Don't use Ceil when measuring.

src/SixLabors.Fonts/TextMeasurer.cs

@@ -203,13 +203,13 @@ internal static FontRectangle GetAdvance(IReadOnlyList<GlyphLayout> glyphLayouts
         Vector2 topLeft = new(left, top);
         Vector2 bottomRight = new(right, bottom);
         Vector2 size = (bottomRight - topLeft) * dpi;
-        return new FontRectangle(0, 0, MathF.Ceiling(size.X), MathF.Ceiling(size.Y));
+        return new FontRectangle(0, 0, size.X, size.Y);
     }
 
     internal static FontRectangle GetSize(IReadOnlyList<GlyphLayout> glyphLayouts, float dpi)
     {
         FontRectangle bounds = GetBounds(glyphLayouts, dpi);
-        return new FontRectangle(0, 0, MathF.Ceiling(bounds.Width), MathF.Ceiling(bounds.Height));
+        return new FontRectangle(0, 0, bounds.Width, bounds.Height);
     }
 
     internal static FontRectangle GetBounds(IReadOnlyList<GlyphLayout> glyphLayouts, float dpi)

tests/SixLabors.Fonts.Tests/ApproximateFloatComparer.cs

@@ -0,0 +1,89 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using System.Numerics;
+
+namespace SixLabors.Fonts.Tests;
+
+internal class ApproximateFloatComparer :
+    IEqualityComparer<float>,
+    IEqualityComparer<Vector2>,
+    IEqualityComparer<IEnumerable<Vector2>>,
+    IEqualityComparer<FontRectangle>
+{
+    private readonly float epsilon;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ApproximateFloatComparer"/> class.
+    /// </summary>
+    /// <param name="epsilon">The comparison error difference epsilon to use.</param>
+    public ApproximateFloatComparer(float epsilon = 1F) => this.epsilon = epsilon;
+
+    public bool Equals(float x, float y)
+    {
+        float d = x - y;
+        return d >= -this.epsilon && d <= this.epsilon;
+    }
+
+    public bool Equals(Vector2 x, Vector2 y)
+        => this.Equals(x.X, y.X) && this.Equals(x.Y, y.Y);
+
+    public bool Equals(IEnumerable<Vector2> x, IEnumerable<Vector2> y)
+    {
+        if (ReferenceEquals(x, y))
+        {
+            return true;
+        }
+
+        if (x is null)
+        {
+            return y is null;
+        }
+
+        if (y is null)
+        {
+            return false;
+        }
+
+        if (x.Count() != y.Count())
+        {
+            return false;
+        }
+
+        using IEnumerator<Vector2> e1 = x.GetEnumerator();
+        using IEnumerator<Vector2> e2 = x.GetEnumerator();
+        while (e1.MoveNext())
+        {
+            if (!(e2.MoveNext() && this.Equals(e1.Current, e2.Current)))
+            {
+                return false;
+            }
+        }
+
+        return !e2.MoveNext();
+    }
+
+    public bool Equals(FontRectangle x, FontRectangle y)
+         => this.Equals(x.X, y.X) &&
+            this.Equals(x.Y, y.Y) &&
+            this.Equals(x.Width, y.Width)
+         && this.Equals(x.Height, y.Height);
+
+    public int GetHashCode(float obj) => obj.GetHashCode();
+
+    public int GetHashCode(Vector2 obj) => obj.GetHashCode();
+
+    public int GetHashCode(IEnumerable<Vector2> obj)
+    {
+        int hash = 17;
+        foreach (Vector2 point in obj)
+        {
+            hash = (hash * 31) + point.GetHashCode();
+        }
+
+        return hash;
+    }
+
+    public int GetHashCode(FontRectangle obj)
+        => obj.GetHashCode();
+}

tests/SixLabors.Fonts.Tests/GlyphTests.cs

@@ -14,6 +14,7 @@ namespace SixLabors.Fonts.Tests;
 public class GlyphTests
 {
     private readonly GlyphRenderer renderer = new();
+    private static readonly ApproximateFloatComparer Comparer = new(.1F);
 
     [Fact]
     public void RenderToPointAndSingleDPI()
@@ -164,8 +165,8 @@ public void EmojiWidthIsComputedCorrectlyWithSubstitutionOnZwj()
         FontRectangle size = TextMeasurer.MeasureSize(text, new TextOptions(font));
         FontRectangle size2 = TextMeasurer.MeasureSize(text2, new TextOptions(font));
 
-        Assert.Equal(51f, size.Width);
-        Assert.Equal(51f, size2.Width);
+        Assert.Equal(50.625F, size.Width, Comparer);
+        Assert.Equal(50.625F, size2.Width, Comparer);
     }
 
     [Theory]

tests/SixLabors.Fonts.Tests/Issues/Issues_269.cs

@@ -5,14 +5,16 @@ namespace SixLabors.Fonts.Tests.Issues;
 
 public class Issues_269
 {
+    private static readonly ApproximateFloatComparer Comparer = new(.1F);
+
     [Fact]
     public void CorrectlySetsMetricsForFontsNotAdheringToSpec()
     {
         // AliceFrancesHMK has invalid subtables.
         Font font = new FontCollection().Add(TestFonts.AliceFrancesHMKRegularFile).CreateFont(25);
 
         FontRectangle size = TextMeasurer.MeasureSize("H", new TextOptions(font));
-        Assert.Equal(32, size.Width, 1F);
-        Assert.Equal(25, size.Height, 1F);
+        Assert.Equal(30.6000004F, size.Width, Comparer);
+        Assert.Equal(24.75F, size.Height, Comparer);
     }
 }

tests/SixLabors.Fonts.Tests/Issues/Issues_367.cs

@@ -4,17 +4,19 @@
 namespace SixLabors.Fonts.Tests.Issues;
 public class Issues_367
 {
+    private static readonly ApproximateFloatComparer Comparer = new(.1F);
+
     [Fact]
     public void ShouldMatchBrowserBreak()
     {
         Font font = new FontCollection().Add(TestFonts.CourierPrimeFile).CreateFont(12);
 
         TextOptions options = new(font)
         {
-            Dpi = 96f // 1in = 96px
+            Dpi = 96F // 1in = 96px
         };
 
-        const float wrappingLengthInInches = 3.875f;
+        const float wrappingLengthInInches = 3.875F;
         options.WrappingLength = wrappingLengthInInches * options.Dpi;
 
         const string text = "Leer, but lonesome has fussin' change a faith. Themself seen and four trample.";
@@ -23,7 +25,7 @@ public void ShouldMatchBrowserBreak()
         Assert.Equal(3, lineCount);
 
         FontRectangle advance = TextMeasurer.MeasureAdvance(text, options);
-        Assert.Equal(355, advance.Width);
-        Assert.Equal(48, advance.Height);
+        Assert.Equal(354.968658F, advance.Width, Comparer);
+        Assert.Equal(48, advance.Height, Comparer);
     }
 }