[v2] Port SVG parsing fix and add SVG benchmarks

ImageSharp.Drawing.sln

@@ -337,6 +337,8 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "workflows", "workflows", "{
 		.github\workflows\build-and-test.yml = .github\workflows\build-and-test.yml
 	EndProjectSection
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ImageSharp.Drawing.ManualBenchmarks", "tests\ImageSharp.Drawing.ManualBenchmarks\ImageSharp.Drawing.ManualBenchmarks.csproj", "{EB9C10E0-59B7-4620-B8EB-220E8FFC73E6}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -359,6 +361,10 @@ Global
 		{5493F024-0A3F-420C-AC2D-05B77A36025B}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{5493F024-0A3F-420C-AC2D-05B77A36025B}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{5493F024-0A3F-420C-AC2D-05B77A36025B}.Release|Any CPU.Build.0 = Release|Any CPU
+		{EB9C10E0-59B7-4620-B8EB-220E8FFC73E6}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{EB9C10E0-59B7-4620-B8EB-220E8FFC73E6}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{EB9C10E0-59B7-4620-B8EB-220E8FFC73E6}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{EB9C10E0-59B7-4620-B8EB-220E8FFC73E6}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -386,6 +392,7 @@ Global
 		{68A8CC40-6AED-4E96-B524-31B1158FDEEA} = {815C0625-CD3D-440F-9F80-2D83856AB7AE}
 		{5493F024-0A3F-420C-AC2D-05B77A36025B} = {528610AC-7C0C-46E8-9A2D-D46FD92FEE29}
 		{23859314-5693-4E6C-BE5C-80A433439D2A} = {1799C43E-5C54-4A8F-8D64-B1475241DB0D}
+		{EB9C10E0-59B7-4620-B8EB-220E8FFC73E6} = {56801022-D71A-4FBE-BC5B-CBA08E2284EC}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {5F8B9D1F-CD8B-4CC5-8216-D531E25BD795}

src/ImageSharp.Drawing/Shapes/Path.cs

@@ -145,7 +145,7 @@ SegmentInfo IPathInternals.PointAlongPath(float distance)
     public static bool TryParseSvgPath(string svgPath, [NotNullWhen(true)] out IPath? value)
         => TryParseSvgPath(svgPath.AsSpan(), out value);
 
-    /// <summary>
+     /// <summary>
     /// Converts an SVG path string into an <see cref="IPath"/>.
     /// </summary>
     /// <param name="svgPath">The string containing the SVG path data.</param>
@@ -381,10 +381,42 @@ private static ReadOnlySpan<char> FindScaler(ReadOnlySpan<char> str, out float s
         str = TrimSeparator(str);
         scaler = 0;
 
+        bool hasDot = false;
         for (int i = 0; i < str.Length; i++)
         {
-            if (IsSeparator(str[i]) || i == str.Length)
+            char ch = str[i];
+
+            if (IsSeparator(ch))
+            {
+                scaler = ParseFloat(str[..i]);
+                return str[i..];
+            }
+
+            if (ch == '.')
+            {
+                if (hasDot)
+                {
+                    // Second decimal point starts a new number.
+                    scaler = ParseFloat(str[..i]);
+                    return str[i..];
+                }
+
+                hasDot = true;
+            }
+            else if ((ch is '-' or '+') && i > 0)
+            {
+                // A sign character mid-number starts a new number,
+                // unless it follows an exponent indicator.
+                char prev = str[i - 1];
+                if (prev is not 'e' and not 'E')
+                {
+                    scaler = ParseFloat(str[..i]);
+                    return str[i..];
+                }
+            }
+            else if (char.IsLetter(ch))
             {
+                // Hit a command letter; end this number.
                 scaler = ParseFloat(str[..i]);
                 return str[i..];
             }
@@ -395,7 +427,7 @@ private static ReadOnlySpan<char> FindScaler(ReadOnlySpan<char> str, out float s
             scaler = ParseFloat(str);
         }
 
-        return ReadOnlySpan<char>.Empty;
+        return Array.Empty<char>();
     }
 
     private static bool IsSeparator(char ch)

tests/ImageSharp.Drawing.Benchmarks/Drawing/FillTiger.cs

@@ -0,0 +1,150 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using System.Drawing;
+using System.Drawing.Drawing2D;
+using BenchmarkDotNet.Attributes;
+using SixLabors.ImageSharp.Drawing.Processing;
+using SixLabors.ImageSharp.Drawing.Tests;
+using SixLabors.ImageSharp.PixelFormats;
+using SixLabors.ImageSharp.Processing;
+using SkiaSharp;
+using SDColor = System.Drawing.Color;
+using SDPen = System.Drawing.Pen;
+using SDSolidBrush = System.Drawing.SolidBrush;
+
+namespace SixLabors.ImageSharp.Drawing.Benchmarks.Drawing;
+
+/// <summary>
+/// Benchmarks rendering the Ghostscript Tiger SVG (~240 path elements with fills and strokes)
+/// across SkiaSharp, System.Drawing, ImageSharp (CPU), and ImageSharp (WebGPU).
+/// </summary>
+public class FillTiger
+{
+    private static readonly string SvgFilePath =
+        TestFile.GetInputFileFullPath(TestImages.Svg.GhostscriptTiger);
+
+    private SKSurface skSurface;
+    private List<(SKPath Path, SKPaint FillPaint, SKPaint StrokePaint)> skElements;
+
+    private Bitmap sdBitmap;
+    private Graphics sdGraphics;
+    private List<(GraphicsPath Path, SDSolidBrush Fill, SDPen Stroke)> sdElements;
+
+    private Image<Rgba32> image;
+    private List<(IPath Path, Processing.SolidBrush Fill, SolidPen Stroke)> isElements;
+
+    [Params(1000, 100)]
+    public int Dimensions { get; set; }
+
+    [GlobalSetup]
+    public void Setup()
+    {
+        int width = this.Dimensions;
+        int height = this.Dimensions;
+        float scale = this.Dimensions / 200f;
+
+        ThreadPool.GetMinThreads(out int minWorkerThreads, out int minCompletionPortThreads);
+        int desiredWorkerThreads = Math.Max(minWorkerThreads, Environment.ProcessorCount);
+        ThreadPool.SetMinThreads(desiredWorkerThreads, minCompletionPortThreads);
+        Parallel.For(0, desiredWorkerThreads, static _ => { });
+
+        List<SvgBenchmarkHelper.SvgElement> elements = SvgBenchmarkHelper.ParseSvg(SvgFilePath);
+
+        this.skSurface = SKSurface.Create(new SKImageInfo(width, height));
+        this.skElements = SvgBenchmarkHelper.BuildSkiaElements(elements, scale);
+
+        this.sdBitmap = new Bitmap(width, height);
+        this.sdGraphics = Graphics.FromImage(this.sdBitmap);
+        this.sdGraphics.SmoothingMode = SmoothingMode.AntiAlias;
+        this.sdElements = SvgBenchmarkHelper.BuildSystemDrawingElements(elements, scale);
+
+        this.image = new Image<Rgba32>(width, height);
+        this.isElements = SvgBenchmarkHelper.BuildImageSharpElements(elements, scale);
+    }
+
+    [IterationSetup]
+    public void IterationSetup()
+    {
+        this.sdGraphics.Clear(SDColor.Transparent);
+        this.skSurface.Canvas.Clear(SKColors.Transparent);
+    }
+
+    [GlobalCleanup]
+    public void Cleanup()
+    {
+        foreach ((SKPath path, SKPaint fill, SKPaint stroke) in this.skElements)
+        {
+            path.Dispose();
+            fill?.Dispose();
+            stroke?.Dispose();
+        }
+
+        this.skSurface.Dispose();
+
+        foreach ((GraphicsPath path, SDSolidBrush fill, SDPen stroke) in this.sdElements)
+        {
+            path.Dispose();
+            fill?.Dispose();
+            stroke?.Dispose();
+        }
+
+        this.sdGraphics.Dispose();
+        this.sdBitmap.Dispose();
+
+        this.image.Dispose();
+    }
+
+    [Benchmark(Baseline = true)]
+    public void SkiaSharp()
+    {
+        SKCanvas canvas = this.skSurface.Canvas;
+        foreach ((SKPath path, SKPaint fillPaint, SKPaint strokePaint) in this.skElements)
+        {
+            if (fillPaint is not null)
+            {
+                canvas.DrawPath(path, fillPaint);
+            }
+
+            if (strokePaint is not null)
+            {
+                canvas.DrawPath(path, strokePaint);
+            }
+        }
+    }
+
+    [Benchmark]
+    public void SystemDrawing()
+    {
+        foreach ((GraphicsPath path, SDSolidBrush fill, SDPen stroke) in this.sdElements)
+        {
+            if (fill is not null)
+            {
+                this.sdGraphics.FillPath(fill, path);
+            }
+
+            if (stroke is not null)
+            {
+                this.sdGraphics.DrawPath(stroke, path);
+            }
+        }
+    }
+
+    [Benchmark]
+    public void ImageSharp()
+        => this.image.Mutate(c =>
+        {
+            foreach ((IPath path, Processing.SolidBrush fill, SolidPen stroke) in this.isElements)
+            {
+                if (fill is not null)
+                {
+                    c.Fill(fill, path);
+                }
+
+                if (stroke is not null)
+                {
+                    c.Draw(stroke, path);
+                }
+            }
+        });
+}

tests/ImageSharp.Drawing.Benchmarks/ImageSharp.Drawing.Benchmarks.csproj

@@ -6,6 +6,7 @@
     <IsPackable>false</IsPackable>
     <GenerateProgramFile>false</GenerateProgramFile>
     <IsTestProject>false</IsTestProject>
+    <LangVersion>latest</LangVersion>
   </PropertyGroup>
 
   <Choose>
@@ -20,7 +21,7 @@
       </PropertyGroup>
     </Otherwise>
   </Choose>
-  
+
   <ItemGroup>
     <PackageReference Include="BenchmarkDotNet" />
     <PackageReference Include="System.Drawing.Common" />
@@ -45,6 +46,9 @@
     <Compile Include="..\ImageSharp.Drawing.Tests\TestUtilities\TestEnvironment.cs">
       <Link>TestEnvironment.cs</Link>
     </Compile>
+    <Compile Include="..\ImageSharp.Drawing.Tests\TestUtilities\SvgBenchmarkHelper.cs">
+      <Link>SvgBenchmarkHelper.cs</Link>
+    </Compile>
   </ItemGroup>
 
 </Project>