encompass-cs/encompass-cs/ComponentUpdateManager.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;

namespace Encompass
{
    internal class ComponentUpdateManager
    {
        private readonly ComponentStore existingAndPendingComponentStore;
        private readonly ComponentStore existingComponentStore;
        private readonly ComponentStore pendingComponentStore;
        private readonly Dictionary<Type, Dictionary<Entity, int>> typeToEntityToPendingComponentPriority = new Dictionary<Type, Dictionary<Entity, int>>(128);
        private Dictionary<Type, int> typeToIndex;
        public ComponentStore UpToDateComponentStore { get; private set; }

        // bitarray references to avoid garbage collection
        BitArray pendingMask;
        BitArray readMask;
        BitArray withMask;
        BitArray withoutMask;
        BitArray notWithMask;
        BitArray solverArrayA;
        BitArray solverArrayB;
        BitArray solverArrayC;

        public ComponentUpdateManager(Dictionary<Type, int> typeToIndex)
        {
            existingAndPendingComponentStore = new ComponentStore(typeToIndex);
            existingComponentStore = new ComponentStore(typeToIndex);
            pendingComponentStore = new ComponentStore(typeToIndex);
            UpToDateComponentStore = new ComponentStore(typeToIndex);
            this.typeToIndex = typeToIndex;
        }

        public void RegisterComponentType<TComponent>() where TComponent : struct, IComponent
        {
            existingAndPendingComponentStore.RegisterComponentType<TComponent>();
            existingComponentStore.RegisterComponentType<TComponent>();
            pendingComponentStore.RegisterComponentType<TComponent>();
            UpToDateComponentStore.RegisterComponentType<TComponent>();
        }

        public void FinishRegistering()
        {
            existingAndPendingComponentStore.FinishRegistering();
            existingComponentStore.FinishRegistering();
            pendingComponentStore.FinishRegistering();
            UpToDateComponentStore.FinishRegistering();

            pendingMask = new BitArray(typeToIndex.Count);
            readMask = new BitArray(typeToIndex.Count);
            withMask = new BitArray(typeToIndex.Count);
            withoutMask = new BitArray(typeToIndex.Count);
            notWithMask = new BitArray(typeToIndex.Count);
            solverArrayA = new BitArray(typeToIndex.Count);
            solverArrayB = new BitArray(typeToIndex.Count);
            solverArrayC = new BitArray(typeToIndex.Count);
        }

        internal void Clear()
        {
            existingAndPendingComponentStore.ClearAll();
            existingComponentStore.ClearAll();
            pendingComponentStore.ClearAll();
            UpToDateComponentStore.ClearAll();

            foreach (var dictionary in typeToEntityToPendingComponentPriority.Values)
            {
                dictionary.Clear();
            }
        }

        internal void SetStartingComponentStore(ComponentStore componentStore)
        {
            UpToDateComponentStore = componentStore;
        }

        internal void AddExistingComponent<TComponent>(Entity entity, TComponent component) where TComponent : struct, IComponent
        {
            RegisterExistingOrPendingComponentMessage(entity, component);

            existingComponentStore.Set(entity, component);
        }

        internal bool AddPendingComponent<TComponent>(Entity entity, TComponent component, int priority) where TComponent : struct, IComponent
        {
            if (pendingComponentStore.Set(entity, component, priority))
            {
                RegisterExistingOrPendingComponentMessage(entity, component);
                return true;
            }

            return false;
        }

        private void RegisterExistingOrPendingComponentMessage<TComponent>(Entity entity, TComponent component) where TComponent : struct, IComponent
        {
            existingAndPendingComponentStore.Set(entity, component);
            UpToDateComponentStore.Set(entity, component);
        }

        public bool UpdateComponent<TComponent>(Entity entity, TComponent component, int priority) where TComponent : struct, IComponent
        {
            return UpToDateComponentStore.Set<TComponent>(entity, component, priority);
        }

        // general component reads by type

        internal IEnumerable<(TComponent, Entity)> ReadExistingAndPendingComponentsByType<TComponent>() where TComponent : struct, IComponent
        {
            return existingAndPendingComponentStore.All<TComponent>();
        }

        internal IEnumerable<(TComponent, Entity)> ReadExistingComponentsByType<TComponent>() where TComponent : struct, IComponent
        {
            return existingComponentStore.All<TComponent>();
        }

        internal IEnumerable<(TComponent, Entity)> ReadPendingComponentsByType<TComponent>() where TComponent : struct, IComponent
        {
            return pendingComponentStore.All<TComponent>();
        }

        // singular component reads by type

        internal (TComponent, Entity) ReadFirstExistingOrPendingComponentByType<TComponent>() where TComponent : struct, IComponent
        {
            if (!SomeExistingOrPendingComponent<TComponent>()) { throw new Exceptions.NoComponentOfTypeException($"No Component with type {typeof(TComponent)} exists"); }
            var enumerator = ReadExistingAndPendingComponentsByType<TComponent>().GetEnumerator();
            enumerator.MoveNext();
            return enumerator.Current;
        }

        internal (TComponent, Entity) ReadFirstExistingComponentByType<TComponent>() where TComponent : struct, IComponent
        {
            if (!SomeExistingComponent<TComponent>()) { throw new Exceptions.NoComponentOfTypeException($"No Component with type {typeof(TComponent)} exists"); }
            var enumerator = ReadExistingComponentsByType<TComponent>().GetEnumerator();
            enumerator.MoveNext();
            return enumerator.Current;
        }

        internal (TComponent, Entity) ReadFirstPendingComponentByType<TComponent>() where TComponent : struct, IComponent
        {
            if (!SomePendingComponent<TComponent>()) { throw new Exceptions.NoComponentOfTypeException($"No Component with type {typeof(TComponent)} exists"); }
            var enumerator = ReadPendingComponentsByType<TComponent>().GetEnumerator();
            enumerator.MoveNext();
            return enumerator.Current;
        }

        // check if some component of type exists in the world

        internal bool SomeExistingOrPendingComponent<TComponent>() where TComponent : struct, IComponent
        {
            return existingAndPendingComponentStore.Any<TComponent>();
        }

        internal bool SomeExistingComponent<TComponent>() where TComponent : struct, IComponent
        {
            return existingComponentStore.Any<TComponent>();
        }

        internal bool SomePendingComponent<TComponent>() where TComponent : struct, IComponent
        {
            return pendingComponentStore.Any<TComponent>();
        }

        // read components by entity and type

        internal TComponent ReadExistingComponentByEntityAndType<TComponent>(Entity entity) where TComponent : struct, IComponent
        {
            return existingComponentStore.Get<TComponent>(entity);
        }

        internal TComponent ReadPendingComponentByEntityAndType<TComponent>(Entity entity) where TComponent : struct, IComponent
        {
            return pendingComponentStore.Get<TComponent>(entity);
        }

        // check if entity has component of type

        internal bool HasExistingOrPendingComponent<TComponent>(Entity entity) where TComponent : struct, IComponent
        {
            return existingAndPendingComponentStore.Has<TComponent>(entity);
        }

        internal bool HasExistingOrPendingComponent(Entity entity, Type type)
        {
            return existingAndPendingComponentStore.Has(type, entity);
        }

        internal bool HasExistingComponent<TComponent>(Entity entity) where TComponent : struct, IComponent
        {
            return existingComponentStore.Has<TComponent>(entity);
        }

        internal bool HasExistingComponent(Entity entity, Type type)
        {
            return existingComponentStore.Has(type, entity);
        }

        internal bool HasPendingComponent<TComponent>(Entity entity) where TComponent : struct, IComponent
        {
            return pendingComponentStore.Has<TComponent>(entity);
        }

        internal bool HasPendingComponent(Entity entity, Type type)
        {
            return pendingComponentStore.Has(type, entity);
        }

        internal void Remove<TComponent>(Entity entity) where TComponent : struct, IComponent
        {
            UpToDateComponentStore.Remove<TComponent>(entity);
        }

        internal IEnumerable<Entity> QueryEntities(IEnumerable<Entity> entities, HashSet<Type> readTypes, HashSet<Type> readPendingTypes, IEnumerable<Type> withTypes, IEnumerable<Type> withoutTypes)
        {
            pendingMask.SetAll(false);
            foreach (var type in readPendingTypes)
            {
                pendingMask.Set(typeToIndex[type], true);
            }

            readMask.SetAll(false);
            foreach (var type in readTypes)
            {
                readMask.Set(typeToIndex[type], true);
            }

            withMask.SetAll(false);
            foreach (var type in withTypes)
            {
                withMask.Set(typeToIndex[type], true);
            }

            withoutMask.SetAll(false);
            foreach (var type in withoutTypes)
            {
                withoutMask.Set(typeToIndex[type], true);
            }

            notWithMask.SetAll(false);
            notWithMask.Or(withMask).Not();

            foreach (var entity in entities)
            {
                var pendingEntity = pendingComponentStore.EntityBitArray(entity);
                var existingEntity = existingComponentStore.EntityBitArray(entity);

                if (VerifyTypes(pendingEntity, existingEntity, readMask, pendingMask, withMask, withoutMask, notWithMask)) { yield return entity; }
            }
        }

        internal bool VerifyTypes(BitArray pendingEntity, BitArray existingEntity, BitArray readMask, BitArray pendingMask, BitArray withMask, BitArray withoutMask, BitArray notWithMask)
        {
            solverArrayA.SetAll(false);
            solverArrayB.SetAll(false);
            solverArrayC.SetAll(false);

            solverArrayA.Or(pendingMask).And(withMask).And(pendingEntity);
            solverArrayB.Or(readMask).And(withMask).And(existingEntity);
            solverArrayA.Or(solverArrayB).Or(notWithMask);

            solverArrayB.SetAll(false);
            solverArrayB.Or(pendingMask).And(withoutMask).And(pendingEntity).Not();
            solverArrayC.Or(readMask).And(withoutMask).And(existingEntity).Not();
            solverArrayB.And(solverArrayC);

            solverArrayA.And(solverArrayB);

            return !solverArrayA.Cast<bool>().Contains(false);
        }
    }
}