GhostEngine/Ghost.Entities/Template/QueryEnumerable.tt

<#@ template language="C#" #>
<#@ output extension=".cs" #>
<#@ assembly name="System.Core" #>
<#@ import namespace="System.Text" #>
<#@ import namespace="System.Linq" #>
<#@ include file="Helpers.ttinclude" #>

using Ghost.Entities.Components;
using Ghost.Entities.Query;
using Ghost.Entities.Utilities;
using Misaki.HighPerformance.Unsafe.Collections;

namespace Ghost.Entities;

<# for (int arity = 1; arity <= Amount; arity++) {
var generics = AppendGenerics(arity);
var restrictions = AppendGenericRestrictions(arity, "struct, IComponentData");
var poolParams = Enumerable.Range(0, arity)
                            .Select(i => $"ComponentPool<T{i}> pool{i}")
                            .Aggregate((a, b) => a + ", " + b);
var constructorParams = Enumerable.Range(0, arity)
                                    .Select(i => $"_pool{i}")
                                    .Aggregate((a, b) => a + ", " + b);
    
#>
public struct QueryEnumerable<<#= generics #>>
    <#= restrictions #>
{
    private readonly World _world;

<# for (int i = 0; i < arity; i++){ #>
    private readonly ComponentPool<T<#= i #>> _pool<#= i #>;
<# } #>
    private readonly int _count;

    private QueryFilter _filters;
    internal readonly QueryFilter Filters => _filters;

    internal QueryEnumerable(World world, <#= poolParams #>, int count)
    {
        _world = world;

<# for (int i = 0; i < arity; i++) { #>
        _pool<#= i #> = pool<#= i #>;
<# } #>

        _count = count;
        
        _filters = new();
<# for (int i = 0; i < arity; i++) {#>
        _filters._all.Add(TypeHandle.Get<T<#= i #>>());
<# } #>
    }

    public readonly Enumerator GetEnumerator() => new (_world, <#= constructorParams #>, _count, _filters);

    public ref struct Enumerator
    {
        private readonly World _world;
        private readonly ReadOnlySpan<Entity> _entities;

<# for (int i = 0; i < arity; i++){ #>
        private readonly ComponentPool<T<#= i #>> _pool<#= i #>;
<# } #>

        private int _index;
        private readonly int _count;

        private BitSet _filterMask;
        
        public QueryItem<<#= generics #>> Current
        {
            get;
            private set;
        }

        internal Enumerator(World world, <#= poolParams #>, int count, QueryFilter filters)
        {
            _world = world;
            _entities = _world.EntityManager.Entities;

<# for (int i = 0; i < arity; i++){ #>
            _pool<#= i #> = pool<#= i #>;
<# } #>

            _count = count;
            _index = -1;
            _filterMask = new BitSet(_world.EntityManager.EntityCount);
            filters.ComputeFilterBitMask(_world, _filterMask);

            Current = default;
        }

        public bool MoveNext()
        {
            _index = _filterMask.NextSetBit(_index + 1);
            if (_index < 0 || _index >= _world.EntityManager.EntityCount)
            {
                return false;
            }

            Current = new QueryItem<<#= generics #>>(_entities[_index], <#= constructorParams #>);
            return true;
        }
    }
<# for (int i = 1; i <= ExtensionAmount; i++) {
var compGenerics = AppendGenerics(i, "TComponent");
var compRestrictions = AppendGenericRestrictions(i, "TComponent", "struct, IComponentData");
#>

	public readonly QueryEnumerable<<#= generics #>> WithAll<<#= compGenerics #>>()
		<#= compRestrictions #>
	{
<# for (int j = 0; j < i; j++) {#>
        _filters._all.Add(TypeHandle.Get<TComponent<#= j #>>());
<# } #>
        return this;
	}

    public readonly QueryEnumerable<<#= generics #>> WithAny<<#= compGenerics #>>()
		<#= compRestrictions #>
	{
<# for (int j = 0; j < i; j++) {#>
        _filters._any.Add(TypeHandle.Get<TComponent<#= j #>>());
<# } #>
        return this;
	}

    public readonly QueryEnumerable<<#= generics #>> WithAbsent<<#= compGenerics #>>()
		<#= compRestrictions #>
	{
<# for (int j = 0; j < i; j++) {#>
        _filters._absent.Add(TypeHandle.Get<TComponent<#= j #>>());
<# } #>
        return this;
	}

    public readonly QueryEnumerable<<#= generics #>> WithDisabled<<#= compGenerics #>>()
		<#= compRestrictions #>
	{
<# for (int j = 0; j < i; j++) {#>
        _filters._disabled.Add(TypeHandle.Get<TComponent<#= j #>>());
<# } #>
        return this;
	}
<# } #>
}

<# } #>