Initial work on using Span<T> instead of pointers.

This eliminates some larger unsafe blocks and seems to also have minor performance improvements. The RadialBlurEffect benchmark went from 5,923.8ms to 5,757.7ms

Switched the benchmark setup to use BenchmarkSwitcher, which allows filtering which benchmarks are run from the command line

Pinta.Core/Extensions/CairoExtensions.cs

@@ -2068,5 +2068,19 @@ public static void SetDashFromString (this Context context, string dash_pattern,
 			CreateDashPattern (dash_pattern, brush_width, line_cap, out var dashes, out var offset);
 			context.SetDash (dashes, offset);
 		}
+
+		public static ReadOnlySpan<ColorBgra> GetReadOnlyData (this ImageSurface surface)
+		{
+			unsafe {
+				return new ReadOnlySpan<ColorBgra> (surface.DataPtr.ToPointer (), surface.Width * surface.Height);
+			}
+		}
+
+		public static Span<ColorBgra> GetData (this ImageSurface surface)
+		{
+			unsafe {
+				return new Span<ColorBgra> (surface.DataPtr.ToPointer (), surface.Width * surface.Height);
+			}
+		}
 	}
 }

Pinta.Effects/Effects/RadialBlurEffect.cs

@@ -8,6 +8,7 @@
 /////////////////////////////////////////////////////////////////////////////////
 
 using System;
+using System.Runtime.InteropServices;
 using Cairo;
 using Pinta.Core;
 using Pinta.Gui.Widgets;
@@ -56,7 +57,7 @@ private static void Rotate (ref int fx, ref int fy, int fr)
 			fy = cy + ((cx >> 8) * fr >> 8) - ((cy >> 14) * (fr * fr >> 11) >> 8);
 		}
 
-		public unsafe override void Render (ImageSurface src, ImageSurface dst, Gdk.Rectangle[] rois)
+		public override void Render (ImageSurface src, ImageSurface dst, Gdk.Rectangle[] rois)
 		{
 			if (Data.Angle == 0) {
 				// Copy src to dest
@@ -65,19 +66,26 @@ public unsafe override void Render (ImageSurface src, ImageSurface dst, Gdk.Rect
 
 			int w = dst.Width;
 			int h = dst.Height;
+			int src_w = src.Width;
 			int fcx = (w << 15) + (int) (Data.Offset.X * (w << 15));
 			int fcy = (h << 15) + (int) (Data.Offset.Y * (h << 15));
 
 			int n = (Data.Quality * Data.Quality) * (30 + Data.Quality * Data.Quality);
 
 			int fr = (int) (Data.Angle * Math.PI * 65536.0 / 181.0);
 
+			var dst_data = dst.GetData ();
+			var src_data = src.GetReadOnlyData ();
+
 			foreach (Gdk.Rectangle rect in rois) {
 				for (int y = rect.Top; y <= rect.GetBottom (); ++y) {
-					ColorBgra* dstPtr = dst.GetPointAddressUnchecked (rect.Left, y);
-					ColorBgra* srcPtr = src.GetPointAddressUnchecked (rect.Left, y);
+					var dst_row = dst_data.Slice (y * w, w);
+					var src_row = src_data.Slice (y * src_w, src_w);
 
 					for (int x = rect.Left; x <= rect.GetRight (); ++x) {
+						ref ColorBgra dst_pixel = ref dst_row[x];
+						ref readonly ColorBgra src_pixel = ref src_row[x];
+
 						int fx = (x << 16) - fcx;
 						int fy = (y << 16) - fcy;
 
@@ -89,20 +97,17 @@ public unsafe override void Render (ImageSurface src, ImageSurface dst, Gdk.Rect
 						int sa = 0;
 						int sc = 0;
 
-						sr += srcPtr->R * srcPtr->A;
-						sg += srcPtr->G * srcPtr->A;
-						sb += srcPtr->B * srcPtr->A;
-						sa += srcPtr->A;
+						sr += src_pixel.R * src_pixel.A;
+						sg += src_pixel.G * src_pixel.A;
+						sb += src_pixel.B * src_pixel.A;
+						sa += src_pixel.A;
 						++sc;
 
 						int ox1 = fx;
 						int ox2 = fx;
 						int oy1 = fy;
 						int oy2 = fy;
 
-						ColorBgra* src_dataptr = (ColorBgra*) src.DataPtr;
-						int src_width = src.Width;
-
 						for (int i = 0; i < n; ++i) {
 							Rotate (ref ox1, ref oy1, fsr);
 							Rotate (ref ox2, ref oy2, -fsr);
@@ -111,41 +116,38 @@ public unsafe override void Render (ImageSurface src, ImageSurface dst, Gdk.Rect
 							int v1 = oy1 + fcy + 32768 >> 16;
 
 							if (u1 > 0 && v1 > 0 && u1 < w && v1 < h) {
-								ColorBgra* sample = src.GetPointAddressUnchecked (src_dataptr, src_width, u1, v1);
+								ref readonly ColorBgra sample = ref src_data[v1 * src_w + u1];
 
-								sr += sample->R * sample->A;
-								sg += sample->G * sample->A;
-								sb += sample->B * sample->A;
-								sa += sample->A;
+								sr += sample.R * sample.A;
+								sg += sample.G * sample.A;
+								sb += sample.B * sample.A;
+								sa += sample.A;
 								++sc;
 							}
 
 							int u2 = ox2 + fcx + 32768 >> 16;
 							int v2 = oy2 + fcy + 32768 >> 16;
 
 							if (u2 > 0 && v2 > 0 && u2 < w && v2 < h) {
-								ColorBgra* sample = src.GetPointAddressUnchecked (src_dataptr, src_width, u2, v2);
+								ref readonly ColorBgra sample = ref src_data[v2 * src_w + u2];
 
-								sr += sample->R * sample->A;
-								sg += sample->G * sample->A;
-								sb += sample->B * sample->A;
-								sa += sample->A;
+								sr += sample.R * sample.A;
+								sg += sample.G * sample.A;
+								sb += sample.B * sample.A;
+								sa += sample.A;
 								++sc;
 							}
 						}
 
 						if (sa > 0) {
-							*dstPtr = ColorBgra.FromBgra (
+							dst_pixel = ColorBgra.FromBgra (
 							    Utility.ClampToByte (sb / sa),
 							    Utility.ClampToByte (sg / sa),
 							    Utility.ClampToByte (sr / sa),
 							    Utility.ClampToByte (sa / sc));
 						} else {
-							dstPtr->Bgra = 0;
+							dst_pixel.Bgra = 0;
 						}
-
-						++dstPtr;
-						++srcPtr;
 					}
 				}
 			}

Pinta.Tools/Tools/PaintBucketTool.cs

@@ -59,7 +59,7 @@ protected override void OnMouseDown (Document document, ToolMouseEventArgs e)
 			base.OnMouseDown (document, e);
 		}
 
-		protected unsafe override void OnFillRegionComputed (Document document, BitMask stencil)
+		protected override void OnFillRegionComputed (Document document, BitMask stencil)
 		{
 			var surf = document.Layers.ToolLayer.Surface;
 
@@ -73,18 +73,17 @@ protected unsafe override void OnFillRegionComputed (Document document, BitMask
 			hist.TakeSnapshotOfLayer (document.Layers.CurrentUserLayer);
 
 			var color = fill_color.ToColorBgra ().ToPremultipliedAlpha ();
-			var dstPtr = (ColorBgra*) surf.DataPtr;
 			var width = surf.Width;
-
 			surf.Flush ();
 
 			// Color in any pixel that the stencil says we need to fill
 			Parallel.For (0, stencil.Height, y => {
 				var stencil_width = stencil.Width;
+				var dst_data = surf.GetData ();
 
 				for (var x = 0; x < stencil_width; ++x) {
 					if (stencil.Get (x, y))
-						surf.SetColorBgraUnchecked (dstPtr, width, color, x, y);
+						dst_data[y * width + x] = color;
 				}
 			});
 

tests/PintaBenchmarks/Program.cs

@@ -4,10 +4,10 @@ namespace PintaBenchmarks;
 
 public class Program
 {
-	public static void Main ()
+	public static void Main (string[] args)
 	{
 		// Run all benchmarks
-		BenchmarkRunner.Run (typeof (Program).Assembly);
+		BenchmarkSwitcher.FromAssembly (typeof (Program).Assembly).Run (args);
 
 		// Run individual benchmark suites
 		//BenchmarkRunner.Run<CanvasRendererBenchmarks> ();