Trtl - Simple Ruby Turtle Graphics

example session

Installation

gem install trtl

Description

Trtl is a simple turtle system inspired by Python's turtle.py. It provides simple turtle drawing capabilities in Ruby, even if you're just at an IRb prompt. It leans on Tk which is part of MRI 1.9's standard library so in theory it should work 'out of the box' with most MRI 1.9 installs.

Usage

If Trtl detects you're in an IRb or Pry session, it'll automatically make turtle methods available directly at the prompt. For example:

$ irb
> require 'trtl'
> forward 100
# At this point, a window appears with the turtle

If you wish to use Trtl from a regular Ruby script, you have a few options. You can create a Trtl instance and use it directly:

require 'trtl'
t = Trtl.new
10.times { t.left(24); t.forward(30); t.ensure_drawn }
t.wait

You can use Trtl's run method to use it in a more interactive fashion:

Trtl.new.run { 10.times { left(24); forward(30); ensure_drawn } }

Or you can include InteractiveTurtle and get a similar effect as if you were in IRb:

include InteractiveTurtle
10.times { left(24); forward(30) }

Note: Using InteractiveTurtle makes drawing slower as it ensures all graphics are drawn after every action (as necessary for IRb use).

Examples

The examples in the examples folder should be reasonably illustrative. If you try any of them, try example4.rb - it renders an awesome looking tree.

tree

Credits

turtle.py for inspiration
Some of the examples taken from examples for an earlier Ruby turtle found at http://www.rubyquiz.com/quiz104.html

Copyright and License

MIT licensed. See LICENSE.md