1611turtle

// a simple version of Papert's turtle

var x = [];

var y = [];

var a = [];

var d = 10;

var t = 30; // turn amount

​

function setup() {

  createCanvas(windowWidth, windowHeight);

  init();

  strokeWeight(10);

  noLoop();

}

​

function draw() {

}

​

function keyTyped() {

  if(key=='c') init();

  if(key=='F') // draw forward

  {

    let x1 = x + d*cos(a);

    let y1 = y + d*sin(a);

    line(x, y, x1, y1);

    x = x1;

    y = y1;

    redraw();

  }

  if(key=='+') // turn right

  {

    a+=radians(t);

  }

  if(key=='-') // turn left

  {

    a-=radians(t);

  }

}

​

function init() {

  background(255);

  x = [];

  y = [];

  a = [];

  x[0] = width/2;

  y[0] = height/2;

  a[0] = PI*3/2;

}

​

​