FN.DEF curvaC(n,c)

 GLOBALS.FNIMP x1,y1,x2,y2,t

 IF n=1 THEN
  GR.LINE ln, x1,y1, x2,y2
  LET x1=x2
  LET y1=y2
 ELSE
  curvaC(n-1,c)
  IF c=1 THEN
   LET y2+=t
   curvaC(n-1,2)
  ELSEIF c=2 THEN
   LET x2-=t
   curvaC(n-1,3)
  ELSEIF c=3 THEN
   LET y2-=t
   curvaC(n-1,4)
  ELSE
   LET x2+=t
   curvaC(n-1,1)
  ENDIF
 ENDIF


FN.END


WAKELOCK 3

GR.OPEN 255,0,0,0,0,1

GR.SCREEN sw,sh

LET sx=sw/2
LET sy=sh/2
LET ncal=0

LET l=1

DO
 GR.COLOR 255,0,255,0
 GR.TEXT.ALIGN 2
 GR.TEXT.SIZE sy/14
 GR.TEXT.DRAW txt,sx,sy/10,"TOUCH TO DRAW, LEVEL: "+INT$(++l)
 GR.RENDER
 DO
  GR.TOUCH tch, tx,ty
  PAUSE 50
 UNTIL tch
 GR.HIDE txt
 GR.RENDER
 GR.CLS
 GR.COLOR 255,128+RND()*128,128+RND()*128,128+RND()*128

 LET t=INT(sx/(1.4^l))
 IF t<1 THEN LET t=1
 LET x1=sx
 LET y1=sy
 LET x2=x1+t
 LET y2=y1

 CALL curvaC(l,1)
 !GR.RENDER

 DO
  GR.TOUCH tch, tx,ty
 UNTIL !tch

UNTIL 0