LIOGO Tutorial

[This is preliminary documentation and subject to change]

In the turtle's world

Liogo can't be a Logo without Turtle Graphic. So Liogo comes with the most famous commands and operations from the Logo world.

The Logo turtle is an image or a triangle facing to the turtle heading. At first, turtle is facing north and is set to 0,0 on the mathematical axis. Two main commands are used to move the turtle: "forward N" to move forward turtle to N steps and "back N" to move back turtle to N steps. "left" and "right" are used to change the turtle heading from an angle in degree. Let's see an academic sample:

repeat 4 [
    forward 100
    right 90
]

Here is the command line to build this sample (called "square.lgo" ;-) and launch it (use "mono square.exe" on Linux)
(Note that when you want build an EXE using graphics, you need to use "/t:winexe" option with LIOGOC).

Here is the output Window:

More drawing

Lot of famous developers had wrote nice drawing using just these few commands. I take two sample from Daniel Ajoy and David Costanzo:

to polygon :n :size
    repeat :n [ 
      forward :size 
      right 360 / :n
    ]
end

to house
    polygon 4 100
    forward 100
    right 30
    polygon 3 100
end

house

TO COLORBALL
  REPEAT 4 [
    SETPENCOLOR REPCOUNT
    REPEAT 120 [ FORWARD REPCOUNT * 2 RIGHT 204 ]
    HOME
    RIGHT 90 * REPCOUNT
  ]
END

COLORBALL

A full list of graphics command and operation in Liogo are listed here