a GLSL depth of field filter with bokeh

This is my first attempt to make a depth of field filter with bokeh (http://en.wikipedia.org/wiki/Bokeh).
I couldn`t find any code example of bokeh effect, so I had to do it from a scratch. Basically I alligned texture samples circularly, instead of vertically and horizontally. That did the trick..

To do: make the bokeh shape hectagonal when apertuare value is raised.

GLSL frag. shader: http://www.pasteall.org/11375