Koch curve
Using the LSystem class defined at Hilbert curve.
var rules = Hash(
F => 'F+F--F+F',
)
var lsys = LSystem(
width: 800,
height: 800,
xoff: -210,
yoff: -90,
len: 8,
angle: 60,
color: 'dark green',
)
lsys.execute('F--F--F', 4, "koch_snowflake.png", rules)