Refactor

src/ImageSharp/Formats/Jxl/IO/Jpeg/JpegBitWriter.cs

@@ -1,6 +1,8 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+using System.Buffers.Binary;
+
 namespace SixLabors.ImageSharp.Formats.Jxl.IO.Jpeg;
 
 internal sealed class JpegBitWriter
@@ -62,14 +64,9 @@ internal sealed class JpegBitWriter
 
     public void StoreBe64(ulong value)
     {
-        this.buffer[this.pos++] = (byte)(value >> 56);
+        Span<byte> span = this.buffer.AsSpan(this.pos);
-        this.buffer[this.pos++] = (byte)(value >> 48);
+        BinaryPrimitives.WriteUInt64BigEndian(span, value);
-        this.buffer[this.pos++] = (byte)(value >> 40);
+        this.pos += 8;
-        this.buffer[this.pos++] = (byte)(value >> 32);
-        this.buffer[this.pos++] = (byte)(value >> 24);
-        this.buffer[this.pos++] = (byte)(value >> 16);
-        this.buffer[this.pos++] = (byte)(value >> 8);
-        this.buffer[this.pos++] = (byte)value;
     }
 
     public void DischargeBitBuffer(int nBits, ulong bits)

src/ImageSharp/Formats/Jxl/IO/Jpeg/JpegSerializationStage.cs

@@ -3,7 +3,7 @@
 
 namespace SixLabors.ImageSharp.Formats.Jxl.IO.Jpeg;
 
-internal enum JpegSerializationStage
+internal enum JpegSerializationStage : byte
 {
     Initialize,
     SerializeSection,

src/ImageSharp/Formats/Jxl/IO/Jpeg/JpegWriter.cs

@@ -226,18 +226,18 @@ internal class JpegWriter
         state.OutputQueue.Add([(byte)(markerLength + 2)]);
 
         Span<byte> data = CollectionsMarshal.AsSpan(state.OutputQueue[^1]);
-        int pos = 0;
+        int pos = 10;
-
+
-        data[pos++] = 0xff;
+        data[0] = 0xff;
-        data[pos++] = marker;
+        data[1] = marker;
-        data[pos++] = (byte)(markerLength >> 8);
+        data[2] = (byte)(markerLength >> 8);
-        data[pos++] = (byte)markerLength;
+        data[3] = (byte)markerLength;
-        data[pos++] = JpegPrecision;
+        data[4] = JpegPrecision;
-        data[pos++] = (byte)(jpg.Height >> 8);
+        data[5] = (byte)(jpg.Height >> 8);
-        data[pos++] = (byte)jpg.Height;
+        data[6] = (byte)jpg.Height;
-        data[pos++] = (byte)(jpg.Width >> 8);
+        data[7] = (byte)(jpg.Width >> 8);
-        data[pos++] = (byte)jpg.Width;
+        data[8] = (byte)jpg.Width;
-        data[pos++] = (byte)componentCount;
+        data[9] = (byte)componentCount;
 
         for (int i = 0; i < componentCount; ++i)
         {
@@ -267,13 +267,13 @@ internal class JpegWriter
         state.OutputQueue.Add([(byte)(markerLength + 2)]);
 
         Span<byte> data = CollectionsMarshal.AsSpan(state.OutputQueue[^1]);
-        int pos = 0;
+        int pos = 5;
 
-        data[pos++] = 0xff;
+        data[0] = 0xff;
-        data[pos++] = 0xda;
+        data[1] = 0xda;
-        data[pos++] = (byte)(markerLength >> 8);
+        data[2] = (byte)(markerLength >> 8);
-        data[pos++] = (byte)markerLength;
+        data[3] = (byte)markerLength;
-        data[pos++] = (byte)scanCount;
+        data[4] = (byte)scanCount;
 
         for (int i = 0; i < scanCount; ++i)
         {
@@ -327,12 +327,12 @@ internal class JpegWriter
         state.OutputQueue.Add([(byte)(markerLength + 2)]);
 
         Span<byte> data = CollectionsMarshal.AsSpan(state.OutputQueue[^1]);
-        int pos = 0;
+        int pos = 4;
 
-        data[pos++] = 0xff;
+        data[0] = 0xff;
-        data[pos++] = 0xc4;
+        data[1] = 0xc4;
-        data[pos++] = (byte)(markerLength >> 8);
+        data[2] = (byte)(markerLength >> 8);
-        data[pos++] = (byte)markerLength;
+        data[3] = (byte)markerLength;
 
         while (true)
         {
@@ -428,12 +428,12 @@ internal class JpegWriter
         state.OutputQueue.Add([(byte)(markerLength + 2)]);
 
         Span<byte> data = CollectionsMarshal.AsSpan(state.OutputQueue[^1]);
-        int pos = 0;
+        int pos = 4;
 
-        data[pos++] = 0xff;
+        data[0] = 0xff;
-        data[pos++] = 0xdb;
+        data[1] = 0xdb;
-        data[pos++] = (byte)(markerLength >> 8);
+        data[2] = (byte)(markerLength >> 8);
-        data[pos++] = (byte)markerLength;
+        data[3] = (byte)markerLength;
 
         while (true)
         {