This class represents the truetype font dictionary. This is definitively detailed in:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; page 257.

This class is always an indirect object because it inherits from FontElement which is always an indirect object.

System.Object
    WebSupergoo.ABCpdf14.Elements.Element
       WebSupergoo.ABCpdf14.Elements.FontElement
          WebSupergoo.ABCpdf14.Elements.TrueTypeFontElement

A TrueType font dictionary describes a font whose glyphs are defined using TrueType outlines. The structure closely follows the type 1 model: BaseFont names the font, Widths gives per-character advance widths, and FontDescriptor carries detailed metrics and the embedded font program.

The Widths array runs from FirstChar to LastChar and gives advance widths in thousandths of a text space unit, consistent with the type 1 convention. Character codes outside this range use MissingWidth from the FontDescriptor.

Encoding works the same way as for type 1 fonts. A named encoding or an EncodingElement dictionary maps single-byte character codes to glyph names, which the font program then resolves to outlines.

TrueType fonts can be embedded as FontFile2 streams in the FontDescriptor. Subsetting is common: only the glyphs actually used in the document are included, with a tag prefix added to the font name to mark it as a subset.