Adding color packing tests - FromVector4 ToVector4.

tests/ImageSharp.Tests/Colors/ColorPackingTests.cs

@@ -0,0 +1,84 @@
+// <copyright file="ColorPackingTests.cs" company="James Jackson-South">
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageSharp.Tests.Colors
+{
+    using System.Collections.Generic;
+    using System.Numerics;
+    using Xunit;
+
+    public class ColorPackingTests
+    {
+        public static IEnumerable<object[]> Vector4PackData
+        {
+            get
+            {
+                var vector4Values = new Vector4[]
+                    {
+                        Vector4.Zero,
+                        Vector4.One,
+                        Vector4.UnitX,
+                        Vector4.UnitY,
+                        Vector4.UnitZ,
+                        Vector4.UnitW,
+                    };
+
+                foreach (var vector4 in vector4Values)
+                {
+                    yield return new object[] { new Argb(), vector4 };
+                    yield return new object[] { new Bgra4444(), vector4 };
+                    yield return new object[] { new Bgra5551(), vector4 };
+                    yield return new object[] { new Byte4(), vector4 };
+                    yield return new object[] { new HalfVector4(), vector4 };
+                    yield return new object[] { new NormalizedByte4(), vector4 };
+                    yield return new object[] { new NormalizedShort4(), vector4 };
+                    yield return new object[] { new Rgba1010102(), vector4 };
+                    yield return new object[] { new Rgba64(), vector4 };
+                    yield return new object[] { new Short4(), vector4 };
+                }
+            }
+        }
+
+        public static IEnumerable<object[]> Vector3PackData
+        {
+            get
+            {
+                var vector4Values = new Vector4[]
+                    {
+                        Vector4.One,
+                        new Vector4(0, 0, 0, 1),
+                        new Vector4(1, 0, 0, 1),
+                        new Vector4(0, 1, 0, 1),
+                        new Vector4(0, 0, 1, 1),
+                    };
+
+                foreach (var vector4 in vector4Values)
+                {
+                    yield return new object[] { new Argb(), vector4 };
+                    yield return new object[] { new Bgr565(), vector4 };
+                }
+            }
+        }
+
+        [Theory]
+        [MemberData(nameof(Vector4PackData))]
+        [MemberData(nameof(Vector3PackData))]
+        public void FromVector4ToVector4(IPackedVector packedVector, Vector4 vector4ToPack)
+        {
+            // Arrange
+            var precision = 2;
+            packedVector.PackFromVector4(vector4ToPack);
+
+            // Act
+            var vector4 = packedVector.ToVector4();
+
+            // Assert
+            Assert.Equal(vector4ToPack.X, vector4.X, precision);
+            Assert.Equal(vector4ToPack.Y, vector4.Y, precision);
+            Assert.Equal(vector4ToPack.Z, vector4.Z, precision);
+            Assert.Equal(vector4ToPack.W, vector4.W, precision);
+        }
+    }
+}