public Task <EngineTickResult> Tick(EngineTickInput input)
{
if (_state != States.Idle)
{
throw new InvalidOperationException($"RuntimeEngine cannot Tick() while while in state `{_state}`");
}
_state = States.Updating;
var tick = new Task <EngineTickResult>(() =>
{
// Clear the "RemovedEntities" list from last frame.
EntityService.CommitRemoved();
// TODO: This is probably not deterministic. Update order is not guaranteeed for multithreaded bursts
// Also this many loops is nasty.
foreach (var updateBurst in SystemUpdateScheduler.UpdateBursts)
{
foreach (var sys in updateBurst.Systems)
{
foreach (var commandHandler in sys.CommandHandlers)
{
foreach (var command in input.Commands)
{
if (commandHandler.CanHandle(command))
{
commandHandler.OnCommand(command);
}
}
}
}
}
// Update all systems
foreach (var updateBurst in SystemUpdateScheduler.UpdateBursts)
{
// Lock the entity access gate if this is a multi-threaded burst.
AddEntityAccessGate.IsLocked = updateBurst.Systems.Count > 1;
// TODO: This still won't be enough to guarantee entity ID consistency.
// across different machines, since entity tick is also multithreaded.
Parallel.ForEach(updateBurst.Systems, system =>
{
if (system.HasTick)
{
((Triggers.IOnTick)system.System).OnTick();
}
if (system.HasEntityTick)
{
Parallel.ForEach(system.Entities,
entity => { ((Triggers.IOnEntityTick)system.System).OnTick(entity); });
}
});
}
// Add any entities from this frame to the system manager
if (EntityService.AddedEntities.Count > 0)
{
SystemManager.AddEntities(EntityService.AddedEntities);
}
// Process the removal from systems of any entities that were removed in this frame.
if (EntityService.RemovedEntities.Count > 0)
{
SystemManager.RemoveEntities(EntityService.RemovedEntities);
}
// Gather all the events that were added during this update step
var events = EventQueue.DequeueAll();
_state = States.AwaitingSync;
return(new EngineTickResult(events));
});
return(tick);
}
