use standardencoding name for seac command in type 1 charstrings

src/UglyToad.PdfPig/Fonts/Type1/CharStrings/Commands/StartFinishOutline/SeacCommand.cs

@@ -1,5 +1,7 @@
 namespace UglyToad.PdfPig.Fonts.Type1.CharStrings.Commands.StartFinishOutline
 {
+    using Encodings;
+
     /// <summary>
     /// Standard encoding accented character.
     /// Makes an accented character from two other characters in the font program.
@@ -21,11 +23,15 @@
             var accentLeftSidebearingX = context.Stack.PopBottom();
             var accentOriginX = context.Stack.PopBottom();
             var accentOriginY = context.Stack.PopBottom();
-            var baseCharacterCode = context.Stack.PopBottom();
+            var baseCharacterCode = (int)context.Stack.PopBottom();
-            var accentCharacterCode = context.Stack.PopBottom();
+            var accentCharacterCode = (int)context.Stack.PopBottom();
 
-            var baseCharacter = context.GetCharacter((int)baseCharacterCode);
+            // Both bchar and achar are codes that these characters are assigned in the Adobe StandardEncoding vector
-            var accentCharacter = context.GetCharacter((int) accentCharacterCode);
+            var baseCharacterName = StandardEncoding.Instance.CodeToNameMap[baseCharacterCode];
+            var accentCharacterName = StandardEncoding.Instance.CodeToNameMap[accentCharacterCode];
+
+            var baseCharacter = context.GetCharacter(baseCharacterName);
+            var accentCharacter = context.GetCharacter(accentCharacterName);
 
             // TODO: full seac implementation.
             context.SetPath(baseCharacter);

src/UglyToad.PdfPig/Fonts/Type1/CharStrings/Commands/Type1BuildCharContext.cs

@@ -8,6 +8,7 @@
     internal class Type1BuildCharContext
     {
         private readonly Func<int, PdfPath> characterByIndexFactory;
+        private readonly Func<string, PdfPath> characterByNameFactory;
         public IReadOnlyDictionary<int, Type1CharStrings.CommandSequence> Subroutines { get; }
 
         public decimal WidthX { get; set; }
@@ -32,9 +33,11 @@
         public IReadOnlyList<PdfPoint> FlexPoints { get; }
 
         public Type1BuildCharContext(IReadOnlyDictionary<int, Type1CharStrings.CommandSequence> subroutines,
-            Func<int, PdfPath> characterByIndexFactory)
+            Func<int, PdfPath> characterByIndexFactory,
+            Func<string, PdfPath> characterByNameFactory)
         {
             this.characterByIndexFactory = characterByIndexFactory ?? throw new ArgumentNullException(nameof(characterByIndexFactory));
+            this.characterByNameFactory = characterByNameFactory ?? throw new ArgumentNullException(nameof(characterByNameFactory));
             Subroutines = subroutines ?? throw new ArgumentNullException(nameof(subroutines));
         }
 
@@ -48,6 +51,11 @@
             return characterByIndexFactory(characterCode);
         }
 
+        public PdfPath GetCharacter(string characterName)
+        {
+            return characterByNameFactory(characterName);
+        }
+
         public void SetPath(PdfPath path)
         {
             Path = path ?? throw new ArgumentNullException(nameof(path));

src/UglyToad.PdfPig/Fonts/Type1/CharStrings/Type1CharStrings.cs

@@ -17,7 +17,7 @@
 
         public IReadOnlyDictionary<int, CommandSequence> Subroutines { get; }
 
-        public Type1CharStrings(IReadOnlyDictionary<string, CommandSequence> charStrings, IReadOnlyDictionary<int, string> charStringIndexToName, 
+        public Type1CharStrings(IReadOnlyDictionary<string, CommandSequence> charStrings, IReadOnlyDictionary<int, string> charStringIndexToName,
             IReadOnlyDictionary<int, CommandSequence> subroutines)
         {
             this.charStringIndexToName = charStringIndexToName ?? throw new ArgumentNullException(nameof(charStringIndexToName));
@@ -71,8 +71,26 @@
 
                 glyphs[name] = path;
 
+                return path;
+            }, s =>
+            {
+                if (glyphs.TryGetValue(s, out var result))
+                {
+                    return result;
+                }
+
+                if (!CharStrings.TryGetValue(s, out var charstring))
+                {
+                    throw new InvalidOperationException($"Tried to retrieve Type 1 charstring by name {s} but it was not found in the charstrings.");
+                }
+
+                var path = Run(charstring);
+
+                glyphs[s] = path;
+
                 return path;
             });
+
             foreach (var command in sequence.Commands)
             {
                 command.Match(x => context.Stack.Push(x),