Contract Name:
PlutocatsToken
Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../utils/Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
abstract contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor () {
address msgSender = _msgSender();
_owner = msgSender;
emit OwnershipTransferred(address(0), msgSender);
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
_;
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
emit OwnershipTransferred(_owner, address(0));
_owner = address(0);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
emit OwnershipTransferred(_owner, newOwner);
_owner = newOwner;
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../IERC721.sol";
/**
* @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
* @dev See https://eips.ethereum.org/EIPS/eip-721
*/
interface IERC721Enumerable is IERC721 {
/**
* @dev Returns the total amount of tokens stored by the contract.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns a token ID owned by `owner` at a given `index` of its token list.
* Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
*/
function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256 tokenId);
/**
* @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
* Use along with {totalSupply} to enumerate all tokens.
*/
function tokenByIndex(uint256 index) external view returns (uint256);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../IERC721.sol";
/**
* @title ERC-721 Non-Fungible Token Standard, optional metadata extension
* @dev See https://eips.ethereum.org/EIPS/eip-721
*/
interface IERC721Metadata is IERC721 {
/**
* @dev Returns the token collection name.
*/
function name() external view returns (string memory);
/**
* @dev Returns the token collection symbol.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
*/
function tokenURI(uint256 tokenId) external view returns (string memory);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../../utils/introspection/IERC165.sol";
/**
* @dev Required interface of an ERC721 compliant contract.
*/
interface IERC721 is IERC165 {
/**
* @dev Emitted when `tokenId` token is transferred from `from` to `to`.
*/
event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
*/
event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
*/
event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
/**
* @dev Returns the number of tokens in ``owner``'s account.
*/
function balanceOf(address owner) external view returns (uint256 balance);
/**
* @dev Returns the owner of the `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function ownerOf(uint256 tokenId) external view returns (address owner);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
* are aware of the ERC721 protocol to prevent tokens from being forever locked.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(address from, address to, uint256 tokenId) external;
/**
* @dev Transfers `tokenId` token from `from` to `to`.
*
* WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
*
* Emits a {Transfer} event.
*/
function transferFrom(address from, address to, uint256 tokenId) external;
/**
* @dev Gives permission to `to` to transfer `tokenId` token to another account.
* The approval is cleared when the token is transferred.
*
* Only a single account can be approved at a time, so approving the zero address clears previous approvals.
*
* Requirements:
*
* - The caller must own the token or be an approved operator.
* - `tokenId` must exist.
*
* Emits an {Approval} event.
*/
function approve(address to, uint256 tokenId) external;
/**
* @dev Returns the account approved for `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function getApproved(uint256 tokenId) external view returns (address operator);
/**
* @dev Approve or remove `operator` as an operator for the caller.
* Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
*
* Requirements:
*
* - The `operator` cannot be the caller.
*
* Emits an {ApprovalForAll} event.
*/
function setApprovalForAll(address operator, bool _approved) external;
/**
* @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
*
* See {setApprovalForAll}
*/
function isApprovedForAll(address owner, address operator) external view returns (bool);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(address from, address to, uint256 tokenId, bytes calldata data) external;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @title ERC721 token receiver interface
* @dev Interface for any contract that wants to support safeTransfers
* from ERC721 asset contracts.
*/
interface IERC721Receiver {
/**
* @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
* by `operator` from `from`, this function is called.
*
* It must return its Solidity selector to confirm the token transfer.
* If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
*
* The selector can be obtained in Solidity with `IERC721.onERC721Received.selector`.
*/
function onERC721Received(address operator, address from, uint256 tokenId, bytes calldata data) external returns (bytes4);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize, which returns 0 for contracts in
// construction, since the code is only stored at the end of the
// constructor execution.
uint256 size;
// solhint-disable-next-line no-inline-assembly
assembly { size := extcodesize(account) }
return size > 0;
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
// solhint-disable-next-line avoid-low-level-calls, avoid-call-value
(bool success, ) = recipient.call{ value: amount }("");
require(success, "Address: unable to send value, recipient may have reverted");
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain`call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason, it is bubbled up by this
* function (like regular Solidity function calls).
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCall(target, data, "Address: low-level call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
* `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but also transferring `value` wei to `target`.
*
* Requirements:
*
* - the calling contract must have an ETH balance of at least `value`.
* - the called Solidity function must be `payable`.
*
* _Available since v3.1._
*/
function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
}
/**
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
* with `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
require(address(this).balance >= value, "Address: insufficient balance for call");
require(isContract(target), "Address: call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.call{ value: value }(data);
return _verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
return functionStaticCall(target, data, "Address: low-level static call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
require(isContract(target), "Address: static call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.staticcall(data);
return _verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
return functionDelegateCall(target, data, "Address: low-level delegate call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
require(isContract(target), "Address: delegate call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.delegatecall(data);
return _verifyCallResult(success, returndata, errorMessage);
}
function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
if (success) {
return returndata;
} else {
// Look for revert reason and bubble it up if present
if (returndata.length > 0) {
// The easiest way to bubble the revert reason is using memory via assembly
// solhint-disable-next-line no-inline-assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/*
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
return msg.data;
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./IERC165.sol";
/**
* @dev Implementation of the {IERC165} interface.
*
* Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
* for the additional interface id that will be supported. For example:
*
* ```solidity
* function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
* return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
* }
* ```
*
* Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
*/
abstract contract ERC165 is IERC165 {
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
return interfaceId == type(IERC165).interfaceId;
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC165 standard, as defined in the
* https://eips.ethereum.org/EIPS/eip-165[EIP].
*
* Implementers can declare support of contract interfaces, which can then be
* queried by others ({ERC165Checker}).
*
* For an implementation, see {ERC165}.
*/
interface IERC165 {
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
* to learn more about how these ids are created.
*
* This function call must use less than 30 000 gas.
*/
function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @dev String operations.
*/
library Strings {
bytes16 private constant alphabet = "0123456789abcdef";
/**
* @dev Converts a `uint256` to its ASCII `string` decimal representation.
*/
function toString(uint256 value) internal pure returns (string memory) {
// Inspired by OraclizeAPI's implementation - MIT licence
// https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
if (value == 0) {
return "0";
}
uint256 temp = value;
uint256 digits;
while (temp != 0) {
digits++;
temp /= 10;
}
bytes memory buffer = new bytes(digits);
while (value != 0) {
digits -= 1;
buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
value /= 10;
}
return string(buffer);
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
*/
function toHexString(uint256 value) internal pure returns (string memory) {
if (value == 0) {
return "0x00";
}
uint256 temp = value;
uint256 length = 0;
while (temp != 0) {
length++;
temp >>= 8;
}
return toHexString(value, length);
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
*/
function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
bytes memory buffer = new bytes(2 * length + 2);
buffer[0] = "0";
buffer[1] = "x";
for (uint256 i = 2 * length + 1; i > 1; --i) {
buffer[i] = alphabet[value & 0xf];
value >>= 4;
}
require(value == 0, "Strings: hex length insufficient");
return string(buffer);
}
}
// SPDX-License-Identifier: MIT
/// @title ERC721 Token Implementation
/*********************************
* ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
* ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
* ░░░░░░█████████░░█████████░░░ *
* ░░░░░░██░░░████░░██░░░████░░░ *
* ░░██████░░░████████░░░████░░░ *
* ░░██░░██░░░████░░██░░░████░░░ *
* ░░██░░██░░░████░░██░░░████░░░ *
* ░░░░░░█████████░░█████████░░░ *
* ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
* ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
*********************************/
// LICENSE
// ERC721.sol modifies OpenZeppelin's ERC721.sol:
// https://github.com/OpenZeppelin/openzeppelin-contracts/blob/6618f9f18424ade44116d0221719f4c93be6a078/contracts/token/ERC721/ERC721.sol
//
// ERC721.sol source code copyright OpenZeppelin licensed under the MIT License.
// With modifications by Nounders DAO.
//
//
// MODIFICATIONS:
// `_safeMint` and `_mint` contain an additional `creator` argument and
// emit two `Transfer` logs, rather than one. The first log displays the
// transfer (mint) from `address(0)` to the `creator`. The second displays the
// transfer from the `creator` to the `to` address. This enables correct
// attribution on various NFT marketplaces.
pragma solidity ^0.8.6;
import '@openzeppelin/contracts/token/ERC721/IERC721.sol';
import '@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol';
import '@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol';
import '@openzeppelin/contracts/utils/Address.sol';
import '@openzeppelin/contracts/utils/Context.sol';
import '@openzeppelin/contracts/utils/Strings.sol';
import '@openzeppelin/contracts/utils/introspection/ERC165.sol';
/**
* @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
* the Metadata extension, but not including the Enumerable extension, which is available separately as
* {ERC721Enumerable}.
*/
contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
using Address for address;
using Strings for uint256;
// Token name
string private _name;
// Token symbol
string private _symbol;
// Mapping from token ID to owner address
mapping(uint256 => address) private _owners;
// Mapping owner address to token count
mapping(address => uint256) private _balances;
// Mapping from token ID to approved address
mapping(uint256 => address) private _tokenApprovals;
// Mapping from owner to operator approvals
mapping(address => mapping(address => bool)) private _operatorApprovals;
/**
* @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
*/
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
}
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
return
interfaceId == type(IERC721).interfaceId ||
interfaceId == type(IERC721Metadata).interfaceId ||
super.supportsInterface(interfaceId);
}
/**
* @dev See {IERC721-balanceOf}.
*/
function balanceOf(address owner) public view virtual override returns (uint256) {
require(owner != address(0), 'ERC721: balance query for the zero address');
return _balances[owner];
}
/**
* @dev See {IERC721-ownerOf}.
*/
function ownerOf(uint256 tokenId) public view virtual override returns (address) {
address owner = _owners[tokenId];
require(owner != address(0), 'ERC721: owner query for nonexistent token');
return owner;
}
/**
* @dev See {IERC721Metadata-name}.
*/
function name() public view virtual override returns (string memory) {
return _name;
}
/**
* @dev See {IERC721Metadata-symbol}.
*/
function symbol() public view virtual override returns (string memory) {
return _symbol;
}
/**
* @dev See {IERC721Metadata-tokenURI}.
*/
function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
require(_exists(tokenId), 'ERC721Metadata: URI query for nonexistent token');
string memory baseURI = _baseURI();
return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : '';
}
/**
* @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
* token will be the concatenation of the `baseURI` and the `tokenId`. Empty
* by default, can be overriden in child contracts.
*/
function _baseURI() internal view virtual returns (string memory) {
return '';
}
/**
* @dev See {IERC721-approve}.
*/
function approve(address to, uint256 tokenId) public virtual override {
address owner = ERC721.ownerOf(tokenId);
require(to != owner, 'ERC721: approval to current owner');
require(
_msgSender() == owner || isApprovedForAll(owner, _msgSender()),
'ERC721: approve caller is not owner nor approved for all'
);
_approve(to, tokenId);
}
/**
* @dev See {IERC721-getApproved}.
*/
function getApproved(uint256 tokenId) public view virtual override returns (address) {
require(_exists(tokenId), 'ERC721: approved query for nonexistent token');
return _tokenApprovals[tokenId];
}
/**
* @dev See {IERC721-setApprovalForAll}.
*/
function setApprovalForAll(address operator, bool approved) public virtual override {
require(operator != _msgSender(), 'ERC721: approve to caller');
_operatorApprovals[_msgSender()][operator] = approved;
emit ApprovalForAll(_msgSender(), operator, approved);
}
/**
* @dev See {IERC721-isApprovedForAll}.
*/
function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
return _operatorApprovals[owner][operator];
}
/**
* @dev See {IERC721-transferFrom}.
*/
function transferFrom(
address from,
address to,
uint256 tokenId
) public virtual override {
//solhint-disable-next-line max-line-length
require(_isApprovedOrOwner(_msgSender(), tokenId), 'ERC721: transfer caller is not owner nor approved');
_transfer(from, to, tokenId);
}
/**
* @dev See {IERC721-safeTransferFrom}.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId
) public virtual override {
safeTransferFrom(from, to, tokenId, '');
}
/**
* @dev See {IERC721-safeTransferFrom}.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId,
bytes memory _data
) public virtual override {
require(_isApprovedOrOwner(_msgSender(), tokenId), 'ERC721: transfer caller is not owner nor approved');
_safeTransfer(from, to, tokenId, _data);
}
/**
* @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
* are aware of the ERC721 protocol to prevent tokens from being forever locked.
*
* `_data` is additional data, it has no specified format and it is sent in call to `to`.
*
* This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.
* implement alternative mechanisms to perform token transfer, such as signature-based.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function _safeTransfer(
address from,
address to,
uint256 tokenId,
bytes memory _data
) internal virtual {
_transfer(from, to, tokenId);
require(_checkOnERC721Received(from, to, tokenId, _data), 'ERC721: transfer to non ERC721Receiver implementer');
}
/**
* @dev Returns whether `tokenId` exists.
*
* Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
*
* Tokens start existing when they are minted (`_mint`),
* and stop existing when they are burned (`_burn`).
*/
function _exists(uint256 tokenId) internal view virtual returns (bool) {
return _owners[tokenId] != address(0);
}
/**
* @dev Returns whether `spender` is allowed to manage `tokenId`.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) {
require(_exists(tokenId), 'ERC721: operator query for nonexistent token');
address owner = ERC721.ownerOf(tokenId);
return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));
}
/**
* @dev Safely mints `tokenId`, transfers it to `to`, and emits two log events -
* 1. Credits the `minter` with the mint.
* 2. Shows transfer from the `minter` to `to`.
*
* Requirements:
*
* - `tokenId` must not exist.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function _safeMint(
address creator,
address to,
uint256 tokenId
) internal virtual {
_safeMint(creator, to, tokenId, '');
}
/**
* @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is
* forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
*/
function _safeMint(
address creator,
address to,
uint256 tokenId,
bytes memory _data
) internal virtual {
_mint(creator, to, tokenId);
require(
_checkOnERC721Received(address(0), to, tokenId, _data),
'ERC721: transfer to non ERC721Receiver implementer'
);
}
/**
* @dev Mints `tokenId`, transfers it to `to`, and emits two log events -
* 1. Credits the `creator` with the mint.
* 2. Shows transfer from the `creator` to `to`.
*
* WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible
*
* Requirements:
*
* - `tokenId` must not exist.
* - `to` cannot be the zero address.
*
* Emits a {Transfer} event.
*/
function _mint(
address creator,
address to,
uint256 tokenId
) internal virtual {
require(to != address(0), 'ERC721: mint to the zero address');
require(!_exists(tokenId), 'ERC721: token already minted');
_beforeTokenTransfer(address(0), to, tokenId);
_balances[to] += 1;
_owners[tokenId] = to;
emit Transfer(address(0), creator, tokenId);
emit Transfer(creator, to, tokenId);
}
/**
* @dev Destroys `tokenId`.
* The approval is cleared when the token is burned.
*
* Requirements:
*
* - `tokenId` must exist.
*
* Emits a {Transfer} event.
*/
function _burn(uint256 tokenId) internal virtual {
address owner = ERC721.ownerOf(tokenId);
_beforeTokenTransfer(owner, address(0), tokenId);
// Clear approvals
_approve(address(0), tokenId);
_balances[owner] -= 1;
delete _owners[tokenId];
emit Transfer(owner, address(0), tokenId);
}
/**
* @dev Transfers `tokenId` from `from` to `to`.
* As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
*
* Emits a {Transfer} event.
*/
function _transfer(
address from,
address to,
uint256 tokenId
) internal virtual {
require(ERC721.ownerOf(tokenId) == from, 'ERC721: transfer of token that is not own');
require(to != address(0), 'ERC721: transfer to the zero address');
_beforeTokenTransfer(from, to, tokenId);
// Clear approvals from the previous owner
_approve(address(0), tokenId);
_balances[from] -= 1;
_balances[to] += 1;
_owners[tokenId] = to;
emit Transfer(from, to, tokenId);
}
/**
* @dev Approve `to` to operate on `tokenId`
*
* Emits a {Approval} event.
*/
function _approve(address to, uint256 tokenId) internal virtual {
_tokenApprovals[tokenId] = to;
emit Approval(ERC721.ownerOf(tokenId), to, tokenId);
}
/**
* @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
* The call is not executed if the target address is not a contract.
*
* @param from address representing the previous owner of the given token ID
* @param to target address that will receive the tokens
* @param tokenId uint256 ID of the token to be transferred
* @param _data bytes optional data to send along with the call
* @return bool whether the call correctly returned the expected magic value
*/
function _checkOnERC721Received(
address from,
address to,
uint256 tokenId,
bytes memory _data
) private returns (bool) {
if (to.isContract()) {
try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {
return retval == IERC721Receiver(to).onERC721Received.selector;
} catch (bytes memory reason) {
if (reason.length == 0) {
revert('ERC721: transfer to non ERC721Receiver implementer');
} else {
assembly {
revert(add(32, reason), mload(reason))
}
}
}
} else {
return true;
}
}
/**
* @dev Hook that is called before any token transfer. This includes minting
* and burning.
*
* Calling conditions:
*
* - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
* transferred to `to`.
* - When `from` is zero, `tokenId` will be minted for `to`.
* - When `to` is zero, ``from``'s `tokenId` will be burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(
address from,
address to,
uint256 tokenId
) internal virtual {}
}
// SPDX-License-Identifier: BSD-3-Clause
/// @title Vote checkpointing for an ERC-721 token
/*********************************
* ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
* ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
* ░░░░░░█████████░░█████████░░░ *
* ░░░░░░██░░░████░░██░░░████░░░ *
* ░░██████░░░████████░░░████░░░ *
* ░░██░░██░░░████░░██░░░████░░░ *
* ░░██░░██░░░████░░██░░░████░░░ *
* ░░░░░░█████████░░█████████░░░ *
* ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
* ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
*********************************/
// LICENSE
// ERC721Checkpointable.sol uses and modifies part of Compound Lab's Comp.sol:
// https://github.com/compound-finance/compound-protocol/blob/ae4388e780a8d596d97619d9704a931a2752c2bc/contracts/Governance/Comp.sol
//
// Comp.sol source code Copyright 2020 Compound Labs, Inc. licensed under the BSD-3-Clause license.
// With modifications by Nounders DAO.
//
// Additional conditions of BSD-3-Clause can be found here: https://opensource.org/licenses/BSD-3-Clause
//
// MODIFICATIONS
// Checkpointing logic from Comp.sol has been used with the following modifications:
// - `delegates` is renamed to `_delegates` and is set to private
// - `delegates` is a public function that uses the `_delegates` mapping look-up, but unlike
// Comp.sol, returns the delegator's own address if there is no delegate.
// This avoids the delegator needing to "delegate to self" with an additional transaction
// - `_transferTokens()` is renamed `_beforeTokenTransfer()` and adapted to hook into OpenZeppelin's ERC721 hooks.
pragma solidity ^0.8.6;
import './ERC721Enumerable.sol';
abstract contract ERC721Checkpointable is ERC721Enumerable {
/// @notice Defines decimals as per ERC-20 convention to make integrations with 3rd party governance platforms easier
uint8 public constant decimals = 0;
/// @notice A record of each accounts delegate
mapping(address => address) private _delegates;
/// @notice A checkpoint for marking number of votes from a given block
struct Checkpoint {
uint32 fromBlock;
uint96 votes;
}
/// @notice A record of votes checkpoints for each account, by index
mapping(address => mapping(uint32 => Checkpoint)) public checkpoints;
/// @notice The number of checkpoints for each account
mapping(address => uint32) public numCheckpoints;
/// @notice The EIP-712 typehash for the contract's domain
bytes32 public constant DOMAIN_TYPEHASH =
keccak256('EIP712Domain(string name,uint256 chainId,address verifyingContract)');
/// @notice The EIP-712 typehash for the delegation struct used by the contract
bytes32 public constant DELEGATION_TYPEHASH =
keccak256('Delegation(address delegatee,uint256 nonce,uint256 expiry)');
/// @notice A record of states for signing / validating signatures
mapping(address => uint256) public nonces;
/// @notice An event thats emitted when an account changes its delegate
event DelegateChanged(address indexed delegator, address indexed fromDelegate, address indexed toDelegate);
/// @notice An event thats emitted when a delegate account's vote balance changes
event DelegateVotesChanged(address indexed delegate, uint256 previousBalance, uint256 newBalance);
/**
* @notice The votes a delegator can delegate, which is the current balance of the delegator.
* @dev Used when calling `_delegate()`
*/
function votesToDelegate(address delegator) public view returns (uint96) {
return safe96(balanceOf(delegator), 'ERC721Checkpointable::votesToDelegate: amount exceeds 96 bits');
}
/**
* @notice Overrides the standard `Comp.sol` delegates mapping to return
* the delegator's own address if they haven't delegated.
* This avoids having to delegate to oneself.
*/
function delegates(address delegator) public view returns (address) {
address current = _delegates[delegator];
return current == address(0) ? delegator : current;
}
/**
* @notice Adapted from `_transferTokens()` in `Comp.sol` to update delegate votes.
* @dev hooks into OpenZeppelin's `ERC721._transfer`
*/
function _beforeTokenTransfer(
address from,
address to,
uint256 tokenId
) internal override {
super._beforeTokenTransfer(from, to, tokenId);
/// @notice Differs from `_transferTokens()` to use `delegates` override method to simulate auto-delegation
_moveDelegates(delegates(from), delegates(to), 1);
}
/**
* @notice Delegate votes from `msg.sender` to `delegatee`
* @param delegatee The address to delegate votes to
*/
function delegate(address delegatee) public {
if (delegatee == address(0)) delegatee = msg.sender;
return _delegate(msg.sender, delegatee);
}
/**
* @notice Delegates votes from signatory to `delegatee`
* @param delegatee The address to delegate votes to
* @param nonce The contract state required to match the signature
* @param expiry The time at which to expire the signature
* @param v The recovery byte of the signature
* @param r Half of the ECDSA signature pair
* @param s Half of the ECDSA signature pair
*/
function delegateBySig(
address delegatee,
uint256 nonce,
uint256 expiry,
uint8 v,
bytes32 r,
bytes32 s
) public {
bytes32 domainSeparator = keccak256(
abi.encode(DOMAIN_TYPEHASH, keccak256(bytes(name())), getChainId(), address(this))
);
bytes32 structHash = keccak256(abi.encode(DELEGATION_TYPEHASH, delegatee, nonce, expiry));
bytes32 digest = keccak256(abi.encodePacked('\x19\x01', domainSeparator, structHash));
address signatory = ecrecover(digest, v, r, s);
require(signatory != address(0), 'ERC721Checkpointable::delegateBySig: invalid signature');
require(nonce == nonces[signatory]++, 'ERC721Checkpointable::delegateBySig: invalid nonce');
require(block.timestamp <= expiry, 'ERC721Checkpointable::delegateBySig: signature expired');
return _delegate(signatory, delegatee);
}
/**
* @notice Gets the current votes balance for `account`
* @param account The address to get votes balance
* @return The number of current votes for `account`
*/
function getCurrentVotes(address account) external view returns (uint96) {
uint32 nCheckpoints = numCheckpoints[account];
return nCheckpoints > 0 ? checkpoints[account][nCheckpoints - 1].votes : 0;
}
/**
* @notice Determine the prior number of votes for an account as of a block number
* @dev Block number must be a finalized block or else this function will revert to prevent misinformation.
* @param account The address of the account to check
* @param blockNumber The block number to get the vote balance at
* @return The number of votes the account had as of the given block
*/
function getPriorVotes(address account, uint256 blockNumber) public view returns (uint96) {
require(blockNumber < block.number, 'ERC721Checkpointable::getPriorVotes: not yet determined');
uint32 nCheckpoints = numCheckpoints[account];
if (nCheckpoints == 0) {
return 0;
}
// First check most recent balance
if (checkpoints[account][nCheckpoints - 1].fromBlock <= blockNumber) {
return checkpoints[account][nCheckpoints - 1].votes;
}
// Next check implicit zero balance
if (checkpoints[account][0].fromBlock > blockNumber) {
return 0;
}
uint32 lower = 0;
uint32 upper = nCheckpoints - 1;
while (upper > lower) {
uint32 center = upper - (upper - lower) / 2; // ceil, avoiding overflow
Checkpoint memory cp = checkpoints[account][center];
if (cp.fromBlock == blockNumber) {
return cp.votes;
} else if (cp.fromBlock < blockNumber) {
lower = center;
} else {
upper = center - 1;
}
}
return checkpoints[account][lower].votes;
}
function _delegate(address delegator, address delegatee) internal {
/// @notice differs from `_delegate()` in `Comp.sol` to use `delegates` override method to simulate auto-delegation
address currentDelegate = delegates(delegator);
_delegates[delegator] = delegatee;
emit DelegateChanged(delegator, currentDelegate, delegatee);
uint96 amount = votesToDelegate(delegator);
_moveDelegates(currentDelegate, delegatee, amount);
}
function _moveDelegates(
address srcRep,
address dstRep,
uint96 amount
) internal {
if (srcRep != dstRep && amount > 0) {
if (srcRep != address(0)) {
uint32 srcRepNum = numCheckpoints[srcRep];
uint96 srcRepOld = srcRepNum > 0 ? checkpoints[srcRep][srcRepNum - 1].votes : 0;
uint96 srcRepNew = sub96(srcRepOld, amount, 'ERC721Checkpointable::_moveDelegates: amount underflows');
_writeCheckpoint(srcRep, srcRepNum, srcRepOld, srcRepNew);
}
if (dstRep != address(0)) {
uint32 dstRepNum = numCheckpoints[dstRep];
uint96 dstRepOld = dstRepNum > 0 ? checkpoints[dstRep][dstRepNum - 1].votes : 0;
uint96 dstRepNew = add96(dstRepOld, amount, 'ERC721Checkpointable::_moveDelegates: amount overflows');
_writeCheckpoint(dstRep, dstRepNum, dstRepOld, dstRepNew);
}
}
}
function _writeCheckpoint(
address delegatee,
uint32 nCheckpoints,
uint96 oldVotes,
uint96 newVotes
) internal {
uint32 blockNumber = safe32(
block.number,
'ERC721Checkpointable::_writeCheckpoint: block number exceeds 32 bits'
);
if (nCheckpoints > 0 && checkpoints[delegatee][nCheckpoints - 1].fromBlock == blockNumber) {
checkpoints[delegatee][nCheckpoints - 1].votes = newVotes;
} else {
checkpoints[delegatee][nCheckpoints] = Checkpoint(blockNumber, newVotes);
numCheckpoints[delegatee] = nCheckpoints + 1;
}
emit DelegateVotesChanged(delegatee, oldVotes, newVotes);
}
function safe32(uint256 n, string memory errorMessage) internal pure returns (uint32) {
require(n < 2**32, errorMessage);
return uint32(n);
}
function safe96(uint256 n, string memory errorMessage) internal pure returns (uint96) {
require(n < 2**96, errorMessage);
return uint96(n);
}
function add96(
uint96 a,
uint96 b,
string memory errorMessage
) internal pure returns (uint96) {
uint96 c = a + b;
require(c >= a, errorMessage);
return c;
}
function sub96(
uint96 a,
uint96 b,
string memory errorMessage
) internal pure returns (uint96) {
require(b <= a, errorMessage);
return a - b;
}
function getChainId() internal view returns (uint256) {
uint256 chainId;
assembly {
chainId := chainid()
}
return chainId;
}
}
// SPDX-License-Identifier: MIT
/// @title ERC721 Enumerable Extension
/*********************************
* ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
* ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
* ░░░░░░█████████░░█████████░░░ *
* ░░░░░░██░░░████░░██░░░████░░░ *
* ░░██████░░░████████░░░████░░░ *
* ░░██░░██░░░████░░██░░░████░░░ *
* ░░██░░██░░░████░░██░░░████░░░ *
* ░░░░░░█████████░░█████████░░░ *
* ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
* ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
*********************************/
// LICENSE
// ERC721.sol modifies OpenZeppelin's ERC721Enumerable.sol:
// https://github.com/OpenZeppelin/openzeppelin-contracts/blob/6618f9f18424ade44116d0221719f4c93be6a078/contracts/token/ERC721/extensions/ERC721Enumerable.sol
//
// ERC721Enumerable.sol source code copyright OpenZeppelin licensed under the MIT License.
// With modifications by Nounders DAO.
//
// MODIFICATIONS:
// Consumes modified `ERC721` contract. See notes in `ERC721.sol`.
pragma solidity ^0.8.0;
import './ERC721.sol';
import '@openzeppelin/contracts/token/ERC721/extensions/IERC721Enumerable.sol';
/**
* @dev This implements an optional extension of {ERC721} defined in the EIP that adds
* enumerability of all the token ids in the contract as well as all token ids owned by each
* account.
*/
abstract contract ERC721Enumerable is ERC721, IERC721Enumerable {
// Mapping from owner to list of owned token IDs
mapping(address => mapping(uint256 => uint256)) private _ownedTokens;
// Mapping from token ID to index of the owner tokens list
mapping(uint256 => uint256) private _ownedTokensIndex;
// Array with all token ids, used for enumeration
uint256[] private _allTokens;
// Mapping from token id to position in the allTokens array
mapping(uint256 => uint256) private _allTokensIndex;
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165, ERC721) returns (bool) {
return interfaceId == type(IERC721Enumerable).interfaceId || super.supportsInterface(interfaceId);
}
/**
* @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
*/
function tokenOfOwnerByIndex(address owner, uint256 index) public view virtual override returns (uint256) {
require(index < ERC721.balanceOf(owner), 'ERC721Enumerable: owner index out of bounds');
return _ownedTokens[owner][index];
}
/**
* @dev See {IERC721Enumerable-totalSupply}.
*/
function totalSupply() public view virtual override returns (uint256) {
return _allTokens.length;
}
/**
* @dev See {IERC721Enumerable-tokenByIndex}.
*/
function tokenByIndex(uint256 index) public view virtual override returns (uint256) {
require(index < ERC721Enumerable.totalSupply(), 'ERC721Enumerable: global index out of bounds');
return _allTokens[index];
}
/**
* @dev Hook that is called before any token transfer. This includes minting
* and burning.
*
* Calling conditions:
*
* - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
* transferred to `to`.
* - When `from` is zero, `tokenId` will be minted for `to`.
* - When `to` is zero, ``from``'s `tokenId` will be burned.
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(
address from,
address to,
uint256 tokenId
) internal virtual override {
super._beforeTokenTransfer(from, to, tokenId);
if (from == address(0)) {
_addTokenToAllTokensEnumeration(tokenId);
} else if (from != to) {
_removeTokenFromOwnerEnumeration(from, tokenId);
}
if (to == address(0)) {
_removeTokenFromAllTokensEnumeration(tokenId);
} else if (to != from) {
_addTokenToOwnerEnumeration(to, tokenId);
}
}
/**
* @dev Private function to add a token to this extension's ownership-tracking data structures.
* @param to address representing the new owner of the given token ID
* @param tokenId uint256 ID of the token to be added to the tokens list of the given address
*/
function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {
uint256 length = ERC721.balanceOf(to);
_ownedTokens[to][length] = tokenId;
_ownedTokensIndex[tokenId] = length;
}
/**
* @dev Private function to add a token to this extension's token tracking data structures.
* @param tokenId uint256 ID of the token to be added to the tokens list
*/
function _addTokenToAllTokensEnumeration(uint256 tokenId) private {
_allTokensIndex[tokenId] = _allTokens.length;
_allTokens.push(tokenId);
}
/**
* @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that
* while the token is not assigned a new owner, the `_ownedTokensIndex` mapping is _not_ updated: this allows for
* gas optimizations e.g. when performing a transfer operation (avoiding double writes).
* This has O(1) time complexity, but alters the order of the _ownedTokens array.
* @param from address representing the previous owner of the given token ID
* @param tokenId uint256 ID of the token to be removed from the tokens list of the given address
*/
function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {
// To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and
// then delete the last slot (swap and pop).
uint256 lastTokenIndex = ERC721.balanceOf(from) - 1;
uint256 tokenIndex = _ownedTokensIndex[tokenId];
// When the token to delete is the last token, the swap operation is unnecessary
if (tokenIndex != lastTokenIndex) {
uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];
_ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
_ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
}
// This also deletes the contents at the last position of the array
delete _ownedTokensIndex[tokenId];
delete _ownedTokens[from][lastTokenIndex];
}
/**
* @dev Private function to remove a token from this extension's token tracking data structures.
* This has O(1) time complexity, but alters the order of the _allTokens array.
* @param tokenId uint256 ID of the token to be removed from the tokens list
*/
function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {
// To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and
// then delete the last slot (swap and pop).
uint256 lastTokenIndex = _allTokens.length - 1;
uint256 tokenIndex = _allTokensIndex[tokenId];
// When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so
// rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding
// an 'if' statement (like in _removeTokenFromOwnerEnumeration)
uint256 lastTokenId = _allTokens[lastTokenIndex];
_allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
_allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
// This also deletes the contents at the last position of the array
delete _allTokensIndex[tokenId];
_allTokens.pop();
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;
/// @notice Signed 18 decimal fixed point (wad) arithmetic library.
/// @author Solmate (https://github.com/transmissions11/solmate/blob/main/src/utils/SignedWadMath.sol)
/// @author Modified from Remco Bloemen (https://xn--2-umb.com/22/exp-ln/index.html)
/// @dev Will not revert on overflow, only use where overflow is not possible.
function toWadUnsafe(uint256 x) pure returns (int256 r) {
/// @solidity memory-safe-assembly
assembly {
// Multiply x by 1e18.
r := mul(x, 1000000000000000000)
}
}
/// @dev Takes an integer amount of seconds and converts it to a wad amount of days.
/// @dev Will not revert on overflow, only use where overflow is not possible.
/// @dev Not meant for negative second amounts, it assumes x is positive.
function toDaysWadUnsafe(uint256 x) pure returns (int256 r) {
/// @solidity memory-safe-assembly
assembly {
// Multiply x by 1e18 and then divide it by 86400.
r := div(mul(x, 1000000000000000000), 86400)
}
}
/// @dev Takes a wad amount of days and converts it to an integer amount of seconds.
/// @dev Will not revert on overflow, only use where overflow is not possible.
/// @dev Not meant for negative day amounts, it assumes x is positive.
function fromDaysWadUnsafe(int256 x) pure returns (uint256 r) {
/// @solidity memory-safe-assembly
assembly {
// Multiply x by 86400 and then divide it by 1e18.
r := div(mul(x, 86400), 1000000000000000000)
}
}
/// @dev Will not revert on overflow, only use where overflow is not possible.
function unsafeWadMul(int256 x, int256 y) pure returns (int256 r) {
/// @solidity memory-safe-assembly
assembly {
// Multiply x by y and divide by 1e18.
r := sdiv(mul(x, y), 1000000000000000000)
}
}
/// @dev Will return 0 instead of reverting if y is zero and will
/// not revert on overflow, only use where overflow is not possible.
function unsafeWadDiv(int256 x, int256 y) pure returns (int256 r) {
/// @solidity memory-safe-assembly
assembly {
// Multiply x by 1e18 and divide it by y.
r := sdiv(mul(x, 1000000000000000000), y)
}
}
function wadMul(int256 x, int256 y) pure returns (int256 r) {
/// @solidity memory-safe-assembly
assembly {
// Store x * y in r for now.
r := mul(x, y)
// Combined overflow check (`x == 0 || (x * y) / x == y`) and edge case check
// where x == -1 and y == type(int256).min, for y == -1 and x == min int256,
// the second overflow check will catch this.
// See: https://secure-contracts.com/learn_evm/arithmetic-checks.html#arithmetic-checks-for-int256-multiplication
// Combining into 1 expression saves gas as resulting bytecode will only have 1 `JUMPI`
// rather than 2.
if iszero(
and(
or(iszero(x), eq(sdiv(r, x), y)),
or(lt(x, not(0)), sgt(y, 0x8000000000000000000000000000000000000000000000000000000000000000))
)
) {
revert(0, 0)
}
// Scale the result down by 1e18.
r := sdiv(r, 1000000000000000000)
}
}
function wadDiv(int256 x, int256 y) pure returns (int256 r) {
/// @solidity memory-safe-assembly
assembly {
// Store x * 1e18 in r for now.
r := mul(x, 1000000000000000000)
// Equivalent to require(y != 0 && ((x * 1e18) / 1e18 == x))
if iszero(and(iszero(iszero(y)), eq(sdiv(r, 1000000000000000000), x))) {
revert(0, 0)
}
// Divide r by y.
r := sdiv(r, y)
}
}
/// @dev Will not work with negative bases, only use when x is positive.
function wadPow(int256 x, int256 y) pure returns (int256) {
// Equivalent to x to the power of y because x ** y = (e ** ln(x)) ** y = e ** (ln(x) * y)
return wadExp((wadLn(x) * y) / 1e18); // Using ln(x) means x must be greater than 0.
}
function wadExp(int256 x) pure returns (int256 r) {
unchecked {
// When the result is < 0.5 we return zero. This happens when
// x <= floor(log(0.5e18) * 1e18) ~ -42e18
if (x <= -42139678854452767551) return 0;
// When the result is > (2**255 - 1) / 1e18 we can not represent it as an
// int. This happens when x >= floor(log((2**255 - 1) / 1e18) * 1e18) ~ 135.
if (x >= 135305999368893231589) revert("EXP_OVERFLOW");
// x is now in the range (-42, 136) * 1e18. Convert to (-42, 136) * 2**96
// for more intermediate precision and a binary basis. This base conversion
// is a multiplication by 1e18 / 2**96 = 5**18 / 2**78.
x = (x << 78) / 5**18;
// Reduce range of x to (-½ ln 2, ½ ln 2) * 2**96 by factoring out powers
// of two such that exp(x) = exp(x') * 2**k, where k is an integer.
// Solving this gives k = round(x / log(2)) and x' = x - k * log(2).
int256 k = ((x << 96) / 54916777467707473351141471128 + 2**95) >> 96;
x = x - k * 54916777467707473351141471128;
// k is in the range [-61, 195].
// Evaluate using a (6, 7)-term rational approximation.
// p is made monic, we'll multiply by a scale factor later.
int256 y = x + 1346386616545796478920950773328;
y = ((y * x) >> 96) + 57155421227552351082224309758442;
int256 p = y + x - 94201549194550492254356042504812;
p = ((p * y) >> 96) + 28719021644029726153956944680412240;
p = p * x + (4385272521454847904659076985693276 << 96);
// We leave p in 2**192 basis so we don't need to scale it back up for the division.
int256 q = x - 2855989394907223263936484059900;
q = ((q * x) >> 96) + 50020603652535783019961831881945;
q = ((q * x) >> 96) - 533845033583426703283633433725380;
q = ((q * x) >> 96) + 3604857256930695427073651918091429;
q = ((q * x) >> 96) - 14423608567350463180887372962807573;
q = ((q * x) >> 96) + 26449188498355588339934803723976023;
/// @solidity memory-safe-assembly
assembly {
// Div in assembly because solidity adds a zero check despite the unchecked.
// The q polynomial won't have zeros in the domain as all its roots are complex.
// No scaling is necessary because p is already 2**96 too large.
r := sdiv(p, q)
}
// r should be in the range (0.09, 0.25) * 2**96.
// We now need to multiply r by:
// * the scale factor s = ~6.031367120.
// * the 2**k factor from the range reduction.
// * the 1e18 / 2**96 factor for base conversion.
// We do this all at once, with an intermediate result in 2**213
// basis, so the final right shift is always by a positive amount.
r = int256((uint256(r) * 3822833074963236453042738258902158003155416615667) >> uint256(195 - k));
}
}
function wadLn(int256 x) pure returns (int256 r) {
unchecked {
require(x > 0, "UNDEFINED");
// We want to convert x from 10**18 fixed point to 2**96 fixed point.
// We do this by multiplying by 2**96 / 10**18. But since
// ln(x * C) = ln(x) + ln(C), we can simply do nothing here
// and add ln(2**96 / 10**18) at the end.
/// @solidity memory-safe-assembly
assembly {
r := shl(7, lt(0xffffffffffffffffffffffffffffffff, x))
r := or(r, shl(6, lt(0xffffffffffffffff, shr(r, x))))
r := or(r, shl(5, lt(0xffffffff, shr(r, x))))
r := or(r, shl(4, lt(0xffff, shr(r, x))))
r := or(r, shl(3, lt(0xff, shr(r, x))))
r := or(r, shl(2, lt(0xf, shr(r, x))))
r := or(r, shl(1, lt(0x3, shr(r, x))))
r := or(r, lt(0x1, shr(r, x)))
}
// Reduce range of x to (1, 2) * 2**96
// ln(2^k * x) = k * ln(2) + ln(x)
int256 k = r - 96;
x <<= uint256(159 - k);
x = int256(uint256(x) >> 159);
// Evaluate using a (8, 8)-term rational approximation.
// p is made monic, we will multiply by a scale factor later.
int256 p = x + 3273285459638523848632254066296;
p = ((p * x) >> 96) + 24828157081833163892658089445524;
p = ((p * x) >> 96) + 43456485725739037958740375743393;
p = ((p * x) >> 96) - 11111509109440967052023855526967;
p = ((p * x) >> 96) - 45023709667254063763336534515857;
p = ((p * x) >> 96) - 14706773417378608786704636184526;
p = p * x - (795164235651350426258249787498 << 96);
// We leave p in 2**192 basis so we don't need to scale it back up for the division.
// q is monic by convention.
int256 q = x + 5573035233440673466300451813936;
q = ((q * x) >> 96) + 71694874799317883764090561454958;
q = ((q * x) >> 96) + 283447036172924575727196451306956;
q = ((q * x) >> 96) + 401686690394027663651624208769553;
q = ((q * x) >> 96) + 204048457590392012362485061816622;
q = ((q * x) >> 96) + 31853899698501571402653359427138;
q = ((q * x) >> 96) + 909429971244387300277376558375;
/// @solidity memory-safe-assembly
assembly {
// Div in assembly because solidity adds a zero check despite the unchecked.
// The q polynomial is known not to have zeros in the domain.
// No scaling required because p is already 2**96 too large.
r := sdiv(p, q)
}
// r is in the range (0, 0.125) * 2**96
// Finalization, we need to:
// * multiply by the scale factor s = 5.549…
// * add ln(2**96 / 10**18)
// * add k * ln(2)
// * multiply by 10**18 / 2**96 = 5**18 >> 78
// mul s * 5e18 * 2**96, base is now 5**18 * 2**192
r *= 1677202110996718588342820967067443963516166;
// add ln(2) * k * 5e18 * 2**192
r += 16597577552685614221487285958193947469193820559219878177908093499208371 * k;
// add ln(2**96 / 10**18) * 5e18 * 2**192
r += 600920179829731861736702779321621459595472258049074101567377883020018308;
// base conversion: mul 2**18 / 2**192
r >>= 174;
}
}
/// @dev Will return 0 instead of reverting if y is zero.
function unsafeDiv(int256 x, int256 y) pure returns (int256 r) {
/// @solidity memory-safe-assembly
assembly {
// Divide x by y.
r := sdiv(x, y)
}
}
// SPDX-License-Identifier: GPL-3.0
/// @title Interface for Blast predeploy
pragma solidity >=0.8.0;
enum YieldMode {
AUTOMATIC,
VOID,
CLAIMABLE
}
enum GasMode {
VOID,
CLAIMABLE
}
interface IBlast {
// configure
function configureContract(address contractAddress, YieldMode _yield, GasMode gasMode, address governor) external;
function configure(YieldMode _yield, GasMode gasMode, address governor) external;
// base configuration options
function configureClaimableYield() external;
function configureClaimableYieldOnBehalf(address contractAddress) external;
function configureAutomaticYield() external;
function configureAutomaticYieldOnBehalf(address contractAddress) external;
function configureVoidYield() external;
function configureVoidYieldOnBehalf(address contractAddress) external;
function configureClaimableGas() external;
function configureClaimableGasOnBehalf(address contractAddress) external;
function configureVoidGas() external;
function configureVoidGasOnBehalf(address contractAddress) external;
function configureGovernor(address _governor) external;
function configureGovernorOnBehalf(address _newGovernor, address contractAddress) external;
// claim yield
function claimYield(address contractAddress, address recipientOfYield, uint256 amount) external returns (uint256);
function claimAllYield(address contractAddress, address recipientOfYield) external returns (uint256);
// claim gas
function claimAllGas(address contractAddress, address recipientOfGas) external returns (uint256);
function claimGasAtMinClaimRate(address contractAddress, address recipientOfGas, uint256 minClaimRateBips)
external
returns (uint256);
function claimMaxGas(address contractAddress, address recipientOfGas) external returns (uint256);
function claimGas(address contractAddress, address recipientOfGas, uint256 gasToClaim, uint256 gasSecondsToConsume)
external
returns (uint256);
// read functions
function readClaimableYield(address contractAddress) external view returns (uint256);
function readYieldConfiguration(address contractAddress) external view returns (uint8);
function readGasParams(address contractAddress)
external
view
returns (uint256 etherSeconds, uint256 etherBalance, uint256 lastUpdated, GasMode);
}
// SPDX-License-Identifier: GPL-3.0
/// @title Interface for Plutocats Descriptor Minimal
pragma solidity >=0.8.0;
import {IPlutocatsSeeder} from "./IPlutocatsSeeder.sol";
interface IPlutocatsDescriptorMinimal {
///
/// USED BY TOKEN
///
function tokenURI(uint256 tokenId, IPlutocatsSeeder.Seed memory seed) external view returns (string memory);
function dataURI(uint256 tokenId, IPlutocatsSeeder.Seed memory seed) external view returns (string memory);
///
/// USED BY SEEDER
///
function backgroundCount() external view returns (uint256);
function bodyCount() external view returns (uint256);
function accessoryCount() external view returns (uint256);
function headCount() external view returns (uint256);
function eyesCount() external view returns (uint256);
function glassesCount() external view returns (uint256);
}
// SPDX-License-Identifier: GPL-3.0
/// @title Interface for Plutocats Seeder
pragma solidity >=0.8.0;
import {IPlutocatsDescriptorMinimal} from "./IPlutocatsDescriptorMinimal.sol";
interface IPlutocatsSeeder {
struct Seed {
uint48 background;
uint48 body;
uint48 accessory;
uint48 head;
uint48 eyes;
uint48 glasses;
}
function generateSeed(uint256 tokenId, IPlutocatsDescriptorMinimal descriptor)
external
view
returns (Seed memory);
}
// SPDX-License-Identifier: GPL-3.0
/// @title Interface for Plutocats Token
pragma solidity >=0.8.0;
import {IERC721} from "@openzeppelin/contracts/token/ERC721/IERC721.sol";
import {IPlutocatsDescriptorMinimal} from "./IPlutocatsDescriptorMinimal.sol";
import {IPlutocatsSeeder} from "./IPlutocatsSeeder.sol";
interface IPlutocatsToken is IERC721 {
struct Contribution {
uint256 amount;
uint256 joinTime;
}
event PlutocatPurchased(
uint256 indexed tokenId, address indexed msgSender, uint256 price, IPlutocatsSeeder.Seed seed
);
event ETHSent(address indexed to, uint256 amount);
event DescriptorUpdated(address indexed newDescriptor);
event SeederUpdated(address indexed newSeeder);
event ReservePriceSet(bool on);
event SetBlastGovernor(address indexed governor);
error InsufficientFundsProvided();
error DescriptorIsLocked();
error SeederIsLocked();
error OnlyReserve();
error TokenDoesNotExist();
error CallerIsNotOwnerOrApproved();
function mint() external payable returns (uint256);
function dataURI(uint256 tokenId) external returns (string memory);
function setDescriptor(address descriptor) external;
function setSeeder(address seeder) external;
function setReservePrice(bool _enableReservePrice) external;
function getPrice() external returns (uint256);
}
// SPDX-License-Identifier: GPL-3.0
/// @title Plutocats NFT
pragma solidity >=0.8.0;
import {ERC721} from "nouns-monorepo/packages/nouns-contracts/contracts/base/ERC721.sol";
import {IBlast} from "./interfaces/IBlast.sol";
import {ERC721Checkpointable} from "nouns-monorepo/packages/nouns-contracts/contracts/base/ERC721Checkpointable.sol";
import {IPlutocatsDescriptorMinimal} from "./interfaces/IPlutocatsDescriptorMinimal.sol";
import {IPlutocatsSeeder} from "./interfaces/IPlutocatsSeeder.sol";
import {IPlutocatsToken} from "./interfaces/IPlutocatsToken.sol";
import {LinearVRGDA} from "VRGDAs/LinearVRGDA.sol";
import {Address} from "@openzeppelin/contracts/utils/Address.sol";
import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";
import {toDaysWadUnsafe} from "solmate/utils/SignedWadMath.sol";
contract PlutocatsToken is IPlutocatsToken, ERC721Checkpointable, LinearVRGDA, Ownable {
using Address for address payable;
/// Timestamp for when minting will start.
uint256 public immutable MINT_START;
/// The internal tokenId tracker.
uint256 private _currentCatId;
/// The address of the reserve.
address public reserve;
/// The Plutocats token URI descriptor.
IPlutocatsDescriptorMinimal public descriptor;
/// The Plutocats token seeder.
IPlutocatsSeeder public seeder;
/// Plutocat seeds.
mapping(uint256 => IPlutocatsSeeder.Seed) public seeds;
/// Whether to turn off dynamic book value reserve price for mints.
bool public enableReservePrice;
/// a mapping that records contributions to the reserve.
mapping(uint256 => Contribution) internal contributions;
// IPFS content hash of contract-level metadata.
string private _contractURIHash = "QmYK3uptbXYQJX26TKUeYDBYHDhy7kPbYPmBHcZRaEqh1g";
/// The address of the pre-deployed Blast contract.
address public constant BLAST_PREDEPLOY_ADDRESS = 0x4300000000000000000000000000000000000002;
IBlast public blast;
/// MEOWMEOWMEOW
constructor(
uint256 _mintStart,
address _reserve,
address _descriptor,
address _seeder,
bool _enableReservePrice,
address _blast
)
ERC721("Plutocats", "PCAT")
LinearVRGDA(
0.1e18, // Target price
0.07e18, // Price decay percent
10e18 // Per time unit
)
{
require(_reserve != address(0), "PlutocatsToken: reserve address cannot be 0");
require(_descriptor != address(0), "PlutocatsToken: descriptor address cannot be 0");
require(_seeder != address(0), "PlutocatsToken: seeder address cannot be 0");
MINT_START = _mintStart;
reserve = _reserve;
descriptor = IPlutocatsDescriptorMinimal(_descriptor);
seeder = IPlutocatsSeeder(_seeder);
enableReservePrice = _enableReservePrice;
if (_blast != address(0)) {
blast = IBlast(_blast);
} else {
blast = IBlast(BLAST_PREDEPLOY_ADDRESS);
}
// capture blast gas for future use
blast.configureClaimableGas();
}
/// IPFS uri for contract-level metadata.
function contractURI() public view returns (string memory) {
return string(abi.encodePacked("ipfs://", _contractURIHash));
}
/// Set the contract uri hash.
function setContractURIHash(string memory newContractURIHash) external onlyOwner {
_contractURIHash = newContractURIHash;
}
/// Mint a Plutocat to the caller.
function mint() public payable override returns (uint256) {
// will revert prior to mint start time, causing an underflow
uint256 currentPrice = getPrice();
if (currentPrice > msg.value) {
revert InsufficientFundsProvided();
}
// send ETH to the reserve
payable(reserve).sendValue(msg.value);
emit ETHSent(reserve, msg.value);
return mintToInternal(msg.sender, _currentCatId++);
}
/// Get the current price of the next Plutocat to be minted. Enforces a minimum price
/// of reserve book value. (reserveBalance / adjustedTotalSupply).
function getPrice() public view returns (uint256) {
// checked math will cause underflow to prevent mints before start time
uint256 timeSinceStart = block.timestamp - MINT_START;
uint256 vrgdaPrice = getVRGDAPrice(toDaysWadUnsafe(timeSinceStart), _currentCatId);
uint256 minPrice = vrgdaPrice;
uint256 adjTotalSupply = adjustedTotalSupply();
/// dynamic reserve price based off book value
if (enableReservePrice && adjTotalSupply > 0) {
minPrice = reserve.balance / adjTotalSupply;
}
// enforce minimum price on membership
if (vrgdaPrice < minPrice) {
return minPrice;
}
return vrgdaPrice;
}
/// Mint a Plutocat with id to the provided address.
function mintToInternal(address _to, uint256 _catId) internal returns (uint256) {
IPlutocatsSeeder.Seed memory seed = seeds[_catId] = seeder.generateSeed(_catId, descriptor);
_mint(address(0), _to, _catId);
contributions[_catId] = Contribution({amount: msg.value, joinTime: block.timestamp});
emit PlutocatPurchased(_catId, msg.sender, msg.value, seed);
return _catId;
}
/// A distinct URI for the given token.
function tokenURI(uint256 _tokenId) public view override returns (string memory) {
if (!_exists(_tokenId)) {
revert TokenDoesNotExist();
}
return descriptor.tokenURI(_tokenId, seeds[_tokenId]);
}
/// Similar to tokenURI but always returns a base64 encoded data URI.
function dataURI(uint256 _tokenId) public view override returns (string memory) {
if (!_exists(_tokenId)) {
revert TokenDoesNotExist();
}
return descriptor.dataURI(_tokenId, seeds[_tokenId]);
}
/// Get the adjusted total supply of the contract.
/// Does not include cats that have quit the club or have been burned.
function adjustedTotalSupply() public view returns (uint256) {
return totalSupply() - balanceOf(address(reserve));
}
/// Get total contributions of a member to the reserve.
function contributionsOf(uint256 _tokenId) external view returns (Contribution memory) {
return contributions[_tokenId];
}
/// Set the Plutocats token URI descriptor.
function setDescriptor(address _descriptor) external onlyOwner {
descriptor = IPlutocatsDescriptorMinimal(_descriptor);
emit DescriptorUpdated(_descriptor);
}
/// Set the Plutocats token seeder.
function setSeeder(address _seeder) external onlyOwner {
seeder = IPlutocatsSeeder(_seeder);
emit SeederUpdated(_seeder);
}
/// Set whether dynamic reserve price is enabled on mints.
function setReservePrice(bool _enableReservePrice) external onlyOwner {
enableReservePrice = _enableReservePrice;
emit ReservePriceSet(_enableReservePrice);
}
/// Sets the blast governor for this contract. If phase 2 is implemented, the
/// DAO will be able to claim the gas of this contract for use. Only callable
/// if this contract is still the governor.
function setGovernor(address _governor) external onlyOwner {
blast.configureGovernor(_governor);
emit SetBlastGovernor(_governor);
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;
import {unsafeWadDiv} from "solmate/utils/SignedWadMath.sol";
import {VRGDA} from "./VRGDA.sol";
/// @title Linear Variable Rate Gradual Dutch Auction
/// @author transmissions11 <[email protected]>
/// @author FrankieIsLost <[email protected]>
/// @notice VRGDA with a linear issuance curve.
abstract contract LinearVRGDA is VRGDA {
/*//////////////////////////////////////////////////////////////
PRICING PARAMETERS
//////////////////////////////////////////////////////////////*/
/// @dev The total number of tokens to target selling every full unit of time.
/// @dev Represented as an 18 decimal fixed point number.
int256 internal immutable perTimeUnit;
/// @notice Sets pricing parameters for the VRGDA.
/// @param _targetPrice The target price for a token if sold on pace, scaled by 1e18.
/// @param _priceDecayPercent The percent price decays per unit of time with no sales, scaled by 1e18.
/// @param _perTimeUnit The number of tokens to target selling in 1 full unit of time, scaled by 1e18.
constructor(
int256 _targetPrice,
int256 _priceDecayPercent,
int256 _perTimeUnit
) VRGDA(_targetPrice, _priceDecayPercent) {
perTimeUnit = _perTimeUnit;
}
/*//////////////////////////////////////////////////////////////
PRICING LOGIC
//////////////////////////////////////////////////////////////*/
/// @dev Given a number of tokens sold, return the target time that number of tokens should be sold by.
/// @param sold A number of tokens sold, scaled by 1e18, to get the corresponding target sale time for.
/// @return The target time the tokens should be sold by, scaled by 1e18, where the time is
/// relative, such that 0 means the tokens should be sold immediately when the VRGDA begins.
function getTargetSaleTime(int256 sold) public view virtual override returns (int256) {
return unsafeWadDiv(sold, perTimeUnit);
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;
import {wadExp, wadLn, wadMul, unsafeWadMul, toWadUnsafe} from "solmate/utils/SignedWadMath.sol";
/// @title Variable Rate Gradual Dutch Auction
/// @author transmissions11 <[email protected]>
/// @author FrankieIsLost <[email protected]>
/// @notice Sell tokens roughly according to an issuance schedule.
abstract contract VRGDA {
/*//////////////////////////////////////////////////////////////
VRGDA PARAMETERS
//////////////////////////////////////////////////////////////*/
/// @notice Target price for a token, to be scaled according to sales pace.
/// @dev Represented as an 18 decimal fixed point number.
int256 public immutable targetPrice;
/// @dev Precomputed constant that allows us to rewrite a pow() as an exp().
/// @dev Represented as an 18 decimal fixed point number.
int256 internal immutable decayConstant;
/// @notice Sets target price and per time unit price decay for the VRGDA.
/// @param _targetPrice The target price for a token if sold on pace, scaled by 1e18.
/// @param _priceDecayPercent The percent price decays per unit of time with no sales, scaled by 1e18.
constructor(int256 _targetPrice, int256 _priceDecayPercent) {
targetPrice = _targetPrice;
decayConstant = wadLn(1e18 - _priceDecayPercent);
// The decay constant must be negative for VRGDAs to work.
require(decayConstant < 0, "NON_NEGATIVE_DECAY_CONSTANT");
}
/*//////////////////////////////////////////////////////////////
PRICING LOGIC
//////////////////////////////////////////////////////////////*/
/// @notice Calculate the price of a token according to the VRGDA formula.
/// @param timeSinceStart Time passed since the VRGDA began, scaled by 1e18.
/// @param sold The total number of tokens that have been sold so far.
/// @return The price of a token according to VRGDA, scaled by 1e18.
function getVRGDAPrice(int256 timeSinceStart, uint256 sold) public view virtual returns (uint256) {
unchecked {
// prettier-ignore
return uint256(wadMul(targetPrice, wadExp(unsafeWadMul(decayConstant,
// Theoretically calling toWadUnsafe with sold can silently overflow but under
// any reasonable circumstance it will never be large enough. We use sold + 1 as
// the VRGDA formula's n param represents the nth token and sold is the n-1th token.
timeSinceStart - getTargetSaleTime(toWadUnsafe(sold + 1))
))));
}
}
/// @dev Given a number of tokens sold, return the target time that number of tokens should be sold by.
/// @param sold A number of tokens sold, scaled by 1e18, to get the corresponding target sale time for.
/// @return The target time the tokens should be sold by, scaled by 1e18, where the time is
/// relative, such that 0 means the tokens should be sold immediately when the VRGDA begins.
function getTargetSaleTime(int256 sold) public view virtual returns (int256);
}