Add NormalizedShort4

src/ImageSharp/Colors/PackedPixel/NormalizedShort4.cs

@@ -0,0 +1,203 @@
+// <copyright file="NormalizedShort4.cs" company="James Jackson-South">
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageSharp
+{
+    using System;
+    using System.Numerics;
+
+    /// <summary>
+    /// Packed pixel type containing four 16-bit signed normalized values, ranging from −1 to 1.
+    /// </summary>
+    public struct NormalizedShort4 : IPackedPixel<ulong>, IEquatable<NormalizedShort4>
+    {
+        /// <summary>
+        /// The maximum byte value.
+        /// </summary>
+        private static readonly Vector4 MaxBytes = new Vector4(255);
+
+        /// <summary>
+        /// The half the maximum byte value.
+        /// </summary>
+        private static readonly Vector4 Half = new Vector4(127);
+
+        /// <summary>
+        /// The vector value used for rounding.
+        /// </summary>
+        private static readonly Vector4 Round = new Vector4(.5F);
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="NormalizedShort4"/> struct.
+        /// </summary>
+        /// <param name="vector">The vector containing the component values.</param>
+        public NormalizedShort4(Vector4 vector)
+        {
+            this.PackedValue = Pack(vector.X, vector.Y, vector.Z, vector.W);
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="NormalizedShort4"/> struct.
+        /// </summary>
+        /// <param name="x">The x-component.</param>
+        /// <param name="y">The y-component.</param>
+        /// <param name="z">The z-component.</param>
+        /// <param name="w">The w-component.</param>
+        public NormalizedShort4(float x, float y, float z, float w)
+        {
+            this.PackedValue = Pack(x, y, z, w);
+        }
+
+        /// <inheritdoc />
+        public ulong PackedValue { get; set; }
+
+        /// <summary>
+        /// Compares two <see cref="NormalizedShort4"/> objects for equality.
+        /// </summary>
+        /// <param name="left">
+        /// The <see cref="NormalizedShort4"/> on the left side of the operand.
+        /// </param>
+        /// <param name="right">
+        /// The <see cref="NormalizedShort4"/> on the right side of the operand.
+        /// </param>
+        /// <returns>
+        /// True if the <paramref name="left"/> parameter is equal to the <paramref name="right"/> parameter; otherwise, false.
+        /// </returns>
+        public static bool operator ==(NormalizedShort4 left, NormalizedShort4 right)
+        {
+            return left.Equals(right);
+        }
+
+        /// <summary>
+        /// Compares two <see cref="NormalizedShort4"/> objects for equality.
+        /// </summary>
+        /// <param name="left">
+        /// The <see cref="NormalizedShort4"/> on the left side of the operand.
+        /// </param>
+        /// <param name="right">
+        /// The <see cref="NormalizedShort4"/> on the right side of the operand.
+        /// </param>
+        /// <returns>
+        /// True if the <paramref name="left"/> parameter is not equal to the <paramref name="right"/> parameter; otherwise, false.
+        /// </returns>
+        public static bool operator !=(NormalizedShort4 left, NormalizedShort4 right)
+        {
+            return !left.Equals(right);
+        }
+
+        /// <inheritdoc />
+        public void PackFromVector4(Vector4 vector)
+        {
+            this.PackedValue = Pack(vector.X, vector.Y, vector.Z, vector.W);
+        }
+
+        /// <inheritdoc />
+        public Vector4 ToVector4()
+        {
+            const float MaxVal = 0x7FFF;
+
+            return new Vector4(
+                         (short)((this.PackedValue >> 0x00) & 0xFFFF) / MaxVal,
+                         (short)((this.PackedValue >> 0x10) & 0xFFFF) / MaxVal,
+                         (short)((this.PackedValue >> 0x20) & 0xFFFF) / MaxVal,
+                         (short)((this.PackedValue >> 0x30) & 0xFFFF) / MaxVal);
+        }
+
+        /// <inheritdoc />
+        public void PackFromBytes(byte x, byte y, byte z, byte w)
+        {
+            Vector4 vector = new Vector4(x, y, z, w);
+            vector -= Round;
+            vector -= Half;
+            vector -= Round;
+            vector /= Half;
+            this.PackFromVector4(vector);
+        }
+
+        /// <inheritdoc />
+        public void ToBytes(byte[] bytes, int startIndex, ComponentOrder componentOrder)
+        {
+            Vector4 vector = this.ToVector4();
+            vector *= Half;
+            vector += Round;
+            vector += Half;
+            vector += Round;
+            vector = Vector4.Clamp(vector, Vector4.Zero, MaxBytes);
+
+            switch (componentOrder)
+            {
+                case ComponentOrder.ZYX:
+                    bytes[startIndex] = (byte)(float)Math.Round(vector.Z);
+                    bytes[startIndex + 1] = (byte)(float)Math.Round(vector.Y);
+                    bytes[startIndex + 2] = (byte)(float)Math.Round(vector.X);
+                    break;
+                case ComponentOrder.ZYXW:
+                    bytes[startIndex] = (byte)(float)Math.Round(vector.Z);
+                    bytes[startIndex + 1] = (byte)(float)Math.Round(vector.Y);
+                    bytes[startIndex + 2] = (byte)(float)Math.Round(vector.X);
+                    bytes[startIndex + 3] = (byte)(float)Math.Round(vector.W);
+                    break;
+                case ComponentOrder.XYZ:
+                    bytes[startIndex] = (byte)(float)Math.Round(vector.X);
+                    bytes[startIndex + 1] = (byte)(float)Math.Round(vector.Y);
+                    bytes[startIndex + 2] = (byte)(float)Math.Round(vector.Z);
+                    break;
+                case ComponentOrder.XYZW:
+                    bytes[startIndex] = (byte)(float)Math.Round(vector.X);
+                    bytes[startIndex + 1] = (byte)(float)Math.Round(vector.Y);
+                    bytes[startIndex + 2] = (byte)(float)Math.Round(vector.Z);
+                    bytes[startIndex + 3] = (byte)(float)Math.Round(vector.W);
+                    break;
+                default:
+                    throw new NotSupportedException();
+            }
+        }
+
+        /// <inheritdoc />
+        public override bool Equals(object obj)
+        {
+            return (obj is NormalizedShort4) && this.Equals((NormalizedShort4)obj);
+        }
+
+        /// <inheritdoc />
+        public bool Equals(NormalizedShort4 other)
+        {
+            return this.PackedValue.Equals(other.PackedValue);
+        }
+
+        /// <inheritdoc />
+        public override int GetHashCode()
+        {
+            return this.PackedValue.GetHashCode();
+        }
+
+        /// <inheritdoc />
+        public override string ToString()
+        {
+            return this.PackedValue.ToString("X");
+        }
+
+        /// <summary>
+        /// Packs the <see cref="float"/> components into a <see cref="ulong"/>.
+        /// </summary>
+        /// <param name="x">The x-component</param>
+        /// <param name="y">The y-component</param>
+        /// <param name="z">The z-component</param>
+        /// <param name="w">The w-component</param>
+        /// <returns>The <see cref="ulong"/> containing the packed values.</returns>
+        private static ulong Pack(float x, float y, float z, float w)
+        {
+            const float MaxPos = 0x7FFF;
+            const float MinNeg = -MaxPos;
+
+            // Clamp the value between min and max values
+            ulong word4 = ((ulong)(float)Math.Round(x * MaxPos).Clamp(MinNeg, MaxPos) & 0xFFFF) << 0x00;
+            ulong word3 = ((ulong)(float)Math.Round(y * MaxPos).Clamp(MinNeg, MaxPos) & 0xFFFF) << 0x10;
+            ulong word2 = ((ulong)(float)Math.Round(z * MaxPos).Clamp(MinNeg, MaxPos) & 0xFFFF) << 0x20;
+            ulong word1 = ((ulong)(float)Math.Round(w * MaxPos).Clamp(MinNeg, MaxPos) & 0xFFFF) << 0x30;
+
+            return word4 | word3 | word2 | word1;
+        }
+    }
+}

tests/ImageSharp.Tests/Colors/PackedPixelTests.cs

@@ -518,6 +518,52 @@ namespace ImageSharp.Tests.Colors
             Assert.Equal(bgra, new byte[] { 0, 90, 141, 255 });
         }
 
+        [Fact]
+        public void NormalizedShort4()
+        {
+            // Test PackedValue
+            Assert.Equal((ulong)0x0, new NormalizedShort4(Vector4.Zero).PackedValue);
+            Assert.Equal((ulong)0x7FFF7FFF7FFF7FFF, new NormalizedShort4(Vector4.One).PackedValue);
+            Assert.Equal(0x8001800180018001, new NormalizedShort4(-Vector4.One).PackedValue);
+
+            // Test ToVector4
+            Assert.True(Equal(Vector4.One, new NormalizedShort4(Vector4.One).ToVector4()));
+            Assert.True(Equal(Vector4.Zero, new NormalizedShort4(Vector4.Zero).ToVector4()));
+            Assert.True(Equal(-Vector4.One, new NormalizedShort4(-Vector4.One).ToVector4()));
+            Assert.True(Equal(Vector4.One, new NormalizedShort4(Vector4.One * 1234.0f).ToVector4()));
+            Assert.True(Equal(-Vector4.One, new NormalizedShort4(Vector4.One * -1234.0f).ToVector4()));
+
+            // Test Ordering
+            float x = 0.1f;
+            float y = -0.3f;
+            float z = 0.5f;
+            float w = -0.7f;
+            Assert.Equal(0xa6674000d99a0ccd, new NormalizedShort4(x, y, z, w).PackedValue);
+            Assert.Equal((ulong)4150390751449251866, new NormalizedShort4(0.0008f, 0.15f, 0.30f, 0.45f).PackedValue);
+
+            byte[] rgb = new byte[3];
+            byte[] rgba = new byte[4];
+            byte[] bgr = new byte[3];
+            byte[] bgra = new byte[4];
+
+            new NormalizedShort4(x, y, z, w).ToBytes(rgb, 0, ComponentOrder.XYZ);
+            Assert.Equal(rgb, new byte[] { 141, 90, 192 });
+
+            new NormalizedShort4(x, y, z, w).ToBytes(rgba, 0, ComponentOrder.XYZW);
+            Assert.Equal(rgba, new byte[] { 141, 90, 192, 39 });
+
+            new NormalizedShort4(x, y, z, w).ToBytes(bgr, 0, ComponentOrder.ZYX);
+            Assert.Equal(bgr, new byte[] { 192, 90, 141 });
+
+            new NormalizedShort4(x, y, z, w).ToBytes(bgra, 0, ComponentOrder.ZYXW);
+            Assert.Equal(bgra, new byte[] { 192, 90, 141, 39 });
+
+            NormalizedShort4 r = new NormalizedShort4();
+            r.PackFromBytes(9, 115, 202, 127);
+            r.ToBytes(rgba, 0, ComponentOrder.XYZW);
+            Assert.Equal(rgba, new byte[] { 9, 115, 202, 127 });
+        }
+
         // Comparison helpers with small tolerance to allow for floating point rounding during computations.
         public static bool Equal(float a, float b)
         {

tests/ImageSharp.Tests/Formats/GeneralFormatTests.cs

@@ -66,6 +66,7 @@ namespace ImageSharp.Tests
                 // Image<NormalizedByte2, ushort> image = file.CreateImage().To<NormalizedByte2, ushort>(v => (2F * v) - Vector4.One);
                 // Image<NormalizedByte4, uint> image = file.CreateImage().To<NormalizedByte4, uint>(v => (2F * v) - Vector4.One);
                 // Image<NormalizedShort2, uint> image = file.CreateImage().To<NormalizedShort2, uint>(v => (2F * v) - Vector4.One);
+                // Image<NormalizedShort4, ulong> image = file.CreateImage().To<NormalizedShort4, ulong>(v => (2F * v) - Vector4.One);
                 using (FileStream output = File.OpenWrite($"{path}/{file.FileName}"))
                 {
                     image.Save(output);