Fix null reference in GlyphDataTable occuring after ReadGlyphs()

UglyToad · Aug 5, 2023 · 4a480ff · 4a480ff
1 parent d1e8b42
commit 4a480ff
Show file tree

Hide file tree

Showing 3 changed files with 15 additions and 14 deletions.
diff --git a/src/UglyToad.PdfPig.Fonts/TrueType/Glyphs/Glyph.cs b/src/UglyToad.PdfPig.Fonts/TrueType/Glyphs/Glyph.cs
@@ -4,7 +4,7 @@
     using System;
     using System.Collections.Generic;
 
-    internal class Glyph : IGlyphDescription
+    internal sealed class Glyph : IGlyphDescription
     {
         /// <summary>
         /// The bounding rectangle for the character.

diff --git a/src/UglyToad.PdfPig.Fonts/TrueType/Tables/GlyphDataTable.cs b/src/UglyToad.PdfPig.Fonts/TrueType/Tables/GlyphDataTable.cs
@@ -2,7 +2,6 @@
 {
     using System;
     using System.Collections.Generic;
-    using System.Linq;
     using Core;
     using Glyphs;
     using Parser;
@@ -12,7 +11,7 @@
     /// The 'glyf' table contains the data that defines the appearance of the glyphs in the font. 
     /// This includes specification of the points that describe the contours that make up a glyph outline and the instructions that grid-fit that glyph.
     /// </summary>
-    internal class GlyphDataTable : ITrueTypeTable
+    internal sealed class GlyphDataTable : ITrueTypeTable
     {
         private readonly IReadOnlyList<uint> glyphOffsets;
         private readonly PdfRectangle maxGlyphBounds;
@@ -71,19 +70,21 @@ public bool TryGetGlyphBounds(int glyphIndex, out PdfRectangle bounds)
                 return true;
             }
 
-            tableBytes.Seek(offset);
+            bounds = Glyphs[glyphIndex].Bounds;
 
-            // ReSharper disable once UnusedVariable
-            var contourCount = tableBytes.ReadSignedShort();
+            return true;
+        }
 
-            var minX = tableBytes.ReadSignedShort();
-            var minY = tableBytes.ReadSignedShort();
-            var maxX = tableBytes.ReadSignedShort();
-            var maxY = tableBytes.ReadSignedShort();
+        public bool TryGetGlyphPath(int glyphIndex, out IReadOnlyList<PdfSubpath> subpaths)
+        {
+            subpaths = null;
 
-            bounds = new PdfRectangle(minX, minY, maxX, maxY);
+            if (glyphIndex < 0 || glyphIndex > Glyphs.Count - 1)
+            {
+                return false;
+            }
 
-            return true;
+            return Glyphs[glyphIndex].TryGetGlyphPath(out subpaths);
         }
 
         public static GlyphDataTable Load(TrueTypeDataBytes data, TrueTypeHeaderTable table, TableRegister.Builder tableRegister)

diff --git a/src/UglyToad.PdfPig.Fonts/TrueType/TrueTypeFont.cs b/src/UglyToad.PdfPig.Fonts/TrueType/TrueTypeFont.cs
@@ -145,7 +145,7 @@ public bool TryGetPath(int characterCode, Func<int, int?> characterCodeToGlyphId
                 return false;
             }
 
-            return TableRegister.GlyphTable.Glyphs[index].TryGetGlyphPath(out path);
+            return TableRegister.GlyphTable.TryGetGlyphPath(index, out path);
         }
 
         /// <summary>
@@ -210,4 +210,4 @@ private bool TryGetGlyphIndex(int characterIdentifier, Func<int, int?> character
             return TableRegister.CMapTable.TryGetGlyphIndex(characterIdentifier, out glyphId);
         }
     }
-}
+}