void Flock::update(const Scene & scene){
for(std::vector<Boid * >::iterator it = boids.begin(); it != boids.end(); ++it) {
int index = it - boids.begin();
Vector v = rule1(index) + rule2(index) + rule3(index);
v = v * damping;
Boid * boid = *it;
v = v + boid->getVelocity();
if(v.getLength() > maxSpeed){
v = v * (maxSpeed/v.getLength());
}
Point p = boid->getCenter();
double wind = 0.12;
Vector windVector;
if(p.x> 900 ){
windVector = Vector(-wind,0);
} else if(p.x< 150 ){
windVector = Vector(wind,0);
} else if(p.y> 350 ){
windVector = Vector(0,-wind);
} else if(p.y< 150 ){
windVector = Vector(0,wind);
}
boid->setVelocity(v + windVector);
boid->setCenter(boid->getCenter() + boid->getVelocity());
}
}
Vector Flock::rule2(unsigned index){
Vector res;
for(std::vector<Boid * >::iterator it = boids.begin(); it != boids.end(); ++it) {
if(*it != boids.at(index)){
Boid * boid = *it;
if(boid->getCenter().distance(boids.at(index)->getCenter()) < separation){
Vector v(boid->getCenter(),boids.at(index)->getCenter());
double factor = separation / (v.getLength() * v.getLength());
if(factor > 100){ factor = 100; } ;
v = v * factor;
res = res + v;
}
}
}
return res;
}
Vector Flock::rule1(unsigned index){
Point flockCenter;
for(std::vector<Boid * >::iterator it = boids.begin(); it != boids.end(); ++it) {
if(*it != boids.at(index)){
Boid * boid = *it;
flockCenter = flockCenter+boid->getCenter();
}
}
flockCenter /= boids.size();
Vector v(boids.at(index)->getCenter(),flockCenter);
v = v*cohesion;
return v;
}
