NFT Merkle Distributor

[META-DREAMER]

In order to efficiently mint and distribute NFT wearables for all our buyers, we need to setup a merkle claim contract so users can pay the gas cost when they claim.

Requirements:

• Merkle distributor contract should be able to receive 1155 NFTs
• Users should be able to claim all the NFTs available to them in one transaction (can use BatchTransfer function from 1155)
• Should allow for ongoing distributions of assets with new merkle roots

Sandbox has developed a lot of this functionality in their contracts so we can likely use that as reference: https://github.com/thesandboxgame/sandbox-smart-contracts/tree/master/src/solc_0.8/claims

They even have a merkle distributor contract that supports ERC20/1155/721 all in one.

Here's the JSON and code used to generate the merkle trees: https://github.com/thesandboxgame/sandbox-smart-contracts/tree/master/data/giveaways/multi_giveaway_1

Known Origin also has something similar, but only for 721s for now: https://github.com/knownorigin/merkle-royalties-distributor/blob/master/contracts/MerkleVault.sol