compute base output key using secp256k1_ec_pubkey_tweak_add
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Calculating
P_k = B_spend + t_k * G
can be done in one shot using the function for additive pubkey tweaking
(-> tweak B_spend with t_k), which is simpler and should also be
slightly faster than multiplying and adding up successively.
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Calculating$P_k = B_{spend} + t_k * G$ (being called "base output key" in this code base) can be done in one shot using the function for additive pubkey tweaking (-> tweak B_spend with t_k), which is simpler and should also be slightly faster than multiplying and adding up successively.
I came across this code in the course of investigating existing BIP-352 implementations w.r.t. scanning, trying to find a proper approach for a new secp256k1 "silentpayments" module (bitcoin-core/secp256k1#1765).