TurretAspect.cs

using Tutorials.Tanks.Step2;
using Unity.Entities;
using Unity.Mathematics;
using Unity.Rendering;

namespace Tutorials.Tanks.Step4
{
    // Instead of directly accessing the Turret component, we are creating an aspect.
    // Aspects allows you to provide a customized API for accessing components.
    public readonly partial struct TurretAspect : IAspect
    {
        // This reference provides read only access to the Turret component.
        // Trying to access ValueRW (instead of ValueRO) from a RefRO is an error.
        readonly RefRO<Turret> m_Turret;

        // Used in Step 8. Making this Optional means instances of the aspect
        // can represent entities which do not have this component.
        readonly RefRO<URPMaterialPropertyBaseColor> m_BaseColor;

        public Entity CannonBallSpawn => m_Turret.ValueRO.CannonBallSpawn;
        public Entity CannonBallPrefab => m_Turret.ValueRO.CannonBallPrefab;
        public float4 Color => m_BaseColor.ValueRO.Value;
    }
}