Task: Hilbert curve







Python: iterations = 7
stroke_len = 600
angle_deg = 90
axiom = 'L'
sentence = axiom
rules = {
    'L': '+RF-LFL-FR+',
    'R': '-LF+RFR+FL-',
}

def setup():
    size(700, 700)
    global xo, yo
    xo, yo = 50, height - 50
    strokeWeight(1)
    noFill()
    generate(iterations)

def draw():
    background(0)
    translate(xo, yo)
    plot(radians(angle_deg))

def generate(n):
    global stroke_len, sentence
    for _ in range(n):
        stroke_len *= 0.5
        next_sentence = ''
        for c in sentence:
            next_sentence += rules.get(c, c)
        sentence = next_sentence

def plot(angle):
    for c in sentence:
        if c == 'F':
            stroke(255)
            line(0, 0, 0, -stroke_len)
            translate(0, -stroke_len)
        elif c == '+':
            rotate(angle)
        elif c == '-':
            rotate(-angle)

def keyPressed():
    global angle_deg, xo, yo, stroke_len
    if key == '-':
        angle_deg -= 5
        print(angle_deg)
    if str(key) in "=+":
        angle_deg += 5
        print(angle_deg)
    if key == 'a':
        stroke_len *= 2
    if key == 'z':
        stroke_len /= 2
    if keyCode == LEFT:
        xo -= 50
    if keyCode == RIGHT:
        xo += 50
    if keyCode == UP:
        yo -= 50
    if keyCode == DOWN:
        yo += 50


VB: option explicit


const pi180= 0.01745329251994329576923690768489 
const pi=3.1415926535897932384626433832795 
class turtle
   
   dim fso
   dim fn
   dim svg
   
   dim iang  
   dim ori   
   dim incr
   dim pdown
   dim clr
   dim x
   dim y

   public property let orient(n):ori = n*pi180 :end property
   public property let iangle(n):iang= n*pi180 :end property
   public sub pd() : pdown=true: end sub 
   public sub pu()  :pdown=FALSE :end sub 
   
   public sub rt(i)  
     ori=ori - i*iang:
     if ori<0 then ori = ori+pi*2
   end sub 
   public sub lt(i):  
     ori=(ori + i*iang) 
     if ori>(pi*2) then ori=ori-pi*2
   end sub
   
   public sub bw(l)
      x= x+ cos(ori+pi)*l*incr
      y= y+ sin(ori+pi)*l*incr
   end sub 
   
   public sub fw(l)
      dim x1,y1 
      x1=x + cos(ori)*l*incr
      y1=y + sin(ori)*l*incr
      if pdown then line x,y,x1,y1
      x=x1:y=y1
   end sub
   
   Private Sub Class_Initialize() 
      setlocale "us"    
      initsvg
      pdown=true
   end sub
   
   Private Sub Class_Terminate()   
      disply
   end sub
   
   private sub line (x,y,x1,y1)
      svg.WriteLine "<line x1=""" & x & """ y1= """& y & """ x2=""" & x1& """ y2=""" & y1 & """/>"
   end sub 

   private sub disply()
       dim shell
       svg.WriteLine "</svg></body></html>"
       svg.close
       Set shell = CreateObject("Shell.Application") 
       shell.ShellExecute fn,1,False
   end sub 

   private sub initsvg()
     dim scriptpath
     Set fso = CreateObject ("Scripting.Filesystemobject")
     ScriptPath= Left(WScript.ScriptFullName, InStrRev(WScript.ScriptFullName, "\"))
     fn=Scriptpath & "SIERP.HTML"
     Set svg = fso.CreateTextFile(fn,True)
     if SVG IS nothing then wscript.echo "Can
     svg.WriteLine "<!DOCTYPE html>" &vbcrlf & "<html>" &vbcrlf & "<head>"
     svg.writeline "<style>" & vbcrlf & "line {stroke:rgb(255,0,0);stroke-width:.5}" &vbcrlf &"</style>"
     svg.writeline "</head>"&vbcrlf & "<body>"
     svg.WriteLine "<svg xmlns=""http://www.w3.org/2000/svg"" width=""800"" height=""800"" viewBox=""0 0 800 800"">" 
   end sub 
end class

sub hilb (n,a)
if n=0 then exit sub
x.rt a
hilb n-1,-a: x.fw 1:x.lt a: Hilb n - 1,a 
x.fw 1
hilb n-1,a : x.lt a: x.fw 1: Hilb n - 1,-a 
x.rt a
end sub

 
dim x
set x=new turtle
x.iangle=90
x.orient=0
x.incr=5
x.x=100:x.y=700

hilb 7,1
set x=nothing