graeme_p - 12:15 pm on Mar 5, 2013 (gmt 0)
My Sinhala is not very good! I think constant clusters are things like "sri" written as a single letter with modifiers added. That can be rendered, but I do not know how to input it (the input methods I have leave out the zero width joiner it requires). I think others do: I need to check with someone more knowledgeable.