//Thomas Wrabetz
//Section C
//twrabetz@andrew.cmu.edu
//Project-11
function turtleLeft(d) {
this.angle -= d;
}
function turtleRight(d) {
this.angle += d;
}
function turtleForward(p) {
var rad = radians(this.angle);
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 turtle;
function setup()
{
createCanvas( 480, 480 );
background( 255 );
turtle = makeTurtle( width / 2, height / 2 );
turtle.penDown;
turtle.setWeight( 3 );
turtle.setColor(0,0,0);
}
var turtleDist = 100;
var turtleSpeed = 1;
var turtleAcceleration = 0.05;
function draw()
{
turtle.forward( turtleSpeed );
if( dist( turtle.x, turtle.y, mouseX, mouseY ) < turtleDist) turtleSpeed += turtleAcceleration;
else turtleSpeed -= turtleAcceleration * 2;
turtleDist = dist( turtle.x, turtle.y, mouseX, mouseY );
if( turtleSpeed < 0 )
{
turtle.left( 180 );
turtleSpeed = -turtleSpeed;
}
turtle.turnToward( mouseX, mouseY, 7 );
}
It’s a turtle that chases you down.