|
|
|
using System;
|
|
|
|
using System.Runtime.InteropServices;
|
|
|
|
using gaemstone.ECS.Utility;
|
|
|
|
using static flecs_hub.flecs;
|
|
|
|
|
|
|
|
namespace gaemstone.ECS;
|
|
|
|
|
|
|
|
public static class ObserverExtensions
|
|
|
|
{
|
|
|
|
public static unsafe Entity<TContext> InitObserver<TContext>(this Entity<TContext> entity,
|
|
|
|
FilterDesc filter, Action<Iterator<TContext>> callback, params Entity[] events)
|
|
|
|
{
|
|
|
|
if (events.Length == 0) throw new ArgumentException("Must specify at least 1 event", nameof(events));
|
|
|
|
if (events.Length > 8) throw new ArgumentException("Must specify at most 8 events", nameof(events));
|
|
|
|
|
|
|
|
var world = entity.World;
|
|
|
|
var internalCallback = (nint iterPtr) => callback(new((ecs_iter_t*)iterPtr));
|
|
|
|
using var alloc = TempAllocator.Use();
|
|
|
|
var desc = new ecs_observer_desc_t {
|
|
|
|
entity = entity,
|
|
|
|
filter = filter.ToFlecs(alloc),
|
|
|
|
binding_ctx = (void*)CallbackContextHelper.Create(internalCallback),
|
|
|
|
binding_ctx_free = new() { Data = new() { Pointer = &FreeContext } },
|
|
|
|
callback = new() { Data = new() { Pointer = &Callback } },
|
|
|
|
};
|
|
|
|
var span = desc.events;
|
|
|
|
for (var i = 0; i < events.Length; i++)
|
|
|
|
span[i] = events[i];
|
|
|
|
if (ecs_observer_init(world, &desc).Data == default)
|
|
|
|
throw new InvalidOperationException();
|
|
|
|
return entity;
|
|
|
|
}
|
|
|
|
|
|
|
|
[UnmanagedCallersOnly]
|
|
|
|
private static unsafe void Callback(ecs_iter_t* iter)
|
|
|
|
=> CallbackContextHelper
|
|
|
|
.Get<Action<nint>>((nint)iter->binding_ctx)
|
|
|
|
.Invoke((nint)iter);
|
|
|
|
|
|
|
|
[UnmanagedCallersOnly]
|
|
|
|
private static unsafe void FreeContext(void* context)
|
|
|
|
=> CallbackContextHelper.Free((nint)context);
|
|
|
|
}
|