These allow you to “skew” (or slant) the created shape and / or compress or expand one “end” of it (trape, or trapezoidal). This allows for a large increase in the number of possible shapes you can create in turtleSpaces.
Also, you can export an arbitrarily-sized render of the current scene using the new SAVEPNG primitive:
SAVEPNG [width height] “filename.png
Note that if you specify a really large size (> 10000 pixels per side) you can cause the application and even your operating system to crash! This is because the rasterisation needs to be done in memory.
The image is saved in the current “working directory”, usually a turtleSpace TSP folder inside of your user folder (inside of the turtleSpaces folder in your home directory).
Don’t want to download the turtleSpaces client just yet? Well, you can take turtleSpaces for a bit of a spin using Myrtlebot, our turtleSpaces Twitter Bot! Myrtlebot executes whatever Logo code (not procedures yet) you tweet at her, and then returns an image of the results. In the future, we plan to allow for the recording of movies, but for now it’s just a still image. If your code runs for more than 60 seconds, it will be cut off at the 60 second mark.
We’ve created a number of ‘short codes’ for various graphics primitives so that you can put more into a tweet. Here are the new ‘short codes’ (along with the typical logo rt, lt, fd, bk, up, dn etc.) See the documentation for a fuller description of each primitive:
turtleSpaces has a new primitive, SAVESTL, which can be used to export 3D models of the current turtleSpace.
creates a new folder in the current project folder (TSP) with the extension MDL (eg modelname.mdl), inside which contains STL format files, one for each color used in the space. These files can be used with other 3D applications (such as the pictured viewstl.com website), and can be 3D printed (although the sides of objects may need to be extruded using another application first, if the desire is for the objects to be hollow).
Another primitive, SETSTLLINETHICKNESS, is used to set the radius of the ropes used to represent lines in exported STL files. It takes a number.
You can communicate with turtleSpaces over a socket (telnet) connection to port 1967.
First you need to issue the API command inside of turtleSpaces to enable API connections, or use the -enable-api flag when starting up.
Then connect to turtleSpaces from an external application or terminal. You can issue instructions to affect turtles and the environment just like you would do inside the turtleSpaces application.
The API connection executes as its own worker. You can also redirect input and output to the API instance by using setread “api and setwrite “api – but these must be issued by the API worker itself to redirect to that worker (if you use another API connection, reading and writing will be redirected to that API instance, for example).
Using the API, you can use turtleSpaces as a visualiser for another application, and have it act as a light organ, or create charts and graphs.
turtleSpaces implements the Logo programming language inside of the OpenGL 3D graphics environment, allowing you to use turtles to construct 3D models and create animations, simulations and games.
We initially implemented a version of Apple Logo II in our microM8 Apple II emulator to make it easier to use for our younger users, and because microM8 itself uses OpenGL to render the Apple II’s graphics (also in 3D) we added some rudimentary 3D commands to it (up, down, rollleft, rollright, etc.)
We received positive feedback from our users and decided to seperate the Logo interpreter from microM8 and work to grow its potential more broadly.
Logo’s benefits for learning how to code are many and varied, but before we explore them, it might be better to address the concerns many have with it first, and get them out of the way.
Why not Logo?
Logo’s problems are mainly historical. In the late 1970s there was great excitement among some quarters regarding the potential benefits of teaching children computer programming. Logo was designed around this time to be an as easily-accessible programming language as could be achieved given the technology of the era, which was not very advanced and led to extreme tradeoffs between usability and practicality. In short, Logo was still difficult to use, while not being useful for very much.
Despite this, evangelists (including and mainly Logo’s co-architect Seymour Papert) still made a big deal of Logo, and attempted (and for a time largely succeeded) to gain its widespread use in education, engaging in a great deal of publicity and the making of overstated promises about its potential to turn every child who used it into a little genius. To make matters worse, Papert’s constructivist philosophy dictated that children be allowed to ‘explore’ Logo at their own whim, which while valid on its face (and is something we encourage with turtleSpaces!) was impractical in the context of the crude interpreters that were made available at the time, which were slow, unforgiving, low-resolution and had limited built-in tools, resources and examples.
To make any use of it, you really had to read the manual, but since reading the manual ran counter to Papert’s philosophy, many kids just figured out how to move the turtle forward and turn, and that was about it. Studies were done that showed some initial tutorial-based hand-holding was required, and improvements needed to be made in the user interface, and while later versions of Logo did attempt to correct these shortcomings, by that time the initial enthusiasm for Logo amongst educators had died out, and they were somewhat jaded to the concept in general.
Logo appeared too early, and pushed too hard.
In response, ‘blocks’-based versions of Logo appeared such as Scratch, which attempted to make a subset of commands and their parameter requirements obvious to young coders, who could ‘snap’ them together in the correct order and change default parameters and witness their effects. While useful perhaps in the near-term (and to be clear, we are in the process of implementing a blocks-style mode in turtleSpaces, so we agree they are not without value as an early introduction to Logo), these reduced the very valuable concept of the Turtle to little more than a gimmick, and they nobbled the potential of the Logo language they were based on so much as to make greater exploration of the language largely impossible in the context of their environments.
They were, and are, ‘dead ends‘, and this causes some concern to parents and educators, many of whom are reluctant to use them.
That isn’t to say there weren’t and aren’t other full-Logo interpreters also out there. There were and are, but they have also faced difficulty. First, they’ve tended to rely heavily on the host operating system’s user interface, which was a popular direction to go in the late 1990s and early 2000s, but not so much recently. MicroWorlds Logo, for example, allowed the user to create buttons and load images, and so forth. But the programs users created were very much restricted to their environments, and those environments were still very much oriented towards children. And this trend continued, making for very limited experiences.
As a result, given today’s cross-platform, limited UI landscape these have not aged well. Other developers implemented variants of Logo (such as NetLogo) designed for simulations, such as ant colonies or viruses. But these are largely targeted toward college students, and many of their mechanisms are in our opinion convoluted and counter-intuitive and not at all suitable for children.
Logo for children was simply a victim of being in the wrong place at the wrong time, and its stunted evolution reflected that. But there’s nothing wrong and a lot very right with Logo, and studies of the language itself have shown that. Its functional nature is fairly easy to grasp, the immediate feedback you get from the turtle promotes exploration and learning, and it is powerful enough to become a go-to language for someone even as an adult, if there was a Logo environment that was flexible enough to be useful for a broader audience, and could occupy that middle ground.
So we thought, “Why couldn’t we find that middle ground? We have the technology! Why don’t we go back to where it all started and work forward from there?”
I’d like to definitively state that we have succeeded in our task, but I’ll more tentatively say that we’re well into working on it. Here’s what we have accomplished so far:
The addition of a few hundred useful primitives from other Logos and programming languages (including some of our own invention), such as multiple turtles and threading, loops and math functions, retro-styled music and sound, turtle models, gamepad and image placement primitives
Several hundred primitives related to the 3D environment, including a wide variety of shapes, positional and vector based functions and tools, and Minecraft-inspired pixelated color schemes
An improved while retro-inspired interface that is able to easily get out of the way – no tiny window into the Logo world, no large obtrusive text areas that you can’t get rid of. You can make a program and execute it full screen just like any other game you might buy or download.
Written in Go so it’s cross-platform (Windows, macOS and Linux) with the potential for mobile platforms
Lots and lots of other smaller things that make the whole experience fun, engaging, productive and straightforward that I can’t even begin to mention.
Here’s a list of some big-ticket items that still need to happen (in no particular order):
Raspberry Pi, iOS and Android support, in particular for running turtleSpace apps
Stand-alone, distributable app generation for mobile and desktop
Private “Classes” that groups of students can join, whose progress can be viewed and monitored by their facilitators / teachers, who can share content between their students
Multi-user, multi-player capabilities so that users can design, code and play together
API to support control by other applications such as IDEs and tutorials
The ability to connect and interact with the outside world
3D model import / export so that users can 3D print their creations, or use them in other 3D environments or vice-versa
Terrain and more complex shape design tools
In-environment tutorials, badges, achievements and so forth to encourage exploration
‘Blocks’-based entry mode to support younger learners
Command-line version without the OpenGL baggage, but with internal FauxGL rendering support to enable image output
Refactoring and optimization!
A whole bunch more primitives!
Finally, and most importantly, to make Logo the relevant all-purpose language it was always meant to be
So, a long way to go. But a good start. Hope to see you around turtleSpaces soon!