Slideleft

These procedures draw a simple tree in a classic Logo lined style, and a forest of these trees. First, let’s take a look at the tree procedure as a whole.

TO tree :scale
  slideleft 8.25 * :scale
  forward 20 * :scale
  repeat 4 [
    slideleft (10 * (5 - repcount)) * :scale
    left 30
    slideright (12 * (5 - repcount)) * :scale
    right 30
  ]
  left 30
  slideright 5 * :scale
  right 60
  slideright 5 * :scale
  left 30
  repeat 4 [
    right 30
    slideright (12 * repcount) * :scale
    left 30
    slideleft (10 * repcount) * :scale
  ]
  back 20 * :scale
  slideleft 8.25 * :scale
END

Now let’s go through it a line at a time. The procedure starts out with the procedure declaration TO , then the name of the procedure tree, then a single parameter, :scale