Turtle graphics

/* logo sample program 
   4 zlai logo online interpreter v0.1
   note: case - insensitive
   and expressions should not contain spaces ~
*/

#  this is a comment.
;  this is also a comment.
// this is also also a comment.

make "T 220     ; Testing Global Variable

# Spiral
to spiral :size :angle 
  if :size>:T [stop]
  forward :size
  right :angle
  spiral :size+2 :angle
end

# Tree
to tree :size
  if :size<10 [stop]
  fd :size
  lt 30 tree :size*0.7  ;left branch, recursive
  rt 60 tree :size*0.7  ;right branch, recursive
  lt 30 
  bk :size
end

# Entry of Program
window           ; set the window mode
setfc logo_black  ; set flood colour to logo_cyan
fill             ; fill the background
penup            ; pen up
setxy 200 -150   ; set turtle position
pd               ; pen down
setpc logo_white   ; set pen colour to white
spiral 0 91      ; do the work

pu               ; pen up
setpc logo_yellow; set to yellowcolour
setxy -180 -100   ; set the location
lt  degree       ; degree is a global variable
pd               ; pen down
tree 100         ; draw a tree
hideturtle       ; ht = hide the turtle, it is actually a small circle
setpc logo_green      ; last pc command sets the color of text

Le Logo.fr