Merge pull request #303 from SixLabors/js/issue-302

Fix out of range exception in typographic utils.

src/SixLabors.Fonts/GlyphMetrics.cs

@@ -190,32 +190,36 @@ internal FontRectangle GetBoundingBox(Vector2 origin, float scaledPointSize)
 
         internal void RenderDecorationsTo(IGlyphRenderer renderer, Vector2 location, float scaledPPEM)
         {
-            (Vector2 Start, Vector2 End, float Thickness) GetEnds(float thickness, float position)
+            (Vector2 Start, Vector2 End, float Thickness) GetEnds(float thickness, float positionY)
             {
-                Vector2 scale = new Vector2(scaledPPEM) / this.ScaleFactor * MirrorScale;
-                Vector2 offset = location + (this.Offset * scale * MirrorScale);
-
-                // Calculate the correct advance for the line.
                 float width = this.AdvanceWidth;
                 if (width == 0)
                 {
-                    // For zero advance glyphs we must calculate our advance width from bearing + width;
-                    width = this.LeftSideBearing + this.Width;
+                    return (Vector2.Zero, Vector2.Zero, 0);
                 }
 
-                Vector2 tl = (new Vector2(0, position) * scale) + offset;
-                Vector2 tr = (new Vector2(width, position) * scale) + offset;
-                Vector2 bl = (new Vector2(0, position + thickness) * scale) + offset;
+                Vector2 scale = new Vector2(scaledPPEM) / this.ScaleFactor;
+                Vector2 offset = location + (this.Offset * scale * MirrorScale) + (new Vector2(0, positionY) * scale * MirrorScale);
+
+                Vector2 tl = new(offset.X, offset.Y);
+                Vector2 tr = new(offset.X + (width * scale.X), offset.Y);
+                Vector2 bl = new(offset.X, offset.Y + (thickness * scale.Y));
 
-                return (tl, tr, tl.Y - bl.Y);
+                return (tl, tr, bl.Y - tl.Y);
             }
 
             void DrawLine(float thickness, float position)
             {
                 renderer.BeginFigure();
 
                 (Vector2 start, Vector2 end, float finalThickness) = GetEnds(thickness, position);
-                var halfHeight = new Vector2(0, -finalThickness * .5F);
+
+                if (finalThickness == 0)
+                {
+                    return;
+                }
+
+                Vector2 halfHeight = new(0, finalThickness * .5F);
 
                 Vector2 tl = start - halfHeight;
                 Vector2 tr = end - halfHeight;
@@ -229,10 +233,10 @@ void DrawLine(float thickness, float position)
                 bl.Y = MathF.Floor(bl.Y);
 
                 // Do the same for vertical components.
-                tl.X = MathF.Floor(tl.X);
-                tr.X = MathF.Floor(tr.X);
-                br.X = MathF.Floor(br.X);
-                bl.X = MathF.Floor(bl.X);
+                tl.X = MathF.Round(tl.X);
+                tr.X = MathF.Round(tr.X);
+                br.X = MathF.Round(br.X);
+                bl.X = MathF.Round(bl.X);
 
                 renderer.MoveTo(tl);
                 renderer.LineTo(bl);
@@ -245,7 +249,10 @@ void DrawLine(float thickness, float position)
             void SetDecoration(TextDecorations decorationType, float thickness, float position)
             {
                 (Vector2 start, Vector2 end, float calcThickness) = GetEnds(thickness, position);
-                ((IGlyphDecorationRenderer)renderer).SetDecoration(decorationType, start, end, calcThickness);
+                if (calcThickness != 0)
+                {
+                    ((IGlyphDecorationRenderer)renderer).SetDecoration(decorationType, start, end, calcThickness);
+                }
             }
 
             // There's no built in metrics for these values so we will need to infer them from the other metrics.

src/SixLabors.Fonts/Tables/AdvancedTypographic/AdvancedTypographicUtils.cs

@@ -317,6 +317,11 @@ private static bool Match<T>(
             int offset = iterator.Increment(increment);
             IGlyphShapingCollection collection = iterator.Collection;
 
+            if (offset < 0)
+            {
+                return false;
+            }
+
             int i = 0;
             while (i < sequence.Length && i < MaxContextLength && offset < collection.Count)
             {

src/SixLabors.Fonts/Tables/TrueType/TrueTypeGlyphMetrics.cs

@@ -118,7 +118,7 @@ internal override void RenderTo(IGlyphRenderer renderer, float pointSize, Vector
                         // Scale and translate the glyph
                         Vector2 scale = new Vector2(scaledPPEM) / this.ScaleFactor;
                         var transform = Matrix3x2.CreateScale(scale);
-                        transform.Translation = this.Offset * scale * MirrorScale;
+                        transform.Translation = this.Offset * scale;
                         scaledVector = GlyphVector.Transform(this.vector, transform);
                         this.FontMetrics.ApplyTrueTypeHinting(options.HintingMode, this, ref scaledVector, scale, scaledPPEM);
                         this.scaledVector[scaledPPEM] = scaledVector;

tests/SixLabors.Fonts.Tests/Issues/Issues_298.cs

@@ -0,0 +1,35 @@
+// Copyright (c) Six Labors.
+// Licensed under the Apache License, Version 2.0.
+
+using System;
+using Xunit;
+
+namespace SixLabors.Fonts.Tests.Issues
+{
+    public class Issues_298
+    {
+        [Fact]
+        public void DoesNotThrowOutOfBounds()
+        {
+            const string content = "Please enter the text";
+
+            FontCollection fontFamilies = new();
+
+            FontFamily fontFamily = fontFamilies.Add(TestFonts.Issues.Issue298File);
+
+            Font font = fontFamily.CreateFont(16, FontStyle.Regular);
+
+            TextOptions renderOptions = new(font)
+            {
+                Dpi = 96,
+                WrappingLength = 0f,
+                VerticalAlignment = VerticalAlignment.Top,
+                HorizontalAlignment = HorizontalAlignment.Left,
+                KerningMode = KerningMode.Auto
+            };
+
+            FontRectangle bounds = TextMeasurer.Measure(content.AsSpan(), renderOptions);
+            Assert.NotEqual(default, bounds);
+        }
+    }
+}

tests/SixLabors.Fonts.Tests/Issues/Issues_302.cs

@@ -0,0 +1,23 @@
+// Copyright (c) Six Labors.
+// Licensed under the Apache License, Version 2.0.
+
+using Xunit;
+
+namespace SixLabors.Fonts.Tests.Issues
+{
+    public class Issues_302
+    {
+#if OS_WINDOWS
+        [Fact]
+        public void DoesNotThrowOutOfBounds()
+        {
+            const string content = "فِيلْمٌ";
+            FontFamily fontFamily = SystemFonts.Get("Arial");
+            Font font = fontFamily.CreateFont(16, FontStyle.Regular);
+            TextOptions renderOptions = new(font);
+
+            Assert.True(TextMeasurer.TryMeasureCharacterBounds(content, renderOptions, out GlyphBounds[] _));
+        }
+#endif
+    }
+}

tests/SixLabors.Fonts.Tests/TestFonts.cs

@@ -245,6 +245,8 @@ public static class Issues
             public static string Issue96File => GetFullPath("Issues/Issue96.fuzz");
 
             public static string Issue97File => GetFullPath("Issues/Issue97.fuzz");
+
+            public static string Issue298File => GetFullPath("Issues/StyleScript.ttf");
         }
 
         private static Stream OpenStream(string path) =>