Update ref and fix line rendering

Author: JimBobSquarePants

nuget.config

@@ -18,7 +18,7 @@
     <None Include="..\..\shared-infrastructure\branding\icons\imagesharp.drawing\sixlabors.imagesharp.drawing.128.png" Pack="true" PackagePath="" />
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="SixLabors.Fonts" Version="1.0.0-beta19.9" />
+    <PackageReference Include="SixLabors.Fonts" Version="1.0.0-beta19.10" />
     <PackageReference Include="SixLabors.ImageSharp" Version="2.1.3" />
   </ItemGroup>
   <Import Project="..\..\shared-infrastructure\src\SharedInfrastructure\SharedInfrastructure.projitems" Label="Shared" />

src/ImageSharp.Drawing/ImageSharp.Drawing.csproj

@@ -123,7 +123,8 @@ private static RichTextOptions ConfigureOptions(RichTextOptions options)
             {
                 return new(options)
                 {
-                    Origin = Vector2.Zero
+                    Origin = Vector2.Zero,
+                    Path = options.Path.Translate(options.Origin)
                 };
             }
 

src/ImageSharp.Drawing/Processing/Processors/Text/DrawTextProcessor{TPixel}.cs

@@ -15,7 +15,9 @@
 
 namespace SixLabors.ImageSharp.Drawing.Processing.Processors.Text
 {
-    // TODO: Add caching.
+    /// <summary>
+    /// Allows the rendering of rich text configured via <see cref="RichTextOptions"/>.
+    /// </summary>
     internal sealed class RichTextGlyphRenderer : BaseGlyphBuilder, IColorGlyphRenderer, IDisposable
     {
         private const byte RenderOrderFill = 0;
@@ -230,20 +232,42 @@ public override void SetDecoration(TextDecorations textDecorations, Vector2 star
             }
 
             // Clamp the line to whole pixels
-            Vector2 thicknessOffset = new(0, thickness * .5F);
-            Vector2 tl = start - thicknessOffset;
-            Vector2 bl = start + thicknessOffset;
-            Vector2 tr = end - thicknessOffset;
-            tl.Y = MathF.Floor(tl.Y);
-            tr.Y = MathF.Floor(tr.Y);
-            bl.Y = MathF.Ceiling(bl.Y);
-            tl.X = MathF.Floor(tl.X);
-            tr.X = MathF.Floor(tr.X);
-            float newThickness = bl.Y - tl.Y;
-            Vector2 offsetNew = new(0, newThickness * .5f);
-
-            pen ??= new SolidPen(this.currentBrush ?? this.defaultBrush);
-            this.AppendDecoration(ref targetDecoration, tl + offsetNew, tr + offsetNew, pen, newThickness);
+            Vector2 pad = new(0, thickness * .5F);
+            Vector2 tl = start - pad;
+            Vector2 bl = start + pad;
+            Vector2 tr = end - pad;
+
+            tl.Y = MathF.Round(tl.Y, MidpointRounding.AwayFromZero);
+            tr.Y = MathF.Round(tr.Y, MidpointRounding.AwayFromZero);
+            bl.Y = MathF.Round(bl.Y, MidpointRounding.AwayFromZero);
+            tl.X = MathF.Round(tl.X, MidpointRounding.AwayFromZero);
+            tr.X = MathF.Round(tr.X, MidpointRounding.AwayFromZero);
+
+            // Always respect the pen stroke width if explicitly set.
+            if (pen is null)
+            {
+                thickness = bl.Y - tl.Y;
+                pen = new SolidPen(this.currentBrush ?? this.defaultBrush, thickness);
+            }
+            else
+            {
+                thickness = pen.StrokeWidth;
+            }
+
+            // Drawing is always centered around the point so we need to offset by half.
+            Vector2 offset = Vector2.Zero;
+            if (textDecorations == TextDecorations.Overline)
+            {
+                // CSS overline is drawn above the position, so we need to move it up.
+                offset = new Vector2(0, -(thickness * .5F));
+            }
+            else if (textDecorations == TextDecorations.Underline)
+            {
+                // CSS underline is drawn below the position, so we need to move it down.
+                offset = new Vector2(0, thickness * .5F);
+            }
+
+            this.AppendDecoration(ref targetDecoration, tl + offset, tr + offset, pen, thickness);
         }
 
         protected override void EndGlyph()
@@ -357,7 +381,7 @@ private void FinalizeDecoration(ref TextDecorationDetails? decoration)
             if (decoration != null)
             {
                 // TODO: If the path is curved a line segment does not work well.
-                // What would be great would be if we could take a slice of a path given an offset and length.
+                // What would be great would be if we could take a slice of a path given start and end positions.
                 IPath path = new Path(new LinearLineSegment(decoration.Value.Start, decoration.Value.End));
                 IPath outline = decoration.Value.Pen.GeneratePath(path, decoration.Value.Thickness);
 

src/ImageSharp.Drawing/Processing/Processors/Text/RichTextGlyphRenderer.cs

@@ -43,7 +43,7 @@ public RichTextOptions(RichTextOptions options)
         /// </summary>
         /// <remarks>
         /// When this property is not <see langword="null"/> the <see cref="TextOptions.Origin"/>
-        /// property is ignored. The text will be drawn along the path starting at the origin of the path.
+        /// property is automatically applied as a translation to a copy of the path for processing.
         /// </remarks>
         public IPath Path { get; set; }
     }

src/ImageSharp.Drawing/Processing/RichTextOptions.cs

@@ -147,11 +147,24 @@ public virtual void SetDecoration(TextDecorations textDecorations, Vector2 start
             Vector2 bl = start + height;
             Vector2 br = end + height;
 
+            // Drawing is always centered around the point so we need to offset by half.
+            Vector2 offset = Vector2.Zero;
+            if (textDecorations == TextDecorations.Overline)
+            {
+                // CSS overline is drawn above the position, so we need to move it up.
+                offset = new(0, -(thickness * .5F));
+            }
+            else if (textDecorations == TextDecorations.Underline)
+            {
+                // CSS underline is drawn below the position, so we need to move it down.
+                offset = new Vector2(0, thickness * .5F);
+            }
+
             // MoveTo calls StartFigure();
-            renderer.MoveTo(tl);
-            renderer.LineTo(bl);
-            renderer.LineTo(br);
-            renderer.LineTo(tr);
+            renderer.MoveTo(tl + offset);
+            renderer.LineTo(bl + offset);
+            renderer.LineTo(br + offset);
+            renderer.LineTo(tr + offset);
             renderer.EndFigure();
         }
     }

src/ImageSharp.Drawing/Shapes/Text/BaseGlyphBuilder.cs

@@ -37,29 +37,30 @@ public static IPathCollection GenerateGlyphs(string text, TextOptions textOption
         /// <returns>The <see cref="IPathCollection"/></returns>
         public static IPathCollection GenerateGlyphs(string text, IPath path, TextOptions textOptions)
         {
-            TextOptions options = ConfigureOptions(textOptions, path);
-
-            PathGlyphBuilder glyphBuilder = new(path, options);
+            (IPath Path, TextOptions TextOptions) transformed = ConfigureOptions(textOptions, path);
+            PathGlyphBuilder glyphBuilder = new(transformed.Path, transformed.TextOptions);
             TextRenderer renderer = new(glyphBuilder);
 
-            renderer.RenderText(text, options);
+            renderer.RenderText(text, transformed.TextOptions);
 
             return glyphBuilder.Paths;
         }
 
-        private static TextOptions ConfigureOptions(TextOptions options, IPath path)
+        private static (IPath Path, TextOptions TextOptions) ConfigureOptions(TextOptions options, IPath path)
         {
             // When a path is specified we should explicitly follow that path
             // and not adjust the origin. Any translation should be applied to the path.
             if (path is not null && options.Origin != Vector2.Zero)
             {
-                return new(options)
+                TextOptions clone = new(options)
                 {
                     Origin = Vector2.Zero
                 };
+
+                return (path.Translate(options.Origin), clone);
             }
 
-            return options;
+            return (path, options);
         }
     }
 }

src/ImageSharp.Drawing/Shapes/Text/TextBuilder.cs

@@ -514,12 +514,21 @@ public void DrawRichText<TPixel>(
                 WrappingLength = 400,
                 TextRuns = new[]
                 {
+                    new RichTextRun
+                    {
+                        Start = 0,
+                        End = 3,
+                        OverlinePen = Pens.Solid(Color.Yellow, 1),
+                        StrikeoutPen = Pens.Solid(Color.HotPink, 5),
+                    },
+
                     new RichTextRun
                     {
                         Start = 4,
                         End = 10,
                         TextDecorations = TextDecorations.Strikeout,
                         StrikeoutPen = Pens.Solid(Color.Red),
+                        OverlinePen = Pens.Solid(Color.Green, 9),
                         Brush = Brushes.Solid(Color.Red),
                     },
 
@@ -529,15 +538,16 @@ public void DrawRichText<TPixel>(
                         End = 13,
                         Font = font2,
                         TextDecorations = TextDecorations.Strikeout,
-                        StrikeoutPen = Pens.Solid(Color.White),
+                        StrikeoutPen = Pens.Solid(Color.White, 6),
+                        OverlinePen = Pens.Solid(Color.Orange, 2),
                     },
 
                     new RichTextRun
                     {
                         Start = 19,
                         End = 23,
                         TextDecorations = TextDecorations.Underline,
-                        UnderlinePen = Pens.Dot(Color.Fuchsia, 2),
+                        UnderlinePen = Pens.Dot(Color.Fuchsia, 5),
                         Brush = Brushes.Solid(Color.Blue),
                     },