additional tests around pen rendering with patterns

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

@@ -121,11 +121,29 @@ namespace SixLabors.ImageSharp.Processing.Text.Processors
                             IBuffer2D<float> buffer = operation.Map;
                             int startY = operation.Location.Y;
                             int startX = operation.Location.X;
+                            int offSetSpan = 0;
+                            if (startX < 0)
+                            {
+                                offSetSpan = -startX;
+                                startX = 0;
+                            }
+
+                            int fistRow = 0;
+                            if (startY < 0)
+                            {
+                                fistRow = -startY;
+                            }
+
                             int end = operation.Map.Height;
-                            for (int row = 0; row < end; row++)
+
+                            int maxHeight = source.Height - startY;
+                            end = Math.Min(end, maxHeight);
+
+                            for (int row = fistRow; row < end; row++)
                             {
                                 int y = startY + row;
-                                app.Apply(buffer.GetRowSpan(row), startX, y);
+                                Span<float> span = buffer.GetRowSpan(row).Slice(offSetSpan);
+                                app.Apply(span, startX, y);
                             }
                         }
                     }
@@ -146,7 +164,7 @@ namespace SixLabors.ImageSharp.Processing.Text.Processors
 
             private Point currentRenderPosition = default(Point);
             private int currentRenderingGlyph = 0;
-
+            private int offset = 0;
             private PointF currentPoint = default(PointF);
             private HashSet<int> renderedGlyphs = new HashSet<int>();
             private Dictionary<int, Buffer2D<float>> glyphMap;
@@ -161,6 +179,7 @@ namespace SixLabors.ImageSharp.Processing.Text.Processors
                 this.Pen = pen;
                 this.renderFill = renderFill;
                 this.renderOutline = pen != null;
+                this.offset = 2;
                 if (this.renderFill)
                 {
                     this.FillOperations = new List<DrawingOperation>(size);
@@ -169,6 +188,7 @@ namespace SixLabors.ImageSharp.Processing.Text.Processors
 
                 if (this.renderOutline)
                 {
+                    this.offset = (int)MathF.Ceiling((pen.StrokeWidth * 2) + 2);
                     this.OutlineOperations = new List<DrawingOperation>(size);
                     this.glyphMapPen = new Dictionary<int, Buffer2D<float>>();
                 }
@@ -194,6 +214,9 @@ namespace SixLabors.ImageSharp.Processing.Text.Processors
             public bool BeginGlyph(RectangleF bounds, int cacheKey)
             {
                 this.currentRenderPosition = Point.Truncate(bounds.Location);
+
+                // we have offset our rendering origion a little bit down to prevent edge cropping, move the draw origin up to compensate
+                this.currentRenderPosition = new Point(this.currentRenderPosition.X - this.offset, this.currentRenderPosition.Y - this.offset);
                 this.currentRenderingGlyph = cacheKey;
                 if (this.renderedGlyphs.Contains(cacheKey))
                 {
@@ -206,7 +229,7 @@ namespace SixLabors.ImageSharp.Processing.Text.Processors
                 this.builder.Clear();
 
                 // ensure all glyphs render around [zero, zero]  so offset negative root positions so when we draw the glyph we can offet it back
-                this.builder.SetOrigin(new PointF(-(int)bounds.X, -(int)bounds.Y));
+                this.builder.SetOrigin(new PointF(-(int)bounds.X + this.offset, -(int)bounds.Y + this.offset));
 
                 this.raterizationRequired = true;
                 return true;
@@ -298,7 +321,9 @@ namespace SixLabors.ImageSharp.Processing.Text.Processors
 
             private Buffer2D<float> Render(IPath path)
             {
-                var size = Rectangle.Ceiling(path.Bounds);
+                Size size = Rectangle.Ceiling(path.Bounds).Size;
+                size = new Size(size.Width + (this.offset * 2), size.Height + (this.offset * 2));
+
                 float subpixelCount = 4;
                 float offset = 0.5f;
                 if (this.Options.Antialias)

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

@@ -52,6 +52,7 @@ namespace SixLabors.ImageSharp.Tests.Drawing.Text
             TPixel color = NamedColors<TPixel>.Black;
 
             provider.VerifyOperation(
+                ImageComparer.Tolerant(imageThreshold: 0.1f, perPixelManhattanThreshold: 20),
                 img =>
                 {
                     img.Mutate(c => c.DrawText(text, new Font(font, fontSize), color, new PointF(x, y)));
@@ -95,6 +96,7 @@ namespace SixLabors.ImageSharp.Tests.Drawing.Text
             TPixel color = NamedColors<TPixel>.Black;
 
             provider.VerifyOperation(
+                ImageComparer.Tolerant(imageThreshold: 0.1f, perPixelManhattanThreshold: 20),
                 img =>
                     {
                         img.Mutate(c => c.DrawText(textOptions, sb.ToString(), font, color, new PointF(10, 5)));
@@ -125,7 +127,36 @@ namespace SixLabors.ImageSharp.Tests.Drawing.Text
                 ImageComparer.Tolerant(imageThreshold: 0.1f, perPixelManhattanThreshold: 20),
                 img =>
                 {
-                    img.Mutate(c => c.DrawText(text, new Font(font, fontSize),null, Pens.Solid(color, 1), new PointF(x, y)));
+                    img.Mutate(c => c.DrawText(text, new Font(font, fontSize), null, Pens.Solid(color, 1), new PointF(x, y)));
+                },
+                $"pen_{fontName}-{fontSize}-{fnDisplayText}-({x},{y})",
+                appendPixelTypeToFileName: false,
+                appendSourceFileOrDescription: true);
+        }
+
+        [Theory]
+        [WithSolidFilledImages(200, 100, "White", PixelTypes.Rgba32, 50, 0, 0, "SixLaborsSampleAB.woff", AB)]
+        [WithSolidFilledImages(900, 100, "White", PixelTypes.Rgba32, 50, 0, 0, "OpenSans-Regular.ttf", TestText)]
+        [WithSolidFilledImages(1100, 200, "White", PixelTypes.Rgba32, 50, 150, 100, "OpenSans-Regular.ttf", TestText)]
+        public void FontShapesAreRenderedCorrectlyWithAPenPatterned<TPixel>(
+            TestImageProvider<TPixel> provider,
+            int fontSize,
+            int x,
+            int y,
+            string fontName,
+            string text)
+            where TPixel : struct, IPixel<TPixel>
+        {
+            Font font = CreateFont(fontName, fontSize);
+            string fnDisplayText = text.Replace("\n", "");
+            fnDisplayText = fnDisplayText.Substring(0, Math.Min(fnDisplayText.Length, 4));
+            TPixel color = NamedColors<TPixel>.Black;
+
+            provider.VerifyOperation(
+                ImageComparer.Tolerant(imageThreshold: 0.1f, perPixelManhattanThreshold: 20),
+                img =>
+                {
+                    img.Mutate(c => c.DrawText(text, new Font(font, fontSize), null, Pens.DashDot(color, 3), new PointF(x, y)));
                 },
                 $"pen_{fontName}-{fontSize}-{fnDisplayText}-({x},{y})",
                 appendPixelTypeToFileName: false,

tests/Images/External

@@ -1 +1 @@
-Subproject commit 07cdbcfca121081eae97d6a9cd0e230c653eeb39
+Subproject commit 09059fae2d8bea3a4c9288ab10fb184f1b648f40