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README.md

TurtleJS

A simple JavaScript clone of the LOGO drawing language. Write turtle programs in JavaScript, saved in your browser.

  • NOTE: this software is a fun toy written in two days. It only supports firefox and chrome right now. It is not supposed to be clean or perfect, mostly I wrote it for fun.

Live Demo

  • Ace code editor.
  • Useful cheat sheet page.
  • Cmd-; to search for selected text on MDN using google JSON search API.
  • Error handling and console.log go to integrated console.

screenshot

Simple API for drawing:

pushColor('red');
forward(50);
right(90);
forward(50);
left(90)
forward(50);
popColor();

Example from screenshot:

var goldenRatio = 1.618;

function square(color, size) {
  pushFillColor(color);
  pushColor('none');
  for(var i = 0; i < 4; i++) {
    forward(size);
    right(90);
  }
  popFillColor();
  popColor();
}

function makeRGBA(r,g,b,a) {
  var rgbaString = 'rgba('
  + Math.round(r > 255 ? 255 : (r < 0 ? 0 : r)) + ','
  + Math.round(g > 255 ? 255 : (g < 0 ? 0 : g)) + ','
  + Math.round(b > 255 ? 255 : (b < 0 ? 0 : b)) + ','
  + (a > 1 ? 1 : (a < 0 ? 0 : a) ) + ')';

  return rgbaString;
}

function fly(x) {
  penUp();
  forward(x);
  penDown();
}

for(var i = 20; i < 130; i++) {
  right(2+(i*goldenRatio));
  fly(i);
  square(
    makeRGBA(i*3, Math.min(i*0.8, 200), 200-(i*2), Math.min(0.5, i * 0.01)),
    (20+i)*Math.random()
  );
  fly(-i);
}

fly(10000);