Post by David Drake on Feb 18, 2020 11:34:19 GMT -5
I created the code below for the Barnsley Fern task on Rosetta Code (rosettacode.org/wiki/Barnsley_fern). The task is described at the top of the page. I adapted already posted code for IS-BASIC. Please post comments or suggestions.
nomainwin
WindowWidth=800
WindowHeight=600
open "Barnsley Fern" for graphics_nf_nsb as #1
#1 "trapclose [q];down;fill black;flush;color green"
for n = 1 To WindowHeight * 50
r = int(rnd(1)*100)
Select Case
Case (r>=0) and (r<=84)
xn=0.85*x+0.04*y
yn=-0.04*x+0.85*y+1.6
Case (r>84) and (r<=91)
xn=0.2*x-0.26*y
yn=0.23*x+0.22*y+1.6
Case (r>91) and (r<=98)
xn=-0.15*x+0.28*y
yn=0.26*x+0.24*y+0.44
Case Else
xn=0
yn=0.16*y
End Select
x=xn
y=yn
#1 "set ";x*80+300;" ";WindowHeight/1.1-y*50
next n
#1 "flush"
wait
[q]
close #1
