Activities/Turtle Art/Logo

Exporting to Berkeley Logo
Turtle Art can export its projects to Berkeley Logo (using either View Source or the Save as Logo button on the Project Toolbar) You can download the Berkeley Logo activity here.

Note: The Save-as-Logo button saves to the Journal as "logosession.lg". UCB Logo does not yet access the Journal directly, so it is necessary to copy the project out of the Journal using the "copy-from-journal" command in the Terminal Activity and then accessing the project using the File menu within the UCB Logo Activity.

copy-from-journal logosession.lg

Alternatively, you can open the logosession in 'Write', copy the Logo code to the clipboard, and then paste it into the UCB Logo Activity.

Internals, how a Turtle Art project is converted to Logo
Shown here is the Logo code generated from the Turtle Art project shown above.

Firstly the Logo code contains procedures for setting up the palette and the shade functionality:

to tasetpalette :i :r :g :b :myshade make "s ((:myshade - 50) / 50) ifelse lessp :s 0 [ make "s (1 + (:s *0.8)) make "r (:r * :s) make "g (:g * :s) make "b (:b * :s) ] [ make "s (:s * 0.9) make "r (:r + ((100-:r) * :s)) make "g (:g + ((100-:g) * :s)) make "b (:b + ((100-:b) * :s)) ] setpalette :i (list :r :g :b) end

to rgb :myi :mycolors :myshade make "myr first :mycolors make "mycolors butfirst :mycolors make "myg first :mycolors make "mycolors butfirst :mycolors make "myb first :mycolors make "mycolors butfirst :mycolors tasetpalette :myi :myr :myg :myb :myshade output :mycolors end

to processcolor :mycolors :myshade if emptyp :mycolors [stop] make "i :i + 1 processcolor (rgb :i :mycolors :myshade) :myshade end

to tasetshade :shade make "myshade modulo :shade 200 if greaterp :myshade 99 [make "myshade (199-:myshade)] make "i 7 make "mycolors :colors processcolor :mycolors :myshade end

to tasetpencolor :c make "color modulo round :c 100 setpencolor :color + 8 end

make "colors [ 100 0 0 100 5 0 100 10 0 100 15 0 100 20 0 100 25 0 100 30 0 100 35 0 100 40 0 100 45 0 100 50 0 100 55 0 100 60 0 100 65 0 100 70 0 100 75 0 100 80 0 100 85 0 100 90 0 100 95 0  100 100 0 90 100 0 80 100 0 70 100 0 60 100 0 50 100 0 40 100 0 30 100 0 20 100 0 10 100 0  0 100 0 0 100 5 0 100 10 0 100 15 0 100 20 0 100 25 0 100 30 0 100 35 0 100 40 0 100 45  0 100 50 0 100 55 0 100 60 0 100 65 0 100 70 0 100 75 0 100 80 0 100 85 0 100 90 0 100 95  0 100 100 0 95 100 0 90 100 0 85 100 0 80 100 0 75 100 0 70 100 0 65 100 0 60 100 0 55 100  0 50 100 0 45 100 0 40 100 0 35 100 0 30 100 0 25 100 0 20 100 0 15 100 0 10 100 0 5 100  0 0 100 5 0 100 10 0 100 15 0 100 20 0 100 25 0 100 30 0 100 35 0 100 40 0 100 45 0 100  50 0 100 55 0 100 60 0 100 65 0 100 70 0 100 75 0 100 80 0 100 85 0 100 90 0 100 95 0 100  100 0 100 100 0 90 100 0 80 100 0 70 100 0 60 100 0 50 100 0 40 100 0 30 100 0 20 100 0 10] make "shade 50 tasetshade :shade

to tasetbackground :color :shade tasetshade :shade setbackground :color + 8 end

Then the Logo code contains the project:

to ta clearscreen tasetbackground 21 100 setpensize 25.0 make "box1 0.0 repeat 300.0 [ tasetpencolor xcor / 6.0 tasetshade heading forward :box1 right 91.0 make "box1 :box1 + 1.0 ] end

ta