposeOperation.cs

@@ -6,7 +6,7 @@ namespace SixLabors.ImageSharp.Formats.Png;
 /// <summary>
 /// Specifies how the output buffer should be changed at the end of the delay (before rendering the next frame).
 /// </summary>
-public enum APngDisposeOperation
+public enum PngDisposeOperation
 {
     /// <summary>
     /// No disposal is done on this frame before rendering the next; the contents of the output buffer are left as is.

src/ImageSharp/Formats/Png/PngEncoder.cs

@@ -19,11 +19,6 @@ public class PngEncoder : QuantizingImageEncoder
         // quantizer with options appropriate to the encoding bit depth.
         this.Quantizer = null!;
 
-    /// <summary>
-    /// Gets whether the file is a simple PNG.
-    /// </summary>
-    public bool? IsSimplePng { get; init; }
-
     /// <summary>
     /// Gets the number of bits per sample or per palette index (not per pixel).
     /// Not all values are allowed for all <see cref="ColorType" /> values.

src/ImageSharp/Formats/Png/PngEncoderCore.cs

@@ -25,7 +25,7 @@ internal sealed class PngEncoderCore : IImageEncoderInternals, IDisposable
     /// <summary>
     /// The maximum block size, defaults at 64k for uncompressed blocks.
     /// </summary>
-    private const int MaxBlockSize = (1 << 16) - 1;
+    private const int MaxBlockSize = 65535;
 
     /// <summary>
     /// Used the manage memory allocations.
@@ -168,20 +168,19 @@ internal sealed class PngEncoderCore : IImageEncoderInternals, IDisposable
         this.WriteXmpChunk(stream, metadata);
         this.WriteTextChunks(stream, pngMetadata);
 
-        if ((this.encoder.IsSimplePng is null && targetImage.Frames.Count > 1)
-            || this.encoder.IsSimplePng is false)
+        if (targetImage.Frames.Count > 1)
         {
             this.WriteAnimationControlChunk(stream, targetImage.Frames.Count, pngMetadata.NumberPlays);
 
-            this.WriteFrameControlChunk(stream, targetImage.Frames.RootFrame.Metadata.GetAPngFrameMetadata(), 0);
+            this.WriteFrameControlChunk(stream, targetImage.Frames.RootFrame.Metadata.GetPngFrameMetadata(), 0);
             _ = this.WriteDataChunks(targetImage.Frames.RootFrame, rootQuantized, stream, false);
 
             int index = 1;
 
             foreach (ImageFrame<TPixel> imageFrame in ((IEnumerable<ImageFrame<TPixel>>)targetImage.Frames).Skip(1))
             {
-                this.WriteFrameControlChunk(stream, imageFrame.Metadata.GetAPngFrameMetadata(), index);
-                ++index;
+                this.WriteFrameControlChunk(stream, imageFrame.Metadata.GetPngFrameMetadata(), index);
+                index++;
                 IndexedImageFrame<TPixel>? quantized = this.CreateQuantizedImageAndUpdateBitDepth(imageFrame);
                 index += this.WriteDataChunks(imageFrame, quantized, stream, true, index);
                 quantized?.Dispose();
@@ -225,10 +224,10 @@ internal sealed class PngEncoderCore : IImageEncoderInternals, IDisposable
                 // TODO: We should be able to speed this up with SIMD and masking.
                 Rgba32 rgba32 = default;
                 Rgba32 transparent = Color.Transparent;
-                for (int y = 0; y < accessor.Height; ++y)
+                for (int y = 0; y < accessor.Height; y++)
                 {
                     Span<TPixel> span = accessor.GetRowSpan(y);
-                    for (int x = 0; x < accessor.Width; ++x)
+                    for (int x = 0; x < accessor.Width; x++)
                     {
                         span[x].ToRgba32(ref rgba32);
 
@@ -278,7 +277,7 @@ internal sealed class PngEncoderCore : IImageEncoderInternals, IDisposable
                 PixelOperations<TPixel>.Instance.ToL16(this.configuration, rowSpan, luminanceSpan);
 
                 // Can't map directly to byte array as it's big-endian.
-                for (int x = 0, o = 0; x < luminanceSpan.Length; ++x, o += 2)
+                for (int x = 0, o = 0; x < luminanceSpan.Length; x++, o += 2)
                 {
                     L16 luminance = Unsafe.Add(ref luminanceRef, (uint)x);
                     BinaryPrimitives.WriteUInt16BigEndian(rawScanlineSpan.Slice(o, 2), luminance.PackedValue);
@@ -318,7 +317,7 @@ internal sealed class PngEncoderCore : IImageEncoderInternals, IDisposable
             PixelOperations<TPixel>.Instance.ToLa32(this.configuration, rowSpan, laSpan);
 
             // Can't map directly to byte array as it's big endian.
-            for (int x = 0, o = 0; x < laSpan.Length; ++x, o += 4)
+            for (int x = 0, o = 0; x < laSpan.Length; x++, o += 4)
             {
                 La32 la = Unsafe.Add(ref laRef, (uint)x);
                 BinaryPrimitives.WriteUInt16BigEndian(rawScanlineSpan.Slice(o, 2), la.L);
@@ -602,11 +601,11 @@ internal sealed class PngEncoderCore : IImageEncoderInternals, IDisposable
     /// <param name="playsCount">The number of times to loop this APNG.</param>
     private void WriteAnimationControlChunk(Stream stream, int framesCount, int playsCount)
     {
-        APngAnimationControl acTL = new(framesCount, playsCount);
+        AnimationControl acTL = new(framesCount, playsCount);
 
         acTL.WriteTo(this.chunkDataBuffer.Span);
 
-        this.WriteChunk(stream, PngChunkType.AnimationControl, this.chunkDataBuffer.Span, 0, APngAnimationControl.Size);
+        this.WriteChunk(stream, PngChunkType.AnimationControl, this.chunkDataBuffer.Span, 0, AnimationControl.Size);
     }
 
     /// <summary>
@@ -643,7 +642,7 @@ 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;
@@ -963,13 +962,13 @@ internal sealed class PngEncoderCore : IImageEncoderInternals, IDisposable
     /// <param name="stream">The <see cref="Stream"/> containing image data.</param>
     /// <param name="frameMetadata">Provides APng specific metadata information for the image frame.</param>
     /// <param name="sequenceNumber">Sequence number.</param>
-    private void WriteFrameControlChunk(Stream stream, APngFrameMetadata frameMetadata, int sequenceNumber)
+    private void WriteFrameControlChunk(Stream stream, PngFrameMetadata frameMetadata, int sequenceNumber)
     {
-        APngFrameControl fcTL = APngFrameControl.FromMetadata(frameMetadata, sequenceNumber);
+        FrameControl fcTL = FrameControl.FromMetadata(frameMetadata, sequenceNumber);
 
         fcTL.WriteTo(this.chunkDataBuffer.Span);
 
-        this.WriteChunk(stream, PngChunkType.FrameControl, this.chunkDataBuffer.Span, 0, APngFrameControl.Size);
+        this.WriteChunk(stream, PngChunkType.FrameControl, this.chunkDataBuffer.Span, 0, FrameControl.Size);
     }
 
     /// <summary>
@@ -1024,10 +1023,10 @@ internal sealed class PngEncoderCore : IImageEncoderInternals, IDisposable
 
         if (bufferLength % maxBlockSize != 0)
         {
-            ++numChunks;
+            numChunks++;
         }
 
-        for (int i = 0; i < numChunks; ++i)
+        for (int i = 0; i < numChunks; i++)
         {
             int length = bufferLength - (i * maxBlockSize);
 
@@ -1078,7 +1077,7 @@ internal sealed class PngEncoderCore : IImageEncoderInternals, IDisposable
     {
         int width = this.width;
         int height = this.height;
-        if (pixels.Metadata.TryGetAPngFrameMetadata(out APngFrameMetadata? pngMetadata))
+        if (pixels.Metadata.TryGetAPngFrameMetadata(out PngFrameMetadata? pngMetadata))
         {
             width = pngMetadata.Width;
             height = pngMetadata.Height;
@@ -1095,7 +1094,7 @@ internal sealed class PngEncoderCore : IImageEncoderInternals, IDisposable
         {
             Span<byte> filter = filterBuffer.GetSpan();
             Span<byte> attempt = attemptBuffer.GetSpan();
-            for (int y = 0; y < height; ++y)
+            for (int y = 0; y < height; y++)
             {
                 this.CollectAndFilterPixelRow(accessor.GetRowSpan(y), ref filter, ref attempt, quantized, y);
                 deflateStream.Write(filter);
@@ -1201,7 +1200,7 @@ internal sealed class PngEncoderCore : IImageEncoderInternals, IDisposable
                     col += Adam7.ColumnIncrement[pass])
                 {
                     block[i] = srcRow[col];
-                    ++i;
+                    i++;
                 }
 
                 // Encode data

src/ImageSharp/Formats/Png/PngFormat.cs

@@ -6,7 +6,7 @@ namespace SixLabors.ImageSharp.Formats.Png;
 /// <summary>
 /// Registers the image encoders, decoders and mime type detectors for the png format.
 /// </summary>
-public sealed class PngFormat : IImageFormat<PngMetadata, APngFrameMetadata>
+public sealed class PngFormat : IImageFormat<PngMetadata, PngFrameMetadata>
 {
     private PngFormat()
     {
@@ -33,5 +33,5 @@ public sealed class PngFormat : IImageFormat<PngMetadata, APngFrameMetadata>
     public PngMetadata CreateDefaultFormatMetadata() => new();
 
     /// <inheritdoc/>
-    public APngFrameMetadata CreateDefaultFormatFrameMetadata() => new();
+    public PngFrameMetadata CreateDefaultFormatFrameMetadata() => new();
 }

src/ImageSharp/Formats/Png/APngFrameMetadata.cs → src/ImageSharp/Formats/Png/PngFrameMetadata.cs

@@ -8,20 +8,20 @@ namespace SixLabors.ImageSharp.Formats.Png;
 /// <summary>
 /// Provides APng specific metadata information for the image frame.
 /// </summary>
-public class APngFrameMetadata : IDeepCloneable
+public class PngFrameMetadata : IDeepCloneable
 {
     /// <summary>
-    /// Initializes a new instance of the <see cref="APngFrameMetadata"/> class.
+    /// Initializes a new instance of the <see cref="PngFrameMetadata"/> class.
     /// </summary>
-    public APngFrameMetadata()
+    public PngFrameMetadata()
     {
     }
 
     /// <summary>
-    /// Initializes a new instance of the <see cref="APngFrameMetadata"/> class.
+    /// Initializes a new instance of the <see cref="PngFrameMetadata"/> class.
     /// </summary>
     /// <param name="other">The metadata to create an instance from.</param>
-    private APngFrameMetadata(APngFrameMetadata other)
+    private PngFrameMetadata(PngFrameMetadata other)
     {
         this.Width = other.Width;
         this.Height = other.Height;
@@ -66,18 +66,18 @@ public class APngFrameMetadata : IDeepCloneable
     /// <summary>
     /// Gets or sets the type of frame area disposal to be done after rendering this frame
     /// </summary>
-    public APngDisposeOperation DisposeOperation { get; set; }
+    public PngDisposeOperation DisposeOperation { get; set; }
 
     /// <summary>
     /// Gets or sets the type of frame area rendering for this frame
     /// </summary>
-    public APngBlendOperation BlendOperation { get; set; }
+    public PngBlendOperation BlendOperation { get; set; }
 
     /// <summary>
-    /// Initializes a new instance of the <see cref="APngFrameMetadata"/> class.
+    /// Initializes a new instance of the <see cref="PngFrameMetadata"/> class.
     /// </summary>
     /// <param name="frameControl">The chunk to create an instance from.</param>
-    internal void FromChunk(APngFrameControl frameControl)
+    internal void FromChunk(FrameControl frameControl)
     {
         this.Width = frameControl.Width;
         this.Height = frameControl.Height;
@@ -90,5 +90,5 @@ public class APngFrameMetadata : IDeepCloneable
     }
 
     /// <inheritdoc/>
-    public IDeepCloneable DeepClone() => new APngFrameMetadata(this);
+    public IDeepCloneable DeepClone() => new PngFrameMetadata(this);
 }

src/ImageSharp/ImageSharp.csproj

@@ -13,7 +13,6 @@
     <PackageTags>Image Resize Crop Gif Jpg Jpeg Bitmap Pbm Png Tga Tiff WebP NetCore</PackageTags>
     <Description>A new, fully featured, fully managed, cross-platform, 2D graphics API for .NET</Description>
     <Configurations>Debug;Release</Configurations>
-    <LangVersion>preview</LangVersion>
   </PropertyGroup>
 
   <!--  This enables the nullable analysis and treats all nullable warnings as error-->