internal FakeFontInstance(
NameTable nameTable,
MaximumProfileTable maxpTable,
CMapTable cmap,
GlyphTable glyphs,
OS2Table os2,
HorizontalHeadTable horizontalHeadTable,
HorizontalMetricsTable horizontalMetrics,
VerticalHeadTable verticalHeadTable,
VerticalMetricsTable verticalMetrics,
HeadTable head,
KerningTable kern)
: base(
nameTable,
maxpTable,
cmap,
glyphs,
os2,
horizontalHeadTable,
horizontalMetrics,
verticalHeadTable,
verticalMetrics,
head,
kern,
null,
null,
null,
null,
null,
null,
null,
null)
{
}
public static HorizontalMetricsTable Load(FontReader reader)
{
// you should load all dependent tables prior to manipulating the reader
HorizontalHeadTable headTable = reader.GetTable <HorizontalHeadTable>();
MaximumProfileTable profileTable = reader.GetTable <MaximumProfileTable>();
// Move to start of table
using BigEndianBinaryReader binaryReader = reader.GetReaderAtTablePosition(TableName);
return(Load(binaryReader, headTable.NumberOfHMetrics, profileTable.GlyphCount));
}
public void ShouldReturnNullWhenTableCouldNotBeFound()
{
var writer = new BinaryWriter();
writer.WriteTrueTypeFileHeader();
using (var stream = writer.GetStream())
{
Assert.Null(HorizontalHeadTable.Load(new FontReader(stream)));
}
}
internal FakeFontInstance(
NameTable nameTable,
CMapTable cmap,
GlyphTable glyphs,
OS2Table os2,
HorizontalHeadTable horizontalHeadTable,
HorizontalMetricsTable horizontalMetrics,
HeadTable head,
KerningTable kern)
: base(nameTable, cmap, glyphs, os2, horizontalHeadTable, horizontalMetrics, head, kern, null, null)
{
}
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));
}
public static void WriteHorizontalHeadTable(this BinaryWriter writer, HorizontalHeadTable table)
{
// Type | Name | Description
// ----------|----------------------|----------------------------------------------------------------------------------------------------
// uint16 | majorVersion | Major version number of the horizontal header table — set to 1.
// uint16 | minorVersion | Minor version number of the horizontal header table — set to 0.
// FWORD | Ascender | Typographic ascent (Distance from baseline of highest ascender).
// FWORD | Descender | Typographic descent (Distance from baseline of lowest descender).
// FWORD | LineGap | Typographic line gap. - Negative LineGap values are treated as zero in Windows 3.1, and in Mac OS System 6 and System 7.
// UFWORD | advanceWidthMax | Maximum advance width value in 'hmtx' table.
// FWORD | minLeftSideBearing | Minimum left sidebearing value in 'hmtx' table.
// FWORD | minRightSideBearing | Minimum right sidebearing value; calculated as Min(aw - lsb - (xMax - xMin)).
// FWORD | xMaxExtent | Max(lsb + (xMax - xMin)).
// int16 | caretSlopeRise | Used to calculate the slope of the cursor (rise/run); 1 for vertical.
// int16 | caretSlopeRun | 0 for vertical.
// int16 | caretOffset | The amount by which a slanted highlight on a glyph needs to be shifted to produce the best appearance. Set to 0 for non-slanted fonts
// int16 | (reserved) | set to 0
// int16 | (reserved) | set to 0
// int16 | (reserved) | set to 0
// int16 | (reserved) | set to 0
// int16 | metricDataFormat | 0 for current format.
// uint16 | numberOfHMetrics | Number of hMetric entries in 'hmtx' table
writer.WriteUInt16(1);
writer.WriteUInt16(1);
writer.WriteFWORD(table.Ascender);
writer.WriteFWORD(table.Descender);
writer.WriteFWORD(table.LineGap);
writer.WriteUFWORD(table.AdvanceWidthMax);
writer.WriteFWORD(table.MinLeftSideBearing);
writer.WriteFWORD(table.MinRightSideBearing);
writer.WriteFWORD(table.XMaxExtent);
writer.WriteInt16(table.CaretSlopeRise);
writer.WriteInt16(table.CaretSlopeRun);
writer.WriteInt16(table.CaretOffset);
writer.WriteInt16(0); // reserved
writer.WriteInt16(0); // reserved
writer.WriteInt16(0); // reserved
writer.WriteInt16(0); // reserved
writer.WriteInt16(0); // metricDataFormat should be 0
writer.WriteUInt16(table.NumberOfHMetrics);
}
public void LoadHorizontalHeadTable()
{
var writer = new BinaryWriter();
writer.WriteHorizontalHeadTable(new HorizontalHeadTable(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11));
HorizontalHeadTable tbl = HorizontalHeadTable.Load(writer.GetReader());
Assert.Equal(1, tbl.Ascender);
Assert.Equal(2, tbl.Descender);
Assert.Equal(3, tbl.LineGap);
Assert.Equal(4, tbl.AdvanceWidthMax);
Assert.Equal(5, tbl.MinLeftSideBearing);
Assert.Equal(6, tbl.MinRightSideBearing);
Assert.Equal(7, tbl.XMaxExtent);
Assert.Equal(8, tbl.CaretSlopeRise);
Assert.Equal(9, tbl.CaretSlopeRun);
Assert.Equal(10, tbl.CaretOffset);
Assert.Equal(11, tbl.NumberOfHMetrics);
}
/// <summary>
/// Initializes a new instance of the <see cref="FontInstance"/> class.
/// </summary>
/// <param name="nameTable">The name table.</param>
/// <param name="cmap">The cmap.</param>
/// <param name="glyphs">The glyphs.</param>
/// <param name="os2">The os2.</param>
/// <param name="horizontalHeadTable">The horizontal head table.</param>
/// <param name="horizontalMetrics">The horizontal metrics.</param>
/// <param name="head">The head.</param>
/// <param name="kern">The kern.</param>
/// <param name="colrTable">The COLR table</param>
/// <param name="cpalTable">The CPAL table</param>
internal FontInstance(
NameTable nameTable,
CMapTable cmap,
GlyphTable glyphs,
OS2Table os2,
HorizontalHeadTable horizontalHeadTable,
HorizontalMetricsTable horizontalMetrics,
HeadTable head,
KerningTable kern,
ColrTable?colrTable,
CpalTable?cpalTable)
{
this.cmap = cmap;
this.os2 = os2;
this.glyphs = glyphs;
this.horizontalMetrics = horizontalMetrics;
this.head = head;
this.glyphCache = new GlyphInstance[this.glyphs.GlyphCount];
if (!(colrTable is null))
{
this.colorGlyphCache = new GlyphInstance[this.glyphs.GlyphCount][];
}
bool useTypoMetrics = os2.FontStyle.HasFlag(OS2Table.FontStyleSelection.USE_TYPO_METRICS);
// https://www.microsoft.com/typography/otspec/recom.htm#tad
this.Ascender = useTypoMetrics ? os2.TypoAscender : horizontalHeadTable.Ascender;
this.Descender = useTypoMetrics ? os2.TypoDescender : horizontalHeadTable.Descender;
this.LineGap = useTypoMetrics ? os2.TypoLineGap : horizontalHeadTable.LineGap;
this.LineHeight = this.Ascender - this.Descender + this.LineGap;
this.EmSize = this.head.UnitsPerEm;
this.kerning = kern;
this.colrTable = colrTable;
this.cpalTable = cpalTable;
this.Description = new FontDescription(nameTable, os2, head);
}
/// <summary>
/// Initializes a new instance of the <see cref="StreamFontMetrics"/> class.
/// </summary>
/// <param name="nameTable">The name table.</param>
/// <param name="maximumProfileTable">The maximum profile table.</param>
/// <param name="cmap">The cmap table.</param>
/// <param name="glyphs">The glyph table.</param>
/// <param name="os2">The os2 table.</param>
/// <param name="horizontalHeadTable">The horizontal head table.</param>
/// <param name="horizontalMetrics">The horizontal metrics table.</param>
/// <param name="verticalHeadTable">The vertical head table.</param>
/// <param name="verticalMetrics">The vertical metrics table.</param>
/// <param name="head">The head table.</param>
/// <param name="kern">The kerning table.</param>
/// <param name="gSubTable">The glyph substitution table.</param>
/// <param name="gPosTable">The glyph positioning table.</param>
/// <param name="colrTable">The COLR table</param>
/// <param name="cpalTable">The CPAL table</param>
/// <param name="fpgm">The font program table.</param>
/// <param name="cvt">The control value table.</param>
/// <param name="prep">The control value program table.</param>
/// <param name="glyphDefinitionTable">The glyph definition table.</param>
internal StreamFontMetrics(
NameTable nameTable,
MaximumProfileTable maximumProfileTable,
CMapTable cmap,
GlyphTable glyphs,
OS2Table os2,
HorizontalHeadTable horizontalHeadTable,
HorizontalMetricsTable horizontalMetrics,
VerticalHeadTable?verticalHeadTable,
VerticalMetricsTable?verticalMetrics,
HeadTable head,
KerningTable kern,
GSubTable?gSubTable,
GPosTable?gPosTable,
ColrTable?colrTable,
CpalTable?cpalTable,
FpgmTable?fpgm,
CvtTable?cvt,
PrepTable?prep,
GlyphDefinitionTable?glyphDefinitionTable)
{
this.maximumProfileTable = maximumProfileTable;
this.cmap = cmap;
this.os2 = os2;
this.glyphs = glyphs;
this.horizontalMetrics = horizontalMetrics;
this.verticalMetricsTable = verticalMetrics;
this.head = head;
this.glyphCache = new GlyphMetrics[this.glyphs.GlyphCount][];
if (colrTable is not null)
{
this.colorGlyphCache = new GlyphMetrics[this.glyphs.GlyphCount][];
}
// https://www.microsoft.com/typography/otspec/recom.htm#tad
// We use the same approach as FreeType for calculating the the global ascender, descender, and
// height of OpenType fonts for consistency.
//
// 1.If the OS/ 2 table exists and the fsSelection bit 7 is set (USE_TYPO_METRICS), trust the font
// and use the Typo* metrics.
// 2.Otherwise, use the HorizontalHeadTable "hhea" table's metrics.
// 3.If they are zero and the OS/ 2 table exists,
// - Use the OS/ 2 table's sTypo* metrics if they are non-zero.
// - Otherwise, use the OS / 2 table's usWin* metrics.
bool useTypoMetrics = os2.FontStyle.HasFlag(OS2Table.FontStyleSelection.USE_TYPO_METRICS);
if (useTypoMetrics)
{
this.Ascender = os2.TypoAscender;
this.Descender = os2.TypoDescender;
this.LineGap = os2.TypoLineGap;
this.LineHeight = (short)(this.Ascender - this.Descender + this.LineGap);
}
else
{
this.Ascender = horizontalHeadTable.Ascender;
this.Descender = horizontalHeadTable.Descender;
this.LineGap = horizontalHeadTable.LineGap;
this.LineHeight = (short)(this.Ascender - this.Descender + this.LineGap);
}
if (this.Ascender == 0 || this.Descender == 0)
{
if (os2.TypoAscender != 0 || os2.TypoDescender != 0)
{
this.Ascender = os2.TypoAscender;
this.Descender = os2.TypoDescender;
this.LineGap = os2.TypoLineGap;
this.LineHeight = (short)(this.Ascender - this.Descender + this.LineGap);
}
else
{
this.Ascender = (short)os2.WinAscent;
this.Descender = (short)-os2.WinDescent;
this.LineHeight = (short)(this.Ascender - this.Descender);
}
}
this.UnitsPerEm = this.head.UnitsPerEm;
// 72 * UnitsPerEm means 1pt = 1px
this.ScaleFactor = this.UnitsPerEm * 72F;
this.AdvanceWidthMax = (short)horizontalHeadTable.AdvanceWidthMax;
this.AdvanceHeightMax = verticalHeadTable == null ? this.LineHeight : verticalHeadTable.AdvanceHeightMax;
this.kerningTable = kern;
this.gSubTable = gSubTable;
this.gPosTable = gPosTable;
this.colrTable = colrTable;
this.cpalTable = cpalTable;
this.fpgm = fpgm;
this.cvt = cvt;
this.prep = prep;
this.glyphDefinitionTable = glyphDefinitionTable;
this.Description = new FontDescription(nameTable, os2, head);
}
