tick method
Implementation
@override
void tick(Duration duration) {
const vecSpeedRatio = 0.1;
for (var p in particles) {
if (p == null) {
continue;
}
p.y -= p.vy * vecSpeedRatio;
p.x -= p.vx * vecSpeedRatio;
if (p.y > height || p.y < 0 || p.life == 0) {
_activateParticle(p);
}
if (p.x > width || p.x < 0 || p.life == 0) {
_activateParticle(p);
}
}
super.tick(duration);
}