The renderable text is a text chunk, enriched with layouting information, such as break opportunities, character sizes, kerning information and spacing information.
Text is given as codepoints. Break opportunities are given as integer values, where zero forbids breaking, and higher values denote better breaks. Spacing and glyph sizes and kerning is given in micro-points; Spacing is the 'added' space between codepoints if text-justification is enabled.
The text is computed as grapheme clusters; this means that several unicode codepoints may result in a single /virtual/ glyph/codepoint/character. (Example: 'A' + accent symbols). If the font supports Lithurges, these lithurges may also be represented as a single grapheme cluster (and thus behave unbreakable).
Grapheme clusters with more than one unicode char have the size of that char added to the first codepoint, all subsequence codepoints of the same cluster have a size/kerning/etc of zero and are unbreakable.
This text chunk is perfectly suitable for horizontal text, going either from left-to-right or right-to-left. (Breaking mixed text is up to the textfactory).
@author Thomas Morgner