/** Internal routine for generating the List of particles on collision. */
public static ArrayList<Particle> generateParticles(Ball ball, Body body) {
double centerX = ball.getCenter().x();
double centerY = ball.getCenter().y();
double speed =
ball.getVelocity().magnitude() * ((body != null) ? (body.getRadius() / 100.0) : 1);
if (speed < .50) speed = .50;
if (speed > 2.50) speed = 2.50;
if (body != null) {
double max = Math.pow(body.getRadius() + ball.getRadius(), 2);
while (body.getCenter().distanceSquared(new Point2d(centerX, centerY)) < max) {
centerX -= ball.getVelocity().xComponent();
centerY -= ball.getVelocity().yComponent();
}
}
ArrayList<Particle> particles = new ArrayList<Particle>();
int num = (int) (300 * speed);
if (num < 150) num = 150;
else if (num > 400) num = 400;
for (int i = 0; i < num; i++) {
double angle = (Math.random() * 2 * Math.PI);
double xSpeed = 0.75 * (Math.random() * speed * Math.cos(angle));
double ySpeed = 0.75 * (Math.random() * speed * Math.sin(angle));
Color c;
double rand = Math.random();
if (body == null) c = CalcHelp.getShiftedColor(ball.getColor(), 100);
else if (rand < 0.3) c = CalcHelp.getShiftedColor(body.getColor(), 100);
else if (rand < 0.40) c = CalcHelp.getShiftedColor(new Color(230, 130, 70), 100);
else c = CalcHelp.getShiftedColor(ball.getColor(), 100);
Particle newParticle = new Particle(centerX, centerY, xSpeed, ySpeed, c);
particles.add(newParticle);
}
return particles;
}
void testHelper(Position position, Velocity velocity, Tester stepTest) {
DummyPhysics physics = new DummyPhysics();
physics.createGoalpost(Direction.NORTH);
physics.createGoalpost(Direction.SOUTH);
Ball ball = physics.createBall();
ball.setPosition(position);
ball.setVelocity(velocity);
for (int i = 0; i < 1000; i++) {
physics.step(dt);
stepTest.test(ball.getPosition(), ball.getVelocity());
}
physics.clean();
}
/**
* Starts the effect.
*
* @param currentLevel the level the effect is taking place on
*/
public static void start(Level currentLevel) {
started = true;
CollisionEffect.currentLevel = currentLevel;
Point2d shift = currentLevel.getShift();
Ball ball = currentLevel.getBall();
Body intersected = currentLevel.getIntersectingBody();
particles = Particle.generateParticles(ball, intersected);
shakeValues = new double[6];
double speed = ball.getVelocity().magnitude();
if (speed < .25) speed = .25;
if (speed > 2.5) speed = 2.5;
double shakeFactor = 3 * speed / currentLevel.getFollowFactor();
if (currentLevel.getFollowFactor() == 0.0) shakeFactor = .25 * speed;
// 1st value is multiplicative factor
int sign1 = -1;
if (ball.getCenter().x() + shift.x() < 0) {
sign1 = 1;
} else if (ball.getCenter().x() + shift.x() > 0) {
sign1 = CalcHelp.randomSign();
}
shakeValues[0] = CalcHelp.randomDouble(35, 40) * shakeFactor * sign1;
int sign2 = -1;
if (ball.getCenter().y() + shift.y() < 0) {
sign2 = 1;
} else if (ball.getCenter().y() + shift.y() > 0) {
sign2 = CalcHelp.randomSign();
}
shakeValues[3] = CalcHelp.randomDouble(35, 40) * shakeFactor * sign2;
// 2nd value is sinusoidal factor
shakeValues[1] = CalcHelp.randomDouble(45, 50);
shakeValues[4] = CalcHelp.randomDouble(45, 50);
// 3rd value is exponential factor
shakeValues[2] = CalcHelp.randomDouble(-.0035, -.0045);
shakeValues[5] = CalcHelp.randomDouble(-.0035, -.0045);
startTime = System.currentTimeMillis();
ball.setLaunched(false);
}