Typeface simulation fixes

src/Avalonia.Base/Media/FontManager.cs

@@ -287,6 +287,58 @@ public bool TryMatchCharacter(int codepoint, FontStyle fontStyle, FontWeight fon
             return PlatformImpl.TryMatchCharacter(codepoint, fontStyle, fontWeight, fontStretch, culture, out typeface);
         }
 
+        /// <summary>
+        /// Tries to create a synthetic glyph typefacefor specified source glyph typeface and font properties.
+        /// </summary>
+        /// <param name="fontManager">The font manager implementation.</param>
+        /// <param name="glyphTypeface">The source glyph typeface.</param>
+        /// <param name="style">The requested font style.</param>
+        /// <param name="weight">The requested font weight.</param>
+        /// <param name="syntheticGlyphTypeface">The created synthetic glyph typeface.</param>
+        /// <returns>
+        ///     <c>True</c>, if the <see cref="FontManager"/> could create a synthetic glyph typeface, <c>False</c> otherwise.
+        /// </returns>
+        internal static bool TryCreateSyntheticGlyphTypeface(IFontManagerImpl fontManager, IGlyphTypeface glyphTypeface, FontStyle style, FontWeight weight,
+           [NotNullWhen(true)] out IGlyphTypeface? syntheticGlyphTypeface)
+        {
+            if (fontManager == null)
+            {
+                syntheticGlyphTypeface = null;
+
+                return false;
+            }
+
+            if (glyphTypeface is IGlyphTypeface2 glyphTypeface2)
+            {
+                var fontSimulations = FontSimulations.None;
+
+                if (style != FontStyle.Normal && glyphTypeface2.Style != style)
+                {
+                    fontSimulations |= FontSimulations.Oblique;
+                }
+
+                if ((int)weight >= 600 && glyphTypeface2.Weight < weight)
+                {
+                    fontSimulations |= FontSimulations.Bold;
+                }
+
+                if (fontSimulations != FontSimulations.None && glyphTypeface2.TryGetStream(out var stream))
+                {
+                    using (stream)
+                    {
+                        fontManager.TryCreateGlyphTypeface(stream, fontSimulations,
+                            out syntheticGlyphTypeface);
+
+                        return syntheticGlyphTypeface != null;
+                    }
+                }
+            }
+
+            syntheticGlyphTypeface = null;
+
+            return false;
+        }
+
         private bool TryGetFontCollection(Uri source, [NotNullWhen(true)] out IFontCollection? fontCollection)
         {
             Debug.Assert(source.IsAbsoluteUri);

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

@@ -1,5 +1,4 @@
 using System;
-using System.Collections;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
@@ -72,33 +71,9 @@ public override bool TryGetGlyphTypeface(string familyName, FontStyle style, Fon
 
                 if (TryGetNearestMatch(glyphTypefaces, key, out glyphTypeface))
                 {
-                    if (glyphTypeface is IGlyphTypeface2 glyphTypeface2)
+                    if(_fontManager != null && FontManager.TryCreateSyntheticGlyphTypeface(_fontManager, glyphTypeface, style, weight, out var syntheticGlyphTypeface))
                     {
-                        var fontSimulations = FontSimulations.None;
-
-                        if (style != FontStyle.Normal && glyphTypeface2.Style != style)
-                        {
-                            fontSimulations |= FontSimulations.Oblique;
-                        }
-
-                        if ((int)weight >= 600 && glyphTypeface2.Weight < weight)
-                        {
-                            fontSimulations |= FontSimulations.Bold;
-                        }
-
-                        if (fontSimulations != FontSimulations.None && glyphTypeface2.TryGetStream(out var stream))
-                        {
-                            using (stream)
-                            {
-                                if(_fontManager is not null && _fontManager.TryCreateGlyphTypeface(stream, fontSimulations, out glyphTypeface) && 
-                                    glyphTypefaces.TryAdd(key, glyphTypeface))
-                                {
-                                    return true;
-                                }
-
-                                return false;
-                            }
-                        }
+                        glyphTypeface = syntheticGlyphTypeface;
                     }
 
                     return true;

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

@@ -86,13 +86,11 @@ public override bool TryGetGlyphTypeface(string familyName, FontStyle style, Fon
                 {
                     glyphTypeface = nearestMatch;
                 }
-                else
+
+                //Try to create a synthetic glyph typeface
+                if (FontManager.TryCreateSyntheticGlyphTypeface(_fontManager.PlatformImpl, glyphTypeface, style, weight, out var syntheticGlyphTypeface))
                 {
-                    //Try to create a synthetic glyph typeface
-                    if (TryCreateSyntheticGlyphTypeface(glyphTypeface, style, weight, out var syntheticGlyphTypeface))
-                    {
-                        glyphTypeface = syntheticGlyphTypeface;
-                    }
+                    glyphTypeface = syntheticGlyphTypeface;
                 }
             }
 
@@ -101,40 +99,6 @@ public override bool TryGetGlyphTypeface(string familyName, FontStyle style, Fon
             return glyphTypeface != null;
         }
 
-        private bool TryCreateSyntheticGlyphTypeface(IGlyphTypeface glyphTypeface, FontStyle style, FontWeight weight,
-            [NotNullWhen(true)] out IGlyphTypeface? syntheticGlyphTypeface)
-        {
-            if (glyphTypeface is IGlyphTypeface2 glyphTypeface2)
-            {
-                var fontSimulations = FontSimulations.None;
-
-                if (style != FontStyle.Normal && glyphTypeface2.Style != style)
-                {
-                    fontSimulations |= FontSimulations.Oblique;
-                }
-
-                if ((int)weight >= 600 && glyphTypeface2.Weight < weight)
-                {
-                    fontSimulations |= FontSimulations.Bold;
-                }
-
-                if (fontSimulations != FontSimulations.None && glyphTypeface2.TryGetStream(out var stream))
-                {
-                    using (stream)
-                    {
-                        _fontManager.PlatformImpl.TryCreateGlyphTypeface(stream, fontSimulations,
-                            out syntheticGlyphTypeface);
-
-                        return syntheticGlyphTypeface != null;
-                    }
-                }
-            }
-
-            syntheticGlyphTypeface = null;
-
-            return false;
-        }
-
         public override void Initialize(IFontManagerImpl fontManager)
         {
             //We initialize the system font collection during construction.