Avoid code duplication for CalculateBytesPerRow and RowsPerBlock

src/ImageSharp/Formats/Exr/ExrDecoderCore.cs

@@ -132,8 +132,8 @@ internal sealed class ExrDecoderCore : ImageDecoderCore
         where TPixel : unmanaged, IPixel<TPixel>
     {
         bool hasAlpha = this.HasAlpha();
-        uint bytesPerRow = this.CalculateBytesPerRow((uint)this.Width);
+        uint bytesPerRow = ExrUtils.CalculateBytesPerRow(this.Channels, (uint)this.Width);
-        uint rowsPerBlock = this.RowsPerBlock();
+        uint rowsPerBlock = ExrUtils.RowsPerBlock(this.Compression);
         uint bytesPerBlock = bytesPerRow * rowsPerBlock;
         int width = this.Width;
         int height = this.Height;
@@ -185,8 +185,8 @@ internal sealed class ExrDecoderCore : ImageDecoderCore
         where TPixel : unmanaged, IPixel<TPixel>
     {
         bool hasAlpha = this.HasAlpha();
-        uint bytesPerRow = this.CalculateBytesPerRow((uint)this.Width);
+        uint bytesPerRow = ExrUtils.CalculateBytesPerRow(this.Channels, (uint)this.Width);
-        uint rowsPerBlock = this.RowsPerBlock();
+        uint rowsPerBlock = ExrUtils.RowsPerBlock(this.Compression);
         uint bytesPerBlock = bytesPerRow * rowsPerBlock;
         int width = this.Width;
         int height = this.Height;
@@ -728,48 +728,6 @@ internal sealed class ExrDecoderCore : ImageDecoderCore
         return false;
     }
 
-    private uint CalculateBytesPerRow(uint width)
-    {
-        uint bytesPerRow = 0;
-        foreach (ExrChannelInfo channelInfo in this.Channels)
-        {
-            if (channelInfo.ChannelName.Equals("A", StringComparison.Ordinal)
-                || channelInfo.ChannelName.Equals("R", StringComparison.Ordinal)
-                || channelInfo.ChannelName.Equals("G", StringComparison.Ordinal)
-                || channelInfo.ChannelName.Equals("B", StringComparison.Ordinal)
-                || channelInfo.ChannelName.Equals("Y", StringComparison.Ordinal))
-            {
-                if (channelInfo.PixelType == ExrPixelType.Half)
-                {
-                    bytesPerRow += 2 * width;
-                }
-                else
-                {
-                    bytesPerRow += 4 * width;
-                }
-            }
-        }
-
-        return bytesPerRow;
-    }
-
-    private uint RowsPerBlock()
-    {
-        switch (this.Compression)
-        {
-            case ExrCompression.Zip:
-            case ExrCompression.Pxr24:
-                return 16;
-            case ExrCompression.B44:
-            case ExrCompression.B44A:
-            case ExrCompression.Piz:
-                return 32;
-
-            default:
-                return 1;
-        }
-    }
-
     private ulong ReadUnsignedLong(BufferedReadStream stream)
     {
         int bytesRead = stream.Read(this.buffer, 0, 8);

src/ImageSharp/Formats/Exr/ExrEncoderCore.cs

@@ -158,8 +158,8 @@ internal sealed class ExrEncoderCore
         ExrCompression compression)
         where TPixel : unmanaged, IPixel<TPixel>
     {
-        uint bytesPerRow = this.CalculateBytesPerRow(channels, (uint)width);
+        uint bytesPerRow = ExrUtils.CalculateBytesPerRow(channels, (uint)width);
-        uint rowsPerBlock = this.RowsPerBlock(compression);
+        uint rowsPerBlock = ExrUtils.RowsPerBlock(compression);
         uint bytesPerBlock = bytesPerRow * rowsPerBlock;
         int channelCount = channels.Count;
 
@@ -234,8 +234,8 @@ internal sealed class ExrEncoderCore
         ExrCompression compression)
         where TPixel : unmanaged, IPixel<TPixel>
     {
-        uint bytesPerRow = this.CalculateBytesPerRow(channels, (uint)width);
+        uint bytesPerRow = ExrUtils.CalculateBytesPerRow(channels, (uint)width);
-        uint rowsPerBlock = this.RowsPerBlock(compression);
+        uint rowsPerBlock = ExrUtils.RowsPerBlock(compression);
         uint bytesPerBlock = bytesPerRow * rowsPerBlock;
         int channelCount = channels.Count;
 
@@ -335,19 +335,19 @@ internal sealed class ExrEncoderCore
         int offset = 0;
         for (int x = 0; x < width; x++)
         {
-            this.WriteHalfSingle(buffer.Slice(offset), blueBuffer[x]);
+            WriteHalfSingle(buffer.Slice(offset), blueBuffer[x]);
             offset += 2;
         }
 
         for (int x = 0; x < width; x++)
         {
-            this.WriteHalfSingle(buffer.Slice(offset), greenBuffer[x]);
+            WriteHalfSingle(buffer.Slice(offset), greenBuffer[x]);
             offset += 2;
         }
 
         for (int x = 0; x < width; x++)
         {
-            this.WriteHalfSingle(buffer.Slice(offset), redBuffer[x]);
+            WriteHalfSingle(buffer.Slice(offset), redBuffer[x]);
             offset += 2;
         }
     }
@@ -357,19 +357,19 @@ internal sealed class ExrEncoderCore
         int offset = 0;
         for (int x = 0; x < width; x++)
         {
-            this.WriteUnsignedInt(buffer.Slice(offset), blueBuffer[x]);
+            WriteUnsignedInt(buffer.Slice(offset), blueBuffer[x]);
             offset += 4;
         }
 
         for (int x = 0; x < width; x++)
         {
-            this.WriteUnsignedInt(buffer.Slice(offset), greenBuffer[x]);
+            WriteUnsignedInt(buffer.Slice(offset), greenBuffer[x]);
             offset += 4;
         }
 
         for (int x = 0; x < width; x++)
         {
-            this.WriteUnsignedInt(buffer.Slice(offset), redBuffer[x]);
+            WriteUnsignedInt(buffer.Slice(offset), redBuffer[x]);
             offset += 4;
         }
     }
@@ -521,10 +521,10 @@ internal sealed class ExrEncoderCore
     private unsafe void WriteSingle(Span<byte> buffer, float value) => BinaryPrimitives.WriteInt32LittleEndian(buffer, *(int*)&value);
 
     [MethodImpl(InliningOptions.ShortMethod)]
-    private void WriteHalfSingle(Span<byte> buffer, float value)
+    private static void WriteHalfSingle(Span<byte> buffer, float value)
     {
         ushort valueAsShort = HalfTypeHelper.Pack(value);
-        BinaryPrimitives.WriteUInt16LittleEndian(this.buffer, valueAsShort);
+        BinaryPrimitives.WriteUInt16LittleEndian(buffer, valueAsShort);
     }
 
     [MethodImpl(InliningOptions.ShortMethod)]
@@ -535,49 +535,5 @@ internal sealed class ExrEncoderCore
     }
 
     [MethodImpl(InliningOptions.ShortMethod)]
-    private void WriteUnsignedInt(Span<byte> buffer, uint value) => BinaryPrimitives.WriteUInt32LittleEndian(buffer, value);
+    private static void WriteUnsignedInt(Span<byte> buffer, uint value) => BinaryPrimitives.WriteUInt32LittleEndian(buffer, value);
-
-    // TODO: avoid code duplication: This code is duplicate in the decoder.
-    private uint CalculateBytesPerRow(List<ExrChannelInfo> channels, uint width)
-    {
-        uint bytesPerRow = 0;
-        foreach (ExrChannelInfo channelInfo in channels)
-        {
-            if (channelInfo.ChannelName.Equals("A", StringComparison.Ordinal)
-                || channelInfo.ChannelName.Equals("R", StringComparison.Ordinal)
-                || channelInfo.ChannelName.Equals("G", StringComparison.Ordinal)
-                || channelInfo.ChannelName.Equals("B", StringComparison.Ordinal)
-                || channelInfo.ChannelName.Equals("Y", StringComparison.Ordinal))
-            {
-                if (channelInfo.PixelType == ExrPixelType.Half)
-                {
-                    bytesPerRow += 2 * width;
-                }
-                else
-                {
-                    bytesPerRow += 4 * width;
-                }
-            }
-        }
-
-        return bytesPerRow;
-    }
-
-    // TODO: avoid code duplication: This code is duplicate in the decoder.
-    private uint RowsPerBlock(ExrCompression compression)
-    {
-        switch (compression)
-        {
-            case ExrCompression.Zip:
-            case ExrCompression.Pxr24:
-                return 16;
-            case ExrCompression.B44:
-            case ExrCompression.B44A:
-            case ExrCompression.Piz:
-                return 32;
-
-            default:
-                return 1;
-        }
-    }
 }

src/ImageSharp/Formats/Exr/ExrUtils.cs

@@ -0,0 +1,41 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using SixLabors.ImageSharp.Formats.Exr.Constants;
+
+namespace SixLabors.ImageSharp.Formats.Exr;
+
+internal static class ExrUtils
+{
+    public static uint CalculateBytesPerRow(IList<ExrChannelInfo> channels, uint width)
+    {
+        uint bytesPerRow = 0;
+        foreach (ExrChannelInfo channelInfo in channels)
+        {
+            if (channelInfo.ChannelName.Equals("A", StringComparison.Ordinal)
+                || channelInfo.ChannelName.Equals("R", StringComparison.Ordinal)
+                || channelInfo.ChannelName.Equals("G", StringComparison.Ordinal)
+                || channelInfo.ChannelName.Equals("B", StringComparison.Ordinal)
+                || channelInfo.ChannelName.Equals("Y", StringComparison.Ordinal))
+            {
+                if (channelInfo.PixelType == ExrPixelType.Half)
+                {
+                    bytesPerRow += 2 * width;
+                }
+                else
+                {
+                    bytesPerRow += 4 * width;
+                }
+            }
+        }
+
+        return bytesPerRow;
+    }
+
+    public static uint RowsPerBlock(ExrCompression compression) => compression switch
+    {
+        ExrCompression.Zip or ExrCompression.Pxr24 => 16,
+        ExrCompression.B44 or ExrCompression.B44A or ExrCompression.Piz => 32,
+        _ => 1,
+    };
+}