Hey everyone - would someone be able to help me with this http://quil.info/sketches/show/-KavAEq-a6XfW2R_gOp5

I’m trying to port Daniel Shiffman’s coding challenges to Quil, but there’s this issue that I’m facing because of which i cannot seem to get the same effect as shown in https://youtu.be/17WoOqgXsRM?t=7m30s