From d63d08a9ac08fa590db9edbabb561c1f6511af9b Mon Sep 17 00:00:00 2001
From: Anton Firszov <antonfir@gmail.com>
Date: Sun, 23 Sep 2018 01:56:05 +0200
Subject: [PATCH] optimize ImageFrame.Clear()

---
 src/ImageSharp/ImageFrame{TPixel}.cs          | 19 ++++++++++---------
 .../Processors/Overlays/GlowProcessor.cs      |  1 -
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/src/ImageSharp/ImageFrame{TPixel}.cs b/src/ImageSharp/ImageFrame{TPixel}.cs
index 92470e254..be1792ced 100644
--- a/src/ImageSharp/ImageFrame{TPixel}.cs
+++ b/src/ImageSharp/ImageFrame{TPixel}.cs
@@ -318,15 +318,16 @@ namespace SixLabors.ImageSharp
         /// <param name="value">The value to initialize the bitmap with.</param>
         internal void Clear(ParallelOptions parallelOptions, TPixel value)
         {
-            Parallel.For(
-                0,
-                this.Height,
-                parallelOptions,
-                y =>
-                {
-                    Span<TPixel> targetRow = this.GetPixelRowSpan(y);
-                    targetRow.Fill(value);
-                });
+            Span<TPixel> span = this.GetPixelSpan();
+
+            if (value.Equals(default))
+            {
+                span.Clear();
+            }
+            else
+            {
+                span.Fill(value);
+            }
         }
 
         /// <inheritdoc/>
diff --git a/src/ImageSharp/Processing/Processors/Overlays/GlowProcessor.cs b/src/ImageSharp/Processing/Processors/Overlays/GlowProcessor.cs
index d774a10ab..93d6edff1 100644
--- a/src/ImageSharp/Processing/Processors/Overlays/GlowProcessor.cs
+++ b/src/ImageSharp/Processing/Processors/Overlays/GlowProcessor.cs
@@ -86,7 +86,6 @@ namespace SixLabors.ImageSharp.Processing.Processors.Overlays
         protected override void OnFrameApply(ImageFrame<TPixel> source, Rectangle sourceRectangle, Configuration configuration)
         {
             // TODO: can we simplify the rectangle calculation?
-
             int startY = sourceRectangle.Y;
             int endY = sourceRectangle.Bottom;
             int startX = sourceRectangle.X;