Split out nested classes

osu.Game/Skinning/LegacySpriteText.cs

@@ -0,0 +1,53 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System.Threading.Tasks;
+using osu.Framework.Graphics.Sprites;
+using osu.Framework.Text;
+using osu.Game.Graphics;
+using osu.Game.Graphics.Sprites;
+
+namespace osu.Game.Skinning
+{
+    public class LegacySpriteText : OsuSpriteText
+    {
+        private readonly LegacyGlyphStore glyphStore;
+
+        public LegacySpriteText(ISkin skin, string font)
+        {
+            Shadow = false;
+            UseFullGlyphHeight = false;
+
+            Font = new FontUsage(font, OsuFont.DEFAULT_FONT_SIZE);
+            glyphStore = new LegacyGlyphStore(skin);
+        }
+
+        protected override TextBuilder CreateTextBuilder(ITexturedGlyphLookupStore store) => base.CreateTextBuilder(glyphStore);
+
+        private class LegacyGlyphStore : ITexturedGlyphLookupStore
+        {
+            private readonly ISkin skin;
+
+            public LegacyGlyphStore(ISkin skin)
+            {
+                this.skin = skin;
+            }
+
+            public ITexturedCharacterGlyph Get(string fontName, char character)
+            {
+                var texture = skin.GetTexture($"{fontName}-{character}");
+
+                if (texture != null)
+                    // Approximate value that brings character sizing roughly in-line with stable
+                    texture.ScaleAdjust *= 18;
+
+                if (texture == null)
+                    return null;
+
+                return new TexturedCharacterGlyph(new CharacterGlyph(character, 0, 0, texture.Width, null), texture, 1f / texture.ScaleAdjust);
+            }
+
+            public Task<ITexturedCharacterGlyph> GetAsync(string fontName, char character) => Task.Run(() => Get(fontName, character));
+        }
+    }
+}