terra is a super customizable framework for creating and analyzing biological simulations. It's open-source and licenced under MIT.

Usage

Including terra

Getting started is as easy as including the script!

<script src="path/to/terra.min.js"></script>

terra can also be used as a module with most popular module systems. ?

Creating creatures

Now that we've included the script, let's create a simple creature using the creatureFactory. Each creature requires a type.

terra.creatureFactory.register({
  type: 'firstCreature'
});

This creature is valid, but it's pretty boring. To make a more interesting creature, let's override some of the default options and methods.

terra.creatureFactory.register({
  type: 'secondCreature',
  color: [41, 128, 185],
  metabolism: 1,
  sustainability: 3,
  reproduceLv: 0.60,
  etc...
});

We've just created a creature that will ____.

Creating the environment

To run a simulation, we'll need to create an environment. Let's make a 25x25 grid and populate 40% of the space with our first creature and 20% with our second.

var ex1 = new terra.Terrarium(25, 25, 'ex1');
ex1.populate([['firstCreature', 40], ['secondCreature', 20]]);

Running a simulation

Terrariums have a few methods that allow you to interact with the simulation. The most important are step and draw.

function stepAndDraw () {
  // run the next step of the simulation
  ex1.step();
  // update its display
  ex1.draw();
}

// start an interval to update the simulation twice per second
var updater = setInterval(stepAndDraw, 500);

step can take an argument for the number of steps to run through. If we want to see how our environment is doing in 1000 steps, we can simply run:

ex1.step(1000);
ex1.draw();

Examples

Conway's Game of Life ?

terra can also run cellular automata. 

terra.creatureFactory.register({
  type: 'GoL',
  colorFn: function () { return this.alive ? this.color + ',1' : '0,0,0,0'; },
  wait: function () {},
  isDead: function () { return false; },
  queue: function (neighbors) {
    var surrounding = _.filter(neighbors, function (spot) {
      return spot.creature.alive;
    }).length;
    this.alive = surrounding === 3 || surrounding === 2 && this.alive;
    return false;
  }
}, function () {
  this.alive = Math.random() < 0.5;
});

Cyclic Cellular Automata

terra.creatureFactory.register({
  type: 'cyclic',
  colors: ['255,0,0,1', '255,217,0,1', '72,255,0,1', '0,255,145,1', '0,145,255,1', '72,0,255,1', '255,0,217,1'],
  colorFn: function () { return this.colors[this.state];},
  wait: function () {},
  isDead: function () { return false; },
  queue: function (neighbors) {
    var next = (this.state + 1) % 7;
    var changing = _.some(neighbors, function (spot) {
      return spot.creature.state === next;
    });
    if (changing) this.state = next;
  }
}, function () {
  this.state = Math.floor(Math.random() * 7);
});

Options

The following options can be passed in an object to creatureFactory.register( ) as the first argument.

Required

Optional

Methods

Events