Store the position of an entity

You can store (write to the state fabric) the position of an entity using an integer data structure. These examples use the following function:

Result<void> StoreEntityIndexKey(
    Transaction& txn, 
    const Entity& entity, 
    TypeId keyTypeId, 
    std::int8_t* src, 
    std::size_t length)

Note

You must provide Api::BuiltinTypeId::Vector3F32 to Api::StoreEntityIndexKey(), as shown in the following examples.

Example using an array to represent the position

Result<void> SetEntityPositionByFloatArray(
    Api::Entity& entity, 
    Transaction& transaction)
{
    std::array<float, 3> position = { /* x */ 25, /* y */ 21, /* z */ 0 };
    
    auto* src = reinterpret_cast<std::int8_t*>(position.data());
    std::size_t length = sizeof(position);
    
    WEAVERRUNTIME_TRY(Api::StoreEntityIndexKey(
        transaction,
        entity,
        Api::BuiltinTypeIdToTypeId(Api::BuiltinTypeId::Vector3F32),
        src,
        length));
}

Example using a struct to represent the position

struct Position 
{
   float x;
   float y;
   float z;
};

Result<void> SetEntityPositionByStruct(
    Api::Entity& entity, 
    Transaction& transaction)
{
    Position position = { /* x */ 25, /* y */ 21, /* z */ 0 };
    
    auto* src = reinterpret_cast<std::int8_t*>(&position);
    std::size_t length = sizeof(position);
    
    WEAVERRUNTIME_TRY(Api::StoreEntityIndexKey(
        transaction,
        entity,
        Api::BuiltinTypeIdToTypeId(Api::BuiltinTypeId::Vector3F32),
        src,
        length));
}