A pango.types.GlyphVisAttr structure communicates information between
the shaping and rendering phases.
Currently, it contains cluster start and color information.
More attributes may be added in the future.
Clusters are stored in visual order, within the cluster, glyphs
are always ordered in logical order, since visual order is meaningless;
that is, in Arabic text, accent glyphs follow the glyphs for the
base character.
A pango.types.GlyphVisAttr structure communicates information between the shaping and rendering phases.
Currently, it contains cluster start and color information. More attributes may be added in the future.
Clusters are stored in visual order, within the cluster, glyphs are always ordered in logical order, since visual order is meaningless; that is, in Arabic text, accent glyphs follow the glyphs for the base character.