envCoord :: [(UGen, UGen)] -> UGen -> UGen -> EnvCurve -> [UGen]

Co-ordinate (break-point) envelope

> import Sound.SC3

> let { c = EnvLin
>     ; p = envCoord [(0,0), (0.5, 0.1), (0.55, 1), (1, 0)] 9 0.1 c
>     ; e = envGen KR 1 1 0 1 RemoveSynth p }
> in audition (out 0 (sinOsc AR 440 0 * e))