Skia - Correctly translate current position when multiple glyphs are added to a path

src/Skia/Avalonia.Skia/PlatformRenderInterface.cs

@@ -70,7 +70,6 @@ namespace Avalonia.Skia
             }
 
             var fontRenderingEmSize = (float)glyphRun.FontRenderingEmSize;
-            var glyphs = glyphRun.GlyphIndices.ToArray();
             var skFont = new SKFont(glyphTypeface.Typeface, fontRenderingEmSize)
             {
                 Size = fontRenderingEmSize,
@@ -79,15 +78,19 @@ namespace Avalonia.Skia
                 LinearMetrics = true
             };
 
-            SKPath path = null;
+            SKPath path = new SKPath();
             var matrix = SKMatrix.Identity;
 
-            skFont.GetGlyphPaths(glyphs, (p, m) =>
+            var currentX = 0f;
+
+            foreach (var glyph in glyphRun.GlyphIndices)
             {
-                matrix = m;
+                var p = skFont.GetGlyphPath(glyph);
+
+                path.AddPath(p, currentX, 0);
 
-                path = p;
-            });
+                currentX += p.Bounds.Right;
+            }
 
             scale = Matrix.CreateScale(matrix.ScaleX, matrix.ScaleY);
 

tests/Avalonia.RenderTests/Media/GlyphRunTests.cs

@@ -1,6 +1,7 @@
 using System.Collections.Generic;
 using System.Threading.Tasks;
 using Avalonia.Controls;
+using Avalonia.Controls.Documents;
 using Avalonia.Controls.Shapes;
 using Avalonia.Media;
 using Avalonia.Media.Imaging;
@@ -25,9 +26,21 @@ namespace Avalonia.Direct2D1.RenderTests.Media
             Decorator target = new Decorator
             {
                 Padding = new Thickness(8),
-                Width = 80,
-                Height = 90,
-                Child = new GlyphRunGeometryControl()
+                Width = 200,
+                Height = 100,
+                Child = new GlyphRunGeometryControl
+                {
+                    [TextElement.ForegroundProperty] = new LinearGradientBrush
+                    {
+                        StartPoint = new RelativePoint(0, 0.5, RelativeUnit.Relative),
+                        EndPoint = new RelativePoint(1, 0.5, RelativeUnit.Relative),
+                        GradientStops =
+                        {
+                            new GradientStop { Color = Colors.Red, Offset = 0 },
+                            new GradientStop { Color = Colors.Blue, Offset = 1 }
+                        }
+                    }
+                }
             };
 
             await RenderToFile(target);
@@ -43,9 +56,9 @@ namespace Avalonia.Direct2D1.RenderTests.Media
             {
                 var glyphTypeface = Typeface.Default.GlyphTypeface;
 
-                var glyphIndices = new[] { glyphTypeface.GetGlyph('A') };
+                var glyphIndices = new[] { glyphTypeface.GetGlyph('A'), glyphTypeface.GetGlyph('B'), glyphTypeface.GetGlyph('C') };
 
-                var characters = new[] { 'A' };
+                var characters = new[] { 'A', 'B', 'C' };
 
                 var glyphRun = new GlyphRun(glyphTypeface, 100, characters, glyphIndices);
 
@@ -59,7 +72,9 @@ namespace Avalonia.Direct2D1.RenderTests.Media
 
             public override void Render(DrawingContext context)
             {
-                context.DrawGeometry(Brushes.Green, null, _geometry);
+                var foreground = TextElement.GetForeground(this);
+
+                context.DrawGeometry(foreground, null, _geometry);
             }
         }
     }