static AxisTable ReadAxisTable(BinaryReader reader)
{
//An Axis table is used to render scripts either horizontally or vertically.
//It consists of offsets, measured from the beginning of the Axis table,
//to a BaseTagList and a BaseScriptList:
//The BaseScriptList enumerates all scripts rendered in the text layout direction.
//The BaseTagList enumerates all baselines used to render the scripts in the text layout direction.
//If no baseline data is available for a text direction,
//the offset to the corresponding BaseTagList may be set to NULL.
//Axis Table
//Type Name Description
//Offset16 baseTagListOffset Offset to BaseTagList table, from beginning of Axis table(may be NULL)
//Offset16 baseScriptListOffset Offset to BaseScriptList table, from beginning of Axis table
long axisTableStartAt = reader.BaseStream.Position;
ushort baseTagListOffset = reader.ReadUInt16();
ushort baseScriptListOffset = reader.ReadUInt16();
AxisTable axisTable = new AxisTable();
if (baseTagListOffset > 0)
{
reader.BaseStream.Position = axisTableStartAt + baseTagListOffset;
axisTable.baseTagList = ReadBaseTagList(reader);
}
if (baseScriptListOffset > 0)
{
reader.BaseStream.Position = axisTableStartAt + baseScriptListOffset;
axisTable.baseScripts = ReadBaseScriptList(reader);
}
return(axisTable);
}
public AxisTable GetVertAxisTable()
{
AxisTable at = null;
if (VertAxisOffset != 0)
{
at = new AxisTable(VertAxisOffset, m_bufTable);
}
return(at);
}
public AxisTable GetHorizAxisTable()
{
AxisTable at = null;
if (HorizAxisOffset != 0)
{
at = new AxisTable(HorizAxisOffset, m_bufTable);
}
return(at);
}
protected override void ReadContentFrom(BinaryReader reader)
{
//BASE Header
//The BASE table begins with a header that starts with a version number.
//Two versions are defined.
//Version 1.0 contains offsets to horizontal and vertical Axis tables(HorizAxis and VertAxis).
//Version 1.1 also includes an offset to an Item Variation Store table.
//Each Axis table stores all baseline information and min / max extents for one layout direction.
//The HorizAxis table contains Y values for horizontal text layout;
//the VertAxis table contains X values for vertical text layout.
// A font may supply information for both layout directions.
//If a font has values for only one text direction,
//the Axis table offset value for the other direction will be set to NULL.
//The optional Item Variation Store table is used in variable fonts to provide variation data
//for BASE metric values within the Axis tables.
// BASE Header, Version 1.0
//Type Name Description
//uint16 majorVersion Major version of the BASE table, = 1
//uint16 minorVersion Minor version of the BASE table, = 0
//Offset16 horizAxisOffset Offset to horizontal Axis table, from beginning of BASE table(may be NULL)
//Offset16 vertAxisOffset Offset to vertical Axis table, from beginning of BASE table(may be NULL)
//BASE Header, Version 1.1
//Type Name Description
//uint16 majorVersion Major version of the BASE table, = 1
//uint16 minorVersion Minor version of the BASE table, = 1
//Offset16 horizAxisOffset Offset to horizontal Axis table, from beginning of BASE table(may be NULL)
//Offset16 vertAxisOffset Offset to vertical Axis table, from beginning of BASE table(may be NULL)
//Offset32 itemVarStoreOffset Offset to Item Variation Store table, from beginning of BASE table(may be null)
long tableStartAt = reader.BaseStream.Position;
ushort majorVersion = reader.ReadUInt16();
ushort minorVersion = reader.ReadUInt16();
ushort horizAxisOffset = reader.ReadUInt16();
ushort vertAxisOffset = reader.ReadUInt16();
uint itemVarStoreOffset = 0;
if (minorVersion == 1)
{
itemVarStoreOffset = reader.ReadUInt32();
}
//Axis Tables: HorizAxis and VertAxis
if (horizAxisOffset > 0)
{
reader.BaseStream.Position = tableStartAt + horizAxisOffset;
_horizontalAxis = ReadAxisTable(reader);
_horizontalAxis.isVerticalAxis = false;
}
if (vertAxisOffset > 0)
{
reader.BaseStream.Position = tableStartAt + vertAxisOffset;
_verticalAxis = ReadAxisTable(reader);
_verticalAxis.isVerticalAxis = true;
}
if (itemVarStoreOffset > 0)
{
//TODO
}
}
public AxisTable GetVertAxisTable()
{
AxisTable at = null;
if (VertAxisOffset != 0)
{
at = new AxisTable(VertAxisOffset, m_bufTable);
}
return at;
}
public AxisTable GetHorizAxisTable()
{
AxisTable at = null;
if (HorizAxisOffset != 0)
{
at = new AxisTable(HorizAxisOffset, m_bufTable);
}
return at;
}
