// A function to rotate a vector
public void rotateVector(PVector v, float theta) {
float m = v.mag();
float a = v.heading2D();
a += theta;
v.x = m * PApplet.cos(a);
v.y = m * PApplet.sin(a);
}
// Method to update location
public void update() {
// Update velocity
vel.add(acc);
// Limit speed
vel.limit(maxspeed);
loc.add(vel);
// Reset accelertion to 0 each cycle
acc.mult(0);
}
// 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
}
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);
}
// Constructor initialize all values
Boid(PVector l, float ms, float mf) {
loc = l.get();
r = 4.0f;
maxspeed = ms;
maxforce = mf;
acc = new PVector(0, 0);
vel = new PVector(maxspeed, 0);
}
public void drag() {
// If we are draging the ball, we calculate the angle between the
// pendulum origin and mouse location
// we assign that angle to the pendulum
if (dragging) {
PVector diff =
PVector.sub(origin, new PVector(mouseX, mouseY)); // Difference between 2 points
theta = atan2(-1 * diff.y, diff.x) - radians(90); // Angle relative to vertical axis
}
}
// This constructor could be improved to allow a greater variety of pendulums
Pendulum(PVector origin_, float r_) {
// Fill all variables
origin = origin_.get();
r = r_;
theta = 0.0f;
// calculate the location of the ball using polar to cartesian conversion
float x = r * sin(theta);
float y = r * cos(theta);
loc = new PVector(origin.x + x, origin.y + y);
theta_vel = 0.0f;
theta_acc = 0.0f;
damping = 0.995f; // Arbitrary damping
ballr = 16.0f; // Arbitrary ball radius
}
public void render() {
// Draw a triangle rotated in the direction of velocity
float theta = vel.heading2D() + PApplet.radians(90);
fill(100);
stroke(0);
pushMatrix();
translate(loc.x, loc.y);
rotate(theta);
beginShape(PConstants.TRIANGLES);
vertex(0, -r * 2);
vertex(-r, r * 2);
vertex(r, r * 2);
endShape();
if (debug) {
stroke(50);
line(0, 0, 0, -sight);
}
popMatrix();
}
// Wraparound
public void borders() {
if (loc.x < -r) loc.x = width + r;
if (loc.y < -r) loc.y = height + r;
if (loc.x > width + r) loc.x = -r;
if (loc.y > height + r) loc.y = -r;
}
public void avoid(ArrayList obstacles) {
// Make a vector that will be the position of the object
// relative to the Boid rotated in the direction of boid's velocity
PVector closestRotated = new PVector(sight + 1, sight + 1);
float closestDistance = 99999;
Obstacle avoid = null;
// Let's look at each obstacle
for (int i = 0; i < obstacles.size(); i++) {
Obstacle o = (Obstacle) obstacles.get(i);
float d = PVector.dist(loc, o.loc);
PVector dir = vel.get();
dir.normalize();
PVector diff = PVector.sub(o.loc, loc);
// Now we use the dot product to rotate the vector that points from boid to obstacle
// Velocity is the new x-axis
PVector rotated = new PVector(diff.dot(dir), diff.dot(getNormal(dir)));
// Is the obstacle in our path?
if (PApplet.abs(rotated.y) < (o.radius + r)) {
// Is it the closest obstacle?
if ((rotated.x > 0) && (rotated.x < closestRotated.x)) {
closestRotated = rotated;
avoid = o;
}
}
}
// Can we actually see the closest one?
if (PApplet.abs(closestRotated.x) < sight) {
// The desired vector should point away from the obstacle
// The closer to the obstacle, the more it should steer
PVector desired =
new PVector(closestRotated.x, -closestRotated.y * sight / closestRotated.x);
desired.normalize();
desired.mult(closestDistance);
desired.limit(maxspeed);
// Rotate back to the regular coordinate system
rotateVector(desired, vel.heading2D());
// Draw some debugging stuff
if (debug) {
stroke(0);
line(loc.x, loc.y, loc.x + desired.x * 10, loc.y + desired.y * 10);
avoid.highlight(true);
}
// Apply Reynolds steering rules
desired.sub(vel);
desired.limit(maxforce);
acc.add(desired);
}
}
