/// <summary>
/// Gets an <see cref="EntityQueryMask"/> that can be used to quickly match if an entity belongs to an EntityQuery.
/// There is a maximum limit of 1024 EntityQueryMasks that can be created. EntityQueryMasks cannot be created
/// from EntityQueries with filters.
/// </summary>
/// <param name="query">The EntityQuery that describes the EntityQueryMask.</param>
/// <returns>The EntityQueryMask corresponding to the EntityQuery.</returns>
public EntityQueryMask GetEntityQueryMask(EntityQuery query)
{
if (query.HasFilter())
{
throw new Exception("GetEntityQueryMask can only be called on an EntityQuery without a filter applied to it."
+ " You can call EntityQuery.ResetFilter to remove the filters from an EntityQuery.");
}
if (query.m_QueryData->EntityQueryMask.IsCreated())
{
return(query.m_QueryData->EntityQueryMask);
}
if (m_EntityQueryManager.m_EntityQueryMasksAllocated >= 1024)
{
throw new Exception("You have reached the limit of 1024 unique EntityQueryMasks, and cannot generate any more.");
}
var mask = new EntityQueryMask(
(byte)(m_EntityQueryManager.m_EntityQueryMasksAllocated / 8),
(byte)(1 << (m_EntityQueryManager.m_EntityQueryMasksAllocated % 8)),
query.EntityComponentStore);
m_EntityQueryManager.m_EntityQueryMasksAllocated++;
for (var i = 0; i < query.m_QueryData->MatchingArchetypes.Length; ++i)
{
query.m_QueryData->MatchingArchetypes.Ptr[i]->Archetype->QueryMaskArray[mask.Index] |= mask.Mask;
}
query.m_QueryData->EntityQueryMask = mask;
return(mask);
}
