Add Bgra5551

src/ImageSharp/Colors/PackedPixel/Bgra5551.cs

@@ -0,0 +1,171 @@
+// <copyright file="Bgra5551.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 unsigned normalized values ranging from 0 to 1. The x , y and z components use 5 bits, and the w component uses 1 bit.
+    /// </summary>
+    public struct Bgra5551 : IPackedPixel<ushort>, IEquatable<Bgra5551>, IPackedVector
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Bgra5551"/> 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 Bgra5551(float x, float y, float z, float w)
+        {
+            this.PackedValue = Pack(x, y, z, w);
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Bgra5551"/> struct.
+        /// </summary>
+        /// <param name="vector">
+        /// The vector containing the components for the packed vector.
+        /// </param>
+        public Bgra5551(Vector4 vector)
+        {
+            this.PackedValue = Pack(vector.X, vector.Y, vector.Z, vector.W);
+        }
+
+        /// <inheritdoc />
+        public ushort PackedValue { get; set; }
+
+        /// <summary>
+        /// Compares two <see cref="Bgra5551"/> objects for equality.
+        /// </summary>
+        /// <param name="left">The <see cref="Bgra5551"/> on the left side of the operand.</param>
+        /// <param name="right">The <see cref="Bgra5551"/> 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 ==(Bgra5551 left, Bgra5551 right)
+        {
+            return left.PackedValue == right.PackedValue;
+        }
+
+        /// <summary>
+        /// Compares two <see cref="Bgra5551"/> objects for equality.
+        /// </summary>
+        /// <param name="left">The <see cref="Bgra5551"/> on the left side of the operand.</param>
+        /// <param name="right">The <see cref="Bgra5551"/> 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 !=(Bgra5551 left, Bgra5551 right)
+        {
+            return left.PackedValue != right.PackedValue;
+        }
+
+        /// <inheritdoc />
+        public Vector4 ToVector4()
+        {
+            return new Vector4(
+                        ((this.PackedValue >> 10) & 0x1F) / 31F,
+                        ((this.PackedValue >> 5) & 0x1F) / 31F,
+                        ((this.PackedValue >> 0) & 0x1F) / 31F,
+                        (this.PackedValue >> 15) & 0x01);
+        }
+
+        /// <inheritdoc />
+        public void PackFromVector4(Vector4 vector)
+        {
+            this.PackedValue = Pack(vector.X, vector.Y, vector.Z, vector.W);
+        }
+
+        /// <inheritdoc />
+        public void PackFromBytes(byte x, byte y, byte z, byte w)
+        {
+            this.PackFromVector4(new Vector4(x, y, z, w) / 255F);
+        }
+
+        /// <inheritdoc />
+        public void ToBytes(byte[] bytes, int startIndex, ComponentOrder componentOrder)
+        {
+            Vector4 vector = this.ToVector4() * 255F;
+
+            switch (componentOrder)
+            {
+                case ComponentOrder.ZYX:
+                    bytes[startIndex] = (byte)vector.Z;
+                    bytes[startIndex + 1] = (byte)vector.Y;
+                    bytes[startIndex + 2] = (byte)vector.X;
+                    break;
+                case ComponentOrder.ZYXW:
+                    bytes[startIndex] = (byte)vector.Z;
+                    bytes[startIndex + 1] = (byte)vector.Y;
+                    bytes[startIndex + 2] = (byte)vector.X;
+                    bytes[startIndex + 3] = (byte)vector.W;
+                    break;
+                case ComponentOrder.XYZ:
+                    bytes[startIndex] = (byte)vector.X;
+                    bytes[startIndex + 1] = (byte)vector.Y;
+                    bytes[startIndex + 2] = (byte)vector.Z;
+                    break;
+                case ComponentOrder.XYZW:
+                    bytes[startIndex] = (byte)vector.X;
+                    bytes[startIndex + 1] = (byte)vector.Y;
+                    bytes[startIndex + 2] = (byte)vector.Z;
+                    bytes[startIndex + 3] = (byte)vector.W;
+                    break;
+                default:
+                    throw new NotSupportedException();
+            }
+        }
+
+        /// <inheritdoc />
+        public override bool Equals(object obj)
+        {
+            return (obj is Bgra5551) && this.Equals((Bgra5551)obj);
+        }
+
+        /// <inheritdoc />
+        public bool Equals(Bgra5551 other)
+        {
+            return this.PackedValue == other.PackedValue;
+        }
+
+        /// <summary>
+        /// Gets a string representation of the packed vector.
+        /// </summary>
+        /// <returns>A string representation of the packed vector.</returns>
+        public override string ToString()
+        {
+            return this.ToVector4().ToString();
+        }
+
+        /// <summary>
+        /// Gets a hash code of the packed vector.
+        /// </summary>
+        /// <returns>The hash code for the packed vector.</returns>
+        public override int GetHashCode()
+        {
+            return this.PackedValue.GetHashCode();
+        }
+
+        /// <summary>
+        /// Packs the <see cref="float"/> components into a <see cref="ushort"/>.
+        /// </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="ushort"/> containing the packed values.</returns>
+        private static ushort Pack(float x, float y, float z, float w)
+        {
+            return (ushort)(
+                   (((int)Math.Round(x.Clamp(0, 1) * 31F) & 0x1F) << 10) |
+                   (((int)Math.Round(y.Clamp(0, 1) * 31F) & 0x1F) << 5) |
+                   (((int)Math.Round(z.Clamp(0, 1) * 31F) & 0x1F) << 0) |
+                   (((int)Math.Round(w.Clamp(0, 1)) & 0x1) << 15));
+        }
+    }
+}

tests/ImageSharp.Tests/Colors/PackedVectorTests.cs

@@ -154,6 +154,52 @@ namespace ImageSharp.Tests.Colors
             Assert.Equal(bgra, new byte[] { 136, 0, 34, 0 });
         }
 
+        [Fact]
+        public void Bgra5551()
+        {
+            // Test the limits.
+            Assert.Equal(0x0, new Bgra5551(Vector4.Zero).PackedValue);
+            Assert.Equal(0xFFFF, new Bgra5551(Vector4.One).PackedValue);
+
+            // Test ToVector4
+            Assert.True(Equal(Vector4.Zero, new Bgra5551(Vector4.Zero).ToVector4()));
+            Assert.True(Equal(Vector4.One, new Bgra5551(Vector4.One).ToVector4()));
+
+            // Test clamping.
+            Assert.Equal(Vector4.Zero, new Bgra5551(Vector4.One * -1234.0f).ToVector4());
+            Assert.Equal(Vector4.One, new Bgra5551(Vector4.One * 1234.0f).ToVector4());
+
+            // Test Ordering
+            float x = 0x1a;
+            float y = 0x16;
+            float z = 0xd;
+            float w = 0x1;
+            Assert.Equal(0xeacd, new Bgra5551(x / 0x1f, y / 0x1f, z / 0x1f, w).PackedValue);
+            x = 0.1f;
+            y = -0.3f;
+            z = 0.5f;
+            w = -0.7f;
+            Assert.Equal(3088, new Bgra5551(x, y, z, w).PackedValue);
+
+            // Test ordering
+            byte[] rgb = new byte[3];
+            byte[] rgba = new byte[4];
+            byte[] bgr = new byte[3];
+            byte[] bgra = new byte[4];
+
+            new Bgra5551(x, y, z, w).ToBytes(rgb, 0, ComponentOrder.XYZ);
+            Assert.Equal(rgb, new byte[] { 24, 0, 131 });
+
+            new Bgra5551(x, y, z, w).ToBytes(rgba, 0, ComponentOrder.XYZW);
+            Assert.Equal(rgba, new byte[] { 24, 0, 131, 0 });
+
+            new Bgra5551(x, y, z, w).ToBytes(bgr, 0, ComponentOrder.ZYX);
+            Assert.Equal(bgr, new byte[] { 131, 0, 24 });
+
+            new Bgra5551(x, y, z, w).ToBytes(bgra, 0, ComponentOrder.ZYXW);
+            Assert.Equal(bgra, new byte[] { 131, 0, 24, 0 });
+        }
+
         // 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

@@ -54,6 +54,7 @@ namespace ImageSharp.Tests
                 Image image = file.CreateImage();
                 // Image<Bgr565, ushort> image = file.CreateImage().To<Bgr565, ushort>();
                 // Image<Bgra4444, ushort> image = file.CreateImage().To<Bgra4444, ushort>();
+                // Image<Bgra5551, ushort> image = file.CreateImage().To<Bgra5551, ushort>();
 
                 using (FileStream output = File.OpenWrite($"{path}/{file.FileName}"))
                 {