public static void InitEmitterRectSource(EntityManager mgr, Entity emitter, NativeArray <Entity> particles, bool isWorld)
{
var source = mgr.GetComponentData <EmitterRectSource>(emitter);
var localToWorld = mgr.GetComponentData <LocalToWorld>(emitter);
foreach (var particle in particles)
{
var pos2 = ParticlesUtil.RandomPointInRect(source.rect);
var pos = new float3(pos2.x, pos2.y, 0.0f);
if (isWorld)
{
pos = math.mul(localToWorld.Rotation, pos);
}
var Translation = mgr.GetComponentData <Translation>(particle);
Translation.Value += pos;
mgr.SetComponentData(particle, Translation);
var particleVelocity = mgr.GetComponentData <ParticleVelocity>(particle);//new ParticleVelocity();
float speed = particleVelocity.initSpeed;
if (speed != 0f)
{
var direction = math.normalizesafe(pos);
var velocity = direction * speed;
particleVelocity.velocity = velocity;
mgr.SetComponentData(particle, particleVelocity);
}
}
}
static void InitTime(EntityManager mgr, float deltaTime, Range lifetime, NativeArray <Entity> newParticles)
{
// The time is evenly distributted from 0.0 to deltaTime.
// The time of each subsequent particle will be increased by this value.
// particle.time[0..n] = (0 * timeStep, 1 * timeStep, 2 * timeStep, ..., n * timeStep).
float timeStep = newParticles.Length > 1 ? (deltaTime / (float)(newParticles.Length - 1)) : 0.0f;
// We need to subtract deltaTime from the particle's relative time, because later in
// the same frame we are adding deltaTime to the particle's relative time when we process
// them. This ensures that the first, newly created particle will start at a relative time 0.0.
float time = -deltaTime;
foreach (var particle in newParticles)
{
var cParticle = mgr.GetComponentData <Particle>(particle);
cParticle.lifetime = ParticlesUtil.RandomRange(lifetime);
cParticle.time = time;
time += timeStep;
mgr.SetComponentData(particle, cParticle);
}
}