XProfan

Windowtitle "SPIRALO - One rekursiver Spiralalgorithmus"
Windowstyle 24:Window 0,0-%maxx,%maxy:randomize
Declare xh&,yh&,x!,y!,xn!,yn!,r!,s!,co&
Repeat:r!=width(%hwnd):s!=pi()/180
xh&=rnd(width(%hwnd)):yh&=rnd(height(%hwnd))
x!=r!:moveto xh&+x!,yh&:co&=rnd(8^8):usepen 0,10,co&
go

until %key=27:end

proc go

if r!>4:s!=s!+sqrt(s!)*0.004:usepen 0,20-38*s!,co&

    xn!=x!*cos(s!)+y!*sin(s!):yn!=y!*cos(s!)-x!*sin(s!)
    xn!=xn!*0.985:yn!=yn!*0.985:r!=r!*0.985
    'locate 1,1:print r!,xn!,yn!
    line xh&+x!,(yh&-y!) - xh&+xn!,(yh&-yn!)
    x!=xn!:y!=yn!

    if rnd(100)<20:waitinput 1:case %key>0:END:endif

        go'REKURSION!

    endif

endproc