Ardour/ardour — pull request #81 by nmains (2014-06-15 14:36:35+00:00)
Title: Various changes intended to improve GUI responsiveness wrt drawing  ops.

* don't redraw the summary incessantly while loading session.
* use a background ImageSurface for summary containing track lines and regions.
Composite with 'live' playhead, view rect etc. using cairo_push/pop_group
* reduce use of cairo_stroke () when drawing waveforms (should be a visual no-op)
* don't queue a draw for canvas items that are off window or !visible.