findNearbyParticlesToOutput method
Finds nearby particles using circular query and fills the given list.
output: List to fill with found particle indices.
Implementation
void findNearbyParticlesToOutput(
double x, double y, double searchRadius, List<int> output) {
final List<QuadTreeParticle> found = [];
_root.queryCircle(x, y, searchRadius, found);
for (var i = 0; i < found.length; i++) {
output.add(found[i].index);
}
}