/// <summary>
/// Reads a <see cref="FontDescription" /> from the specified stream.
/// </summary>
/// <param name="reader">The reader.</param>
/// <returns>
/// a <see cref="FontDescription" />.
/// </returns>
internal static FontDescription LoadDescription(FontReader reader)
{
DebugGuard.NotNull(reader, nameof(reader));
// NOTE: These fields are read in their optimized order
// https://docs.microsoft.com/en-gb/typography/opentype/spec/recom#optimized-table-ordering
HeadTable?head = reader.TryGetTable <HeadTable>();
OS2Table? os2 = reader.TryGetTable <OS2Table>();
NameTable nameTable = reader.GetTable <NameTable>();
return(new FontDescription(nameTable, os2, head));
}
internal static FontInstance LoadFont(FontReader reader)
{
// https://www.microsoft.com/typography/otspec/recom.htm#TableOrdering
// recomended order
HeadTable head = reader.GetTable <HeadTable>(); // head - not saving but loading in suggested order
HorizontalHeadTable hhea = reader.GetTable <HorizontalHeadTable>(); // hhea
reader.GetTable <MaximumProfileTable>(); // maxp
OS2Table os2 = reader.GetTable <OS2Table>(); // OS/2
HorizontalMetricsTable horizontalMetrics = reader.GetTable <HorizontalMetricsTable>(); // hmtx
// LTSH - Linear threshold data
// VDMX - Vertical device metrics
// hdmx - Horizontal device metrics
CMapTable cmap = reader.GetTable <CMapTable>(); // cmap
// fpgm - Font Program
// prep - Control Value Program
// cvt - Control Value Table
reader.GetTable <IndexLocationTable>(); // loca
GlyphTable glyphs = reader.GetTable <GlyphTable>(); // glyf
KerningTable kern = reader.GetTable <KerningTable>(); // kern - Kerning
NameTable nameTable = reader.GetTable <NameTable>(); // name
ColrTable?colrTable = reader.TryGetTable <ColrTable>(); // colr
CpalTable?cpalTable;
if (colrTable != null)
{
cpalTable = reader.GetTable <CpalTable>(); // CPAL - required if COLR is provided
}
else
{
cpalTable = reader.TryGetTable <CpalTable>(); // colr
}
// post - PostScript information
// gasp - Grid-fitting/Scan-conversion (optional table)
// PCLT - PCL 5 data
// DSIG - Digital signature
return(new FontInstance(
nameTable,
cmap,
glyphs,
os2,
hhea,
horizontalMetrics,
head,
kern,
colrTable,
cpalTable));
}
