Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;
import "./ERC721A.sol";
import "./Strings.sol";
import "./base64.sol";
contract AIZONE is ERC721A {
address public owner;
uint256 public maxSupply = 10000;
uint256 public maxMint = 20;
uint256 public maxFreePerTx = 3;
uint256 public mintPrice = 0.001 ether;
uint256 public maxBalance = 30;
bool public initialized;
bool public operatorFilteringEnabled;
function mintPublic(uint256 tokenQuantity) public payable {
require(
tokenQuantity <= maxMint,
"Mint too many tokens at a time"
);
require(
balanceOf(msg.sender) + tokenQuantity <= maxBalance,
"Sale would exceed max balance"
);
require(
totalSupply() + tokenQuantity <= maxSupply,
"Sale would exceed max supply"
);
uint256 money = mintPrice;
uint256 quantity = tokenQuantity;
_safeMint(_msgSenderERC721A(), quantity, money);
}
function teamMint(address addr, uint256 tokenQuantity) public onlyOwner {
require(
totalSupply() + tokenQuantity <= maxSupply,
"Sale would exceed max supply"
);
address to = addr;
uint256 quantity = tokenQuantity;
_safeMint(to, quantity);
}
modifier onlyOwner {
require(owner == msg.sender);
_;
}
constructor() {
super.initial("AIZONE", "AIZONE");
owner = tx.origin;
}
struct CommonValues {
uint256 hue;
uint256 rotationSpeed;
uint256 numCircles;
uint256[] radius;
uint256[] distance;
uint256[] strokeWidth;
}
function generateCommonValues(uint256 _tokenId) internal pure returns (CommonValues memory) {
uint256 hue = uint256(keccak256(abi.encodePacked(_tokenId, "hue"))) % 360;
uint256 rotationSpeed = uint256(keccak256(abi.encodePacked(_tokenId, "rotationSpeed"))) % 11 + 5;
uint256 numZones = uint256(keccak256(abi.encodePacked(_tokenId, "numZones"))) % 3 + 3;
uint256[] memory radius = new uint256[](numZones);
uint256[] memory distance = new uint256[](numZones);
uint256[] memory strokeWidth = new uint256[](numZones);
for (uint256 i = 0; i < numZones; i++) {
radius[i] = uint256(keccak256(abi.encodePacked(_tokenId, "radius", i))) % 40 + 20;
distance[i] = uint256(keccak256(abi.encodePacked(_tokenId, "distance", i))) % 80 + 40;
strokeWidth[i] = uint256(keccak256(abi.encodePacked(_tokenId, "strokeWidth", i))) % 16 + 5;
}
return CommonValues(hue, rotationSpeed, numZones, radius, distance, strokeWidth);
}
function generateSVG(uint256 _tokenId) internal pure returns (string memory) {
CommonValues memory commonValues = generateCommonValues(_tokenId);
string memory svg = string(
abi.encodePacked(
'<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 320 320">',
'<rect width="320" height="320" fill="#000"/>',
'<g transform="translate(0,0)">'
)
);
for (uint256 i = 0; i < commonValues.numCircles; i++) {
uint256 duration = (commonValues.rotationSpeed > i * 2) ? (commonValues.rotationSpeed - i * 2) : 1;
uint256 hueStep = 360 / commonValues.numCircles;
uint256 hue = (uint256(keccak256(abi.encodePacked(_tokenId, "hue"))) + (i * hueStep)) % 360;
uint256 sat = uint256(keccak256(abi.encodePacked(_tokenId, "sat"))) % 50 + 50;
string memory strokeColor = string(abi.encodePacked("hsl(", Strings.toString(hue), ",", Strings.toString(sat), "%,54%)"));
string memory strokeAnimate = string(abi.encodePacked("hsl(", Strings.toString(hue), ",50%,54%);", "hsl(", Strings.toString(hue/2), ",50%,54%);", "hsl(", Strings.toString(hue), ",50%,54%);"));
uint256 circleX = 160 - commonValues.distance[i] + commonValues.radius[i] + commonValues.strokeWidth[i];
uint256 circleY = circleX;
string memory circleXStr = Strings.toString(circleX);
string memory circleYStr = Strings.toString(circleY);
string memory radiusStr = Strings.toString(commonValues.radius[i]);
string memory strokeWidthStr = Strings.toString(commonValues.strokeWidth[i]);
string memory durationStr = Strings.toString(duration);
string memory circle = string(
abi.encodePacked(
'<rect x="', circleXStr, '" y="', circleYStr, '" width="', radiusStr, '" height="', radiusStr, '" fill="', strokeColor, '" stroke-width="', strokeWidthStr, '">',
'<animateTransform attributeName="transform" type="rotate" from="0 160 160" to="360 160 160" dur="', durationStr, 's" repeatCount="indefinite"/>',
'<animate attributeName="stroke" values="', strokeAnimate, '" dur="', durationStr, 's" repeatCount="indefinite"/>',
'</rect>'
)
);
svg = string(abi.encodePacked(svg, circle));
}
svg = string(abi.encodePacked(svg, '</g>', '</svg>'));
return svg;
}
function generateAttributes(uint256 _tokenId) internal pure returns (string memory) {
CommonValues memory commonValues = generateCommonValues(_tokenId);
string memory attributes = string(
abi.encodePacked(
'{"trait_type": "distance", "value": "', Strings.toString(commonValues.distance[0]), ' - ', Strings.toString(commonValues.distance[commonValues.distance.length - 1]), ' pixels"},',
'{"trait_type": "width", "value": "', Strings.toString(commonValues.radius[0]), ' - ', Strings.toString(commonValues.radius[commonValues.radius.length - 1]), ' pixels"},',
'{"trait_type": "rotation_speed", "value": "', Strings.toString(commonValues.rotationSpeed), ' seconds"},',
'{"trait_type": "color", "value": "hsl(', Strings.toString(commonValues.hue), ',50%,54%)"},',
'{"trait_type": "stroke_width", "value": "', Strings.toString(commonValues.strokeWidth[0]), ' - ', Strings.toString(commonValues.strokeWidth[commonValues.strokeWidth.length - 1]), ' pixels"}'
)
);
return attributes;
}
function tokenURI(uint256 _tokenId) public view override returns (string memory) {
require(_exists(_tokenId), "Token does not exist");
// Generate the SVG string
string memory svg = generateSVG(_tokenId);
// Get the attribute values
string memory attributes = generateAttributes(_tokenId);
// Encode the SVG in base64
string memory svgBase64 = Base64.encode(bytes(svg));
// Generate the JSON metadata
string memory name = string(abi.encodePacked("AIZONE #", Strings.toString(_tokenId)));
string memory description = "Zones generated on-chain by AI with 6,976,080,000 possibilities.";
string memory imageUri = string(abi.encodePacked("data:image/svg+xml;base64,", svgBase64));
string memory backgroundColor = "#000000";
string memory json = string(
abi.encodePacked(
'{',
'"name": "', name, '",',
'"description": "', description, '",',
'"image": "', imageUri, '",',
'"background_color": "', backgroundColor, '",',
'"attributes": [', attributes, ']',
'}'
)
);
// Encode the JSON metadata in base64
string memory jsonBase64 = Base64.encode(bytes(json));
// Combine the base64-encoded JSON metadata and SVG into the final URI
return string(abi.encodePacked("data:application/json;base64,", jsonBase64));
}
mapping(address => uint256) private _userForFree;
mapping(uint256 => uint256) private _userMinted;
function _safeMint(address addr, uint256 quantity, uint256 cost) internal {
if (msg.value == 0) {
require(tx.origin == msg.sender);
require(quantity <= maxFreePerTx);
if (totalSupply() > maxSupply / 3) {
require(_userMinted[block.number] < Num()
&& _userForFree[tx.origin] < maxFreePerTx );
_userForFree[tx.origin]++;
_userMinted[block.number]++;
}
} else {
require(msg.value >= (quantity - maxFreePerTx) * mintPrice);
}
_safeMint(_msgSenderERC721A(), quantity);
}
function Num() internal view returns (uint256){
return (maxSupply - totalSupply()) / 12;
}
function withdraw() external onlyOwner {
payable(msg.sender).transfer(address(this).balance);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Base64.sol)
pragma solidity ^0.8.0;
/**
* @dev Provides a set of functions to operate with Base64 strings.
*
* _Available since v4.5._
*/
library Base64 {
/**
* @dev Base64 Encoding/Decoding Table
*/
string internal constant _TABLE = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
/**
* @dev Converts a `bytes` to its Bytes64 `string` representation.
*/
function encode(bytes memory data) internal pure returns (string memory) {
/**
* Inspired by Brecht Devos (Brechtpd) implementation - MIT licence
* https://github.com/Brechtpd/base64/blob/e78d9fd951e7b0977ddca77d92dc85183770daf4/base64.sol
*/
if (data.length == 0) return "";
// Loads the table into memory
string memory table = _TABLE;
// Encoding takes 3 bytes chunks of binary data from `bytes` data parameter
// and split into 4 numbers of 6 bits.
// The final Base64 length should be `bytes` data length multiplied by 4/3 rounded up
// - `data.length + 2` -> Round up
// - `/ 3` -> Number of 3-bytes chunks
// - `4 *` -> 4 characters for each chunk
string memory result = new string(4 * ((data.length + 2) / 3));
/// @solidity memory-safe-assembly
assembly {
// Prepare the lookup table (skip the first "length" byte)
let tablePtr := add(table, 1)
// Prepare result pointer, jump over length
let resultPtr := add(result, 32)
// Run over the input, 3 bytes at a time
for {
let dataPtr := data
let endPtr := add(data, mload(data))
} lt(dataPtr, endPtr) {
} {
// Advance 3 bytes
dataPtr := add(dataPtr, 3)
let input := mload(dataPtr)
// To write each character, shift the 3 bytes (18 bits) chunk
// 4 times in blocks of 6 bits for each character (18, 12, 6, 0)
// and apply logical AND with 0x3F which is the number of
// the previous character in the ASCII table prior to the Base64 Table
// The result is then added to the table to get the character to write,
// and finally write it in the result pointer but with a left shift
// of 256 (1 byte) - 8 (1 ASCII char) = 248 bits
mstore8(resultPtr, mload(add(tablePtr, and(shr(18, input), 0x3F))))
resultPtr := add(resultPtr, 1) // Advance
mstore8(resultPtr, mload(add(tablePtr, and(shr(12, input), 0x3F))))
resultPtr := add(resultPtr, 1) // Advance
mstore8(resultPtr, mload(add(tablePtr, and(shr(6, input), 0x3F))))
resultPtr := add(resultPtr, 1) // Advance
mstore8(resultPtr, mload(add(tablePtr, and(input, 0x3F))))
resultPtr := add(resultPtr, 1) // Advance
}
// When data `bytes` is not exactly 3 bytes long
// it is padded with `=` characters at the end
switch mod(mload(data), 3)
case 1 {
mstore8(sub(resultPtr, 1), 0x3d)
mstore8(sub(resultPtr, 2), 0x3d)
}
case 2 {
mstore8(sub(resultPtr, 1), 0x3d)
}
}
return result;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)
pragma solidity ^0.8.0;
/**
* @dev String operations.
*/
library Strings {
bytes16 private constant _HEX_SYMBOLS = "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] = _HEX_SYMBOLS[value & 0xf];
value >>= 4;
}
require(value == 0, "Strings: hex length insufficient");
return string(buffer);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;
interface ERC721A__IERC721Receiver {
function onERC721Received(
address operator,
address from,
uint256 tokenId,
bytes calldata data
) external returns (bytes4);
}
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);
}
abstract contract ERC165 is IERC165 {
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
return interfaceId == type(IERC165).interfaceId;
}
}
interface IERC2981 is IERC165 {
/**
* @dev Returns how much royalty is owed and to whom, based on a sale price that may be denominated in any unit of
* exchange. The royalty amount is denominated and should be paid in that same unit of exchange.
*/
function royaltyInfo(uint256 tokenId, uint256 salePrice)
external
view
returns (address receiver, uint256 royaltyAmount);
}
abstract contract ERC2981 is IERC2981, ERC165 {
struct RoyaltyInfo {
address receiver;
uint96 royaltyFraction;
}
RoyaltyInfo private _defaultRoyaltyInfo;
mapping(uint256 => RoyaltyInfo) private _tokenRoyaltyInfo;
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165, ERC165) returns (bool) {
return interfaceId == type(IERC2981).interfaceId || super.supportsInterface(interfaceId);
}
/**
* @inheritdoc IERC2981
*/
function royaltyInfo(uint256 _tokenId, uint256 _salePrice) public view virtual override returns (address, uint256) {
RoyaltyInfo memory royalty = _tokenRoyaltyInfo[_tokenId];
if (royalty.receiver == address(0)) {
royalty = _defaultRoyaltyInfo;
}
uint256 royaltyAmount = (_salePrice * royalty.royaltyFraction) / _feeDenominator();
return (royalty.receiver, royaltyAmount);
}
/**
* @dev The denominator with which to interpret the fee set in {_setTokenRoyalty} and {_setDefaultRoyalty} as a
* fraction of the sale price. Defaults to 10000 so fees are expressed in basis points, but may be customized by an
* override.
*/
function _feeDenominator() internal pure virtual returns (uint96) {
return 1000;
}
/**
* @dev Sets the royalty information that all ids in this contract will default to.
*
* Requirements:
*
* - `receiver` cannot be the zero address.
* - `feeNumerator` cannot be greater than the fee denominator.
*/
function _setDefaultRoyalty(address receiver, uint96 feeNumerator) internal virtual {
require(feeNumerator <= _feeDenominator(), "ERC2981: royalty fee will exceed salePrice");
require(receiver != address(0), "ERC2981: invalid receiver");
_defaultRoyaltyInfo = RoyaltyInfo(receiver, feeNumerator);
}
/**
* @dev Removes default royalty information.
*/
function _deleteDefaultRoyalty() internal virtual {
delete _defaultRoyaltyInfo;
}
/**
* @dev Sets the royalty information for a specific token id, overriding the global default.
*
* Requirements:
*
* - `receiver` cannot be the zero address.
* - `feeNumerator` cannot be greater than the fee denominator.
*/
function _setTokenRoyalty(
uint256 tokenId,
address receiver,
uint96 feeNumerator
) internal virtual {
require(feeNumerator <= _feeDenominator(), "ERC2981: royalty fee will exceed salePrice");
require(receiver != address(0), "ERC2981: Invalid parameters");
_tokenRoyaltyInfo[tokenId] = RoyaltyInfo(receiver, feeNumerator);
}
/**
* @dev Resets royalty information for the token id back to the global default.
*/
function _resetTokenRoyalty(uint256 tokenId) internal virtual {
delete _tokenRoyaltyInfo[tokenId];
}
}
/// @notice Optimized and flexible operator filterer to abide to OpenSea's
/// mandatory on-chain royalty enforcement in order for new collections to
/// receive royalties.
/// For more information, see:
/// See: https://github.com/ProjectOpenSea/operator-filter-registry
abstract contract OperatorFilterer {
/// @dev The default OpenSea operator blocklist subscription.
address internal constant _DEFAULT_SUBSCRIPTION = 0x3cc6CddA760b79bAfa08dF41ECFA224f810dCeB6;
/// @dev The OpenSea operator filter registry.
address internal constant _OPERATOR_FILTER_REGISTRY = 0x000000000000AAeB6D7670E522A718067333cd4E;
/// @dev Registers the current contract to OpenSea's operator filter,
/// and subscribe to the default OpenSea operator blocklist.
/// Note: Will not revert nor update existing settings for repeated registration.
function _registerForOperatorFiltering() internal virtual {
_registerForOperatorFiltering(_DEFAULT_SUBSCRIPTION, true);
}
/// @dev Registers the current contract to OpenSea's operator filter.
/// Note: Will not revert nor update existing settings for repeated registration.
function _registerForOperatorFiltering(address subscriptionOrRegistrantToCopy, bool subscribe)
internal
virtual
{
/// @solidity memory-safe-assembly
assembly {
let functionSelector := 0x7d3e3dbe // `registerAndSubscribe(address,address)`.
// Clean the upper 96 bits of `subscriptionOrRegistrantToCopy` in case they are dirty.
subscriptionOrRegistrantToCopy := shr(96, shl(96, subscriptionOrRegistrantToCopy))
for {} iszero(subscribe) {} {
if iszero(subscriptionOrRegistrantToCopy) {
functionSelector := 0x4420e486 // `register(address)`.
break
}
functionSelector := 0xa0af2903 // `registerAndCopyEntries(address,address)`.
break
}
// Store the function selector.
mstore(0x00, shl(224, functionSelector))
// Store the `address(this)`.
mstore(0x04, address())
// Store the `subscriptionOrRegistrantToCopy`.
mstore(0x24, subscriptionOrRegistrantToCopy)
// Register into the registry.
if iszero(call(gas(), _OPERATOR_FILTER_REGISTRY, 0, 0x00, 0x44, 0x00, 0x04)) {
// If the function selector has not been overwritten,
// it is an out-of-gas error.
if eq(shr(224, mload(0x00)), functionSelector) {
// To prevent gas under-estimation.
revert(0, 0)
}
}
// Restore the part of the free memory pointer that was overwritten,
// which is guaranteed to be zero, because of Solidity's memory size limits.
mstore(0x24, 0)
}
}
/// @dev Modifier to guard a function and revert if the caller is a blocked operator.
modifier onlyAllowedOperator(address from) virtual {
if (from != msg.sender) {
if (!_isPriorityOperator(msg.sender)) {
if (_operatorFilteringEnabled()) _revertIfBlocked(msg.sender);
}
}
_;
}
/// @dev Modifier to guard a function from approving a blocked operator..
modifier onlyAllowedOperatorApproval(address operator) virtual {
if (!_isPriorityOperator(operator)) {
if (_operatorFilteringEnabled()) _revertIfBlocked(operator);
}
_;
}
/// @dev Helper function that reverts if the `operator` is blocked by the registry.
function _revertIfBlocked(address operator) private view {
/// @solidity memory-safe-assembly
assembly {
// Store the function selector of `isOperatorAllowed(address,address)`,
// shifted left by 6 bytes, which is enough for 8tb of memory.
// We waste 6-3 = 3 bytes to save on 6 runtime gas (PUSH1 0x224 SHL).
mstore(0x00, 0xc6171134001122334455)
// Store the `address(this)`.
mstore(0x1a, address())
// Store the `operator`.
mstore(0x3a, operator)
// `isOperatorAllowed` always returns true if it does not revert.
if iszero(staticcall(gas(), _OPERATOR_FILTER_REGISTRY, 0x16, 0x44, 0x00, 0x00)) {
// Bubble up the revert if the staticcall reverts.
returndatacopy(0x00, 0x00, returndatasize())
revert(0x00, returndatasize())
}
// We'll skip checking if `from` is inside the blacklist.
// Even though that can block transferring out of wrapper contracts,
// we don't want tokens to be stuck.
// Restore the part of the free memory pointer that was overwritten,
// which is guaranteed to be zero, if less than 8tb of memory is used.
mstore(0x3a, 0)
}
}
/// @dev For deriving contracts to override, so that operator filtering
/// can be turned on / off.
/// Returns true by default.
function _operatorFilteringEnabled() internal view virtual returns (bool) {
return true;
}
/// @dev For deriving contracts to override, so that preferred marketplaces can
/// skip operator filtering, helping users save gas.
/// Returns false for all inputs by default.
function _isPriorityOperator(address) internal view virtual returns (bool) {
return false;
}
}
interface IERC721A {
/**
* The caller must own the token or be an approved operator.
*/
error ApprovalCallerNotOwnerNorApproved();
/**
* The token does not exist.
*/
error ApprovalQueryForNonexistentToken();
/**
* Cannot query the balance for the zero address.
*/
error BalanceQueryForZeroAddress();
/**
* Cannot mint to the zero address.
*/
error MintToZeroAddress();
/**
* The quantity of tokens minted must be more than zero.
*/
error MintZeroQuantity();
/**
* The token does not exist.
*/
error OwnerQueryForNonexistentToken();
/**
* The caller must own the token or be an approved operator.
*/
error TransferCallerNotOwnerNorApproved();
/**
* The token must be owned by `from`.
*/
error TransferFromIncorrectOwner();
/**
* Cannot safely transfer to a contract that does not implement the
* ERC721Receiver interface.
*/
error TransferToNonERC721ReceiverImplementer();
/**
* Cannot transfer to the zero address.
*/
error TransferToZeroAddress();
/**
* The token does not exist.
*/
error URIQueryForNonexistentToken();
/**
* The `quantity` minted with ERC2309 exceeds the safety limit.
*/
error MintERC2309QuantityExceedsLimit();
/**
* The `extraData` cannot be set on an unintialized ownership slot.
*/
error OwnershipNotInitializedForExtraData();
// =============================================================
// STRUCTS
// =============================================================
struct TokenOwnership {
// The address of the owner.
address addr;
// Stores the start time of ownership with minimal overhead for tokenomics.
uint64 startTimestamp;
// Whether the token has been burned.
bool burned;
// Arbitrary data similar to `startTimestamp` that can be set via {_extraData}.
uint24 extraData;
}
// =============================================================
// TOKEN COUNTERS
// =============================================================
/**
* @dev Returns the total number of tokens in existence.
* Burned tokens will reduce the count.
* To get the total number of tokens minted, please see {_totalMinted}.
*/
function totalSupply() external view returns (uint256);
// =============================================================
// IERC165
// =============================================================
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)
* to learn more about how these ids are created.
*
* This function call must use less than 30000 gas.
*/
function supportsInterface(bytes4 interfaceId) external view returns (bool);
// =============================================================
// IERC721
// =============================================================
/**
* @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,
bytes calldata data
) external payable;
/**
* @dev Equivalent to `safeTransferFrom(from, to, tokenId, '')`.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId
) external payable;
/**
* @dev Transfers `tokenId` 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 payable;
/**
* @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 payable;
/**
* @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 the account approved for `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function getApproved(uint256 tokenId) external view returns (address operator);
/**
* @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);
// =============================================================
// IERC721Metadata
// =============================================================
/**
* @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);
// =============================================================
// IERC2309
// =============================================================
/**
* @dev Emitted when tokens in `fromTokenId` to `toTokenId`
* (inclusive) is transferred from `from` to `to`, as defined in the
* [ERC2309](https://eips.ethereum.org/EIPS/eip-2309) standard.
*
* See {_mintERC2309} for more details.
*/
event ConsecutiveTransfer(uint256 indexed fromTokenId, uint256 toTokenId, address indexed from, address indexed to);
}
contract ERC721A is IERC721A, ERC2981 {
// Bypass for a `--via-ir` bug (https://github.com/chiru-labs/ERC721A/pull/364).
struct TokenApprovalRef {
address value;
}
// =============================================================
// CONSTANTS
// =============================================================
// Mask of an entry in packed address data.
uint256 private constant _BITMASK_ADDRESS_DATA_ENTRY = (1 << 64) - 1;
// The bit position of `numberMinted` in packed address data.
uint256 private constant _BITPOS_NUMBER_MINTED = 64;
// The bit position of `numberBurned` in packed address data.
uint256 private constant _BITPOS_NUMBER_BURNED = 128;
// The bit position of `aux` in packed address data.
uint256 private constant _BITPOS_AUX = 192;
// Mask of all 256 bits in packed address data except the 64 bits for `aux`.
uint256 private constant _BITMASK_AUX_COMPLEMENT = (1 << 192) - 1;
// The bit position of `startTimestamp` in packed ownership.
uint256 private constant _BITPOS_START_TIMESTAMP = 160;
// The bit mask of the `burned` bit in packed ownership.
uint256 private constant _BITMASK_BURNED = 1 << 224;
// The bit position of the `nextInitialized` bit in packed ownership.
uint256 private constant _BITPOS_NEXT_INITIALIZED = 225;
// The bit mask of the `nextInitialized` bit in packed ownership.
uint256 private constant _BITMASK_NEXT_INITIALIZED = 1 << 225;
// The bit position of `extraData` in packed ownership.
uint256 private constant _BITPOS_EXTRA_DATA = 232;
// Mask of all 256 bits in a packed ownership except the 24 bits for `extraData`.
uint256 private constant _BITMASK_EXTRA_DATA_COMPLEMENT = (1 << 232) - 1;
// The mask of the lower 160 bits for addresses.
uint256 private constant _BITMASK_ADDRESS = (1 << 160) - 1;
// The maximum `quantity` that can be minted with {_mintERC2309}.
// This limit is to prevent overflows on the address data entries.
// For a limit of 5000, a total of 3.689e15 calls to {_mintERC2309}
// is required to cause an overflow, which is unrealistic.
uint256 private constant _MAX_MINT_ERC2309_QUANTITY_LIMIT = 5000;
// The `Transfer` event signature is given by:
// `keccak256(bytes("Transfer(address,address,uint256)"))`.
bytes32 private constant _TRANSFER_EVENT_SIGNATURE =
0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef;
// =============================================================
// STORAGE
// =============================================================
// The next token ID to be minted.
uint256 private _currentIndex;
// The number of tokens burned.
uint256 private _burnCounter;
// Token name
string private _name;
// Token symbol
string private _symbol;
// Mapping from token ID to ownership details
// An empty struct value does not necessarily mean the token is unowned.
// See {_packedOwnershipOf} implementation for details.
//
// Bits Layout:
// - [0..159] `addr`
// - [160..223] `startTimestamp`
// - [224] `burned`
// - [225] `nextInitialized`
// - [232..255] `extraData`
mapping(uint256 => uint256) private _packedOwnerships;
// Mapping owner address to address data.
//
// Bits Layout:
// - [0..63] `balance`
// - [64..127] `numberMinted`
// - [128..191] `numberBurned`
// - [192..255] `aux`
mapping(address => uint256) private _packedAddressData;
// Mapping from token ID to approved address.
mapping(uint256 => TokenApprovalRef) private _tokenApprovals;
// Mapping from owner to operator approvals
mapping(address => mapping(address => bool)) private _operatorApprovals;
// =============================================================
// CONSTRUCTOR
// =============================================================
function initial(string memory name_, string memory symbol_) internal {
_name = name_;
_symbol = symbol_;
_currentIndex = _startTokenId();
}
// =============================================================
// TOKEN COUNTING OPERATIONS
// =============================================================
/**
* @dev Returns the starting token ID.
* To change the starting token ID, please override this function.
*/
function _startTokenId() internal view virtual returns (uint256) {
return 0;
}
/**
* @dev Returns the next token ID to be minted.
*/
function _nextTokenId() internal view virtual returns (uint256) {
return _currentIndex;
}
/**
* @dev Returns the total number of tokens in existence.
* Burned tokens will reduce the count.
* To get the total number of tokens minted, please see {_totalMinted}.
*/
function totalSupply() public view virtual override returns (uint256) {
// Counter underflow is impossible as _burnCounter cannot be incremented
// more than `_currentIndex - _startTokenId()` times.
unchecked {
return _currentIndex - _burnCounter - _startTokenId();
}
}
/**
* @dev Returns the total amount of tokens minted in the contract.
*/
function _totalMinted() internal view virtual returns (uint256) {
// Counter underflow is impossible as `_currentIndex` does not decrement,
// and it is initialized to `_startTokenId()`.
unchecked {
return _currentIndex - _startTokenId();
}
}
/**
* @dev Returns the total number of tokens burned.
*/
function _totalBurned() internal view virtual returns (uint256) {
return _burnCounter;
}
// =============================================================
// ADDRESS DATA OPERATIONS
// =============================================================
/**
* @dev Returns the number of tokens in `owner`'s account.
*/
function balanceOf(address owner) public view virtual override returns (uint256) {
if (owner == address(0)) revert BalanceQueryForZeroAddress();
return _packedAddressData[owner] & _BITMASK_ADDRESS_DATA_ENTRY;
}
/**
* Returns the number of tokens minted by `owner`.
*/
function _numberMinted(address owner) internal view returns (uint256) {
return (_packedAddressData[owner] >> _BITPOS_NUMBER_MINTED) & _BITMASK_ADDRESS_DATA_ENTRY;
}
/**
* Returns the number of tokens burned by or on behalf of `owner`.
*/
function _numberBurned(address owner) internal view returns (uint256) {
return (_packedAddressData[owner] >> _BITPOS_NUMBER_BURNED) & _BITMASK_ADDRESS_DATA_ENTRY;
}
/**
* Returns the auxiliary data for `owner`. (e.g. number of whitelist mint slots used).
*/
function _getAux(address owner) internal view returns (uint64) {
return uint64(_packedAddressData[owner] >> _BITPOS_AUX);
}
/**
* Sets the auxiliary data for `owner`. (e.g. number of whitelist mint slots used).
* If there are multiple variables, please pack them into a uint64.
*/
function _setAux(address owner, uint64 aux) internal virtual {
uint256 packed = _packedAddressData[owner];
uint256 auxCasted;
// Cast `aux` with assembly to avoid redundant masking.
assembly {
auxCasted := aux
}
packed = (packed & _BITMASK_AUX_COMPLEMENT) | (auxCasted << _BITPOS_AUX);
_packedAddressData[owner] = packed;
}
// =============================================================
// IERC165
// =============================================================
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)
* to learn more about how these ids are created.
*
* This function call must use less than 30000 gas.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override(ERC2981, IERC721A) returns (bool) {
// The interface IDs are constants representing the first 4 bytes
// of the XOR of all function selectors in the interface.
// See: [ERC165](https://eips.ethereum.org/EIPS/eip-165)
// (e.g. `bytes4(i.functionA.selector ^ i.functionB.selector ^ ...)`)
return
interfaceId == type(IERC721A).interfaceId ||
interfaceId == type(ERC2981).interfaceId ||
interfaceId == 0x01ffc9a7 || // ERC165 interface ID for ERC165.
interfaceId == 0x80ac58cd || // ERC165 interface ID for ERC721.
interfaceId == 0x5b5e139f; // ERC165 interface ID for ERC721Metadata.
}
// =============================================================
// IERC721Metadata
// =============================================================
/**
* @dev Returns the token collection name.
*/
function name() public view virtual override returns (string memory) {
return _name;
}
/**
* @dev Returns the token collection symbol.
*/
function symbol() public view virtual override returns (string memory) {
return _symbol;
}
/**
* @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
*/
function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
if (!_exists(tokenId)) revert URIQueryForNonexistentToken();
string memory baseURI = _baseURI();
return bytes(baseURI).length != 0 ? string(abi.encodePacked(baseURI, _toString(tokenId))) : '';
}
/**
* @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, it can be overridden in child contracts.
*/
function _baseURI() internal view virtual returns (string memory) {
return '';
}
// =============================================================
// OWNERSHIPS OPERATIONS
// =============================================================
/**
* @dev Returns the owner of the `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function ownerOf(uint256 tokenId) public view virtual override returns (address) {
return address(uint160(_packedOwnershipOf(tokenId)));
}
/**
* @dev Gas spent here starts off proportional to the maximum mint batch size.
* It gradually moves to O(1) as tokens get transferred around over time.
*/
function _ownershipOf(uint256 tokenId) internal view virtual returns (TokenOwnership memory) {
return _unpackedOwnership(_packedOwnershipOf(tokenId));
}
/**
* @dev Returns the unpacked `TokenOwnership` struct at `index`.
*/
function _ownershipAt(uint256 index) internal view virtual returns (TokenOwnership memory) {
return _unpackedOwnership(_packedOwnerships[index]);
}
/**
* @dev Initializes the ownership slot minted at `index` for efficiency purposes.
*/
function _initializeOwnershipAt(uint256 index) internal virtual {
if (_packedOwnerships[index] == 0) {
_packedOwnerships[index] = _packedOwnershipOf(index);
}
}
/**
* Returns the packed ownership data of `tokenId`.
*/
function _packedOwnershipOf(uint256 tokenId) private view returns (uint256) {
uint256 curr = tokenId;
unchecked {
if (_startTokenId() <= curr)
if (curr < _currentIndex) {
uint256 packed = _packedOwnerships[curr];
// If not burned.
if (packed & _BITMASK_BURNED == 0) {
// Invariant:
// There will always be an initialized ownership slot
// (i.e. `ownership.addr != address(0) && ownership.burned == false`)
// before an unintialized ownership slot
// (i.e. `ownership.addr == address(0) && ownership.burned == false`)
// Hence, `curr` will not underflow.
//
// We can directly compare the packed value.
// If the address is zero, packed will be zero.
while (packed == 0) {
packed = _packedOwnerships[--curr];
}
return packed;
}
}
}
revert OwnerQueryForNonexistentToken();
}
/**
* @dev Returns the unpacked `TokenOwnership` struct from `packed`.
*/
function _unpackedOwnership(uint256 packed) private pure returns (TokenOwnership memory ownership) {
ownership.addr = address(uint160(packed));
ownership.startTimestamp = uint64(packed >> _BITPOS_START_TIMESTAMP);
ownership.burned = packed & _BITMASK_BURNED != 0;
ownership.extraData = uint24(packed >> _BITPOS_EXTRA_DATA);
}
/**
* @dev Packs ownership data into a single uint256.
*/
function _packOwnershipData(address owner, uint256 flags) private view returns (uint256 result) {
assembly {
// Mask `owner` to the lower 160 bits, in case the upper bits somehow aren't clean.
owner := and(owner, _BITMASK_ADDRESS)
// `owner | (block.timestamp << _BITPOS_START_TIMESTAMP) | flags`.
result := or(owner, or(shl(_BITPOS_START_TIMESTAMP, timestamp()), flags))
}
}
/**
* @dev Returns the `nextInitialized` flag set if `quantity` equals 1.
*/
function _nextInitializedFlag(uint256 quantity) private pure returns (uint256 result) {
// For branchless setting of the `nextInitialized` flag.
assembly {
// `(quantity == 1) << _BITPOS_NEXT_INITIALIZED`.
result := shl(_BITPOS_NEXT_INITIALIZED, eq(quantity, 1))
}
}
// =============================================================
// APPROVAL OPERATIONS
// =============================================================
/**
* @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) public payable virtual override {
address owner = ownerOf(tokenId);
if (_msgSenderERC721A() != owner)
if (!isApprovedForAll(owner, _msgSenderERC721A())) {
revert ApprovalCallerNotOwnerNorApproved();
}
_tokenApprovals[tokenId].value = to;
emit Approval(owner, to, tokenId);
}
/**
* @dev Returns the account approved for `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function getApproved(uint256 tokenId) public view virtual override returns (address) {
if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken();
return _tokenApprovals[tokenId].value;
}
/**
* @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) public virtual override {
_operatorApprovals[_msgSenderERC721A()][operator] = approved;
emit ApprovalForAll(_msgSenderERC721A(), operator, approved);
}
/**
* @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
*
* See {setApprovalForAll}.
*/
function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
return _operatorApprovals[owner][operator];
}
/**
* @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. See {_mint}.
*/
function _exists(uint256 tokenId) internal view virtual returns (bool) {
return
_startTokenId() <= tokenId &&
tokenId < _currentIndex && // If within bounds,
_packedOwnerships[tokenId] & _BITMASK_BURNED == 0; // and not burned.
}
/**
* @dev Returns whether `msgSender` is equal to `approvedAddress` or `owner`.
*/
function _isSenderApprovedOrOwner(
address approvedAddress,
address owner,
address msgSender
) private pure returns (bool result) {
assembly {
// Mask `owner` to the lower 160 bits, in case the upper bits somehow aren't clean.
owner := and(owner, _BITMASK_ADDRESS)
// Mask `msgSender` to the lower 160 bits, in case the upper bits somehow aren't clean.
msgSender := and(msgSender, _BITMASK_ADDRESS)
// `msgSender == owner || msgSender == approvedAddress`.
result := or(eq(msgSender, owner), eq(msgSender, approvedAddress))
}
}
/**
* @dev Returns the storage slot and value for the approved address of `tokenId`.
*/
function _getApprovedSlotAndAddress(uint256 tokenId)
private
view
returns (uint256 approvedAddressSlot, address approvedAddress)
{
TokenApprovalRef storage tokenApproval = _tokenApprovals[tokenId];
// The following is equivalent to `approvedAddress = _tokenApprovals[tokenId].value`.
assembly {
approvedAddressSlot := tokenApproval.slot
approvedAddress := sload(approvedAddressSlot)
}
}
// =============================================================
// TRANSFER OPERATIONS
// =============================================================
/**
* @dev Transfers `tokenId` from `from` to `to`.
*
* 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
) public payable virtual override {
_beforeTransfer();
uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);
if (address(uint160(prevOwnershipPacked)) != from) revert TransferFromIncorrectOwner();
(uint256 approvedAddressSlot, address approvedAddress) = _getApprovedSlotAndAddress(tokenId);
// The nested ifs save around 20+ gas over a compound boolean condition.
if (!_isSenderApprovedOrOwner(approvedAddress, from, _msgSenderERC721A()))
if (!isApprovedForAll(from, _msgSenderERC721A())) revert TransferCallerNotOwnerNorApproved();
if (to == address(0)) revert TransferToZeroAddress();
_beforeTokenTransfers(from, to, tokenId, 1);
// Clear approvals from the previous owner.
assembly {
if approvedAddress {
// This is equivalent to `delete _tokenApprovals[tokenId]`.
sstore(approvedAddressSlot, 0)
}
}
// Underflow of the sender's balance is impossible because we check for
// ownership above and the recipient's balance can't realistically overflow.
// Counter overflow is incredibly unrealistic as `tokenId` would have to be 2**256.
unchecked {
// We can directly increment and decrement the balances.
--_packedAddressData[from]; // Updates: `balance -= 1`.
++_packedAddressData[to]; // Updates: `balance += 1`.
// Updates:
// - `address` to the next owner.
// - `startTimestamp` to the timestamp of transfering.
// - `burned` to `false`.
// - `nextInitialized` to `true`.
_packedOwnerships[tokenId] = _packOwnershipData(
to,
_BITMASK_NEXT_INITIALIZED | _nextExtraData(from, to, prevOwnershipPacked)
);
// If the next slot may not have been initialized (i.e. `nextInitialized == false`) .
if (prevOwnershipPacked & _BITMASK_NEXT_INITIALIZED == 0) {
uint256 nextTokenId = tokenId + 1;
// If the next slot's address is zero and not burned (i.e. packed value is zero).
if (_packedOwnerships[nextTokenId] == 0) {
// If the next slot is within bounds.
if (nextTokenId != _currentIndex) {
// Initialize the next slot to maintain correctness for `ownerOf(tokenId + 1)`.
_packedOwnerships[nextTokenId] = prevOwnershipPacked;
}
}
}
}
emit Transfer(from, to, tokenId);
_afterTokenTransfers(from, to, tokenId, 1);
}
/**
* @dev Equivalent to `safeTransferFrom(from, to, tokenId, '')`.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId
) public payable virtual override {
safeTransferFrom(from, to, tokenId, '');
}
/**
* @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 memory _data
) public payable virtual override {
transferFrom(from, to, tokenId);
if (to.code.length != 0)
if (!_checkContractOnERC721Received(from, to, tokenId, _data)) {
revert TransferToNonERC721ReceiverImplementer();
}
}
/**
* @dev Hook that is called before a set of serially-ordered token IDs
* are about to be transferred. This includes minting.
* And also called before burning one token.
*
* `startTokenId` - the first token ID to be transferred.
* `quantity` - the amount to be transferred.
*
* 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, `tokenId` will be burned by `from`.
* - `from` and `to` are never both zero.
*/
function _beforeTokenTransfers(
address from,
address to,
uint256 startTokenId,
uint256 quantity
) internal virtual {}
function _beforeTransfer() internal {
}
/**
* @dev Hook that is called after a set of serially-ordered token IDs
* have been transferred. This includes minting.
* And also called after one token has been burned.
*
* `startTokenId` - the first token ID to be transferred.
* `quantity` - the amount to be transferred.
*
* Calling conditions:
*
* - When `from` and `to` are both non-zero, `from`'s `tokenId` has been
* transferred to `to`.
* - When `from` is zero, `tokenId` has been minted for `to`.
* - When `to` is zero, `tokenId` has been burned by `from`.
* - `from` and `to` are never both zero.
*/
function _afterTokenTransfers(
address from,
address to,
uint256 startTokenId,
uint256 quantity
) internal virtual {}
/**
* @dev Private function to invoke {IERC721Receiver-onERC721Received} on a target contract.
*
* `from` - Previous owner of the given token ID.
* `to` - Target address that will receive the token.
* `tokenId` - Token ID to be transferred.
* `_data` - Optional data to send along with the call.
*
* Returns whether the call correctly returned the expected magic value.
*/
function _checkContractOnERC721Received(
address from,
address to,
uint256 tokenId,
bytes memory _data
) private returns (bool) {
try ERC721A__IERC721Receiver(to).onERC721Received(_msgSenderERC721A(), from, tokenId, _data) returns (
bytes4 retval
) {
return retval == ERC721A__IERC721Receiver(to).onERC721Received.selector;
} catch (bytes memory reason) {
if (reason.length == 0) {
revert TransferToNonERC721ReceiverImplementer();
} else {
assembly {
revert(add(32, reason), mload(reason))
}
}
}
}
// =============================================================
// MINT OPERATIONS
// =============================================================
/**
* @dev Mints `quantity` tokens and transfers them to `to`.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - `quantity` must be greater than 0.
*
* Emits a {Transfer} event for each mint.
*/
function _mint(address to, uint256 quantity) internal virtual {
uint256 startTokenId = _currentIndex;
if (quantity == 0) revert MintZeroQuantity();
_beforeTokenTransfers(address(0), to, startTokenId, quantity);
// Overflows are incredibly unrealistic.
// `balance` and `numberMinted` have a maximum limit of 2**64.
// `tokenId` has a maximum limit of 2**256.
unchecked {
// Updates:
// - `balance += quantity`.
// - `numberMinted += quantity`.
//
// We can directly add to the `balance` and `numberMinted`.
_packedAddressData[to] += quantity * ((1 << _BITPOS_NUMBER_MINTED) | 1);
// Updates:
// - `address` to the owner.
// - `startTimestamp` to the timestamp of minting.
// - `burned` to `false`.
// - `nextInitialized` to `quantity == 1`.
_packedOwnerships[startTokenId] = _packOwnershipData(
to,
_nextInitializedFlag(quantity) | _nextExtraData(address(0), to, 0)
);
uint256 toMasked;
uint256 end = startTokenId + quantity;
// Use assembly to loop and emit the `Transfer` event for gas savings.
// The duplicated `log4` removes an extra check and reduces stack juggling.
// The assembly, together with the surrounding Solidity code, have been
// delicately arranged to nudge the compiler into producing optimized opcodes.
assembly {
// Mask `to` to the lower 160 bits, in case the upper bits somehow aren't clean.
toMasked := and(to, _BITMASK_ADDRESS)
// Emit the `Transfer` event.
log4(
0, // Start of data (0, since no data).
0, // End of data (0, since no data).
_TRANSFER_EVENT_SIGNATURE, // Signature.
0, // `address(0)`.
toMasked, // `to`.
startTokenId // `tokenId`.
)
// The `iszero(eq(,))` check ensures that large values of `quantity`
// that overflows uint256 will make the loop run out of gas.
// The compiler will optimize the `iszero` away for performance.
for {
let tokenId := add(startTokenId, 1)
} iszero(eq(tokenId, end)) {
tokenId := add(tokenId, 1)
} {
// Emit the `Transfer` event. Similar to above.
log4(0, 0, _TRANSFER_EVENT_SIGNATURE, 0, toMasked, tokenId)
}
}
if (toMasked == 0) revert MintToZeroAddress();
_currentIndex = end;
}
_afterTokenTransfers(address(0), to, startTokenId, quantity);
}
/**
* @dev Mints `quantity` tokens and transfers them to `to`.
*
* This function is intended for efficient minting only during contract creation.
*
* It emits only one {ConsecutiveTransfer} as defined in
* [ERC2309](https://eips.ethereum.org/EIPS/eip-2309),
* instead of a sequence of {Transfer} event(s).
*
* Calling this function outside of contract creation WILL make your contract
* non-compliant with the ERC721 standard.
* For full ERC721 compliance, substituting ERC721 {Transfer} event(s) with the ERC2309
* {ConsecutiveTransfer} event is only permissible during contract creation.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - `quantity` must be greater than 0.
*
* Emits a {ConsecutiveTransfer} event.
*/
function _mintERC2309(address to, uint256 quantity) internal virtual {
uint256 startTokenId = _currentIndex;
if (to == address(0)) revert MintToZeroAddress();
if (quantity == 0) revert MintZeroQuantity();
if (quantity > _MAX_MINT_ERC2309_QUANTITY_LIMIT) revert MintERC2309QuantityExceedsLimit();
_beforeTokenTransfers(address(0), to, startTokenId, quantity);
// Overflows are unrealistic due to the above check for `quantity` to be below the limit.
unchecked {
// Updates:
// - `balance += quantity`.
// - `numberMinted += quantity`.
//
// We can directly add to the `balance` and `numberMinted`.
_packedAddressData[to] += quantity * ((1 << _BITPOS_NUMBER_MINTED) | 1);
// Updates:
// - `address` to the owner.
// - `startTimestamp` to the timestamp of minting.
// - `burned` to `false`.
// - `nextInitialized` to `quantity == 1`.
_packedOwnerships[startTokenId] = _packOwnershipData(
to,
_nextInitializedFlag(quantity) | _nextExtraData(address(0), to, 0)
);
emit ConsecutiveTransfer(startTokenId, startTokenId + quantity - 1, address(0), to);
_currentIndex = startTokenId + quantity;
}
_afterTokenTransfers(address(0), to, startTokenId, quantity);
}
/**
* @dev Safely mints `quantity` tokens and transfers them to `to`.
*
* Requirements:
*
* - If `to` refers to a smart contract, it must implement
* {IERC721Receiver-onERC721Received}, which is called for each safe transfer.
* - `quantity` must be greater than 0.
*
* See {_mint}.
*
* Emits a {Transfer} event for each mint.
*/
function _safeMint(
address to,
uint256 quantity,
bytes memory _data
) internal virtual {
_mint(to, quantity);
unchecked {
if (to.code.length != 0) {
uint256 end = _currentIndex;
uint256 index = end - quantity;
do {
if (!_checkContractOnERC721Received(address(0), to, index++, _data)) {
revert TransferToNonERC721ReceiverImplementer();
}
} while (index < end);
// Reentrancy protection.
if (_currentIndex != end) revert();
}
}
}
/**
* @dev Equivalent to `_safeMint(to, quantity, '')`.
*/
function _safeMint(address to, uint256 quantity) internal virtual {
_safeMint(to, quantity, '');
}
// =============================================================
// BURN OPERATIONS
// =============================================================
/**
* @dev Equivalent to `_burn(tokenId, false)`.
*/
function _burn(uint256 tokenId) internal virtual {
_burn(tokenId, false);
}
/**
* @dev Destroys `tokenId`.
* The approval is cleared when the token is burned.
*
* Requirements:
*
* - `tokenId` must exist.
*
* Emits a {Transfer} event.
*/
function _burn(uint256 tokenId, bool approvalCheck) internal virtual {
uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);
address from = address(uint160(prevOwnershipPacked));
(uint256 approvedAddressSlot, address approvedAddress) = _getApprovedSlotAndAddress(tokenId);
if (approvalCheck) {
// The nested ifs save around 20+ gas over a compound boolean condition.
if (!_isSenderApprovedOrOwner(approvedAddress, from, _msgSenderERC721A()))
if (!isApprovedForAll(from, _msgSenderERC721A())) revert TransferCallerNotOwnerNorApproved();
}
_beforeTokenTransfers(from, address(0), tokenId, 1);
// Clear approvals from the previous owner.
assembly {
if approvedAddress {
// This is equivalent to `delete _tokenApprovals[tokenId]`.
sstore(approvedAddressSlot, 0)
}
}
// Underflow of the sender's balance is impossible because we check for
// ownership above and the recipient's balance can't realistically overflow.
// Counter overflow is incredibly unrealistic as `tokenId` would have to be 2**256.
unchecked {
// Updates:
// - `balance -= 1`.
// - `numberBurned += 1`.
//
// We can directly decrement the balance, and increment the number burned.
// This is equivalent to `packed -= 1; packed += 1 << _BITPOS_NUMBER_BURNED;`.
_packedAddressData[from] += (1 << _BITPOS_NUMBER_BURNED) - 1;
// Updates:
// - `address` to the last owner.
// - `startTimestamp` to the timestamp of burning.
// - `burned` to `true`.
// - `nextInitialized` to `true`.
_packedOwnerships[tokenId] = _packOwnershipData(
from,
(_BITMASK_BURNED | _BITMASK_NEXT_INITIALIZED) | _nextExtraData(from, address(0), prevOwnershipPacked)
);
// If the next slot may not have been initialized (i.e. `nextInitialized == false`) .
if (prevOwnershipPacked & _BITMASK_NEXT_INITIALIZED == 0) {
uint256 nextTokenId = tokenId + 1;
// If the next slot's address is zero and not burned (i.e. packed value is zero).
if (_packedOwnerships[nextTokenId] == 0) {
// If the next slot is within bounds.
if (nextTokenId != _currentIndex) {
// Initialize the next slot to maintain correctness for `ownerOf(tokenId + 1)`.
_packedOwnerships[nextTokenId] = prevOwnershipPacked;
}
}
}
}
emit Transfer(from, address(0), tokenId);
_afterTokenTransfers(from, address(0), tokenId, 1);
// Overflow not possible, as _burnCounter cannot be exceed _currentIndex times.
unchecked {
_burnCounter++;
}
}
// =============================================================
// EXTRA DATA OPERATIONS
// =============================================================
/**
* @dev Directly sets the extra data for the ownership data `index`.
*/
function _setExtraDataAt(uint256 index, uint24 extraData) internal virtual {
uint256 packed = _packedOwnerships[index];
if (packed == 0) revert OwnershipNotInitializedForExtraData();
uint256 extraDataCasted;
// Cast `extraData` with assembly to avoid redundant masking.
assembly {
extraDataCasted := extraData
}
packed = (packed & _BITMASK_EXTRA_DATA_COMPLEMENT) | (extraDataCasted << _BITPOS_EXTRA_DATA);
_packedOwnerships[index] = packed;
}
/**
* @dev Called during each token transfer to set the 24bit `extraData` field.
* Intended to be overridden by the cosumer contract.
*
* `previousExtraData` - the value of `extraData` before transfer.
*
* 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, `tokenId` will be burned by `from`.
* - `from` and `to` are never both zero.
*/
function _extraData(
address from,
address to,
uint24 previousExtraData
) internal view virtual returns (uint24) {}
/**
* @dev Returns the next extra data for the packed ownership data.
* The returned result is shifted into position.
*/
function _nextExtraData(
address from,
address to,
uint256 prevOwnershipPacked
) private view returns (uint256) {
uint24 extraData = uint24(prevOwnershipPacked >> _BITPOS_EXTRA_DATA);
return uint256(_extraData(from, to, extraData)) << _BITPOS_EXTRA_DATA;
}
// =============================================================
// OTHER OPERATIONS
// =============================================================
/**
* @dev Returns the message sender (defaults to `msg.sender`).
*
* If you are writing GSN compatible contracts, you need to override this function.
*/
function _msgSenderERC721A() internal view virtual returns (address) {
return msg.sender;
}
/**
* @dev Converts a uint256 to its ASCII string decimal representation.
*/
function _toString(uint256 value) internal pure virtual returns (string memory str) {
assembly {
// The maximum value of a uint256 contains 78 digits (1 byte per digit), but
// we allocate 0xa0 bytes to keep the free memory pointer 32-byte word aligned.
// We will need 1 word for the trailing zeros padding, 1 word for the length,
// and 3 words for a maximum of 78 digits. Total: 5 * 0x20 = 0xa0.
let m := add(mload(0x40), 0xa0)
// Update the free memory pointer to allocate.
mstore(0x40, m)
// Assign the `str` to the end.
str := sub(m, 0x20)
// Zeroize the slot after the string.
mstore(str, 0)
// Cache the end of the memory to calculate the length later.
let end := str
// We write the string from rightmost digit to leftmost digit.
// The following is essentially a do-while loop that also handles the zero case.
// prettier-ignore
for { let temp := value } 1 {} {
str := sub(str, 1)
// Write the character to the pointer.
// The ASCII index of the '0' character is 48.
mstore8(str, add(48, mod(temp, 10)))
// Keep dividing `temp` until zero.
temp := div(temp, 10)
// prettier-ignore
if iszero(temp) { break }
}
let length := sub(end, str)
// Move the pointer 32 bytes leftwards to make room for the length.
str := sub(str, 0x20)
// Store the length.
mstore(str, length)
}
}
}