public static void InitEmitterBoxSource(EntityManager mgr, Entity emitter, NativeArray <Entity> particles)
{
var source = mgr.GetComponentData <EmitterBoxSource>(emitter);
foreach (var particle in particles)
{
var pos = ParticlesUtil.RandomPointInRect(source.rect);
// center the box at the origin.
// TODO: we could precompute the proper source rect (basically move the origin x/y by half) and
// stash it somewhere to avoid division here
pos.x -= source.rect.width / 2.0f;
pos.y -= source.rect.height / 2.0f;
var Translation = mgr.GetComponentData <Translation>(particle);
Translation.Value += new float3(pos.x, pos.y, 0.0f);
mgr.SetComponentData(particle, Translation);
}
}
