Promote PixelTypeInfo to TPixel

Fixes #2534

Author: stefannikolei

src/ImageSharp/Formats/PixelTypeInfo.cs

@@ -12,7 +12,7 @@ namespace SixLabors.ImageSharp.Formats;
 /// <summary>
 /// Contains information about the pixels that make up an images visual data.
 /// </summary>
-public class PixelTypeInfo
+public readonly struct PixelTypeInfo
 {
     /// <summary>
     /// Initializes a new instance of the <see cref="PixelTypeInfo"/> class.
@@ -21,33 +21,25 @@ public class PixelTypeInfo
     public PixelTypeInfo(int bitsPerPixel)
         => this.BitsPerPixel = bitsPerPixel;
 
-    /// <summary>
-    /// Initializes a new instance of the <see cref="PixelTypeInfo"/> class.
-    /// </summary>
-    /// <param name="bitsPerPixel">Color depth, in number of bits per pixel.</param>
-    /// <param name="alpha">The pixel alpha transparency behavior.</param>
-    public PixelTypeInfo(int bitsPerPixel, PixelAlphaRepresentation alpha)
-    {
-        this.BitsPerPixel = bitsPerPixel;
-        this.AlphaRepresentation = alpha;
-    }
-
     /// <summary>
     /// Gets color depth, in number of bits per pixel.
     /// </summary>
-    public int BitsPerPixel { get; }
+    public int BitsPerPixel { get; init; }
+
+    public byte ComponentCount { get; init; }
 
     /// <summary>
     /// Gets the pixel alpha transparency behavior.
     /// <see langword="null"/> means unknown, unspecified.
     /// </summary>
-    public PixelAlphaRepresentation? AlphaRepresentation { get; }
-
-    internal static PixelTypeInfo Create<TPixel>()
-        where TPixel : unmanaged, IPixel<TPixel>
-        => new(Unsafe.SizeOf<TPixel>() * 8);
+    public PixelAlphaRepresentation? AlphaRepresentation { get; init; }
 
-    internal static PixelTypeInfo Create<TPixel>(PixelAlphaRepresentation alpha)
+    internal static PixelTypeInfo Create<TPixel>(byte componentCount, PixelAlphaRepresentation pixelAlphaRepresentation)
         where TPixel : unmanaged, IPixel<TPixel>
-        => new(Unsafe.SizeOf<TPixel>() * 8, alpha);
+        => new()
+        {
+            BitsPerPixel = Unsafe.SizeOf<TPixel>() * 8,
+            ComponentCount = componentCount,
+            AlphaRepresentation = pixelAlphaRepresentation
+        };
 }

src/ImageSharp/Image{TPixel}.cs

@@ -78,7 +78,7 @@ public Image(int width, int height)
     /// <param name="height">The height of the image in pixels.</param>
     /// <param name="metadata">The images metadata.</param>
     internal Image(Configuration configuration, int width, int height, ImageMetadata? metadata)
-        : base(configuration, PixelTypeInfo.Create<TPixel>(), metadata ?? new(), width, height)
+        : base(configuration, TPixel.GetPixelTypeInfo(), metadata ?? new(), width, height)
         => this.frames = new ImageFrameCollection<TPixel>(this, width, height, default(TPixel));
 
     /// <summary>
@@ -111,7 +111,7 @@ internal Image(
         int width,
         int height,
         ImageMetadata metadata)
-        : base(configuration, PixelTypeInfo.Create<TPixel>(), metadata, width, height)
+        : base(configuration, TPixel.GetPixelTypeInfo(), metadata, width, height)
         => this.frames = new ImageFrameCollection<TPixel>(this, width, height, memoryGroup);
 
     /// <summary>
@@ -129,7 +129,7 @@ internal Image(
         int height,
         TPixel backgroundColor,
         ImageMetadata? metadata)
-        : base(configuration, PixelTypeInfo.Create<TPixel>(), metadata ?? new(), width, height)
+        : base(configuration, TPixel.GetPixelTypeInfo(), metadata ?? new(), width, height)
         => this.frames = new ImageFrameCollection<TPixel>(this, width, height, backgroundColor);
 
     /// <summary>
@@ -140,7 +140,7 @@ internal Image(
     /// <param name="metadata">The images metadata.</param>
     /// <param name="frames">The frames that will be owned by this image instance.</param>
     internal Image(Configuration configuration, ImageMetadata metadata, IEnumerable<ImageFrame<TPixel>> frames)
-        : base(configuration, PixelTypeInfo.Create<TPixel>(), metadata, ValidateFramesAndGetSize(frames))
+        : base(configuration, TPixel.GetPixelTypeInfo(), metadata, ValidateFramesAndGetSize(frames))
         => this.frames = new ImageFrameCollection<TPixel>(this, frames);
 
     /// <inheritdoc />

src/ImageSharp/PixelFormats/IPixel.cs

@@ -2,6 +2,7 @@
 // Licensed under the Six Labors Split License.
 
 using System.Numerics;
+using SixLabors.ImageSharp.Formats;
 
 namespace SixLabors.ImageSharp.PixelFormats;
 
@@ -14,6 +15,8 @@ namespace SixLabors.ImageSharp.PixelFormats;
 public interface IPixel<TSelf> : IPixel, IEquatable<TSelf>
     where TSelf : unmanaged, IPixel<TSelf>
 {
+    static abstract PixelTypeInfo GetPixelTypeInfo();
+
     /// <summary>
     /// Creates a <see cref="PixelOperations{TPixel}"/> instance for this pixel type.
     /// This method is not intended to be consumed directly. Use <see cref="PixelOperations{TPixel}.Instance"/> instead.

src/ImageSharp/PixelFormats/PixelImplementations/A8.cs

@@ -3,6 +3,7 @@
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
+using SixLabors.ImageSharp.Formats;
 
 namespace SixLabors.ImageSharp.PixelFormats;
 
@@ -55,6 +56,8 @@ public partial struct A8 : IPixel<A8>, IPackedVector<byte>
     [MethodImpl(InliningOptions.ShortMethod)]
     public static bool operator !=(A8 left, A8 right) => !left.Equals(right);
 
+    public static PixelTypeInfo GetPixelTypeInfo() => PixelTypeInfo.Create<A8>(1, PixelAlphaRepresentation.Unassociated);
+
     /// <inheritdoc />
     public readonly PixelOperations<A8> CreatePixelOperations() => new PixelOperations();
 

src/ImageSharp/PixelFormats/PixelImplementations/Abgr32.cs

@@ -4,6 +4,7 @@
 using System.Numerics;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
+using SixLabors.ImageSharp.Formats;
 
 namespace SixLabors.ImageSharp.PixelFormats;
 
@@ -183,6 +184,8 @@ public uint PackedValue
     [MethodImpl(InliningOptions.ShortMethod)]
     public static bool operator !=(Abgr32 left, Abgr32 right) => !left.Equals(right);
 
+    public static PixelTypeInfo GetPixelTypeInfo() => PixelTypeInfo.Create<Abgr32>(4, PixelAlphaRepresentation.Unassociated);
+
     /// <inheritdoc />
     public readonly PixelOperations<Abgr32> CreatePixelOperations() => new PixelOperations();
 

src/ImageSharp/PixelFormats/PixelImplementations/Argb32.cs

@@ -4,6 +4,7 @@
 using System.Numerics;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
+using SixLabors.ImageSharp.Formats;
 
 namespace SixLabors.ImageSharp.PixelFormats;
 
@@ -183,6 +184,8 @@ public uint PackedValue
     [MethodImpl(InliningOptions.ShortMethod)]
     public static bool operator !=(Argb32 left, Argb32 right) => !left.Equals(right);
 
+    public static PixelTypeInfo GetPixelTypeInfo() => PixelTypeInfo.Create<Argb32>(4, PixelAlphaRepresentation.Unassociated);
+
     /// <inheritdoc />
     public readonly PixelOperations<Argb32> CreatePixelOperations() => new PixelOperations();
 

src/ImageSharp/PixelFormats/PixelImplementations/Bgr24.cs

@@ -4,6 +4,7 @@
 using System.Numerics;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
+using SixLabors.ImageSharp.Formats;
 
 namespace SixLabors.ImageSharp.PixelFormats;
 
@@ -87,6 +88,8 @@ public Bgr24(byte r, byte g, byte b)
     [MethodImpl(InliningOptions.ShortMethod)]
     public static bool operator !=(Bgr24 left, Bgr24 right) => !left.Equals(right);
 
+    public static PixelTypeInfo GetPixelTypeInfo() => PixelTypeInfo.Create<Bgr24>(3, PixelAlphaRepresentation.None);
+
     /// <inheritdoc/>
     public readonly PixelOperations<Bgr24> CreatePixelOperations() => new PixelOperations();
 

src/ImageSharp/PixelFormats/PixelImplementations/Bgr565.cs

@@ -3,6 +3,7 @@
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
+using SixLabors.ImageSharp.Formats;
 
 namespace SixLabors.ImageSharp.PixelFormats;
 
@@ -59,6 +60,8 @@ public Bgr565(float x, float y, float z)
     [MethodImpl(InliningOptions.ShortMethod)]
     public static bool operator !=(Bgr565 left, Bgr565 right) => !left.Equals(right);
 
+    public static PixelTypeInfo GetPixelTypeInfo() => PixelTypeInfo.Create<Bgr565>(3, PixelAlphaRepresentation.None);
+
     /// <inheritdoc />
     public readonly PixelOperations<Bgr565> CreatePixelOperations() => new PixelOperations();
 

src/ImageSharp/PixelFormats/PixelImplementations/Bgra32.cs

@@ -4,6 +4,7 @@
 using System.Numerics;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
+using SixLabors.ImageSharp.Formats;
 
 namespace SixLabors.ImageSharp.PixelFormats;
 
@@ -136,6 +137,8 @@ public uint PackedValue
     [MethodImpl(InliningOptions.ShortMethod)]
     public static bool operator !=(Bgra32 left, Bgra32 right) => !left.Equals(right);
 
+    public static PixelTypeInfo GetPixelTypeInfo() => PixelTypeInfo.Create<Bgra32>(4, PixelAlphaRepresentation.Unassociated);
+
     /// <inheritdoc/>
     public readonly PixelOperations<Bgra32> CreatePixelOperations() => new PixelOperations();
 

src/ImageSharp/PixelFormats/PixelImplementations/Bgra4444.cs

@@ -3,6 +3,7 @@
 
 using System.Numerics;
 using System.Runtime.CompilerServices;
+using SixLabors.ImageSharp.Formats;
 
 namespace SixLabors.ImageSharp.PixelFormats;
 
@@ -57,6 +58,8 @@ public Bgra4444(float x, float y, float z, float w)
     [MethodImpl(InliningOptions.ShortMethod)]
     public static bool operator !=(Bgra4444 left, Bgra4444 right) => !left.Equals(right);
 
+    public static PixelTypeInfo GetPixelTypeInfo() => PixelTypeInfo.Create<Bgra4444>(4, PixelAlphaRepresentation.Unassociated);
+
     /// <inheritdoc />
     public readonly PixelOperations<Bgra4444> CreatePixelOperations() => new PixelOperations();