Tempo line updating done immediately/directly rather than in an idle handler.
Looking for feedback how this works for other people, performance wise...
Feel-wise, the obvious lag between scrolling and tempo lines being drawn is now gone.
git-svn-id: svn://localhost/ardour2/branches/3.0@3799 d708f5d6-7413-0410-9779-e7cbd77b26cf
Draw tempo lines on time canvas and connect them up all pretty-like to the ruler ticks.
Still needs some visual tweaking, but... they draw! Finally!
git-svn-id: svn://localhost/ardour2/trunk@2247 d708f5d6-7413-0410-9779-e7cbd77b26cf