rem dragon
scale =1.5
phi=1.618

gr.open 255,0,0,0
gr.screen w,h
gr.color 255,255,255,255
gr.bitmap.create bmp,w,h
x=w/3.5
y=h/3.5
angle=pi()*0.7

!calc dragon
list$="FX+"
!itirations
form=0 to 13

list2$=""
col=0.1
num=0
forn=1 to len(list$)

read$= mid$(list$,n,1)
if read$="F" then list2$=list2$+"F"
if read$="+" then list2$=list2$+"+"
if read$="-" then list2$=list2$+"-"
if read$="X" then list2$=list2$+"X+YF"
if read$="Y" then list2$=list2$+"FX-Y"

next n
list$=list2$
next m

!draw dragon

angle=angle-(pi()/180)*100.12019975

forn=1 to len(list$)
gr.bitmap.drawinto.start bmp
read$= mid$(list$,n,1)

gr.set.antialias 0
gr.set.stroke 0

if read$="+" then
scale=scale/phi

for a=1 to 10
num=num+1
col=num*phi
angle =angle+((pi()/180)* 7.987980025)
ox=x
oy=y
x=ox+sin(angle)*scale
y=oy+cos(angle)*scale
gr.color 255,abs(cos(col)*155)+100,abs(sin(col))*155+100,abs(sin(col)*155)+100
gr.line ln,ox,oy,x,y
next a
end if

if read$="-" then
scale=scale*phi
for a=1 to 10
num=num+1
col=num*phi
angle =angle-((pi()/180)*7.987980025)
ox=x
oy=y
x=ox+sin(angle)*scale
y=oy+cos(angle)*scale
gr.color 255,abs(cos(col)*255),abs(sin(col))*255,abs(sin(col)*255)
gr.line ln,ox,oy,x,y
next a
end if

gr.bitmap.drawinto.end
gr.cls
gr.bitmap.draw b,bmp,0,0
!gr.render
next n
gr.render
gr.bitmap.save b,"dragon"
do
until 0