have waves die on pool edges

[antimodular]

very beautiful work.

i having been looking at your shader code in water.js and am wondering what addition i would need to make so the water ripples do not bounce of the edges of the pool, but rather die there?

i have been looking at this water ripple approach so far:
http://jsfiddle.net/esteewhy/5Ht3b/6/

thanks for your advice.