Examples

Terrain can be saved as STL files (under the File menu in the web IDE) and then 3D printed!

setterrain

[x1 y1 x2 y2] (list) | [height floor ceiling] (list) | seed (number) | algorithm (word) OR [algorithm magnification] | style (word)

Creates terrain on the z-plane between the specified x and y co-ordinates.

These co-ordinates represent 10 turtle-units, and the output can be scaled using setterrainresolution.

height specifies the maximum height in terms of single turtle-units, similarly scaled using setterrainresolution. The floor value specifies the lowest level rendered, and any values lower than that value are rendered at the floor level. Similarly, the ceiling value represents the highest value rendered, and anything higher is lowered to that value.

Wordle, a cross between Mastermind and Hangman, seems to be the rage these days. Also, implementing it in as few lines as possible. In Logo we get to cheat a little about the second bit, as we can stack multiple commands on the same line. But we still need to keep things within a reasonable line length.

We’re happy to say we succeeded in our efforts, and even expanded on the model somewhat, adding progressively longer words and hints, among other things. This is a pretty good example of string and list management in Logo, which is what it was initially created for, even before the turtle!

Floaty Turtle is a simple clone of Flappy Bird written in the Logo programming language that turtleSpaces uses.

Open in the integrated development environment (IDE)

NEWTURTLE "myrtle

TO floaty
  ;here is yet another example of a relatively complex
  ;game that can be rather simply implemented in Logo:
  ;a flappy bird clone!

  ;to make it work we use two turtles, one is the player
  ;and the other creates, moves and erases the pipes
  ;these are two seperate 'workers' or threads

  ;this procedure kicks off the game, displays a title
  ;screen, and then manages the player, processing
  ;input and moving the player appropriately

  ;the pipemaker turtle and its pipes procedure
  ;manages the pipes and checks for collisions

  ;the turtle does not move horizontally,
  ;instead the pipes do!

  reset
  cleartext
  setbackgroundcolor pick [6 7 14 5 10 11 14 15]
  ;select a random background color from the given list

  noaudiowait
  ;don't wait for audio to finish playing

  setmodel [penup back 7 stamp "myrtle]
  ;we need to offset Myrtle's actual position more
  ;toward her center for the purposes of this game

  setmodelscale 5
  ;make myrtle big!

  playsound "doodoo
  ;startup sound

  pipemaker:newworker [pipes]
  ;'kicks off' the pipemaker turtle, who
  ;creates and moves the pipes

  ;create the title screen:

  penup
  randomfillcolor
  slideleft 180 forward 5
  settypesize 60
  pushturtle
  ;'push' the turtle's state (position etc) on
  ;to a stack, from which it can be 'popped'
  ;off later

  typeset "Floaty
  popturtle
  ;restore the previously pushed state

  back 100
  randfc
  ;short for randomfillcolor

  pushturtle
  typeset "Turtle
  popturtle
  bk 10 sr 70
  ;back and slideright

  settypesize 10
  randfc
  typeset |Press any key to float!|
  ;title screen complete!

  home
  dn 90 rt 90
  ;down and right

  make "raise 0
  ;the :raise container holds the current
  ;value remaining to float Myrtle upwards

  forever [

    if loopcount = 1 [say "Ready!]
    if loopcount = 16 [say "Set!]
    if loopcount = 31 [say "Go!]
    ;the loopcount is the number of times the forever
    ;loop has executed. Based on that count, say the
    ;appropriate ready set go component

    if divisorp 100 loopcount [
      ;every 100 loops pick a random background
      setbg pick [6 7 14 5 10 11 14 15]
      ;from the given list
    ]
    ;setbg short for setbackground

    dosleep [50] [
      ;try to maintain an average of 50ms to do
      ;the following:

      if loopcount > 30 [
        ;if the loopcount is greater than 30:

        if :raise = 0 [
          ;if the value inside the :raise container
          ;is 0, then lower the turtle 2.5 turtle-units:

          lower 2.5
        ]
        [
          ;otherwise raise the turtle 2.5 turtle-units
          ;and decrease the value inside the :raise
          ;container by 2.5
          raise 2.5
          make "raise :raise - 2.5
        ]

        if keyp [
          ;if a key is pressed, play a sound,
          ;remove the key from the keyboard buffer
          ;and increase the value of the :raise
          ;container by 20:

          playsound "air
          clearchar
          make "raise :raise + 20
        ]

        clean
        ;remove the turtle's 'track' -- it's not
        ;drawing or creating anything so we don't
        ;need to have it piling up

      ]
    ]
  ]
END

NEWTURTLE "pipemaker

TO pipes
  ;the pipemaker turtle's job is to
  ;create the pipes, shift them to the left
  ;and check if they've hit the turtle

  clearscreen
  noaudiowait
  penup
  home
  slideright 250
  back 120
  up 90
  ;position the turtle appropriately for
  ;creating the pipes offscreen to the right

  begintag "move
  endtag
  ;this tag is used to shift the pipes,
  ;by replacing its contents with an ever-
  ;increasing slideleft directive

  make "height 100
  ;this is the starting height of the pipes

  make "heights [0 0 0 0 0]
  ;initialize an 'zeroes' list of pipe heights

  make "score 0
  make "count 0
  ;initialize the score and the pipe count

  settypesize 20
  ;set the type size. Type is the text you
  ;create inside the 3D world

  forever [
    ;do this forever:

    sleep [50]
    ;try to do this stuff in an average of
    ;50ms -- less or more as needed to keep
    ;that average:

    if divisorp 20 loopcount [
      ;every 20 loops:

      inc "count
      ;increase the contents of the :count container
      ;by one

      if loopcount > 60 [
        ;if the loopcount is greater than 60:
        playsound "clang
        inc "score
        say :score
        ;make a sound, increment :score and say it
      ]

      slideright 100

      begintag loopcount
      ;create a new 'tag' for the pipe
      ;so we can remove it after it passes the
      ;left side of the screen

      randomfillshade
      ;select a random fill shade

      make "col 1 + random 5
      ;select a random number and put it in :col

      setfillcolor item :col [12 9 7 6 11 14 10 13]
      ;set that color based on :col's index in the
      ;provided list

      make "height :height + (-60 + random 120)
      ;increase or decrease :height based on a
      ;random number

      if :height < 20 [make "height 30 + random 20] if :height > 120 [make "height 110 - random 20]
      ;if too high or low, pick a new value higher
      ;or lower as needed

      queue :height "heights
      ;add the new height to the list of heights

      ;create the lower pipe:
      cylinder 20 :height 50
      lower :height
      setfillcolor item :col [4 8 6 2 1 12 5 3]
      ;select the complementary color for the pipe

      cylinder 25 20 50
      lower 50

      ;type the pipe number:
      down 90 right 90 back 10
      if :count > 9 [bk 10]
      inscribe :count
      if :count > 9 [fd 10]
      forward 10 left 90 up 90
      ;if gameplay is too slow, comment out
      ;the above five lines

      ;create the upper pipe:
      lower 50
      ;remember, the turtle is upside down!
      cylinder 25 20 50
      lower 20
      setfillcolor item :col [12 9 7 6 11 14 10 13]
      cylinder 20 120 - ypos 50
      raise :height + 120

      endtag
      ;close the pipe 'tag'

      if loopcount > 119 [erasetag loopcount - 100]
      ;erase the pipe that has left the screen

      ignore pop "heights
      ;remove its height from the :heights container
      ;and just throw it away (ignore it)
    ]

    if loopcount > 60 [
      ;check for crash:
      if (or
        myrtle:ypos > (-120 + (90 + item 3 :heights))
        myrtle:ypos < (-120 + (20 + item 3 :heights))
        ;the third item in the :heights list is the
        ;height of the pipe around where the turtle
        ;is, so we can use that to see if we've hit
        ;anything
      ) [
        (print |Crash! Final Score: | :score)
        print |Press flag icon to play again!|

        calm "myrtle
        myrtle:run [setfillcolor 1 icosphere 30]
        ;red ball

        audiowait
        playsound "crack
        playsound "aw

        myrtle:clean
        ;gets rid of the red ball

        noaudiowait
        playsound "fall
        say |too bad|

        myrtle:repeat 90 [
          forward 3 lower 3 wait 1
        ]
        ;fall to the ground

        audiowait
        playsound "crash
        finish
        ;that's all folks

      ]
    ]

    replacetag "move [slideleft loopcount * 5]
    ;increase the value of the slideleft
    ;command in the move tag, shifting the
    ;pipes to the left

  ]

  ;and that's it! Not really much code, is it?

END

Dodgeball is a very simple game using a bale wherein the player moves the turtle from the left to right sides of the screen using the keyboard.

This is similar to a popular example used to teach Scratch, and the basic concept should be familiar to most Scratch learners.

In the case of this example, there are multiple balls that are controlled by a ‘bale’, a group of turtles who all execute the same code, first the code in the bale’s init procedure, and then the code in the ‘main’ procedure repeatedly. Each member of the bale executes consecutively, and once all members of a bale have executed (a cycle), the bale’s graphical output (its ‘turtle tracks’) is updated.

Build this cool island scene using turtleSpaces Logo and a few basic shapes!

First we begin with a tree. We can build a trunk using a repeat loop of cylinders that get narrower in diameter and longer as we go. We can introduce a slight curve as well by tilting the turtle up a bit each cylinder we create:

Next we need to create the leaves, which we can do using the fiso (filled triangle) primitive. We can use a repeat loop to create a series of triangles growing in size, and then a second repeat loop to create a further series of triangles shrinking in size. In both cases, we tilt the turtle down a bit each triangle we create:

The above animation was created inside turtleSpaces, and then exported as a webm video file using the savewebm primitive. I then used Final Cut Pro to add the audio and the titles.

The Logo code used to create the animation is fairly straightforward. The turtle moves in an arc outwards from the center, creating arcs around it and generating the pattern. The location and sizes of the arcs depends on the current loop iterations. Graphics rendering is suspended while each ‘frame’ is created, after which the code renders the frame and pauses to ensure the user sees it, then continues on.

Witches, pumpkins, devils, ghosts and black cats are all haunting turtleSpaces this Hallowe’en! turtleSpaces is great for creating 3D models using code.

You can also find these models in the Published projects section of the webLogo interpreter.

The Pumpkin:

The pumpkin is created using the spheroidslice primitive, which creates an elongated slice of a sphere. By creating ten of these slices (every 36 degrees) we can easily create the pumpkin’s body:

This rendition of Towers of Hanoi is a simple game to code and makes introductory use of 3D shapes. Recreating it could serve as a great introduction to turtleSpaces and Logo coding in general.

In the game, you attempt to transfer the disks on post 1 to post 3 ending in the same order the disks started in (smallest to largest, starting from the top). To do this, you can transfer disks between posts, but disks can only be placed on top of disks smaller than they are.

/img/uploads/2021/08/torusplane.webm

This example demonstrates the use of various camera-related functions, shape inversion, the premodel primitive and others to create this cool animation of a plane trapped in a torus!

The procedure first sets the turtle model to the built-in plane model, before creating a tag that sets the color of the torus. Then it creates an inverted torus (one whose inside is rendered instead of its outslde) because we’re going to fly inside it!

This simple commented project allows for the introduction of 3D movements and shapes (the rocket procedure) including a basic introduction to repeat, the creation of turtle models and the use of premodel, an introduction to the orbit primitives and the use of a new worker (thread) for orbiting the camera!

TO rocket
  forward 70
  down 90
  ;these two commands orient the rocket better for use as
  ;a turtle model

  setfillcolor yellow
  ;yellow is a function that returns the value 13
  ;it is a shortcut used for convenience in learning
  ;as is red, green, blue etc.

  cylinder 20 120 10
  ;cylinder takes

  rollright 180
  ;flip the turtle over to create the nose cone

  cone 20 50 10

  lower 50
  ;lower the turtle to create the 'nose'

  setfillcolor red
  icosphere 3

  setfillcolor orange
  ra 50 + 120
  ;ra is short for raise

  rr 180
  ;rr is shorthand for rollright

  cutcone 20 30 30 10
  ;move the turtle to the bottom of the rocket and
  ;create the tail

  up 90 bk 30.1
  ;bk is short for back

  setfillcolor white
  repeat 2 [cylinderslice 40 5 20 10 rr 90]
  ;create the fins

  setfillcolor red
  dn 90 sl 10 bk 10 cylinder 10 10 10
  ;sl is short for slideleft

  fd 20 cylinder 10 10 10 sr 20
  ;fd is short for forward
  ;sr is short for slideright

  cylinder 10 10 10 bk 20 cylinder 10 10 10
  ;create the jets

END

TO createmodel
  clearscreen
  ;cs is short for clearscreen

  begintag "rocketmodel
  ;tags are used to create turtle models
  ;among other uses. You can also use them to
  ;show or hide parts of the 'turtle track'

  rocket
  ;run the rocket procedure

  endtag
  ;close the tag

  newmodel "rocket "rocketmodel
  ;create a new model called 'rocket' based on the
  ;rocketmodel tag

  setmodel "rocket
  ;set the turtle's model to the rocket model

  clearscreen
  ;clear away the tagged model, leaving only the
  ;turtle
END

TO starfield :number
  hideturtle
  norender
  ;suspend rendering of the scene until we're done drawing the stars
  penup
  repeat :number [
    home
    randomvectors randomfillcolor
    ;randomvectors orients the turtle randomly
    ;while randomfillcolor sets a random fill color

    forward 1000 + random 1000
    ;move forward a random distance

    up 90
    ;orient the turtle up in preparation of creating a spot
    ;because the spot is created around and below the turtle

    spot 10 + random 10
    ;create a randomly-sized spot

  ]

  home
  showturtle
  render
  ;resume rendering

END

TO main
  reset
  ;resets turtleSpaces to a default state

  createmodel
  ;execute the createmodel procedure

  starfield 200
  ;execute the starfield procedure, passing the parameter value 200

  setmodelscale 0.5
  ;decrease the size of the turtle model to half normal

  setpremodel [lt 90]
  ;inserts 'left 90' into the turtle track between the scene
  ;and the turtle model ('pre' the model)

  setfillcolor 14
  ;sets the fillcolor to 14. Type 'showcolors' or 'sc' in the console
  ;to see a list of default colors. You can also definecolor your own!

  ico 50
  ;create an icosphere (the planet)

  penup
  dropanchor
  ;set the 'anchor point', or the point the turtle 'orbits' around
  ;using the orbit commands, to the current turtle position

  pullout 80
  ;pull away 80 turtle units from the anchor point

  snappy:newworker [forever [orbitleft 0.1]]
  ;tell snappy the camera turtle to create a new routine or thread
  ;that forever orbits around the scene to its left one tenth of
  ;a degree at a time

  make "rotation 0
  ;define a container (variable) called 'rotation'
  ;and set it to 0. We're going to use it to keep track of the
  ;rotation of the rocket

  forever [
    inc "rotation
    ;same as make "rotation :rotation + 1
    ;there is also dec (decrement)

    setpremodel {"lt 90 "rollright :rotation % 360}
    ;curly braces indicate a 'softlist', a list that is evaluated
    ;at runtime. In this case, so that we can have a dynamic
    ;rotation value we pass to setpremodel

    ;% is shorthand for modulus

    orbitleft 1
    ;orbit the rocket one degree to the left

    wait 1
    ;wait one sixtieth of a second

  ]
END