public void draw() {
stroke(0, 0, 0);
change = round(random(1, 10));
if (change == 10) {
direction = round(random(0, 8));
point(pointX, pointY);
point(pointX + 1, pointY + 1);
point(pointX - 1, pointY - 1);
point(pointX - 1, pointY + 1);
point(pointX + 1, pointY - 1);
stroke(200, 200, 200);
point(pointX + 1, pointY);
point(pointX - 1, pointY);
point(pointX, pointY + 1);
point(pointX, pointY - 1);
stroke(0, 0, 0);
}
if (direction == 1) {
speed.set(0, -1, 0);
}
if (direction == 2) {
speed.set(1, 0, 0);
}
if (direction == 3) {
speed.set(0, 1, 0);
}
if (direction == 4) {
speed.set(-1, 0, 0);
}
if (direction == 5) {
speed.set(-1, -1, 0);
}
if (direction == 6) {
speed.set(1, 1, 0);
}
if (direction == 7) {
speed.set(-1, 1, 0);
}
if (direction == 8) {
speed.set(1, -1, 0);
}
if (pointX == width) {
pointX = 1;
}
if (pointX == 0) {
pointX = width - 1;
}
if (pointY == height) {
pointY = 1;
}
if (pointY == 0) {
pointY = height - 1;
}
pointX = pointX + speed.x;
pointY = pointY + speed.y;
point(pointX, pointY);
}
// Function to update location
public void update() {
// As long as we aren't dragging the pendulum, let it swing!
if (!dragging) {
float G = 0.4f; // Arbitrary universal gravitational constant
theta_acc =
(-1 * G / r)
* sin(
theta); // Calculate acceleration (see:
// http://www.myphysicslab.com/pendulum1.html)
theta_vel += theta_acc; // Increment velocity
theta_vel *= damping; // Arbitrary damping
theta += theta_vel; // Increment theta
}
loc.set(r * sin(theta), r * cos(theta), 0); // Polar to cartesian conversion
loc.add(origin); // Make sure the location is relative to the pendulum's origin
}