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#21 use built in encoding to populate widths array

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Eliot Jones
2018-12-11 20:03:18 +00:00
parent dc5d2b8fdd
commit d1722dd23e
3 changed files with 51 additions and 66 deletions
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2
src/UglyToad.PdfPig/Fonts/Encodings/GlyphList.cs
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@@ -117,7 +117,7 @@
}
else
{
throw new InvalidFontFormatException($"Could not find the unicode glyph for the name {name}.");
return null;
}
oddNameToUnicodeCache[name] = unicode;

104
src/UglyToad.PdfPig/Writer/TrueTypeWritingFont.cs
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@@ -5,10 +5,10 @@
using System.IO;
using System.Linq;
using Fonts;
using Fonts.Encodings;
using Fonts.Exceptions;
using Fonts.TrueType;
using Fonts.TrueType.Tables;
using Fonts.TrueType.Tables.CMapSubTables;
using Geometry;
using Tokens;
@@ -125,77 +125,63 @@
private class CharacterCodeToGlyphIdMapper
{
private readonly TrueTypeFontProgram font;
private readonly ICMapSubTable cmapSubTable;
public CharacterCodeToGlyphIdMapper(TrueTypeFontProgram font)
{
var microsoftUnicode = font.TableRegister.CMapTable.SubTables.FirstOrDefault(x => x.PlatformId == TrueTypeCMapPlatform.Windows && x.EncodingId == 1);
cmapSubTable = microsoftUnicode ?? font.TableRegister.CMapTable.SubTables.FirstOrDefault(x => x.PlatformId == TrueTypeCMapPlatform.Macintosh && x.EncodingId == 0);
this.font = font ?? throw new ArgumentNullException(nameof(font));
}
public FontDictionaryMetrics GetMetrics()
{
var widths = font.TableRegister.HorizontalMetricsTable.AdvancedWidths;
var encoding = ReadFontEncoding();
var firstCharacter = encoding.CodeToNameMap.Keys.Min();
var lastCharacter = encoding.CodeToNameMap.Keys.Max();
var lastCharacter = 0;
var fullWidths = new List<NumericToken>();
switch (cmapSubTable)
var glyphList = GlyphList.AdobeGlyphList;
var length = lastCharacter - firstCharacter + 1;
var widths = Enumerable.Range(0, length).Select(x => new NumericToken(0)).ToList();
foreach (var pair in encoding.CodeToNameMap)
{
case Format4CMapTable format4:
var unicode = glyphList.NameToUnicode(pair.Value);
if (unicode == null)
{
var firstCharacter = format4.Segments[0].StartCode;
var gid = format4.CharacterCodeToGlyphIndex(firstCharacter);
// Include unmapped character codes except for .notdef
firstCharacter -= gid - 1;
var widthIndex = 0;
var lastSegment = default(Format4CMapTable.Segment?);
for (var i = 0; i < format4.Segments.Count; i++)
{
var segment = format4.Segments[i];
if (segment.StartCode + segment.IdDelta >= 0xFFF)
{
break;
}
if (lastSegment.HasValue)
{
var endGlyph = lastSegment.Value.EndCode + lastSegment.Value.IdDelta;
var startGlyph = segment.StartCode + segment.IdDelta;
var gap = startGlyph - endGlyph - 1;
for (int j = 0; j < gap; j++)
{
fullWidths.Add(new NumericToken(0));
}
}
lastCharacter = segment.EndCode;
for (int j = 0; j < (segment.EndCode - segment.StartCode); j++)
{
var width = widths[widthIndex];
fullWidths.Add(new NumericToken(width));
widthIndex++;
}
lastSegment = segment;
}
return new FontDictionaryMetrics
{
Widths = new ArrayToken(fullWidths),
FirstChar = new NumericToken(firstCharacter),
LastChar = new NumericToken(lastCharacter)
};
continue;
}
case ByteEncodingCMapTable bytes:
default:
throw new NotSupportedException($"No dictionary mapping for format yet: {cmapSubTable.GetType().Name}.");
var characterCode = (int) unicode[0];
if (!font.TryGetBoundingAdvancedWidth(characterCode, out var width))
{
throw new InvalidFontFormatException();
}
widths[pair.Key - firstCharacter] = new NumericToken(width);
}
return new FontDictionaryMetrics
{
FirstChar = new NumericToken(firstCharacter),
LastChar = new NumericToken(lastCharacter),
Widths = new ArrayToken(widths)
};
}
private Encoding ReadFontEncoding()
{
var codeToName = new Dictionary<int, string>();
var postscript = font.TableRegister.PostScriptTable;
for (int i = 0; i <= 256; i++)
{
if (!font.TableRegister.CMapTable.TryGetGlyphIndex(i, out var glyphIndex))
{
continue;
}
codeToName[i] = postscript.GlyphNames[glyphIndex];
}
return new BuiltInEncoding(codeToName);
}
}