public static GlyphDataTable Load(TrueTypeDataBytes data, TrueTypeHeaderTable table, TableRegister.Builder tableRegister)
{
data.Seek(table.Offset);
var indexToLocationTable = tableRegister.IndexToLocationTable;
var offsets = indexToLocationTable.GlyphOffsets;
var entryCount = offsets.Length;
var glyphCount = entryCount - 1;
var glyphs = new IGlyphDescription[glyphCount];
var emptyGlyph = Glyph.Empty(tableRegister.HeaderTable.Bounds);
var compositeLocations = new Dictionary <int, TemporaryCompositeLocation>();
for (var i = 0; i < glyphCount; i++)
{
if (offsets[i] == offsets[i + 1])
{
// empty glyph
glyphs[i] = emptyGlyph;
continue;
}
data.Seek(offsets[i] + table.Offset);
var contourCount = data.ReadSignedShort();
var minX = data.ReadSignedShort();
var minY = data.ReadSignedShort();
var maxX = data.ReadSignedShort();
var maxY = data.ReadSignedShort();
var bounds = new PdfRectangle(minX, minY, maxX, maxY);
// If the number of contours is greater than or equal zero it's a simple glyph.
if (contourCount >= 0)
{
glyphs[i] = ReadSimpleGlyph(data, contourCount, bounds);
}
else
{
compositeLocations.Add(i, new TemporaryCompositeLocation(data.Position, bounds, contourCount));
}
}
// Build composite glyphs by combining simple and other composite glyphs.
foreach (var compositeLocation in compositeLocations)
{
glyphs[compositeLocation.Key] = ReadCompositeGlyph(data, compositeLocation.Value, compositeLocations, glyphs, emptyGlyph);
}
return(new GlyphDataTable(table, glyphs));
}
public static HorizontalMetricsTable Load(TrueTypeDataBytes data, TrueTypeHeaderTable table, TableRegister.Builder tableRegister)
{
var glyphCount = tableRegister.MaximumProfileTable.NumberOfGlyphs;
var metricCount = tableRegister.HorizontalHeaderTable.NumberOfHeaderMetrics;
data.Seek(table.Offset);
// The number of entries in the left side bearing field per entry is number of glyphs - number of metrics
var additionalLeftSideBearingLength = glyphCount - metricCount;
var advancedWidths = new int[metricCount];
// For bearings over the metric count, the width is the same as the last width in advanced widths.
var leftSideBearings = new short[glyphCount];
for (var i = 0; i < metricCount; i++)
{
advancedWidths[i] = data.ReadUnsignedShort();
leftSideBearings[i] = data.ReadSignedShort();
}
for (var i = 0; i < additionalLeftSideBearingLength; i++)
{
leftSideBearings[metricCount + i] = data.ReadSignedShort();
}
return(new HorizontalMetricsTable(table, advancedWidths, leftSideBearings, metricCount));
}
public static IndexToLocationTable Load(TrueTypeDataBytes data, TrueTypeHeaderTable table, TableRegister.Builder tableRegister)
{
const short shortFormat = 0;
const short longFormat = 1;
data.Seek(table.Offset);
var headerTable = tableRegister.HeaderTable;
var maximumProfileTable = tableRegister.MaximumProfileTable;
var format = headerTable.IndexToLocFormat;
var glyphCount = maximumProfileTable.NumberOfGlyphs + 1;
var offsets = new long[glyphCount];
switch (format)
{
case shortFormat:
{ // The local offset divided by 2 is stored.
for (int i = 0; i < glyphCount; i++)
{
offsets[i] = data.ReadUnsignedShort() * 2;
}
break;
}
case longFormat:
{
// The actual offset is stored.
data.ReadUnsignedIntArray(offsets, glyphCount);
break;
}
default:
throw new InvalidOperationException($"The format {format} was invalid for the index to location (loca) table.");
}
return(new IndexToLocationTable(table, offsets));
}
public static GlyphDataTable Load(TrueTypeDataBytes data, TrueTypeHeaderTable table, TableRegister.Builder tableRegister)
{
data.Seek(table.Offset);
var bytes = data.ReadByteArray((int)table.Length);
return(new GlyphDataTable(table, tableRegister.IndexToLocationTable.GlyphOffsets,
tableRegister.HeaderTable.Bounds,
new TrueTypeDataBytes(bytes)));
}
/// <summary>
/// Load the index to location (loca) table from the TrueType font. Requires the maximum profile (maxp) and header (head) table
/// to have been parsed.
/// </summary>
internal static IndexToLocationTable Load(TrueTypeDataBytes data, TrueTypeHeaderTable table, TableRegister.Builder tableRegister)
{
if (data == null)
{
throw new ArgumentNullException(nameof(data));
}
if (tableRegister == null)
{
throw new ArgumentNullException(nameof(tableRegister));
}
data.Seek(table.Offset);
var headerTable = tableRegister.HeaderTable;
var maximumProfileTable = tableRegister.MaximumProfileTable;
if (headerTable == null)
{
throw new InvalidFontFormatException("No header (head) table was defined in this font.");
}
if (maximumProfileTable == null)
{
throw new InvalidFontFormatException("No maximum profile (maxp) table was defined in this font.");
}
var format = (EntryFormat)headerTable.IndexToLocFormat;
var glyphCount = maximumProfileTable.NumberOfGlyphs + 1;
uint[] offsets;
switch (format)
{
case EntryFormat.Short:
{
// The local offset divided by 2 is stored.
offsets = new uint[glyphCount];
for (var i = 0; i < glyphCount; i++)
{
offsets[i] = (uint)(data.ReadUnsignedShort() * 2);
}
break;
}
case EntryFormat.Long:
{
// The actual offset is stored.
offsets = data.ReadUnsignedIntArray(glyphCount);
break;
}
default:
throw new InvalidOperationException($"The format {format} was invalid for the index to location (loca) table.");
}
return(new IndexToLocationTable(table, format, offsets));
}
public static CMapTable Load(TrueTypeDataBytes data, TrueTypeHeaderTable table, TableRegister.Builder tableRegister)
{
data.Seek(table.Offset);
var tableVersionNumber = data.ReadUnsignedShort();
var numberOfEncodingTables = data.ReadUnsignedShort();
var subTableHeaders = new SubTableHeaderEntry[numberOfEncodingTables];
for (int i = 0; i < numberOfEncodingTables; i++)
{
var platformId = data.ReadUnsignedShort();
var encodingId = data.ReadUnsignedShort();
var offset = data.ReadUnsignedInt();
subTableHeaders[i] = new SubTableHeaderEntry(platformId, encodingId, offset);
}
var tables = new List <ICMapSubTable>(numberOfEncodingTables);
var numberofGlyphs = tableRegister.MaximumProfileTable.NumberOfGlyphs;
for (var i = 0; i < subTableHeaders.Length; i++)
{
var header = subTableHeaders[i];
data.Seek(table.Offset + header.Offset);
var format = data.ReadUnsignedShort();
/*
* There are 9 currently available formats:
* 0: Character code and glyph indices are restricted to a single byte. Rare.
* 2: Suitable for CJK characters. Contain mixed 8/16 byte encoding.
* 4: 2 byte encoding format. Used when character codes fall into (gappy) contiguous ranges.
* 6: 'Trimmed table mapping', used when character codes fall into a single contiguous range. This is dense mapping.
* 8: 16/32 bit coverage. Uses mixed length character codes.
* 10: Similar to format 6, trimmed table/array for 32 bits.
* 12: Segmented coverage, similar to format 4 but for 32 bit/4 byte.
* 13: Many to one mappings. Used by Apple for the LastResort font.
* 14: Unicode variation sequences.
*
* Many of the formats are obsolete or not really used. Modern fonts will tend to use formats 4, 6 and 12.
* For PDF we will support 0, 2 and 4 since these are in the original TrueType spec.
*/
switch (format)
{
case 0:
{
// Simple 1 to 1 mapping of character codes to glyph codes.
var item = ByteEncodingCMapTable.Load(data, header.PlatformId, header.EncodingId);
tables.Add(item);
break;
}
case 2:
{
// Useful for CJK characters. Use mixed 8/16 bit encoding.
var item = HighByteMappingCMapTable.Load(data, numberofGlyphs, header.PlatformId, header.EncodingId);
tables.Add(item);
break;
}
case 4:
{
// Microsoft's standard mapping table.
var item = Format4CMapTable.Load(data, header.PlatformId, header.EncodingId);
tables.Add(item);
break;
}
case 6:
{
var item = TrimmedTableMappingCMapTable.Load(data, header.PlatformId, header.EncodingId);
tables.Add(item);
break;
}
}
}
return(new CMapTable(tableVersionNumber, table, tables));
}
