Only use IGlyphTypeface

api/Avalonia.nupkg.xml

@@ -703,6 +703,12 @@
     <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
     <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0006</DiagnosticId>
+    <Target>M:Avalonia.Media.Fonts.IFontCollection.TryCreateSyntheticGlyphTypeface(Avalonia.Media.IGlyphTypeface,Avalonia.Media.FontStyle,Avalonia.Media.FontWeight,Avalonia.Media.FontStretch,Avalonia.Media.IGlyphTypeface@)</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0006</DiagnosticId>
     <Target>M:Avalonia.Media.Fonts.IFontCollection.TryGetFamilyTypefaces(System.String,System.Collections.Generic.IReadOnlyList{Avalonia.Media.Typeface}@)</Target>
@@ -721,6 +727,12 @@
     <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
     <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0006</DiagnosticId>
+    <Target>M:Avalonia.Media.Fonts.IFontCollection.TryGetNearestMatch(System.String,Avalonia.Media.FontStyle,Avalonia.Media.FontWeight,Avalonia.Media.FontStretch,Avalonia.Media.IGlyphTypeface@)</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0006</DiagnosticId>
     <Target>M:Avalonia.Media.IGlyphTypeface.GetGlyphAdvance(System.UInt16)</Target>
@@ -961,6 +973,12 @@
     <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
     <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0006</DiagnosticId>
+    <Target>M:Avalonia.Media.Fonts.IFontCollection.TryCreateSyntheticGlyphTypeface(Avalonia.Media.IGlyphTypeface,Avalonia.Media.FontStyle,Avalonia.Media.FontWeight,Avalonia.Media.FontStretch,Avalonia.Media.IGlyphTypeface@)</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0006</DiagnosticId>
     <Target>M:Avalonia.Media.Fonts.IFontCollection.TryGetFamilyTypefaces(System.String,System.Collections.Generic.IReadOnlyList{Avalonia.Media.Typeface}@)</Target>
@@ -979,6 +997,12 @@
     <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
     <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0006</DiagnosticId>
+    <Target>M:Avalonia.Media.Fonts.IFontCollection.TryGetNearestMatch(System.String,Avalonia.Media.FontStyle,Avalonia.Media.FontWeight,Avalonia.Media.FontStretch,Avalonia.Media.IGlyphTypeface@)</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0006</DiagnosticId>
     <Target>M:Avalonia.Media.IGlyphTypeface.GetGlyphAdvance(System.UInt16)</Target>

samples/RenderDemo/Pages/GlyphRunPage.xaml.cs

@@ -22,7 +22,7 @@ namespace RenderDemo.Pages
 
     public class GlyphRunControl : Control
     {
-        private GlyphTypeface _glyphTypeface = Typeface.Default.GlyphTypeface;
+        private IGlyphTypeface _glyphTypeface = Typeface.Default.GlyphTypeface;
         private readonly Random _rand = new Random();
         private ushort[] _glyphIndices = new ushort[1];
         private char[] _characters = new char[1];
@@ -81,7 +81,7 @@ namespace RenderDemo.Pages
 
     public class GlyphRunGeometryControl : Control
     {
-        private GlyphTypeface _glyphTypeface = Typeface.Default.GlyphTypeface;
+        private IGlyphTypeface _glyphTypeface = Typeface.Default.GlyphTypeface;
         private readonly Random _rand = new Random();
         private ushort[] _glyphIndices = new ushort[1];
         private char[] _characters = new char[1];

samples/TextTestApp/MainWindow.axaml.cs

@@ -223,12 +223,12 @@ namespace TextTestApp
             }
         }
 
-        private IImage CreateGlyphDrawing(GlyphTypeface glyphTypeface, double emSize, GlyphInfo info)
+        private IImage CreateGlyphDrawing(IGlyphTypeface glyphTypeface, double emSize, GlyphInfo info)
         {
             return new DrawingImage { Drawing = new GeometryDrawing { Brush = Brushes.Black, Geometry = GetGlyphOutline(glyphTypeface, emSize, info) } };
         }
 
-        private Geometry GetGlyphOutline(GlyphTypeface typeface, double emSize, GlyphInfo info)
+        private Geometry GetGlyphOutline(IGlyphTypeface typeface, double emSize, GlyphInfo info)
         {
             // substitute for GlyphTypeface.GetGlyphOutline
             return new GlyphRun(typeface, emSize, new[] { '\0' }, [info]).BuildGeometry();

src/Avalonia.Base/Media/FontManager.cs

@@ -98,7 +98,7 @@ namespace Avalonia.Media
         /// <returns>
         ///     <c>True</c>, if the <see cref="FontManager"/> could create the glyph typeface, <c>False</c> otherwise.
         /// </returns>
-        public bool TryGetGlyphTypeface(Typeface typeface, [NotNullWhen(true)] out GlyphTypeface? glyphTypeface)
+        public bool TryGetGlyphTypeface(Typeface typeface, [NotNullWhen(true)] out IGlyphTypeface? glyphTypeface)
         {
             glyphTypeface = null;
 
@@ -187,7 +187,7 @@ namespace Avalonia.Media
             }
         }
 
-        private bool TryGetGlyphTypefaceByKeyAndName(Typeface typeface, FontFamilyKey key, string familyName, [NotNullWhen(true)] out GlyphTypeface? glyphTypeface)
+        private bool TryGetGlyphTypefaceByKeyAndName(Typeface typeface, FontFamilyKey key, string familyName, [NotNullWhen(true)] out IGlyphTypeface? glyphTypeface)
         {
             var source = key.Source.EnsureAbsolute(key.BaseUri);
 

src/Avalonia.Base/Media/Fonts/FontCollectionBase.cs

@@ -15,7 +15,7 @@ namespace Avalonia.Media.Fonts
             Comparer<FontFamily>.Create((a, b) => string.Compare(a.Name, b.Name, StringComparison.OrdinalIgnoreCase));
 
         // Make this internal for testing purposes
-        internal readonly ConcurrentDictionary<string, ConcurrentDictionary<FontCollectionKey, GlyphTypeface?>> _glyphTypefaceCache = new();
+        internal readonly ConcurrentDictionary<string, ConcurrentDictionary<FontCollectionKey, IGlyphTypeface?>> _glyphTypefaceCache = new();
 
         private readonly object _fontFamiliesLock = new();
         private volatile FontFamily[] _fontFamilies = Array.Empty<FontFamily>();
@@ -87,11 +87,11 @@ namespace Avalonia.Media.Fonts
         }
 
         public virtual bool TryCreateSyntheticGlyphTypeface(
-            GlyphTypeface glyphTypeface,
+            IGlyphTypeface glyphTypeface,
             FontStyle style,
             FontWeight weight,
             FontStretch stretch,
-            [NotNullWhen(true)] out GlyphTypeface? syntheticGlyphTypeface)
+            [NotNullWhen(true)] out IGlyphTypeface? syntheticGlyphTypeface)
         {
             syntheticGlyphTypeface = null;
 
@@ -154,7 +154,7 @@ namespace Avalonia.Media.Fonts
         public IEnumerator<FontFamily> GetEnumerator() => ((IEnumerable<FontFamily>)_fontFamilies).GetEnumerator();
 
         public virtual bool TryGetGlyphTypeface(string familyName, FontStyle style, FontWeight weight,
-                    FontStretch stretch, [NotNullWhen(true)] out GlyphTypeface? glyphTypeface)
+                    FontStretch stretch, [NotNullWhen(true)] out IGlyphTypeface? glyphTypeface)
         {
             var typeface = new Typeface(familyName, style, weight, stretch).Normalize(out familyName);
 
@@ -189,7 +189,7 @@ namespace Avalonia.Media.Fonts
             return false;
         }
 
-        public bool TryGetNearestMatch(string familyName, FontStyle style, FontWeight weight, FontStretch stretch, [NotNullWhen(true)] out GlyphTypeface? glyphTypeface)
+        public bool TryGetNearestMatch(string familyName, FontStyle style, FontWeight weight, FontStretch stretch, [NotNullWhen(true)] out IGlyphTypeface? glyphTypeface)
         {
             if (!_glyphTypefaceCache.TryGetValue(familyName, out var glyphTypefaces))
             {
@@ -206,15 +206,15 @@ namespace Avalonia.Media.Fonts
         /// <summary>
         /// Attempts to add the specified <see cref="IGlyphTypeface"/> to the font collection.
         /// </summary>
-        /// <remarks>This method checks the <see cref="GlyphTypeface.FamilyName"/> and, if applicable,
-        /// the typographic family name and other family names provided by the <see cref="GlyphTypeface"/> interface.
+        /// <remarks>This method checks the <see cref="IGlyphTypeface.FamilyName"/> and, if applicable,
+        /// the typographic family name and other family names provided by the <see cref="IGlyphTypeface"/> interface.
         /// If any of these names can be associated with the glyph typeface, the typeface is added to the collection.
         /// The method ensures that duplicate entries are not added.</remarks>
         /// <param name="glyphTypeface">The glyph typeface to add. Must not be <see langword="null"/> and must have a non-empty <see
         /// cref="IGlyphTypeface.FamilyName"/>.</param>
         /// <returns><see langword="true"/> if the glyph typeface was successfully added to the collection; otherwise, <see
         /// langword="false"/>.</returns>
-        public bool TryAddGlyphTypeface(GlyphTypeface glyphTypeface)
+        public bool TryAddGlyphTypeface(IGlyphTypeface glyphTypeface)
         {
             if (glyphTypeface == null || string.IsNullOrEmpty(glyphTypeface.FamilyName))
             {
@@ -263,7 +263,7 @@ namespace Avalonia.Media.Fonts
         /// succeeds; otherwise, <see langword="null"/>.</param>
         /// <returns><see langword="true"/> if the glyph typeface was successfully created and added; otherwise, <see
         /// langword="false"/>.</returns>
-        public bool TryAddGlyphTypeface(Stream stream, [NotNullWhen(true)] out GlyphTypeface? glyphTypeface)
+        public bool TryAddGlyphTypeface(Stream stream, [NotNullWhen(true)] out IGlyphTypeface? glyphTypeface)
         {
             glyphTypeface = null;
 
@@ -272,7 +272,7 @@ namespace Avalonia.Media.Fonts
                 return false;
             }
 
-            glyphTypeface = new GlyphTypeface(platformTypeface, FontSimulations.None);
+            glyphTypeface = new GlyphTypeface(platformTypeface);
 
             return TryAddGlyphTypeface(glyphTypeface);
         }
@@ -313,7 +313,7 @@ namespace Avalonia.Media.Fonts
                                 continue;
                             }
 
-                            var glyphTypeface = new GlyphTypeface(platformTypeface, FontSimulations.None);
+                            var glyphTypeface = new GlyphTypeface(platformTypeface);
 
                             var key = glyphTypeface.ToFontCollectionKey();
 
@@ -348,7 +348,7 @@ namespace Avalonia.Media.Fonts
 
                             if (_fontManagerImpl.TryCreateGlyphTypeface(stream, FontSimulations.None, out var platformTypeface))
                             {
-                                var glyphTypeface = new GlyphTypeface(platformTypeface, FontSimulations.None);
+                                var glyphTypeface = new GlyphTypeface(platformTypeface);
 
                                 if (TryAddGlyphTypeface(glyphTypeface))
                                 {
@@ -372,7 +372,7 @@ namespace Avalonia.Media.Fonts
 
                                     if (_fontManagerImpl.TryCreateGlyphTypeface(stream, FontSimulations.None, out var platformTypeface))
                                     {
-                                        var glyphTypeface = new GlyphTypeface(platformTypeface, FontSimulations.None);
+                                        var glyphTypeface = new GlyphTypeface(platformTypeface);
 
                                         if (TryAddGlyphTypeface(glyphTypeface))
                                         {
@@ -452,7 +452,7 @@ namespace Avalonia.Media.Fonts
         /// <param name="glyphTypeface">When this method returns, contains the matching <see cref="IGlyphTypeface"/> if a match is found; otherwise,
         /// <see langword="null"/>.</param>
         /// <returns><see langword="true"/> if a matching glyph typeface is found; otherwise, <see langword="false"/>.</returns>
-        protected bool TryGetGlyphTypeface(string familyName, FontCollectionKey key, [NotNullWhen(true)] out GlyphTypeface? glyphTypeface)
+        protected bool TryGetGlyphTypeface(string familyName, FontCollectionKey key, [NotNullWhen(true)] out IGlyphTypeface? glyphTypeface)
         {
             glyphTypeface = null;
 
@@ -558,7 +558,8 @@ namespace Avalonia.Media.Fonts
         /// provided collection of glyph typefaces.
         /// </summary>
         /// <remarks>This method attempts to find the best match for the specified font key by considering
-        /// various fallback strategies, such as normalizing the font style, stretch, and weight. If no suitable match is found, the method will return the first available non-null <see cref="IGlyphTypeface"/> from the
+        /// various fallback strategies, such as normalizing the font style, stretch, and weight. 
+        /// If no suitable match is found, the method will return the first available non-null <see cref="IGlyphTypeface"/> from the
         /// collection, if any.</remarks>
         /// <param name="glyphTypefaces">A collection of glyph typefaces, indexed by <see cref="FontCollectionKey"/>.</param>
         /// <param name="key">The <see cref="FontCollectionKey"/> representing the desired font attributes.</param>
@@ -566,7 +567,8 @@ namespace Avalonia.Media.Fonts
         /// key, if a match is found; otherwise, <see langword="null"/>.</param>
         /// <returns><see langword="true"/> if a matching <see cref="IGlyphTypeface"/> is found; otherwise, <see
         /// langword="false"/>.</returns>
-        protected bool TryGetNearestMatch(IDictionary<FontCollectionKey, GlyphTypeface?> glyphTypefaces, FontCollectionKey key, [NotNullWhen(true)] out GlyphTypeface? glyphTypeface)
+        protected bool TryGetNearestMatch(IDictionary<FontCollectionKey, IGlyphTypeface?> glyphTypefaces, 
+            FontCollectionKey key, [NotNullWhen(true)] out IGlyphTypeface? glyphTypeface)
         {
             if (glyphTypefaces.TryGetValue(key, out glyphTypeface) && glyphTypeface != null)
             {
@@ -631,7 +633,7 @@ namespace Avalonia.Media.Fonts
         /// <param name="glyphTypeface">The glyph typeface to add to the cache. Can be null.</param>
         /// <returns><see langword="true"/> if the glyph typeface was successfully added to the cache; otherwise, <see
         /// langword="false"/>.</returns>
-        protected bool TryAddGlyphTypeface(string familyName, FontCollectionKey key, GlyphTypeface? glyphTypeface)
+        protected bool TryAddGlyphTypeface(string familyName, FontCollectionKey key, IGlyphTypeface? glyphTypeface)
         {
             if (string.IsNullOrEmpty(familyName))
             {
@@ -655,7 +657,7 @@ namespace Avalonia.Media.Fonts
             }
 
             // Family doesn't exist yet. Create a new dictionary instance and try to install it.
-            var newDict = new ConcurrentDictionary<FontCollectionKey, GlyphTypeface?>();
+            var newDict = new ConcurrentDictionary<FontCollectionKey, IGlyphTypeface?>();
 
             // GetOrAdd will return the instance that ended up in the dictionary. If it's our
             // newDict instance then we won the race to add the family and should publish it.
@@ -697,9 +699,9 @@ namespace Avalonia.Media.Fonts
         /// null.</param>
         /// <returns>true if a suitable fallback glyph typeface is found; otherwise, false.</returns>
         private static bool TryFindStretchFallback(
-           IDictionary<FontCollectionKey, GlyphTypeface?> glyphTypefaces,
+           IDictionary<FontCollectionKey, IGlyphTypeface?> glyphTypefaces,
            FontCollectionKey key,
-           [NotNullWhen(true)] out GlyphTypeface? glyphTypeface)
+           [NotNullWhen(true)] out IGlyphTypeface? glyphTypeface)
         {
             glyphTypeface = null;
 
@@ -744,9 +746,9 @@ namespace Avalonia.Media.Fonts
         /// null.</param>
         /// <returns>true if a fallback glyph typeface matching the requested weight is found; otherwise, false.</returns>
         private static bool TryFindWeightFallback(
-            IDictionary<FontCollectionKey, GlyphTypeface?> glyphTypefaces,
+            IDictionary<FontCollectionKey, IGlyphTypeface?> glyphTypefaces,
             FontCollectionKey key,
-            [NotNullWhen(true)] out GlyphTypeface? glyphTypeface)
+            [NotNullWhen(true)] out IGlyphTypeface? glyphTypeface)
         {
             glyphTypeface = null;
             var weight = (int)key.Weight;

src/Avalonia.Base/Media/Fonts/IFontCollection.cs

@@ -5,6 +5,12 @@ using System.Globalization;
 
 namespace Avalonia.Media.Fonts
 {
+    /// <summary>
+    /// Represents a collection of font families and provides methods for querying and managing font typefaces
+    /// within the collection.
+    /// </summary>
+    /// <remarks>Implementations of this interface allow applications to retrieve font families, match
+    /// characters to typefaces, and obtain glyph typefaces based on specific font properties.</remarks>
     public interface IFontCollection : IReadOnlyList<FontFamily>, IDisposable
     {
         /// <summary>
@@ -22,7 +28,7 @@ namespace Avalonia.Media.Fonts
         /// <param name="glyphTypeface">The glyph typeface.</param>
         /// <returns>Returns <c>true</c> if a glyph typface can be found; otherwise, <c>false</c></returns>
         bool TryGetGlyphTypeface(string familyName, FontStyle style, FontWeight weight,
-            FontStretch stretch, [NotNullWhen(true)] out GlyphTypeface? glyphTypeface);
+            FontStretch stretch, [NotNullWhen(true)] out IGlyphTypeface? glyphTypeface);
 
         /// <summary>
         ///     Tries to match a specified character to a <see cref="Typeface"/> that supports specified font properties.
@@ -59,7 +65,8 @@ namespace Avalonia.Media.Fonts
         /// <param name="stretch">The font stretch.</param>
         /// <param name="syntheticGlyphTypeface"></param>
         /// <returns>Returns <c>true</c> if a synthetic glyph typface can be created; otherwise, <c>false</c></returns>
-        bool TryCreateSyntheticGlyphTypeface(GlyphTypeface glyphTypeface, FontStyle style, FontWeight weight, FontStretch stretch, [NotNullWhen(true)] out GlyphTypeface? syntheticGlyphTypeface);
+        bool TryCreateSyntheticGlyphTypeface(IGlyphTypeface glyphTypeface, FontStyle style, FontWeight weight, FontStretch stretch,
+            [NotNullWhen(true)] out IGlyphTypeface? syntheticGlyphTypeface);
 
         /// <summary>
         /// Attempts to retrieve the glyph typeface that most closely matches the specified font family name, style,
@@ -74,9 +81,10 @@ namespace Avalonia.Media.Fonts
         /// <param name="style">The desired font style.</param>
         /// <param name="weight">The desired font weight.</param>
         /// <param name="stretch">The desired font stretch.</param>
-        /// <param name="glyphTypeface">When this method returns, contains the <see cref="GlyphTypeface"/> that most closely matches the specified
+        /// <param name="glyphTypeface">When this method returns, contains the <see cref="IGlyphTypeface"/> that most closely matches the specified
         /// parameters, if a match is found; otherwise, <see langword="null"/>. This parameter is passed uninitialized.</param>
         /// <returns><see langword="true"/> if a matching glyph typeface is found; otherwise, <see langword="false"/>.</returns>
-        bool TryGetNearestMatch(string familyName, FontStyle style, FontWeight weight, FontStretch stretch, [NotNullWhen(true)] out GlyphTypeface? glyphTypeface);
+        bool TryGetNearestMatch(string familyName, FontStyle style, FontWeight weight, FontStretch stretch, 
+            [NotNullWhen(true)] out IGlyphTypeface? glyphTypeface);
     }
 }

src/Avalonia.Base/Media/Fonts/SystemFontCollection.cs

@@ -26,7 +26,7 @@ namespace Avalonia.Media.Fonts
         public override Uri Key => FontManager.SystemFontsKey;
 
         public override bool TryGetGlyphTypeface(string familyName, FontStyle style, FontWeight weight,
-            FontStretch stretch, [NotNullWhen(true)] out GlyphTypeface? glyphTypeface)
+            FontStretch stretch, [NotNullWhen(true)] out IGlyphTypeface? glyphTypeface)
         {
             var typeface = new Typeface(familyName, style, weight, stretch).Normalize(out familyName);
 
@@ -86,13 +86,34 @@ namespace Avalonia.Media.Fonts
 
             if (_platformImpl.TryMatchCharacter(codepoint, style, weight, stretch, familyName, culture, out var platformTypeface))
             {
-                var glyphTypeface = new GlyphTypeface(platformTypeface);
-
+                // Construct the resulting Typeface
                 match = new Typeface(platformTypeface.FamilyName, platformTypeface.Style, platformTypeface.Weight,
                        platformTypeface.Stretch);
 
-                // Add to cache if not already present
-                return TryAddGlyphTypeface(glyphTypeface);
+                // Compute the key for cache lookup this can be different from the requested key
+                var key = match.ToFontCollectionKey();
+
+                // Check cache first: if an entry exists and is non-null, match succeeded and we can return true.
+                if (_glyphTypefaceCache.TryGetValue(platformTypeface.FamilyName, out var glyphTypefaces) && glyphTypefaces.TryGetValue(key, out var existing))
+                {
+                    return existing != null;
+                }
+
+                // Not in cache yet: create glyph typeface and try to add it.
+                var glyphTypeface = new GlyphTypeface(platformTypeface);
+
+                if (TryAddGlyphTypeface(platformTypeface.FamilyName, key, glyphTypeface))
+                {
+                    return true;
+                }
+
+                // TryAddGlyphTypeface failed: another thread may have added an entry. Re-check the cache.
+                if (_glyphTypefaceCache.TryGetValue(platformTypeface.FamilyName, out glyphTypefaces) && glyphTypefaces.TryGetValue(key, out existing))
+                {
+                    return existing != null;
+                }
+
+                return false;
             }
 
             return false;

src/Avalonia.Base/Media/GlyphRun.cs

@@ -39,7 +39,7 @@ namespace Avalonia.Media
         /// <param name="baselineOrigin">The baseline origin of the run.</param>
         /// <param name="biDiLevel">The bidi level.</param>
         public GlyphRun(
-            GlyphTypeface glyphTypeface,
+            IGlyphTypeface glyphTypeface,
             double fontRenderingEmSize,
             ReadOnlyMemory<char> characters,
             IReadOnlyList<ushort> glyphIndices,
@@ -61,7 +61,7 @@ namespace Avalonia.Media
         /// <param name="baselineOrigin">The baseline origin of the run.</param>
         /// <param name="biDiLevel">The bidi level.</param>
         public GlyphRun(
-            GlyphTypeface glyphTypeface,
+            IGlyphTypeface glyphTypeface,
             double fontRenderingEmSize,
             ReadOnlyMemory<char> characters,
             IReadOnlyList<GlyphInfo> glyphInfos,
@@ -90,7 +90,7 @@ namespace Avalonia.Media
         }
 
         private static IReadOnlyList<GlyphInfo> CreateGlyphInfos(IReadOnlyList<ushort> glyphIndices,
-            double fontRenderingEmSize, GlyphTypeface glyphTypeface)
+            double fontRenderingEmSize, IGlyphTypeface glyphTypeface)
         {
             var glyphIndexSpan = ListToSpan(glyphIndices);
 
@@ -142,7 +142,7 @@ namespace Avalonia.Media
         /// <summary>
         ///     Gets the <see cref="GlyphTypeface"/> for the <see cref="GlyphRun"/>.
         /// </summary>
-        public GlyphTypeface GlyphTypeface { get; }
+        public IGlyphTypeface GlyphTypeface { get; }
 
         /// <summary>
         ///     Gets or sets the em size used for rendering the <see cref="GlyphRun"/>.

src/Avalonia.Base/Media/IPlatformTypeface.cs

@@ -31,6 +31,11 @@ namespace Avalonia.Media
         /// </summary>
         FontStretch Stretch { get; }
 
+        /// <summary>
+        ///     Gets the algorithmic style simulations applied to <see cref="IPlatformTypeface"/> object.
+        /// </summary>
+        FontSimulations FontSimulations { get; }
+
         /// <summary>
         /// Returns the font file stream represented by the <see cref="IGlyphTypeface"/>.
         /// </summary>

src/Avalonia.Base/Media/TextFormatting/ShapedBuffer.cs

@@ -13,7 +13,7 @@ namespace Avalonia.Media.TextFormatting
         private GlyphInfo[]? _rentedBuffer;
         private ArraySlice<GlyphInfo> _glyphInfos;
 
-        public ShapedBuffer(ReadOnlyMemory<char> text, int bufferLength, GlyphTypeface glyphTypeface, double fontRenderingEmSize, sbyte bidiLevel)
+        public ShapedBuffer(ReadOnlyMemory<char> text, int bufferLength, IGlyphTypeface glyphTypeface, double fontRenderingEmSize, sbyte bidiLevel)
         {
             Text = text;
             _rentedBuffer = ArrayPool<GlyphInfo>.Shared.Rent(bufferLength);
@@ -23,7 +23,7 @@ namespace Avalonia.Media.TextFormatting
             BidiLevel = bidiLevel;
         }
 
-        internal ShapedBuffer(ReadOnlyMemory<char> text, ArraySlice<GlyphInfo> glyphInfos, GlyphTypeface glyphTypeface, double fontRenderingEmSize, sbyte bidiLevel)
+        internal ShapedBuffer(ReadOnlyMemory<char> text, ArraySlice<GlyphInfo> glyphInfos, IGlyphTypeface glyphTypeface, double fontRenderingEmSize, sbyte bidiLevel)
         {
             Text = text;
             _glyphInfos = glyphInfos;
@@ -40,7 +40,7 @@ namespace Avalonia.Media.TextFormatting
         /// <summary>
         /// The buffer's glyph typeface.
         /// </summary>
-        public GlyphTypeface GlyphTypeface { get; }
+        public IGlyphTypeface GlyphTypeface { get; }
 
         /// <summary>
         /// The buffers font rendering em size.

src/Avalonia.Base/Media/TextFormatting/TextCharacters.cs

@@ -167,8 +167,8 @@ namespace Avalonia.Media.TextFormatting
         /// <returns></returns>
         internal static bool TryGetShapeableLength(
             ReadOnlySpan<char> text,
-            GlyphTypeface glyphTypeface,
-            GlyphTypeface? defaultGlyphTypeface,
+            IGlyphTypeface glyphTypeface,
+            IGlyphTypeface? defaultGlyphTypeface,
             out int length)
         {
             length = 0;

src/Avalonia.Base/Media/TextFormatting/TextMetrics.cs

@@ -5,7 +5,7 @@
     /// </summary>
     public readonly record struct TextMetrics
     {
-        public TextMetrics(GlyphTypeface glyphTypeface, double fontRenderingEmSize)
+        public TextMetrics(IGlyphTypeface glyphTypeface, double fontRenderingEmSize)
         {
             var fontMetrics = glyphTypeface.Metrics;
 

src/Avalonia.Base/Media/TextFormatting/TextRunProperties.cs

@@ -12,7 +12,7 @@ namespace Avalonia.Media.TextFormatting
     /// </remarks>
     public abstract class TextRunProperties : IEquatable<TextRunProperties>
     {
-        private GlyphTypeface? _cachedGlyphTypeFace;
+        private IGlyphTypeface? _cachedGlyphTypeFace;
 
         /// <summary>
         /// Run typeface
@@ -54,7 +54,7 @@ namespace Avalonia.Media.TextFormatting
         /// </summary>
         public virtual BaselineAlignment BaselineAlignment => BaselineAlignment.Baseline;
 
-        internal GlyphTypeface CachedGlyphTypeface
+        internal IGlyphTypeface CachedGlyphTypeface
             => _cachedGlyphTypeFace ??= Typeface.GlyphTypeface;
 
         public bool Equals(TextRunProperties? other)

src/Avalonia.Base/Media/TextFormatting/TextShaperOptions.cs

@@ -10,7 +10,7 @@ namespace Avalonia.Media.TextFormatting
     {
         // TODO12: Remove in 12.0.0 and make fontFeatures parameter in main ctor optional
         public TextShaperOptions(
-            GlyphTypeface typeface,
+            IGlyphTypeface typeface,
             double fontRenderingEmSize = 12,
             sbyte bidiLevel = 0,
             CultureInfo? culture = null,
@@ -22,7 +22,7 @@ namespace Avalonia.Media.TextFormatting
 
         // TODO12:Change signature in 12.0.0
         public TextShaperOptions(
-            GlyphTypeface typeface, 
+            IGlyphTypeface typeface, 
             IReadOnlyList<FontFeature>? fontFeatures,
             double fontRenderingEmSize = 12, 
             sbyte bidiLevel = 0, 
@@ -42,7 +42,7 @@ namespace Avalonia.Media.TextFormatting
         /// <summary>
         /// Get the typeface.
         /// </summary>
-        public GlyphTypeface GlyphTypeface { get; }
+        public IGlyphTypeface GlyphTypeface { get; }
         /// <summary>
         /// Get the font rendering em size.
         /// </summary>

src/Avalonia.Base/Media/Typeface.cs

@@ -83,7 +83,7 @@ namespace Avalonia.Media
         /// <value>
         /// The glyph typeface.
         /// </value>
-        public GlyphTypeface GlyphTypeface
+        public IGlyphTypeface GlyphTypeface
         {
             get
             {

src/Avalonia.Base/Rendering/Composition/Server/DiagnosticTextRenderer.cs

@@ -29,7 +29,7 @@ namespace Avalonia.Rendering.Composition.Server
             return maxHeight;
         }
 
-        public DiagnosticTextRenderer(GlyphTypeface glyphTypeface, double fontRenderingEmSize)
+        public DiagnosticTextRenderer(IGlyphTypeface glyphTypeface, double fontRenderingEmSize)
         {
             var chars = new char[LastChar - FirstChar + 1];
             for (var c = FirstChar; c <= LastChar; c++)

src/Headless/Avalonia.Headless/HeadlessPlatformStubs.cs

@@ -76,7 +76,7 @@ namespace Avalonia.Headless
         {
             _fontMemory = UnmanagedFontMemory.LoadFromStream(stream);
 
-            var dummy = new GlyphTypeface(this, FontSimulations.None);
+            var dummy = new GlyphTypeface(this);
 
             FamilyName = familyName;
             Weight = dummy.Weight;
@@ -92,6 +92,8 @@ namespace Avalonia.Headless
 
         public FontStretch Stretch { get; }
 
+        public FontSimulations FontSimulations => FontSimulations.None;
+
         public void Dispose()
         {
             _fontMemory.Dispose();

tests/Avalonia.Base.UnitTests/Media/GlyphTypefaceTests.cs

@@ -90,6 +90,8 @@ namespace Avalonia.Base.UnitTests.Media
 
             public string FamilyName { get; }
 
+            public FontSimulations FontSimulations => FontSimulations.None;
+
             public void Dispose()
             {
                 _fontMemory.Dispose();

tests/Avalonia.Skia.UnitTests/Media/EmbeddedFontCollectionTests.cs

@@ -139,14 +139,14 @@ namespace Avalonia.Skia.UnitTests.Media
                 _createSyntheticTypefaces = createSyntheticTypefaces;
             }
 
-            public IDictionary<string, ConcurrentDictionary<FontCollectionKey, GlyphTypeface?>> GlyphTypefaceCache => _glyphTypefaceCache;
+            public IDictionary<string, ConcurrentDictionary<FontCollectionKey, IGlyphTypeface?>> GlyphTypefaceCache => _glyphTypefaceCache;
 
             public override bool TryCreateSyntheticGlyphTypeface(
-               GlyphTypeface glyphTypeface,
+               IGlyphTypeface glyphTypeface,
                FontStyle style, 
                FontWeight weight,
                FontStretch stretch,
-               [NotNullWhen(true)] out GlyphTypeface? syntheticGlyphTypeface)
+               [NotNullWhen(true)] out IGlyphTypeface? syntheticGlyphTypeface)
             {
                 if (!_createSyntheticTypefaces)
                 {

tests/Avalonia.Skia.UnitTests/Media/FontCollectionTests.cs

@@ -45,7 +45,7 @@ namespace Avalonia.Skia.UnitTests.Media
             {
             }
 
-            public IDictionary<string, ConcurrentDictionary<FontCollectionKey, GlyphTypeface?>> GlyphTypefaceCache => _glyphTypefaceCache;
+            public IDictionary<string, ConcurrentDictionary<FontCollectionKey, IGlyphTypeface?>> GlyphTypefaceCache => _glyphTypefaceCache;
         }
 
         [Fact]
@@ -126,11 +126,11 @@ namespace Avalonia.Skia.UnitTests.Media
             }
 
             public override bool TryCreateSyntheticGlyphTypeface(
-                GlyphTypeface glyphTypeface, 
+                IGlyphTypeface glyphTypeface, 
                 FontStyle style, 
                 FontWeight weight,
                 FontStretch stretch, 
-                [NotNullWhen(true)] out GlyphTypeface? syntheticGlyphTypeface)
+                [NotNullWhen(true)] out IGlyphTypeface? syntheticGlyphTypeface)
             {
                 syntheticGlyphTypeface = null;
 

tests/Avalonia.Skia.UnitTests/Media/FontManagerTests.cs

@@ -313,13 +313,18 @@ namespace Avalonia.Skia.UnitTests.Media
                         new Uri(s_fontUri, UriKind.Absolute)));
 
                     Assert.True(FontManager.Current.TryGetGlyphTypeface(new Typeface("Noto Mono", FontStyle.Italic, FontWeight.Bold),
-                        out var glyphTypeface));
+                        out var italicBoldTypeface));
 
-                    Assert.Equal("Noto Mono", glyphTypeface.FamilyName);
+                    Assert.Equal("Noto Mono", italicBoldTypeface.FamilyName);
 
-                    Assert.Equal(FontWeight.Bold, glyphTypeface.Weight);
+                    Assert.True(italicBoldTypeface.PlatformTypeface.FontSimulations.HasFlag(FontSimulations.Bold));
 
-                    Assert.Equal(FontStyle.Italic, glyphTypeface.Style);
+                    Assert.True(italicBoldTypeface.PlatformTypeface.FontSimulations.HasFlag(FontSimulations.Oblique));
+
+                    Assert.True(FontManager.Current.TryGetGlyphTypeface(new Typeface("Noto Mono", FontStyle.Normal, FontWeight.Normal),
+                       out var regularTypeface));
+
+                    Assert.NotEqual(((SkiaTypeface)regularTypeface.PlatformTypeface).SKTypeface, ((SkiaTypeface)italicBoldTypeface.PlatformTypeface).SKTypeface);
                 }
             }
         }