// calculate the y-direction on collision
public void bounceY() {
double tx = vel * Math.cos(theta);
double ty = vel * Math.sin(theta);
theta = Math.atan2(-ty, tx);
if (y < 0) {
y = -y;
}
if (y > Engine.getGameHeight()) {
y = Engine.getGameHeight() * 2 - y;
}
if (y < 0 || y > Engine.getGameHeight()) {
y = Math.random() * Engine.getGameHeight();
}
}
public Entity() {
x = Math.random() * Engine.getGameWidth();
y = Math.random() * Engine.getGameHeight();
fTheta = Math.random() * Math.PI * 2;
pTheta = Math.random() * Math.PI * 2;
dFTheta = (Math.random() * 2 - 1) * Math.PI / 50;
dPTheta = (Math.random() * 2 - 1) * Math.PI / 50;
mass = 100;
}