From 6fcd81158fa825787d28b3de9e9837d503c8b846 Mon Sep 17 00:00:00 2001
From: Olivia <olivia_git@outlook.com>
Date: Wed, 28 Dec 2016 12:42:37 +0200
Subject: [PATCH] Adding backing vector3 to YCbCr.

---
 src/ImageSharp/Colors/ColorspaceTransforms.cs | 12 +++---
 src/ImageSharp/Colors/Spaces/YCbCr.cs         | 37 ++++++++++++-------
 2 files changed, 29 insertions(+), 20 deletions(-)

diff --git a/src/ImageSharp/Colors/ColorspaceTransforms.cs b/src/ImageSharp/Colors/ColorspaceTransforms.cs
index 7315b9e9d2..3994e2407b 100644
--- a/src/ImageSharp/Colors/ColorspaceTransforms.cs
+++ b/src/ImageSharp/Colors/ColorspaceTransforms.cs
@@ -63,13 +63,13 @@ namespace ImageSharp
         /// </returns>
         public static implicit operator Color(YCbCr color)
         {
-            byte y = color.Y;
-            int cb = color.Cb - 128;
-            int cr = color.Cr - 128;
+            float y = color.Y;
+            float cb = color.Cb - 128;
+            float cr = color.Cr - 128;
 
-            byte r = (byte)(y + (1.402F * cr)).Clamp(0, 255);
-            byte g = (byte)(y - (0.34414F * cb) - (0.71414F * cr)).Clamp(0, 255);
-            byte b = (byte)(y + (1.772F * cb)).Clamp(0, 255);
+            float r = (y + (1.402F * cr)).Clamp(0, 255);
+            float g = (y - (0.34414F * cb) - (0.71414F * cr)).Clamp(0, 255);
+            float b = (y + (1.772F * cb)).Clamp(0, 255);
 
             return new Color(r, g, b);
         }
diff --git a/src/ImageSharp/Colors/Spaces/YCbCr.cs b/src/ImageSharp/Colors/Spaces/YCbCr.cs
index 8d94ebccaf..ada36c831e 100644
--- a/src/ImageSharp/Colors/Spaces/YCbCr.cs
+++ b/src/ImageSharp/Colors/Spaces/YCbCr.cs
@@ -7,6 +7,7 @@ namespace ImageSharp.Colors.Spaces
 {
     using System;
     using System.ComponentModel;
+    using System.Numerics;
 
     /// <summary>
     /// Represents an YCbCr (luminance, blue chroma, red chroma) color conforming to the full range standard used in digital imaging systems.
@@ -19,6 +20,11 @@ namespace ImageSharp.Colors.Spaces
         /// </summary>
         public static readonly YCbCr Empty = default(YCbCr);
 
+        /// <summary>
+        /// The backing vector for SIMD support.
+        /// </summary>
+        private Vector3 backingVector;
+
         /// <summary>
         /// Initializes a new instance of the <see cref="YCbCr"/> struct.
         /// </summary>
@@ -28,28 +34,26 @@ namespace ImageSharp.Colors.Spaces
         public YCbCr(byte y, byte cb, byte cr)
             : this()
         {
-            this.Y = y;
-            this.Cb = cb;
-            this.Cr = cr;
+            this.backingVector = Vector3.Clamp(new Vector3(y, cb, cr), Vector3.Zero, new Vector3(255));
         }
 
         /// <summary>
         /// Gets the Y luminance component.
         /// <remarks>A value ranging between 0 and 255.</remarks>
         /// </summary>
-        public byte Y { get; }
+        public float Y => this.backingVector.X;
 
         /// <summary>
         /// Gets the Cb chroma component.
         /// <remarks>A value ranging between 0 and 255.</remarks>
         /// </summary>
-        public byte Cb { get; }
+        public float Cb => this.backingVector.Y;
 
         /// <summary>
         /// Gets the Cr chroma component.
         /// <remarks>A value ranging between 0 and 255.</remarks>
         /// </summary>
-        public byte Cr { get; }
+        public float Cr => this.backingVector.Z;
 
         /// <summary>
         /// Gets a value indicating whether this <see cref="YCbCr"/> is empty.
@@ -117,13 +121,7 @@ namespace ImageSharp.Colors.Spaces
         /// <inheritdoc/>
         public override int GetHashCode()
         {
-            unchecked
-            {
-                int hashCode = this.Y.GetHashCode();
-                hashCode = (hashCode * 397) ^ this.Cb.GetHashCode();
-                hashCode = (hashCode * 397) ^ this.Cr.GetHashCode();
-                return hashCode;
-            }
+            return GetHashCode(this);
         }
 
         /// <inheritdoc/>
@@ -151,7 +149,18 @@ namespace ImageSharp.Colors.Spaces
         /// <inheritdoc/>
         public bool Equals(YCbCr other)
         {
-            return this.Y == other.Y && this.Cb == other.Cb && this.Cr == other.Cr;
+            return this.backingVector.Equals(other.backingVector);
         }
+
+        /// <summary>
+        /// Returns the hash code for this instance.
+        /// </summary>
+        /// <param name="color">
+        /// The instance of <see cref="YCbCr"/> to return the hash code for.
+        /// </param>
+        /// <returns>
+        /// A 32-bit signed integer that is the hash code for this instance.
+        /// </returns>
+        private static int GetHashCode(YCbCr color) => color.backingVector.GetHashCode();
     }
 }
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