First working version with TextShaping and subsetting

Author: swmal

src/EPPlus.Fonts.OpenType/FontSubsetBuilder.cs

@@ -10,14 +10,10 @@ Date               Author                       Change
  *************************************************************************************************
   10/07/2025         EPPlus Software AB           EPPlus.Fonts.OpenType 1.0
  *************************************************************************************************/
-using EPPlus.Fonts.OpenType.Tables;
 using EPPlus.Fonts.OpenType.Tables.Glyph;
 using EPPlus.Fonts.OpenType.Tables.Head;
 using EPPlus.Fonts.OpenType.Tables.Loca;
-using System;
 using System.Collections.Generic;
-using System.Linq;
-using System.Text;
 
 namespace EPPlus.Fonts.OpenType
 {
@@ -49,18 +45,14 @@ public OpenTypeFont BuildSubset(HashSet<ushort> glyphIds, IEnumerable<char> used
                 ? HeadTable.IndexToLocFormats.Offset16
                 : HeadTable.IndexToLocFormats.Offset32;
 
-            // Uppdatera HeadTable också
+            // Update HeadTable
             subsetFont.HeadTable.IndexToLocFormat = indexToLocFormat;
 
-            // Bygg Loca-tabellen
+            // Build Loca-table for the subset
             subsetFont.AddOrReplaceTable(
                 LocaTable.CreateSubset(glyphSubsetResult.LocaOffsets, indexToLocFormat)
             );
 
-            //subsetFont.ReplaceTable(TableNames.Hmtx, BuildHmtxSubset(glyphIds));
-            //subsetFont.ReplaceTable(TableNames.Cmap, BuildCmapSubset(usedChars));
-
-            //subsetFont.RecalculateChecksums();
             return subsetFont;
         }
     }

src/EPPlus.Fonts.OpenType/FontTableReaderFactory.cs

@@ -1,4 +1,16 @@
-using System;
+/*************************************************************************************************
+  Required Notice: Copyright (C) EPPlus Software AB. 
+  This software is licensed under PolyForm Noncommercial License 1.0.0 
+  and may only be used for noncommercial purposes 
+  https://polyformproject.org/licenses/noncommercial/1.0.0/
+
+  A commercial license to use this software can be purchased at https://epplussoftware.com
+ *************************************************************************************************
+  Date               Author                       Change
+ *************************************************************************************************
+  10/07/2025         EPPlus Software AB           EPPlus.Fonts.OpenType 1.0
+ *************************************************************************************************/
+using System;
 using System.IO;
 
 namespace EPPlus.Fonts.OpenType

src/EPPlus.Fonts.OpenType/OpenTypeFontFactory.cs

@@ -19,20 +19,21 @@ internal static class OpenTypeFontFactory
     {
         public static OpenTypeFont CreateFromFace(FontFaceInfo face)
         {
-            // Read entire file into memory first
             byte[] fontData = File.ReadAllBytes(face.FilePath);
-            var stream = new MemoryStream(fontData);
 
-            //var reader = new FontsBinaryReader(stream);
-            //reader.BaseStream.Position = face.OffsetInFile;
-
-            var format = face.OffsetInFile > 0
-               ? FontFormat.Ttf
-               : Path.GetExtension(face.FilePath).ToLowerInvariant() == ".otf"
-                   ? FontFormat.Otf
-                   : FontFormat.Ttf;
-
-            return new OpenTypeFont(fontData, format);
+            if (face.OffsetInFile > 0) // Font inside TTC
+            {
+                // Pass the start offset to the constructor
+                // This tells OpenTypeFont where this font's table directory starts
+                return new OpenTypeFont(fontData, face.OffsetInFile, FontFormat.Ttf);
+            }
+            else // Regular TTF/OTF
+            {
+                var format = Path.GetExtension(face.FilePath).ToLowerInvariant() == ".otf"
+                    ? FontFormat.Otf
+                    : FontFormat.Ttf;
+                return new OpenTypeFont(fontData, format);
+            }
         }
 
         public static OpenTypeFont CreateFromBytes(byte[] bytes, FontFormat format)

src/EPPlus.Fonts.OpenType/OpenTypeFontSerializer.cs

@@ -27,8 +27,6 @@ public OpenTypeFontSerializer(OpenTypeFont font)
             _font = font ?? throw new ArgumentNullException(nameof(font));
         }
 
-        // In OpenTypeFontSerializer class
-
         public byte[] Serialize()
         {
             using (var stream = new MemoryStream())

src/EPPlus.Fonts.OpenType/Scanner/FontScannerV2.Ttc.cs

@@ -98,6 +98,8 @@ ex is InvalidOperationException ||
                 }
             }
 
+
+
             return faces;
         }
     }

src/EPPlus.Fonts.OpenType/Scanner/FontScannerV2Core.cs

@@ -70,6 +70,7 @@ internal static FontFaceInfo ScanSingleFace(string filePath, long offset)
 
                 for (int i = 0; i < numTables; i++)
                 {
+                    long tagPos = fs.Position;
                     var record = new TableRecord
                     {
                         Tag = new Tag(reader),

src/EPPlus.Fonts.OpenType/Subsetting/CmapSubsetProcessor.cs

@@ -55,8 +55,6 @@ public void Rewrite(FontSubsettingContext context)
             // Build mapping: Unicode code point → NEW glyph ID in subset
             Dictionary<uint, ushort> cmapMapping = new Dictionary<uint, ushort>();
 
-            Console.WriteLine("\n=== CMAP REWRITE DEBUG ===");
-
             foreach (uint codePoint in context.UsedCodePoints)
             {
                 ushort oldGid;
@@ -67,11 +65,6 @@ public void Rewrite(FontSubsettingContext context)
                     if (context.OldToNewGlyphId.TryGetValue(oldGid, out newGid))
                     {
                         cmapMapping[codePoint] = newGid;
-                        // Debug first few
-                        if (codePoint >= 'a' && codePoint <= 'c')
-                        {
-                            Console.WriteLine($"  U+{codePoint:X4} ('{(char)codePoint}') : oldGID {oldGid:X4} -> newGID {newGid:X4}");
-                        }
                     }
                     else
                     {

src/EPPlus.Fonts.OpenType/Subsetting/GlyphAndLocaSubsetProcessor.cs

@@ -79,8 +79,6 @@ public void Rewrite(FontSubsettingContext context)
 
                     offsets.Add((uint)ms.Position);
                 }
-
-                Console.WriteLine($"Total glyf table size: {ms.Position} bytes, loca last offset: {offsets[offsets.Count - 1]}");
             }
 
             // 4. Update head and create loca

src/EPPlus.Fonts.OpenType/Subsetting/SubsetFontBuilder.cs

@@ -80,28 +80,14 @@ private void BuildGlyphMapping(FontSubsettingContext context)
             var sortedGlyphs = new List<ushort>(context.IncludedGlyphs);
             sortedGlyphs.Sort();
 
-            Console.WriteLine($"\n=== BUILD GLYPH MAPPING DEBUG ===");
-            Console.WriteLine($"Total included glyphs: {sortedGlyphs.Count}");
-            Console.WriteLine($"First 10: {string.Join(", ", sortedGlyphs.Take(10).Select(g => $"{g:X4}").ToArray())}");
-            Console.WriteLine($"Around 'a' (looking for 0x0045):");
 
             for (ushort newId = 0; newId < sortedGlyphs.Count; newId++)
             {
                 ushort oldId = sortedGlyphs[newId];
                 context.OldToNewGlyphId[oldId] = newId;
                 context.NewToOldGlyphId.Add(oldId);
 
-                if (oldId >= 0x0043 && oldId <= 0x0048)
-                {
-                    Console.WriteLine($"  oldGID {oldId:X4} -> newGID {newId:X4}");
-                }
             }
-            Console.WriteLine($"All {sortedGlyphs.Count} glyphs after sort:");
-            for (int i = 0; i < Math.Min(50, sortedGlyphs.Count); i++)
-            {
-                Console.WriteLine($"  [{i}] = oldGID {sortedGlyphs[i]:X4}");
-            }
-            Console.WriteLine($"==================================\n");
         }
     }
 }

src/EPPlus.Fonts.OpenType/Tables/Glyph/Glyph.cs

@@ -40,6 +40,10 @@ public int GetSize()
 
         internal override void Serialize(FontsBinaryWriter writer)
         {
+            if (Header.numberOfContours == 0 && SimpleData == null && CompositeData == null)
+            {
+                return; // Don't write anything for empty glyphs!
+            }
             Header.Serialize(writer);
 
             if (Header.numberOfContours > 0 && SimpleData != null)