m2b-ar-tp2/fish_schooling.cpp
2021-10-06 19:49:42 +02:00

62 lines
1.7 KiB
C++

#include "fish_schooling.h"
#include <QRandomGenerator>
static double generateDoubleBetween(QRandomGenerator *rng,
double min, double max) {
return rng->generateDouble() * (max - min) + min;
}
FishSchooling::FishSchooling(size_t count, QVector3D bounds)
:bounds(bounds) {
QRandomGenerator *rng = QRandomGenerator::global();
for (size_t i = 0; i < count; i++) {
QVector3D position(
generateDoubleBetween(rng, -bounds.x()/2, bounds.x()/2),
generateDoubleBetween(rng, -bounds.y()/2, bounds.y()/2),
generateDoubleBetween(rng, -bounds.z()/2, bounds.z()/2));
QVector3D velocity(
generateDoubleBetween(rng, -5, 5),
generateDoubleBetween(rng, -5, 5),
generateDoubleBetween(rng, -5, 5));
float size = 10;
fishes.push_back({position, velocity, size, size * 10});
}
}
void FishSchooling::animate(float dt) {
for (Fish &fish : fishes) {
size_t n_neighbors = 0;
QVector3D distance;
QVector3D cog;
QVector3D velocity;
for (Fish &fish2 : fishes) {
if (&fish2 != &fish && fish.isCloseTo(fish2.position)) {
distance += fish2.position - fish.position;
cog += fish2.position;
velocity += fish2.velocity;
n_neighbors++;
}
}
if (n_neighbors != 0) {
distance /= n_neighbors;
cog /= n_neighbors;
velocity /= n_neighbors;
QVector3D separation = -distance;
QVector3D alignment = fish.velocity - velocity;
QVector3D cohesion = cog - fish.position;
QVector3D velocity_tgt = .8 * separation + 1.5 * alignment + cohesion;
const float L = .1;
fish.velocity = L * velocity_tgt + (1 - L) * fish.velocity;
}
float speed = fish.velocity.length();
if (speed > 10) {
fish.velocity = fish.velocity / speed * 10;
}
fish.position += fish.velocity * dt;
}
}