From 4fcc5c6c57f46ed295e7cbd422c535549d2ec03c Mon Sep 17 00:00:00 2001
From: Jason Nelson <jason@carbonmade.com>
Date: Mon, 1 Apr 2024 19:01:32 -0700
Subject: [PATCH] Eliminate a few allocations in ColorSpace transformers

---
 .../Graphics/Colors/ColorSpaceDetails.cs             | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/UglyToad.PdfPig/Graphics/Colors/ColorSpaceDetails.cs b/src/UglyToad.PdfPig/Graphics/Colors/ColorSpaceDetails.cs
index 558cd3367..1a1f94412 100644
--- a/src/UglyToad.PdfPig/Graphics/Colors/ColorSpaceDetails.cs
+++ b/src/UglyToad.PdfPig/Graphics/Colors/ColorSpaceDetails.cs
@@ -4,6 +4,7 @@
     using System.Collections.Concurrent;
     using System.Collections.Generic;
     using System.Linq;
+    using System.Runtime.InteropServices;
     using Tokens;
     using UglyToad.PdfPig.Content;
     using UglyToad.PdfPig.Functions;
@@ -572,7 +573,12 @@ internal override ReadOnlySpan<byte> Transform(ReadOnlySpan<byte> decoded)
                     transformed.Add(ConvertToByte(colors[c]));
                 }
             }
+
+#if NET8_0_OR_GREATER
+            return CollectionsMarshal.AsSpan(transformed);
+#else
             return transformed.ToArray();
+#endif
         }
 
         /// <inheritdoc/>
@@ -721,7 +727,7 @@ public override IColor GetColor(params double[] values)
         internal override ReadOnlySpan<byte> Transform(ReadOnlySpan<byte> values)
         {
             var cache = new Dictionary<int, double[]>();
-            var transformed = new List<byte>();
+            var transformed = new List<byte>(values.Length * 3);
             for (var i = 0; i < values.Length; i += 3)
             {
                 byte b = values[i++];
@@ -737,7 +743,11 @@ internal override ReadOnlySpan<byte> Transform(ReadOnlySpan<byte> values)
                 }
             }
 
+#if NET8_0_OR_GREATER
+            return CollectionsMarshal.AsSpan(transformed);
+#else
             return transformed.ToArray();
+#endif
         }
 
         /// <inheritdoc/>