Issue 551 solidbrush blend performance

src/ImageSharp.Drawing/Processing/Drawing/Brushes/SolidBrush{TPixel}.cs

@@ -90,16 +90,23 @@ internal override void Apply(Span<float> scanline, int x, int y)
 
                 MemoryManager memoryManager = this.Target.MemoryManager;
 
-                using (IBuffer<float> amountBuffer = memoryManager.Allocate<float>(scanline.Length))
+                if (this.Options.BlendPercentage == 1f)
                 {
-                    Span<float> amountSpan = amountBuffer.Span;
-
-                    for (int i = 0; i < scanline.Length; i++)
+                    this.Blender.Blend(memoryManager, destinationRow, destinationRow, this.Colors.Span, scanline);
+                }
+                else
+                {
+                    using (IBuffer<float> amountBuffer = memoryManager.Allocate<float>(scanline.Length))
                     {
-                        amountSpan[i] = scanline[i] * this.Options.BlendPercentage;
-                    }
+                        Span<float> amountSpan = amountBuffer.Span;
+
+                        for (int i = 0; i < scanline.Length; i++)
+                        {
+                            amountSpan[i] = scanline[i] * this.Options.BlendPercentage;
+                        }
 
-                    this.Blender.Blend(memoryManager, destinationRow, destinationRow, this.Colors.Span, amountSpan);
+                        this.Blender.Blend(memoryManager, destinationRow, destinationRow, this.Colors.Span, amountSpan);
+                    }
                 }
             }
         }

src/ImageSharp.Drawing/Processing/Drawing/Processors/FillProcessor.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Threading.Tasks;
+using SixLabors.ImageSharp.Advanced;
 using SixLabors.ImageSharp.Memory;
 using SixLabors.ImageSharp.PixelFormats;
 using SixLabors.ImageSharp.Processing.Drawing.Brushes;
@@ -49,38 +50,61 @@ protected override void OnFrameApply(ImageFrame<TPixel> source, Rectangle source
             int minY = Math.Max(0, startY);
             int maxY = Math.Min(source.Height, endY);
 
-            // Reset offset if necessary.
-            if (minX > 0)
-            {
-                startX = 0;
-            }
-
-            if (minY > 0)
-            {
-                startY = 0;
-            }
-
             int width = maxX - minX;
 
-            using (IBuffer<float> amount = source.MemoryManager.Allocate<float>(width))
-            using (BrushApplicator<TPixel> applicator = this.brush.CreateApplicator(
-                source,
-                sourceRectangle,
-                this.options))
-            {
-                amount.Span.Fill(this.options.BlendPercentage);
+            var solidBrush = this.brush as SolidBrush<TPixel>;
 
+            // If there's no reason for blending, then avoid it.
+            if (solidBrush != null &&
+                (
+                    (this.options.BlenderMode == PixelBlenderMode.Normal && this.options.BlendPercentage == 1f && solidBrush.Color.ToVector4().W == 1f) ||
+                    (this.options.BlenderMode == PixelBlenderMode.Over && this.options.BlendPercentage == 1f && solidBrush.Color.ToVector4().W == 1f) ||
+                    (this.options.BlenderMode == PixelBlenderMode.Src)))
+            {
                 Parallel.For(
                     minY,
                     maxY,
                     configuration.ParallelOptions,
                     y =>
-                        {
-                            int offsetY = y - startY;
-                            int offsetX = minX - startX;
+                    {
+                        int offsetY = y - startY;
+                        int offsetX = minX - startX;
+                        source.GetPixelRowSpan(y).Slice(minX, width).Fill(solidBrush.Color);
+                    });
+            }
+            else
+            {
+                // Reset offset if necessary.
+                if (minX > 0)
+                {
+                    startX = 0;
+                }
+
+                if (minY > 0)
+                {
+                    startY = 0;
+                }
+
+                using (IBuffer<float> amount = source.MemoryManager.Allocate<float>(width))
+                using (BrushApplicator<TPixel> applicator = this.brush.CreateApplicator(
+                    source,
+                    sourceRectangle,
+                    this.options))
+                {
+                    amount.Span.Fill(this.options.BlendPercentage);
+
+                    Parallel.For(
+                        minY,
+                        maxY,
+                        configuration.ParallelOptions,
+                        y =>
+                            {
+                                int offsetY = y - startY;
+                                int offsetX = minX - startX;
 
-                            applicator.Apply(amount.Span, offsetX, offsetY);
-                        });
+                                applicator.Apply(amount.Span, offsetX, offsetY);
+                            });
+                }
             }
         }
     }

src/ImageSharp/ImageFrameCollection.cs

@@ -23,7 +23,14 @@ internal ImageFrameCollection(Image<TPixel> parent, int width, int height)
             this.parent = parent;
 
             // Frames are already cloned within the caller
-            this.frames.Add(new ImageFrame<TPixel>(parent.GetConfiguration().MemoryManager, width, height));
+            if (parent.ClearColor.HasValue)
+            {
+                this.frames.Add(new ImageFrame<TPixel>(parent.GetConfiguration(), width, height, parent.ClearColor.Value));
+            }
+            else
+            {
+                this.frames.Add(new ImageFrame<TPixel>(parent.GetConfiguration().MemoryManager, width, height));
+            }
         }
 
         internal ImageFrameCollection(Image<TPixel> parent, IEnumerable<ImageFrame<TPixel>> frames)
@@ -143,7 +150,16 @@ public Image<TPixel> CloneFrame(int index)
         /// <inheritdoc/>
         public ImageFrame<TPixel> CreateFrame()
         {
-            var frame = new ImageFrame<TPixel>(this.parent.GetConfiguration().MemoryManager, this.RootFrame.Width, this.RootFrame.Height);
+            ImageFrame<TPixel> frame;
+            if (this.parent.ClearColor.HasValue)
+            {
+                frame = new ImageFrame<TPixel>(this.parent.GetConfiguration(), this.RootFrame.Width, this.RootFrame.Height, this.parent.ClearColor.Value);
+            }
+            else
+            {
+                frame = new ImageFrame<TPixel>(this.parent.GetConfiguration().MemoryManager, this.RootFrame.Width, this.RootFrame.Height);
+            }
+
             this.frames.Add(frame);
             return frame;
         }

src/ImageSharp/Image{TPixel}.cs

@@ -22,6 +22,7 @@ public sealed class Image<TPixel> : IImage, IConfigurable
     {
         private readonly Configuration configuration;
         private readonly ImageFrameCollection<TPixel> frames;
+        private readonly TPixel? clearColor;
 
         /// <summary>
         /// Initializes a new instance of the <see cref="Image{TPixel}"/> class
@@ -37,6 +38,21 @@ public Image(Configuration configuration, int width, int height)
         {
         }
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Image{TPixel}"/> class
+        /// with the height and the width of the image.
+        /// </summary>
+        /// <param name="configuration">
+        /// The configuration providing initialization code which allows extending the library.
+        /// </param>
+        /// <param name="width">The width of the image in pixels.</param>
+        /// <param name="height">The height of the image in pixels.</param>
+        /// <param name="clearColor">The color to initialize the pixels with.</param>
+        public Image(Configuration configuration, int width, int height, TPixel clearColor)
+            : this(configuration, width, height, clearColor, new ImageMetaData())
+        {
+        }
+
         /// <summary>
         /// Initializes a new instance of the <see cref="Image{TPixel}"/> class
         /// with the height and the width of the image.
@@ -66,6 +82,25 @@ internal Image(Configuration configuration, int width, int height, ImageMetaData
             this.frames = new ImageFrameCollection<TPixel>(this, width, height);
         }
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Image{TPixel}"/> class
+        /// with the height and the width of the image.
+        /// </summary>
+        /// <param name="configuration">
+        /// The configuration providing initialization code which allows extending the library.
+        /// </param>
+        /// <param name="width">The width of the image in pixels.</param>
+        /// <param name="height">The height of the image in pixels.</param>
+        /// <param name="clearColor">The clear color.</param>
+        /// <param name="metadata">The images metadata.</param>
+        internal Image(Configuration configuration, int width, int height, TPixel clearColor, ImageMetaData metadata) {
+            this.configuration = configuration ?? Configuration.Default;
+            this.PixelType = new PixelTypeInfo(Unsafe.SizeOf<TPixel>() * 8);
+            this.MetaData = metadata ?? new ImageMetaData();
+            this.clearColor = clearColor;
+            this.frames = new ImageFrameCollection<TPixel>(this, width, height);
+        }
+
         /// <summary>
         /// Initializes a new instance of the <see cref="Image{TPixel}" /> class
         /// with the height and the width of the image.
@@ -104,6 +139,11 @@ internal Image(Configuration configuration, ImageMetaData metadata, IEnumerable<
         /// </summary>
         public IImageFrameCollection<TPixel> Frames => this.frames;
 
+        /// <summary>
+        /// Gets the clear color to initialize the image frame pixels with.
+        /// </summary>
+        internal TPixel? ClearColor => this.clearColor;
+
         /// <summary>
         /// Gets the root frame.
         /// </summary>

src/ImageSharp/Memory/BufferExtensions.cs

@@ -52,6 +52,18 @@ public static void Clear<T>(this IBuffer<T> buffer)
             buffer.Span.Clear();
         }
 
+        /// <summary>
+        /// Fills the contents of this buffer.
+        /// </summary>
+        /// <param name="buffer">The buffer</param>
+        /// <param name="value">The value to fill the buffer with.</param>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void Fill<T>(this IBuffer<T> buffer, T value)
+            where T : struct
+        {
+            buffer.Span.Fill(value);
+        }
+
         public static ref T DangerousGetPinnableReference<T>(this IBuffer<T> buffer)
             where T : struct =>
             ref MemoryMarshal.GetReference(buffer.Span);

src/ImageSharp/PixelFormats/PixelBlenderMode.cs

@@ -54,62 +54,62 @@ public enum PixelBlenderMode
         HardLight,
 
         /// <summary>
-        /// returns the source colors
+        /// returns the source colors.
         /// </summary>
         Src,
 
         /// <summary>
-        /// returns the source over the destination
+        /// returns the source over the destination.
         /// </summary>
         Atop,
 
         /// <summary>
-        /// returns the detination over the source
+        /// returns the destination over the source.
         /// </summary>
         Over,
 
         /// <summary>
-        /// the source where the desitnation and source overlap
+        /// The source where the destination and source overlap.
         /// </summary>
         In,
 
         /// <summary>
-        /// the destination where the desitnation and source overlap
+        /// The destination where the destination and source overlap.
         /// </summary>
         Out,
 
         /// <summary>
-        /// the destination where the source does not overlap it
+        /// The destination where the source does not overlap it.
         /// </summary>
         Dest,
 
         /// <summary>
-        /// the source where they dont overlap othersie dest in overlapping parts
+        /// The source where they don't overlap othersie dest in overlapping parts.
         /// </summary>
         DestAtop,
 
         /// <summary>
-        /// the destnation over the source
+        /// The destination over the source.
         /// </summary>
         DestOver,
 
         /// <summary>
-        /// the destination where the desitnation and source overlap
+        /// The destination where the destination and source overlap.
         /// </summary>
         DestIn,
 
         /// <summary>
-        /// the source where the desitnation and source overlap
+        /// The source where the destination and source overlap.
         /// </summary>
         DestOut,
 
         /// <summary>
-        /// the clear.
+        /// The clear.
         /// </summary>
         Clear,
 
         /// <summary>
-        /// clear where they overlap
+        /// Clear where they overlap.
         /// </summary>
         Xor
     }