Update refs and add tests

Author: JimBobSquarePants

src/ImageSharp.Drawing/ImageSharp.Drawing.csproj

@@ -17,8 +17,8 @@
     <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-beta16" />
-    <PackageReference Include="SixLabors.ImageSharp" Version="2.1.1-alpha.0.1" />
+    <PackageReference Include="SixLabors.Fonts" Version="1.0.0-beta16.13" />
+    <PackageReference Include="SixLabors.ImageSharp" Version="2.1.1-alpha.0.2" />
   </ItemGroup>
   <Import Project="..\..\shared-infrastructure\src\SharedInfrastructure\SharedInfrastructure.projitems" Label="Shared" />
 </Project>

src/ImageSharp.Drawing/Shapes/Path.cs

@@ -274,9 +274,11 @@ public static bool TryParseSvgPath(ReadOnlySpan<char> svgPath, out IPath value)
                         svgPath = FindScaler(svgPath, out float largeArc);
                         svgPath = TrimSeparator(svgPath);
                         svgPath = FindScaler(svgPath, out float sweep);
-
                         svgPath = FindPoint(svgPath, out PointF point, relative, c);
-                        if (svgPath.Length > 0)
+
+                        // TODO: Skia compares the input SVG with the chars not the length.
+                        // Maybe we can do something with SpanAction<T>?
+                        // if (svgPath.Length > 0)
                         {
                             builder.ArcTo(radiiX, radiiY, angle, largeArc == 1, sweep == 1, point);
                             c = point;

src/ImageSharp.Drawing/Shapes/PathBuilder.cs

@@ -451,6 +451,8 @@ public void Clear()
             this.currentFigure = new Figure();
             this.figures.Clear();
             this.figures.Add(this.currentFigure);
+
+            // TODO: Should we reset currentPoint here instead?
         }
 
         private class Figure

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

@@ -59,7 +59,7 @@ bool IGlyphRenderer.BeginGlyph(FontRectangle bounds, GlyphRendererParameters par
         /// <param name="point">The point.</param>
         void IGlyphRenderer.CubicBezierTo(Vector2 secondControlPoint, Vector2 thirdControlPoint, Vector2 point)
         {
-            this.Builder.AddBezier(this.currentPoint, secondControlPoint, thirdControlPoint, point);
+            this.Builder.AddCubicBezier(this.currentPoint, secondControlPoint, thirdControlPoint, point);
             this.currentPoint = point;
         }
 
@@ -100,7 +100,7 @@ void IGlyphRenderer.MoveTo(Vector2 point)
         /// <param name="point">The point.</param>
         void IGlyphRenderer.QuadraticBezierTo(Vector2 secondControlPoint, Vector2 point)
         {
-            this.Builder.AddBezier(this.currentPoint, secondControlPoint, point);
+            this.Builder.AddQuadraticBezier(this.currentPoint, secondControlPoint, point);
             this.currentPoint = point;
         }
 

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

@@ -16,7 +16,7 @@ internal sealed class PathGlyphBuilder : GlyphBuilder
         private const float Pi = MathF.PI;
         private readonly IPathInternals path;
         private Vector2 textOffset;
-        private TextOptions textOptions;
+        private readonly TextOptions textOptions;
 
         /// <summary>
         /// Initializes a new instance of the <see cref="PathGlyphBuilder"/> class.
@@ -72,9 +72,9 @@ private void TransformGlyph(FontRectangle bounds)
             SegmentInfo pathPoint = this.path.PointAlongPath(bounds.Left + halfWidth);
 
             // Now offset our target point since we're aligning the bottom-left location of our glyph against the path.
-            // TODO: This is good and accurate when we are vertically aligned to the path however the distance between
+            // This is good and accurate when we are vertically aligned to the path however the distance between
             // characters in multiline text scales with the angle and vertical offset.
-            // It would be good to be able to fix this.
+            // This is expected and consistant with other libraries. Multiple line text should be rendered using multiple paths to avoid this behavior.
             Vector2 targetPoint = (Vector2)pathPoint.Point + new Vector2(-halfWidth, bounds.Top) - bounds.Location - this.textOffset;
 
             // Due to how matrix combining works you have to combine this in the reverse order of operation.

tests/ImageSharp.Drawing.Tests/Drawing/Text/DrawTextOnImageTests.cs

@@ -494,6 +494,60 @@ public void CanRotateOutlineFont_Issue175<TPixel>(
                 appendSourceFileOrDescription: true);
         }
 
+        [Theory]
+        [WithBlankImage(100, 100, PixelTypes.Rgba32, "M10,90 Q90,90 90,45 Q90,10 50,10 Q10,10 10,40 Q10,70 45,70 Q70,70 75,50", "spiral")]
+        [WithBlankImage(350, 350, PixelTypes.Rgba32, "M275 175 A100 100 0 1 1 275 174", "circle")]
+        [WithBlankImage(120, 120, PixelTypes.Rgba32, "M50,10 L 90 90 L 10 90 L50 10", "triangle")]
+        public void CanDrawTextAlongPathHorizontal<TPixel>(TestImageProvider<TPixel> provider, string svgPath, string exampleImageKey)
+            where TPixel : unmanaged, IPixel<TPixel>
+        {
+            bool parsed = Path.TryParseSvgPath(svgPath, out IPath path);
+            Assert.True(parsed);
+
+            Font font = CreateFont(TestFonts.OpenSans, 13);
+            TextOptions textOptions = new(font)
+            {
+                WrappingLength = path.ComputeLength(),
+                VerticalAlignment = VerticalAlignment.Bottom,
+                HorizontalAlignment = HorizontalAlignment.Left,
+            };
+
+            const string text = "Quick brown fox jumps over the lazy dog.";
+            IPathCollection glyphs = TextBuilder.GenerateGlyphs(text, path, textOptions);
+
+            provider.RunValidatingProcessorTest(
+                c => c.Fill(Color.White).Draw(Color.Red, 1, path).Fill(Color.Black, glyphs),
+                new { type = exampleImageKey },
+                comparer: ImageComparer.TolerantPercentage(0.002f));
+        }
+
+        [Theory]
+        [WithBlankImage(350, 350, PixelTypes.Rgba32, "M225 175 A50 50 0 1 1 225 174", "circle")]
+        [WithBlankImage(250, 250, PixelTypes.Rgba32, "M100,60 L 140 140 L 60 140 L100 60", "triangle")]
+        public void CanDrawTextAlongPathVertical<TPixel>(TestImageProvider<TPixel> provider, string svgPath, string exampleImageKey)
+            where TPixel : unmanaged, IPixel<TPixel>
+        {
+            bool parsed = Path.TryParseSvgPath(svgPath, out IPath path);
+            Assert.True(parsed);
+
+            Font font = CreateFont(TestFonts.OpenSans, 13);
+            TextOptions textOptions = new(font)
+            {
+                WrappingLength = path.ComputeLength() / 4,
+                VerticalAlignment = VerticalAlignment.Bottom,
+                HorizontalAlignment = HorizontalAlignment.Left,
+                LayoutMode = LayoutMode.VerticalLeftRight
+            };
+
+            const string text = "Quick brown fox jumps over the lazy dog.";
+            IPathCollection glyphs = TextBuilder.GenerateGlyphs(text, path, textOptions);
+
+            provider.RunValidatingProcessorTest(
+                c => c.Fill(Color.White).Draw(Color.Red, 1, path).Fill(Color.Black, glyphs),
+                new { type = exampleImageKey },
+                comparer: ImageComparer.TolerantPercentage(0.002f));
+        }
+
         private static string Repeat(string str, int times) => string.Concat(Enumerable.Repeat(str, times));
 
         private static string ToTestOutputDisplayText(string text)

tests/ImageSharp.Drawing.Tests/Shapes/SvgPath.cs

@@ -13,15 +13,15 @@ public class SvgPath
         [Theory]
         [WithBlankImage(110, 70, PixelTypes.Rgba32, "M20,30 L40,5 L60,30 L80, 55 L100, 30", "zag")]
         [WithBlankImage(110, 50, PixelTypes.Rgba32, "M20,30 Q40,5 60,30 T100,30", "wave")]
-        [WithBlankImage(500, 400, PixelTypes.Rgba32, @"M10,350 l 50,-25 a25,25 -30 0,1 50,-25 l 50,-25 a25,50 -30 0,1 50,-25 l 50,-25 a25,75 -30 0,1 50,-25 l 50,-25 a25,100 -30 0,1 50,-25 l 50,-25", "bumpy")]
-        [WithBlankImage(500, 400, PixelTypes.Rgba32, @"M300,200 h-150 a150,150 0 1,0 150,-150 z", "pie_small")]
-        [WithBlankImage(500, 400, PixelTypes.Rgba32, @"M275,175 v-150 a150,150 0 0,0 -150,150 z", "pie_big")]
-        [WithBlankImage(100, 100, PixelTypes.Rgba32, @"M50,50 L50,20 L80,50 z M40,60 L40,90 L10,60 z", "arrows")]
-        [WithBlankImage(500, 400, PixelTypes.Rgba32, @"M 10 315 L 110 215 A 30 50 0 0 1 162.55 162.45 L 172.55 152.45 A 30 50 -45 0 1 215.1 109.9 L 315 10", "chopped_oval")]
+        [WithBlankImage(500, 400, PixelTypes.Rgba32, "M10,350 l 50,-25 a25,25 -30 0,1 50,-25 l 50,-25 a25,50 -30 0,1 50,-25 l 50,-25 a25,75 -30 0,1 50,-25 l 50,-25 a25,100 -30 0,1 50,-25 l 50,-25", "bumpy")]
+        [WithBlankImage(500, 400, PixelTypes.Rgba32, "M300,200 h-150 a150,150 0 1,0 150,-150 z", "pie_small")]
+        [WithBlankImage(500, 400, PixelTypes.Rgba32, "M275,175 v-150 a150,150 0 0,0 -150,150 z", "pie_big")]
+        [WithBlankImage(100, 100, PixelTypes.Rgba32, "M50,50 L50,20 L80,50 z M40,60 L40,90 L10,60 z", "arrows")]
+        [WithBlankImage(500, 400, PixelTypes.Rgba32, "M 10 315 L 110 215 A 30 50 0 0 1 162.55 162.45 L 172.55 152.45 A 30 50 -45 0 1 215.1 109.9 L 315 10", "chopped_oval")]
         public void RenderSvgPath<TPixel>(TestImageProvider<TPixel> provider, string svgPath, string exampleImageKey)
             where TPixel : unmanaged, IPixel<TPixel>
         {
-            var parsed = Path.TryParseSvgPath(svgPath, out var path);
+            bool parsed = Path.TryParseSvgPath(svgPath, out IPath path);
             Assert.True(parsed);
 
             provider.RunValidatingProcessorTest(