3.1.1.6.2 Glyph Run Resource

Lines of text are organized in units called glyph runs. A glyph run is a sequence of glyphs drawn with a common set of font and size parameters. All of the information necessary to draw a glyph run is retained by a Glyph Run Resource. This consists of a sequence of glyph indices and the pre-contrast level that controls how the text is to be rendered. In addition, a Glyph Run Resource also references one or more realizations for each glyph. Because a single glyph run can be encountered more than once in a full traversal of the scene graph, the glyph run references a set of realizations for each scale at which it will be drawn.