A mixed text and image layout algorithm capable of supporting Unicode text and arbitrary content definitions for geometric layout with worst case two-pass layout placement procedure. Layout of Unicode text requires a number of distinct processing steps commencing with classification of input characters into contiguous groups of identical directionality, writing system and possibly script (and language) followed by mapping of character groups to glyphs for display purposes followed by a layout taking into account font display characteristics, embedded directionality level and shape of container for layout contents. Layout is best-case achieved in a single layout pass and worst-case in two passes. During layout information is cached to facilitate incremental changes to an existing layout in order to minimize refresh operations for editing display purposes. An optional two-pass operation on the layout result may be used to generate ordered rendering operation to support so-called Z-index display. An optimized Unicode character classification method utilizing reduced memory is also disclosed. Additionally a method to selectively display caret location for mixed font and/or directional text is disclosed.