53 lines
1.6 KiB
C#
53 lines
1.6 KiB
C#
using System;
|
|
using System.Collections.Generic;
|
|
|
|
namespace MfGames.Gallium;
|
|
|
|
/// <summary>
|
|
/// Extension methods for selecting components from a list.
|
|
/// </summary>
|
|
public static class SelectComponentOrDefaultExtensions
|
|
{
|
|
/// <summary>
|
|
/// Retrieves a component from an entity and return it. If the entity does not have
|
|
/// the component, then null will be returned.
|
|
/// </summary>
|
|
/// <param name="entities">The entities to process.</param>
|
|
/// <param name="t1">The component type being searched.</param>
|
|
/// <returns>A sequence of T1 or nulls.</returns>
|
|
public static IEnumerable<object?> SelectComponent(
|
|
IEnumerable<Entity> entities,
|
|
Type t1)
|
|
{
|
|
foreach (Entity entity in entities)
|
|
{
|
|
if (entity.Has(t1))
|
|
{
|
|
yield return entity.Get<object>(t1);
|
|
}
|
|
|
|
yield return null;
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// Retrieves a component from an entity and return it. If the entity does not have
|
|
/// the component, then the default value will be returned.
|
|
/// </summary>
|
|
/// <param name="entities">The entities to process.</param>
|
|
/// <typeparam name="T1">The component type being searched.</typeparam>
|
|
/// <returns>A sequence of T1.</returns>
|
|
public static IEnumerable<T1?> SelectComponentOrDefault<T1>(this IEnumerable<Entity> entities)
|
|
{
|
|
foreach (Entity entity in entities)
|
|
{
|
|
if (entity.TryGet(out T1 v1))
|
|
{
|
|
yield return v1;
|
|
}
|
|
|
|
yield return default;
|
|
}
|
|
}
|
|
}
|