AuraAccess

A general aura transfer contract. Targets distinguish auras by Holder<Aura>; capacities, requests and remainders are finite, non-negative double values, including fractions. Block stores and position-bound world pools can implement it. See ItemAuraAccess for items.

Member	Meaning
Object2DoubleMap<Holder<Aura>> getCapacity(@Nullable LivingEntity entity, Provider registries)	Query capacity by aura; the holder may be absent.
double getCapacity(@Nullable LivingEntity entity, Provider registries, Holder<Aura> aura)	Query one aura's capacity; reads the map by default.
double insert(@Nullable LivingEntity entity, Provider registries, Holder<Aura> aura, double amount, boolean exact, boolean simulate)	Insert aura and return the amount not moved.
double extract(@Nullable LivingEntity entity, Provider registries, Holder<Aura> aura, double amount, boolean exact, boolean simulate)	Extract aura and return the amount not moved.
static double requireNonNegative(double amount)	Reject negatives, NaN and infinities; invalid Java calls throw IllegalArgumentException.

exact=true requires the entire request or no write; exact=false moves the portion that fits. simulate=true only checks: it must not write components, create attachments, run callbacks or normalize existing stock. Zero requests write nothing. Ordinary floating-point noise may be reconciled, but a tiny request against an empty store must still fail, and a positive request that cannot produce a representable change must not report a transfer.

A remainder of 0.0 means the entire request can move; the original request means nothing can move. Each call handles one aura. Capacity is not stock: simulate extract to query extractable amounts.

Holder<Aura> names the aura; Aura.resource() only names its numeric unit. The explicit Provider also supports machines and absent holders. Calculation, persistence and synchronization retain fractions; displayed values use two decimal places.