fix bug, improve bencmharks

Author: antonfirsov

src/ImageSharp.Drawing/Shapes/Rasterization/RasterizerExtensions.cs

@@ -61,7 +61,11 @@ private static void ScanCurrentSubpixelLineInto(this ref PolygonScanner scanner,
                 endX = Math.Min(endX, scanline.Length); // reduce to end to the right edge
                 nextX = Math.Max(nextX, 0);
 
-                scanline.Slice(nextX, endX - nextX).AddToAllElements(scanner.SubpixelDistance);
+                if (endX > nextX)
+                {
+                    scanline.Slice(nextX, endX - nextX).AddToAllElements(scanner.SubpixelDistance);
+                    scanlineDirty = true;
+                }
             }
         }
     }

tests/ImageSharp.Drawing.Benchmarks/Drawing/DrawText.cs

@@ -39,9 +39,9 @@ public class DrawText
         private Image<Rgba32> image;
         private SDBitmap sdBitmap;
         private Graphics sdGraphics;
-        private SKSurface skSurface;
-        
-        
+        private SKBitmap skBitmap;
+        private SKCanvas skCanvas;
+
         private SDFont sdFont;
         private Fonts.Font font;
         private SKTypeface skTypeface;
@@ -56,7 +56,8 @@ public void Setup()
             this.sdGraphics.SmoothingMode = SmoothingMode.AntiAlias;
             this.sdGraphics.InterpolationMode = InterpolationMode.Default;
             this.sdGraphics.SmoothingMode = SmoothingMode.AntiAlias;
-            this.skSurface = SKSurface.Create(new SKImageInfo(Width, Height));
+            this.skBitmap = new SKBitmap(Width, Height);
+            this.skCanvas = new SKCanvas(this.skBitmap);
 
             this.sdFont = new SDFont("Arial", 12, GraphicsUnit.Point);
             this.font = Fonts.SystemFonts.CreateFont("Arial", 12);
@@ -69,7 +70,8 @@ public void Cleanup()
             this.image.Dispose();
             this.sdGraphics.Dispose();
             this.sdBitmap.Dispose();
-            this.skSurface.Dispose();
+            this.skCanvas.Dispose();
+            this.skBitmap.Dispose();
             this.sdFont.Dispose();
             this.skTypeface.Dispose();
         }
@@ -108,7 +110,7 @@ public void SkiaSharp()
                 Typeface = skTypeface
             };
 
-            this.skSurface.Canvas.DrawText(TextToRender, 10, 10, paint);
+            this.skCanvas.DrawText(TextToRender, 10, 10, paint);
         }
     }
 }

tests/ImageSharp.Drawing.Benchmarks/Drawing/FillPolygon.cs

@@ -31,7 +31,8 @@ public abstract class FillPolygon
         private Image<Rgba32> image;
         private SDBitmap sdBitmap;
         private Graphics sdGraphics;
-        private SKSurface skSurface;
+        private SKBitmap skBitmap;
+        private SKCanvas skCanvas;
 
         protected abstract int Width { get; }
         protected abstract int Height { get; }
@@ -69,7 +70,8 @@ public void Setup()
             this.sdGraphics = Graphics.FromImage(this.sdBitmap);
             this.sdGraphics.InterpolationMode = InterpolationMode.Default;
             this.sdGraphics.SmoothingMode = SmoothingMode.AntiAlias;
-            this.skSurface = SKSurface.Create(new SKImageInfo(Width, Height));
+            this.skBitmap = new SKBitmap(Width, Height);
+            this.skCanvas = new SKCanvas(skBitmap);
         }
 
         [GlobalCleanup]
@@ -78,7 +80,8 @@ public void Cleanup()
             this.image.Dispose();
             this.sdGraphics.Dispose();
             this.sdBitmap.Dispose();
-            this.skSurface.Dispose();
+            this.skCanvas.Dispose();
+            this.skBitmap.Dispose();
             foreach (SKPath skPath in this.skPaths)
             {
                 skPath.Dispose();
@@ -120,7 +123,7 @@ public void SkiaSharp()
                     Color = SKColors.White,
                     IsAntialias = true,
                 };
-                this.skSurface.Canvas.DrawPath(path, paint);
+                this.skCanvas.DrawPath(path, paint);
             }
         }
     }

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

@@ -3,7 +3,8 @@
   <PropertyGroup>
     <OutputType>Exe</OutputType>
     <RootNamespace>SixLabors.ImageSharp.Drawing.Benchmarks</RootNamespace>
-    <TargetFrameworks>netcoreapp3.1;netcoreapp2.1;net472</TargetFrameworks>
+<!--    <TargetFrameworks>netcoreapp3.1;netcoreapp2.1;net472</TargetFrameworks>-->
+    <TargetFrameworks>netcoreapp3.1</TargetFrameworks>
     <IsPackable>false</IsPackable>
     <GenerateProgramFile>false</GenerateProgramFile>
     <!--Used to hide test project from dotnet test-->