# agusman-Project11-TurtleGraphicsFreestyle

``````//Anna Gusman
//agusman@andrew.cmu.edu
//Section E
//Turtle Graphics

function turtleLeft(d) {
this.angle -= d;
}

function turtleRight(d) {
this.angle += d;
}

function turtleForward(p) {
var newx = this.x + cos(rad) * p;
var newy = this.y + sin(rad) * p;
this.goto(newx, newy);
}

function turtleBack(p) {
this.forward(-p);
}

function turtlePenDown() {
this.penIsDown = true;
}

function turtlePenUp() {
this.penIsDown = false;
}

function turtleGoTo(x, y) {
if (this.penIsDown) {
stroke(this.color);
strokeWeight(this.weight);
line(this.x, this.y, x, y);
}
this.x = x;
this.y = y;
}

function turtleDistTo(x, y) {
return sqrt(sq(this.x - x) + sq(this.y - y));
}

function turtleAngleTo(x, y) {
var absAngle = degrees(atan2(y - this.y, x - this.x));
var angle = ((absAngle - this.angle) + 360) % 360.0;
return angle;
}

function turtleTurnToward(x, y, d) {
var angle = this.angleTo(x, y);
if (angle < 180) {
this.angle += d;
} else {
this.angle -= d;
}
}

function turtleSetColor(c) {
this.color = c;
}

function turtleSetWeight(w) {
this.weight = w;
}

function turtleFace(angle) {
this.angle = angle;
}

function makeTurtle(tx, ty) {
var turtle = {x: tx, y: ty,
angle: 0.0,
penIsDown: true,
color: color(128),
weight: 1,
left: turtleLeft, right: turtleRight,
forward: turtleForward, back: turtleBack,
penDown: turtlePenDown, penUp: turtlePenUp,
goto: turtleGoTo, angleto: turtleAngleTo,
turnToward: turtleTurnToward,
distanceTo: turtleDistTo, angleTo: turtleAngleTo,
setColor: turtleSetColor, setWeight: turtleSetWeight,
face: turtleFace};
return turtle;
}

var t1;

function setup() {
createCanvas(400,400);
background(0);
t1 = makeTurtle(200, 200);
t1.setColor(255);
t1.setWeight(1);
t1.penDown();

var sideLength = 20;
for(var i = 0; i < 100; i++) {
t1.penDown();
sideLength = sideLength - 20;
t1.right(2);
makeSquare(sideLength);

}
}

function makeSquare(sideLength)
{t1.forward(sideLength);
t1.right(90);
t1.forward(sideLength);
t1.right(90);
t1.forward(sideLength);
t1.right(90);
t1.forward(sideLength);
t1.right(90);

ellipse(t1.x,t1.y,10,10)
t1.penUp();
t1.right(90);
t1.forward(sideLength)
t1.right(90);
t1.forward(sideLength)

ellipse(t1.x,t1.y,10,10)
}
``````

Inspired by my struggles with the lab this week, I wanted to dive a bit further into the mechanism of iterated rotation. Here’s a simple transformation I thought looked really lovely.