Blittable color

src/libraries/NetCoreAppLibrary.props

@@ -103,6 +103,7 @@
       System.Net.WebProxy;
       System.Net.WebSockets;
       System.Net.WebSockets.Client;
+      System.Numerics.Colors;
       System.Numerics.Vectors;
       System.ObjectModel;
       System.Private.CoreLib;

src/libraries/System.ComponentModel.TypeConverter/src/System.ComponentModel.TypeConverter.csproj

@@ -255,6 +255,7 @@
     <Reference Include="System.Linq" />
     <Reference Include="System.Memory" />
     <Reference Include="System.Net.Security" />
+    <Reference Include="System.Numerics.Colors" />
     <Reference Include="System.ObjectModel" />
     <Reference Include="System.Resources.Writer" />
     <Reference Include="System.Runtime" />

src/libraries/System.Drawing.Primitives/ref/System.Drawing.Primitives.cs

@@ -167,6 +167,7 @@ namespace System.Drawing
         public bool Equals(System.Drawing.Color other) { throw null; }
         public override bool Equals([System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] object? obj) { throw null; }
         public static System.Drawing.Color FromArgb(int argb) { throw null; }
+        public static System.Drawing.Color FromArgb(System.Numerics.Colors.Argb<byte> argb) { throw null; }
         public static System.Drawing.Color FromArgb(int alpha, System.Drawing.Color baseColor) { throw null; }
         public static System.Drawing.Color FromArgb(int red, int green, int blue) { throw null; }
         public static System.Drawing.Color FromArgb(int alpha, int red, int green, int blue) { throw null; }
@@ -178,7 +179,10 @@ namespace System.Drawing
         public float GetSaturation() { throw null; }
         public static bool operator ==(System.Drawing.Color left, System.Drawing.Color right) { throw null; }
         public static bool operator !=(System.Drawing.Color left, System.Drawing.Color right) { throw null; }
+        public static explicit operator System.Numerics.Colors.Argb<byte>(in System.Drawing.Color color) { throw null; }
+        public static implicit operator System.Drawing.Color(System.Numerics.Colors.Argb<byte> argb) { throw null; }
         public int ToArgb() { throw null; }
+        public System.Numerics.Colors.Argb<byte> ToArgbValue() { throw null; }
         public System.Drawing.KnownColor ToKnownColor() { throw null; }
         public override string ToString() { throw null; }
     }

src/libraries/System.Drawing.Primitives/ref/System.Drawing.Primitives.csproj

@@ -9,6 +9,7 @@
     <ProjectReference Include="..\..\System.ObjectModel\ref\System.ObjectModel.csproj" />
     <ProjectReference Include="..\..\System.Runtime\ref\System.Runtime.csproj" />
     <ProjectReference Include="..\..\System.ComponentModel.Primitives\ref\System.ComponentModel.Primitives.csproj" />
+    <ProjectReference Include="..\..\System.Numerics.Colors\ref\System.Numerics.Colors.csproj" />
     <ProjectReference Include="..\..\System.Numerics.Vectors\ref\System.Numerics.Vectors.csproj" />
   </ItemGroup>
 </Project>

src/libraries/System.Drawing.Primitives/src/System.Drawing.Primitives.csproj

@@ -49,6 +49,7 @@
     <Reference Include="System.Collections" />
     <Reference Include="System.ComponentModel.Primitives" />
     <Reference Include="System.Memory" />
+    <Reference Include="System.Numerics.Colors" />
     <Reference Include="System.Numerics.Vectors" />
     <Reference Include="System.ObjectModel" />
     <Reference Include="System.Runtime" />

src/libraries/System.Drawing.Primitives/src/System/Drawing/Color.cs

@@ -4,6 +4,7 @@
 using System.ComponentModel;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
+using System.Numerics.Colors;
 using System.Runtime.CompilerServices;
 
 namespace System.Drawing
@@ -333,7 +334,7 @@ namespace System.Drawing
         internal const uint ARGBBlueMask = 0xFFu << ARGBBlueShift;
 
         // User supplied name of color. Will not be filled in if
-        // we map to a "knowncolor"
+        // we map to a "knownColor"
         private readonly string? name; // Do not rename (binary serialization)
 
         // Standard 32bit sRGB (ARGB)
@@ -398,10 +399,10 @@ public string Name
 
                 if (IsKnownColor)
                 {
-                    string tablename = KnownColorNames.KnownColorToName((KnownColor)knownColor);
-                    Debug.Assert(tablename != null, $"Could not find known color '{(KnownColor)knownColor}' in the KnownColorTable");
+                    string tableName = KnownColorNames.KnownColorToName((KnownColor)knownColor);
+                    Debug.Assert(tableName != null, $"Could not find known color '{(KnownColor)knownColor}' in the KnownColorTable");
 
-                    return tablename;
+                    return tableName;
                 }
 
                 // if we reached here, just encode the value
@@ -442,6 +443,10 @@ static void ThrowOutOfByteRange(int v, string n) =>
 
         public static Color FromArgb(int argb) => FromArgb(unchecked((uint)argb));
 
+        public static Color FromArgb(Argb<byte> argb) => FromArgb(BitConverter.IsLittleEndian ?
+            Argb.ToUInt32LittleEndian(argb) :
+            Argb.ToUInt32BigEndian(argb));
+
         public static Color FromArgb(int alpha, int red, int green, int blue)
         {
             CheckByte(alpha, nameof(alpha));
@@ -567,6 +572,10 @@ public float GetSaturation()
 
         public int ToArgb() => unchecked((int)Value);
 
+        public Argb<byte> ToArgbValue() => BitConverter.IsLittleEndian ?
+            Argb.CreateLittleEndian(unchecked((uint)Value)) :
+            Argb.CreateBigEndian(unchecked((uint)Value));
+
         public KnownColor ToKnownColor() => (KnownColor)knownColor;
 
         public override string ToString() =>
@@ -582,6 +591,10 @@ public override string ToString() =>
 
         public static bool operator !=(Color left, Color right) => !(left == right);
 
+        public static implicit operator Color(Argb<byte> argb) => FromArgb(argb);
+
+        public static explicit operator Argb<byte>(in Color color) => color.ToArgbValue();
+
         public override bool Equals([NotNullWhen(true)] object? obj) => obj is Color other && Equals(other);
 
         public bool Equals(Color other) => this == other;

src/libraries/System.Drawing.Primitives/tests/ColorTests.cs

@@ -4,6 +4,7 @@
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
+using System.Numerics.Colors;
 using System.Runtime.InteropServices;
 using Xunit;
 
@@ -194,23 +195,45 @@ public void ArgbValues(string name, int alpha, int red, int green, int blue)
         [InlineData(1, 2, 3, 4)]
         public void FromArgb_Roundtrips(int a, int r, int g, int b)
         {
-            Color c1 = Color.FromArgb(unchecked((int)((uint)a << 24 | (uint)r << 16 | (uint)g << 8 | (uint)b)));
-            Assert.Equal(a, c1.A);
-            Assert.Equal(r, c1.R);
-            Assert.Equal(g, c1.G);
-            Assert.Equal(b, c1.B);
+            {
+                Color c = Color.FromArgb(unchecked((int)((uint)a << 24 | (uint)r << 16 | (uint)g << 8 | (uint)b)));
+                Assert.Equal(a, c.A);
+                Assert.Equal(r, c.R);
+                Assert.Equal(g, c.G);
+                Assert.Equal(b, c.B);
+            }
+            {
+                Color c = Color.FromArgb(a, r, g, b);
+                Assert.Equal(a, c.A);
+                Assert.Equal(r, c.R);
+                Assert.Equal(g, c.G);
+                Assert.Equal(b, c.B);
+            }
+            {
 
-            Color c2 = Color.FromArgb(a, r, g, b);
-            Assert.Equal(a, c2.A);
-            Assert.Equal(r, c2.R);
-            Assert.Equal(g, c2.G);
-            Assert.Equal(b, c2.B);
+                Color c = Color.FromArgb(r, g, b);
+                Assert.Equal(255, c.A);
+                Assert.Equal(r, c.R);
+                Assert.Equal(g, c.G);
+                Assert.Equal(b, c.B);
+            }
+            {
+
+                Color c = Color.FromArgb(new Argb<byte>((byte)a, (byte)r, (byte)g, (byte)b));
+                Assert.Equal(a, c.A);
+                Assert.Equal(r, c.R);
+                Assert.Equal(g, c.G);
+                Assert.Equal(b, c.B);
+            }
+            {
 
-            Color c3 = Color.FromArgb(r, g, b);
-            Assert.Equal(255, c3.A);
-            Assert.Equal(r, c3.R);
-            Assert.Equal(g, c3.G);
-            Assert.Equal(b, c3.B);
+                // implicit operator Color(Argb<byte> argb)
+                Color c = new Argb<byte>((byte)a, (byte)r, (byte)g, (byte)b);
+                Assert.Equal(a, c.A);
+                Assert.Equal(r, c.R);
+                Assert.Equal(g, c.G);
+                Assert.Equal(b, c.B);
+            }
         }
 
         [Fact]
@@ -267,6 +290,28 @@ public void ToArgb(int argb, int alpha, int red, int green, int blue)
             Assert.Equal(argb, Color.FromArgb(alpha, red, green, blue).ToArgb());
         }
 
+        [Theory]
+        [InlineData(0x11, 0xcc, 0x88, 0x33)]
+        [InlineData(0xf1, 0xcc, 0x88, 0x33)]
+        public void ToArgbValue(int alpha, int red, int green, int blue)
+        {
+            {
+                var c = Color.FromArgb(alpha, red, green, blue).ToArgbValue();
+                Assert.Equal(alpha, c.A);
+                Assert.Equal(red, c.R);
+                Assert.Equal(green, c.G);
+                Assert.Equal(blue, c.B);
+            }
+            {
+                // explicit operator Argb<byte>(in Color color)
+                Argb<byte> c = (Argb<byte>)Color.FromArgb(alpha, red, green, blue);
+                Assert.Equal(alpha, c.A);
+                Assert.Equal(red, c.R);
+                Assert.Equal(green, c.G);
+                Assert.Equal(blue, c.B);
+            }
+        }
+
         [Fact]
         public void ToStringEmpty()
         {

src/libraries/System.Drawing.Primitives/tests/ColorTranslatorTests.cs

@@ -8,7 +8,7 @@
 using System.Threading;
 using Xunit;
 
-namespace System.Drawing.Tests
+namespace System.Drawing.Primitives.Tests
 {
     public class ColorTranslatorTests
     {

src/libraries/System.Drawing.Primitives/tests/PointFTests.cs

@@ -6,7 +6,7 @@
 using System.Reflection;
 using Xunit;
 
-namespace System.Drawing.PrimitivesTests
+namespace System.Drawing.Primitives.Tests
 {
     public class PointFTests
     {

src/libraries/System.Drawing.Primitives/tests/PointTests.cs

@@ -4,7 +4,7 @@
 using System.Globalization;
 using Xunit;
 
-namespace System.Drawing.PrimitivesTests
+namespace System.Drawing.Primitives.Tests
 {
     public class PointTests
     {

src/libraries/System.Drawing.Primitives/tests/RectangleFTests.cs

@@ -5,7 +5,7 @@
 using System.Numerics;
 using Xunit;
 
-namespace System.Drawing.PrimitivesTest
+namespace System.Drawing.Primitives.Tests
 {
     public class RectangleFTests
     {

src/libraries/System.Drawing.Primitives/tests/RectangleTests.cs

@@ -4,7 +4,7 @@
 using System.Globalization;
 using Xunit;
 
-namespace System.Drawing.PrimitivesTest
+namespace System.Drawing.Primitives.Tests
 {
     public class RectangleTests
     {

src/libraries/System.Drawing.Primitives/tests/SizeFTests.cs

@@ -5,7 +5,7 @@
 using System.Numerics;
 using Xunit;
 
-namespace System.Drawing.PrimitivesTest
+namespace System.Drawing.Primitives.Tests
 {
     public class SizeFTests
     {

src/libraries/System.Drawing.Primitives/tests/SizeTests.cs

@@ -4,7 +4,7 @@
 using System.Globalization;
 using Xunit;
 
-namespace System.Drawing.PrimitivesTests
+namespace System.Drawing.Primitives.Tests
 {
     public class SizeTests
     {

src/libraries/System.Numerics.Colors/Directory.Build.props

@@ -0,0 +1,6 @@
+<Project>
+  <Import Project="..\Directory.Build.props" />
+  <PropertyGroup>
+    <StrongNameKeyId>Microsoft</StrongNameKeyId>
+  </PropertyGroup>
+</Project>

src/libraries/System.Numerics.Colors/README.md

@@ -0,0 +1,7 @@
+# System.Numerics.Colors
+
+Provides APIs for convertible colors that contains only raw color data.
+
+The intent is NOT to start building a general purpose image manipulation library. Libraries such as ImageSharp are the right answer for this.
+
+WinForms and System.Drawing will be able to leverage this for performance, which was the original driver for this request.