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/** | |
*Submitted for verification at Etherscan.io on 2020-01-19 | |
*/ | |
/** | |
*Submitted for verification at Etherscan.io on 2020-01-18 | |
*/ | |
/** | |
*Submitted for verification at Etherscan.io on 2020-01-17 | |
*/ | |
pragma solidity ^0.5.12; | |
/* | |
* @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 GSN 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. | |
*/ | |
contract Context { | |
// Empty internal constructor, to prevent people from mistakenly deploying | |
// an instance of this contract, which should be used via inheritance. | |
constructor () internal { } | |
// solhint-disable-previous-line no-empty-blocks | |
function _msgSender() internal view returns (address payable) { | |
return msg.sender; | |
} | |
function _msgData() internal view returns (bytes memory) { | |
this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691 | |
return msg.data; | |
} | |
} | |
/** | |
* @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); | |
} | |
/** | |
* @dev Required interface of an ERC721 compliant contract. | |
*/ | |
contract IERC721 is IERC165 { | |
event Transfer(address indexed from, address indexed to, uint256 indexed tokenId); | |
event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId); | |
event ApprovalForAll(address indexed owner, address indexed operator, bool approved); | |
/** | |
* @dev Returns the number of NFTs in `owner`'s account. | |
*/ | |
function balanceOf(address owner) public view returns (uint256 balance); | |
/** | |
* @dev Returns the owner of the NFT specified by `tokenId`. | |
*/ | |
function ownerOf(uint256 tokenId) public view returns (address owner); | |
/** | |
* @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to | |
* another (`to`). | |
* | |
* | |
* | |
* Requirements: | |
* - `from`, `to` cannot be zero. | |
* - `tokenId` must be owned by `from`. | |
* - If the caller is not `from`, it must be have been allowed to move this | |
* NFT by either {approve} or {setApprovalForAll}. | |
*/ | |
function safeTransferFrom(address from, address to, uint256 tokenId) public; | |
/** | |
* @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to | |
* another (`to`). | |
* | |
* Requirements: | |
* - If the caller is not `from`, it must be approved to move this NFT by | |
* either {approve} or {setApprovalForAll}. | |
*/ | |
function transferFrom(address from, address to, uint256 tokenId) public; | |
function approve(address to, uint256 tokenId) public; | |
function getApproved(uint256 tokenId) public view returns (address operator); | |
function setApprovalForAll(address operator, bool _approved) public; | |
function isApprovedForAll(address owner, address operator) public view returns (bool); | |
function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public; | |
} | |
/** | |
* @title ERC721 token receiver interface | |
* @dev Interface for any contract that wants to support safeTransfers | |
* from ERC721 asset contracts. | |
*/ | |
contract IERC721Receiver { | |
/** | |
* @notice Handle the receipt of an NFT | |
* @dev The ERC721 smart contract calls this function on the recipient | |
* after a {IERC721-safeTransferFrom}. This function MUST return the function selector, | |
* otherwise the caller will revert the transaction. The selector to be | |
* returned can be obtained as `this.onERC721Received.selector`. This | |
* function MAY throw to revert and reject the transfer. | |
* Note: the ERC721 contract address is always the message sender. | |
* @param operator The address which called `safeTransferFrom` function | |
* @param from The address which previously owned the token | |
* @param tokenId The NFT identifier which is being transferred | |
* @param data Additional data with no specified format | |
* @return bytes4 `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))` | |
*/ | |
function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data) | |
public returns (bytes4); | |
} | |
/** | |
* @dev Wrappers over Solidity's arithmetic operations with added overflow | |
* checks. | |
* | |
* Arithmetic operations in Solidity wrap on overflow. This can easily result | |
* in bugs, because programmers usually assume that an overflow raises an | |
* error, which is the standard behavior in high level programming languages. | |
* `SafeMath` restores this intuition by reverting the transaction when an | |
* operation overflows. | |
* | |
* Using this library instead of the unchecked operations eliminates an entire | |
* class of bugs, so it's recommended to use it always. | |
*/ | |
library SafeMath { | |
/** | |
* @dev Returns the addition of two unsigned integers, reverting on | |
* overflow. | |
* | |
* Counterpart to Solidity's `+` operator. | |
* | |
* Requirements: | |
* - Addition cannot overflow. | |
*/ | |
function add(uint256 a, uint256 b) internal pure returns (uint256) { | |
uint256 c = a + b; | |
require(c >= a, "SafeMath: addition overflow"); | |
return c; | |
} | |
/** | |
* @dev Returns the subtraction of two unsigned integers, reverting on | |
* overflow (when the result is negative). | |
* | |
* Counterpart to Solidity's `-` operator. | |
* | |
* Requirements: | |
* - Subtraction cannot overflow. | |
*/ | |
function sub(uint256 a, uint256 b) internal pure returns (uint256) { | |
return sub(a, b, "SafeMath: subtraction overflow"); | |
} | |
/** | |
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on | |
* overflow (when the result is negative). | |
* | |
* Counterpart to Solidity's `-` operator. | |
* | |
* Requirements: | |
* - Subtraction cannot overflow. | |
* | |
* _Available since v2.4.0._ | |
*/ | |
function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { | |
require(b <= a, errorMessage); | |
uint256 c = a - b; | |
return c; | |
} | |
/** | |
* @dev Returns the multiplication of two unsigned integers, reverting on | |
* overflow. | |
* | |
* Counterpart to Solidity's `*` operator. | |
* | |
* Requirements: | |
* - Multiplication cannot overflow. | |
*/ | |
function mul(uint256 a, uint256 b) internal pure returns (uint256) { | |
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the | |
// benefit is lost if 'b' is also tested. | |
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522 | |
if (a == 0) { | |
return 0; | |
} | |
uint256 c = a * b; | |
require(c / a == b, "SafeMath: multiplication overflow"); | |
return c; | |
} | |
/** | |
* @dev Returns the integer division of two unsigned integers. Reverts on | |
* division by zero. The result is rounded towards zero. | |
* | |
* Counterpart to Solidity's `/` operator. Note: this function uses a | |
* `revert` opcode (which leaves remaining gas untouched) while Solidity | |
* uses an invalid opcode to revert (consuming all remaining gas). | |
* | |
* Requirements: | |
* - The divisor cannot be zero. | |
*/ | |
function div(uint256 a, uint256 b) internal pure returns (uint256) { | |
return div(a, b, "SafeMath: division by zero"); | |
} | |
/** | |
* @dev Returns the integer division of two unsigned integers. Reverts with custom message on | |
* division by zero. The result is rounded towards zero. | |
* | |
* Counterpart to Solidity's `/` operator. Note: this function uses a | |
* `revert` opcode (which leaves remaining gas untouched) while Solidity | |
* uses an invalid opcode to revert (consuming all remaining gas). | |
* | |
* Requirements: | |
* - The divisor cannot be zero. | |
* | |
* _Available since v2.4.0._ | |
*/ | |
function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { | |
// Solidity only automatically asserts when dividing by 0 | |
require(b > 0, errorMessage); | |
uint256 c = a / b; | |
// assert(a == b * c + a % b); // There is no case in which this doesn't hold | |
return c; | |
} | |
/** | |
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo), | |
* Reverts when dividing by zero. | |
* | |
* Counterpart to Solidity's `%` operator. This function uses a `revert` | |
* opcode (which leaves remaining gas untouched) while Solidity uses an | |
* invalid opcode to revert (consuming all remaining gas). | |
* | |
* Requirements: | |
* - The divisor cannot be zero. | |
*/ | |
function mod(uint256 a, uint256 b) internal pure returns (uint256) { | |
return mod(a, b, "SafeMath: modulo by zero"); | |
} | |
/** | |
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo), | |
* Reverts with custom message when dividing by zero. | |
* | |
* Counterpart to Solidity's `%` operator. This function uses a `revert` | |
* opcode (which leaves remaining gas untouched) while Solidity uses an | |
* invalid opcode to revert (consuming all remaining gas). | |
* | |
* Requirements: | |
* - The divisor cannot be zero. | |
* | |
* _Available since v2.4.0._ | |
*/ | |
function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { | |
require(b != 0, errorMessage); | |
return a % b; | |
} | |
} | |
/** | |
* @dev Collection of functions related to the address type | |
*/ | |
library Address { | |
/** | |
* @dev Returns true if `account` is a contract. | |
* | |
* This test is non-exhaustive, and there may be false-negatives: during the | |
* execution of a contract's constructor, its address will be reported as | |
* not containing 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. | |
*/ | |
function isContract(address account) internal view returns (bool) { | |
// This method relies in extcodesize, which returns 0 for contracts in | |
// construction, since the code is only stored at the end of the | |
// constructor execution. | |
// According to EIP-1052, 0x0 is the value returned for not-yet created accounts | |
// and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned | |
// for accounts without code, i.e. `keccak256('')` | |
bytes32 codehash; | |
bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470; | |
// solhint-disable-next-line no-inline-assembly | |
assembly { codehash := extcodehash(account) } | |
return (codehash != 0x0 && codehash != accountHash); | |
} | |
/** | |
* @dev Converts an `address` into `address payable`. Note that this is | |
* simply a type cast: the actual underlying value is not changed. | |
* | |
* _Available since v2.4.0._ | |
*/ | |
function toPayable(address account) internal pure returns (address payable) { | |
return address(uint160(account)); | |
} | |
/** | |
* @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]. | |
* | |
* _Available since v2.4.0._ | |
*/ | |
function sendValue(address payable recipient, uint256 amount) internal { | |
require(address(this).balance >= amount, "Address: insufficient balance"); | |
// solhint-disable-next-line avoid-call-value | |
(bool success, ) = recipient.call.value(amount)(""); | |
require(success, "Address: unable to send value, recipient may have reverted"); | |
} | |
} | |
/** | |
* @title Counters | |
* @author Matt Condon (@shrugs) | |
* @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number | |
* of elements in a mapping, issuing ERC721 ids, or counting request ids. | |
* | |
* Include with `using Counters for Counters.Counter;` | |
* Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the {SafeMath} | |
* overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never | |
* directly accessed. | |
*/ | |
library Counters { | |
using SafeMath for uint256; | |
struct Counter { | |
// This variable should never be directly accessed by users of the library: interactions must be restricted to | |
// the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add | |
// this feature: see https://github.com/ethereum/solidity/issues/4637 | |
uint256 _value; // default: 0 | |
} | |
function current(Counter storage counter) internal view returns (uint256) { | |
return counter._value; | |
} | |
function increment(Counter storage counter) internal { | |
counter._value += 1; | |
} | |
function decrement(Counter storage counter) internal { | |
counter._value = counter._value.sub(1); | |
} | |
} | |
/** | |
* @dev Implementation of the {IERC165} interface. | |
* | |
* Contracts may inherit from this and call {_registerInterface} to declare | |
* their support of an interface. | |
*/ | |
contract ERC165 is IERC165 { | |
/* | |
* bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7 | |
*/ | |
bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7; | |
/** | |
* @dev Mapping of interface ids to whether or not it's supported. | |
*/ | |
mapping(bytes4 => bool) private _supportedInterfaces; | |
constructor () internal { | |
// Derived contracts need only register support for their own interfaces, | |
// we register support for ERC165 itself here | |
_registerInterface(_INTERFACE_ID_ERC165); | |
} | |
/** | |
* @dev See {IERC165-supportsInterface}. | |
* | |
* Time complexity O(1), guaranteed to always use less than 30 000 gas. | |
*/ | |
function supportsInterface(bytes4 interfaceId) external view returns (bool) { | |
return _supportedInterfaces[interfaceId]; | |
} | |
/** | |
* @dev Registers the contract as an implementer of the interface defined by | |
* `interfaceId`. Support of the actual ERC165 interface is automatic and | |
* registering its interface id is not required. | |
* | |
* See {IERC165-supportsInterface}. | |
* | |
* Requirements: | |
* | |
* - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`). | |
*/ | |
function _registerInterface(bytes4 interfaceId) internal { | |
require(interfaceId != 0xffffffff, "ERC165: invalid interface id"); | |
_supportedInterfaces[interfaceId] = true; | |
} | |
} | |
/** | |
* @title ERC721 Non-Fungible Token Standard basic implementation | |
* @dev see https://eips.ethereum.org/EIPS/eip-721 | |
*/ | |
contract ERC721 is Context, ERC165, IERC721 { | |
using SafeMath for uint256; | |
using Address for address; | |
using Counters for Counters.Counter; | |
// Equals to `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))` | |
// which can be also obtained as `IERC721Receiver(0).onERC721Received.selector` | |
bytes4 private constant _ERC721_RECEIVED = 0x150b7a02; | |
// Mapping from token ID to owner | |
mapping (uint256 => address) private _tokenOwner; | |
// Mapping from token ID to approved address | |
mapping (uint256 => address) private _tokenApprovals; | |
// Mapping from owner to number of owned token | |
mapping (address => Counters.Counter) private _ownedTokensCount; | |
// Mapping from owner to operator approvals | |
mapping (address => mapping (address => bool)) private _operatorApprovals; | |
/* | |
* bytes4(keccak256('balanceOf(address)')) == 0x70a08231 | |
* bytes4(keccak256('ownerOf(uint256)')) == 0x6352211e | |
* bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3 | |
* bytes4(keccak256('getApproved(uint256)')) == 0x081812fc | |
* bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465 | |
* bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c5 | |
* bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd | |
* bytes4(keccak256('safeTransferFrom(address,address,uint256)')) == 0x42842e0e | |
* bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)')) == 0xb88d4fde | |
* | |
* => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^ | |
* 0xa22cb465 ^ 0xe985e9c ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd | |
*/ | |
bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd; | |
constructor () public { | |
// register the supported interfaces to conform to ERC721 via ERC165 | |
_registerInterface(_INTERFACE_ID_ERC721); | |
} | |
/** | |
* @dev Gets the balance of the specified address. | |
* @param owner address to query the balance of | |
* @return uint256 representing the amount owned by the passed address | |
*/ | |
function balanceOf(address owner) public view returns (uint256) { | |
require(owner != address(0), "ERC721: balance query for the zero address"); | |
return _ownedTokensCount[owner].current(); | |
} | |
/** | |
* @dev Gets the owner of the specified token ID. | |
* @param tokenId uint256 ID of the token to query the owner of | |
* @return address currently marked as the owner of the given token ID | |
*/ | |
function ownerOf(uint256 tokenId) public view returns (address) { | |
address owner = _tokenOwner[tokenId]; | |
require(owner != address(0), "ERC721: owner query for nonexistent token"); | |
return owner; | |
} | |
/** | |
* @dev Approves another address to transfer the given token ID | |
* The zero address indicates there is no approved address. | |
* There can only be one approved address per token at a given time. | |
* Can only be called by the token owner or an approved operator. | |
* @param to address to be approved for the given token ID | |
* @param tokenId uint256 ID of the token to be approved | |
*/ | |
function approve(address to, uint256 tokenId) public { | |
address owner = 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" | |
); | |
_tokenApprovals[tokenId] = to; | |
emit Approval(owner, to, tokenId); | |
} | |
/** | |
* @dev Gets the approved address for a token ID, or zero if no address set | |
* Reverts if the token ID does not exist. | |
* @param tokenId uint256 ID of the token to query the approval of | |
* @return address currently approved for the given token ID | |
*/ | |
function getApproved(uint256 tokenId) public view returns (address) { | |
require(_exists(tokenId), "ERC721: approved query for nonexistent token"); | |
return _tokenApprovals[tokenId]; | |
} | |
/** | |
* @dev Sets or unsets the approval of a given operator | |
* An operator is allowed to transfer all tokens of the sender on their behalf. | |
* @param to operator address to set the approval | |
* @param approved representing the status of the approval to be set | |
*/ | |
function setApprovalForAll(address to, bool approved) public { | |
require(to != _msgSender(), "ERC721: approve to caller"); | |
_operatorApprovals[_msgSender()][to] = approved; | |
emit ApprovalForAll(_msgSender(), to, approved); | |
} | |
/** | |
* @dev Tells whether an operator is approved by a given owner. | |
* @param owner owner address which you want to query the approval of | |
* @param operator operator address which you want to query the approval of | |
* @return bool whether the given operator is approved by the given owner | |
*/ | |
function isApprovedForAll(address owner, address operator) public view returns (bool) { | |
return _operatorApprovals[owner][operator]; | |
} | |
/** | |
* @dev Transfers the ownership of a given token ID to another address. | |
* Usage of this method is discouraged, use {safeTransferFrom} whenever possible. | |
* Requires the msg.sender to be the owner, approved, or operator. | |
* @param from current owner of the token | |
* @param to address to receive the ownership of the given token ID | |
* @param tokenId uint256 ID of the token to be transferred | |
*/ | |
function transferFrom(address from, address to, uint256 tokenId) public { | |
//solhint-disable-next-line max-line-length | |
require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved"); | |
_transferFrom(from, to, tokenId); | |
} | |
/** | |
* @dev Safely transfers the ownership of a given token ID to another address | |
* If the target address is a contract, it must implement {IERC721Receiver-onERC721Received}, | |
* which is called upon a safe transfer, and return the magic value | |
* `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise, | |
* the transfer is reverted. | |
* Requires the msg.sender to be the owner, approved, or operator | |
* @param from current owner of the token | |
* @param to address to receive the ownership of the given token ID | |
* @param tokenId uint256 ID of the token to be transferred | |
*/ | |
function safeTransferFrom(address from, address to, uint256 tokenId) public { | |
safeTransferFrom(from, to, tokenId, ""); | |
} | |
/** | |
* @dev Safely transfers the ownership of a given token ID to another address | |
* If the target address is a contract, it must implement {IERC721Receiver-onERC721Received}, | |
* which is called upon a safe transfer, and return the magic value | |
* `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise, | |
* the transfer is reverted. | |
* Requires the _msgSender() to be the owner, approved, or operator | |
* @param from current owner of the token | |
* @param to address to receive the ownership of the given token ID | |
* @param tokenId uint256 ID of the token to be transferred | |
* @param _data bytes data to send along with a safe transfer check | |
*/ | |
function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public { | |
require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved"); | |
_safeTransferFrom(from, to, tokenId, _data); | |
} | |
/** | |
* @dev Safely transfers the ownership of a given token ID to another address | |
* If the target address is a contract, it must implement `onERC721Received`, | |
* which is called upon a safe transfer, and return the magic value | |
* `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise, | |
* the transfer is reverted. | |
* Requires the msg.sender to be the owner, approved, or operator | |
* @param from current owner of the token | |
* @param to address to receive the ownership of the given token ID | |
* @param tokenId uint256 ID of the token to be transferred | |
* @param _data bytes data to send along with a safe transfer check | |
*/ | |
function _safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) internal { | |
_transferFrom(from, to, tokenId); | |
require(_checkOnERC721Received(from, to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer"); | |
} | |
/** | |
* @dev Returns whether the specified token exists. | |
* @param tokenId uint256 ID of the token to query the existence of | |
* @return bool whether the token exists | |
*/ | |
function _exists(uint256 tokenId) internal view returns (bool) { | |
address owner = _tokenOwner[tokenId]; | |
return owner != address(0); | |
} | |
/** | |
* @dev Returns whether the given spender can transfer a given token ID. | |
* @param spender address of the spender to query | |
* @param tokenId uint256 ID of the token to be transferred | |
* @return bool whether the msg.sender is approved for the given token ID, | |
* is an operator of the owner, or is the owner of the token | |
*/ | |
function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) { | |
require(_exists(tokenId), "ERC721: operator query for nonexistent token"); | |
address owner = ownerOf(tokenId); | |
return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender)); | |
} | |
/** | |
* @dev Internal function to safely mint a new token. | |
* Reverts if the given token ID already exists. | |
* If the target address is a contract, it must implement `onERC721Received`, | |
* which is called upon a safe transfer, and return the magic value | |
* `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise, | |
* the transfer is reverted. | |
* @param to The address that will own the minted token | |
* @param tokenId uint256 ID of the token to be minted | |
*/ | |
function _safeMint(address to, uint256 tokenId) internal { | |
_safeMint(to, tokenId, ""); | |
} | |
/** | |
* @dev Internal function to safely mint a new token. | |
* Reverts if the given token ID already exists. | |
* If the target address is a contract, it must implement `onERC721Received`, | |
* which is called upon a safe transfer, and return the magic value | |
* `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise, | |
* the transfer is reverted. | |
* @param to The address that will own the minted token | |
* @param tokenId uint256 ID of the token to be minted | |
* @param _data bytes data to send along with a safe transfer check | |
*/ | |
function _safeMint(address to, uint256 tokenId, bytes memory _data) internal { | |
_mint(to, tokenId); | |
require(_checkOnERC721Received(address(0), to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer"); | |
} | |
/** | |
* @dev Internal function to mint a new token. | |
* Reverts if the given token ID already exists. | |
* @param to The address that will own the minted token | |
* @param tokenId uint256 ID of the token to be minted | |
*/ | |
function _mint(address to, uint256 tokenId) internal { | |
require(to != address(0), "ERC721: mint to the zero address"); | |
require(!_exists(tokenId), "ERC721: token already minted"); | |
_tokenOwner[tokenId] = to; | |
_ownedTokensCount[to].increment(); | |
emit Transfer(address(0), to, tokenId); | |
} | |
/** | |
* @dev Internal function to burn a specific token. | |
* Reverts if the token does not exist. | |
* Deprecated, use {_burn} instead. | |
* @param owner owner of the token to burn | |
* @param tokenId uint256 ID of the token being burned | |
*/ | |
function _burn(address owner, uint256 tokenId) internal { | |
require(ownerOf(tokenId) == owner, "ERC721: burn of token that is not own"); | |
_clearApproval(tokenId); | |
_ownedTokensCount[owner].decrement(); | |
_tokenOwner[tokenId] = address(0); | |
emit Transfer(owner, address(0), tokenId); | |
} | |
/** | |
* @dev Internal function to burn a specific token. | |
* Reverts if the token does not exist. | |
* @param tokenId uint256 ID of the token being burned | |
*/ | |
function _burn(uint256 tokenId) internal { | |
_burn(ownerOf(tokenId), tokenId); | |
} | |
/** | |
* @dev Internal function to transfer ownership of a given token ID to another address. | |
* As opposed to {transferFrom}, this imposes no restrictions on msg.sender. | |
* @param from current owner of the token | |
* @param to address to receive the ownership of the given token ID | |
* @param tokenId uint256 ID of the token to be transferred | |
*/ | |
function _transferFrom(address from, address to, uint256 tokenId) internal { | |
require(ownerOf(tokenId) == from, "ERC721: transfer of token that is not own"); | |
require(to != address(0), "ERC721: transfer to the zero address"); | |
_clearApproval(tokenId); | |
_ownedTokensCount[from].decrement(); | |
_ownedTokensCount[to].increment(); | |
_tokenOwner[tokenId] = to; | |
emit Transfer(from, 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. | |
* | |
* This function is deprecated. | |
* @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) | |
internal returns (bool) | |
{ | |
if (!to.isContract()) { | |
return true; | |
} | |
bytes4 retval = IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data); | |
return (retval == _ERC721_RECEIVED); | |
} | |
/** | |
* @dev Private function to clear current approval of a given token ID. | |
* @param tokenId uint256 ID of the token to be transferred | |
*/ | |
function _clearApproval(uint256 tokenId) private { | |
if (_tokenApprovals[tokenId] != address(0)) { | |
_tokenApprovals[tokenId] = address(0); | |
} | |
} | |
} | |
/** | |
* @title ERC-721 Non-Fungible Token Standard, optional enumeration extension | |
* @dev See https://eips.ethereum.org/EIPS/eip-721 | |
*/ | |
contract IERC721Enumerable is IERC721 { | |
function totalSupply() public view returns (uint256); | |
function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256 tokenId); | |
function tokenByIndex(uint256 index) public view returns (uint256); | |
} | |
/** | |
* @title ERC-721 Non-Fungible Token with optional enumeration extension logic | |
* @dev See https://eips.ethereum.org/EIPS/eip-721 | |
*/ | |
contract ERC721Enumerable is Context, ERC165, ERC721, IERC721Enumerable { | |
// Mapping from owner to list of owned token IDs | |
mapping(address => 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; | |
/* | |
* bytes4(keccak256('totalSupply()')) == 0x18160ddd | |
* bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) == 0x2f745c59 | |
* bytes4(keccak256('tokenByIndex(uint256)')) == 0x4f6ccce7 | |
* | |
* => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63 | |
*/ | |
bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63; | |
/** | |
* @dev Constructor function. | |
*/ | |
constructor () public { | |
// register the supported interface to conform to ERC721Enumerable via ERC165 | |
_registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE); | |
} | |
/** | |
* @dev Gets the token ID at a given index of the tokens list of the requested owner. | |
* @param owner address owning the tokens list to be accessed | |
* @param index uint256 representing the index to be accessed of the requested tokens list | |
* @return uint256 token ID at the given index of the tokens list owned by the requested address | |
*/ | |
function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256) { | |
require(index < balanceOf(owner), "ERC721Enumerable: owner index out of bounds"); | |
return _ownedTokens[owner][index]; | |
} | |
/** | |
* @dev Gets the total amount of tokens stored by the contract. | |
* @return uint256 representing the total amount of tokens | |
*/ | |
function totalSupply() public view returns (uint256) { | |
return _allTokens.length; | |
} | |
/** | |
* @dev Gets the token ID at a given index of all the tokens in this contract | |
* Reverts if the index is greater or equal to the total number of tokens. | |
* @param index uint256 representing the index to be accessed of the tokens list | |
* @return uint256 token ID at the given index of the tokens list | |
*/ | |
function tokenByIndex(uint256 index) public view returns (uint256) { | |
require(index < totalSupply(), "ERC721Enumerable: global index out of bounds"); | |
return _allTokens[index]; | |
} | |
/** | |
* @dev Internal function to transfer ownership of a given token ID to another address. | |
* As opposed to transferFrom, this imposes no restrictions on msg.sender. | |
* @param from current owner of the token | |
* @param to address to receive the ownership of the given token ID | |
* @param tokenId uint256 ID of the token to be transferred | |
*/ | |
function _transferFrom(address from, address to, uint256 tokenId) internal { | |
super._transferFrom(from, to, tokenId); | |
_removeTokenFromOwnerEnumeration(from, tokenId); | |
_addTokenToOwnerEnumeration(to, tokenId); | |
} | |
/** | |
* @dev Internal function to mint a new token. | |
* Reverts if the given token ID already exists. | |
* @param to address the beneficiary that will own the minted token | |
* @param tokenId uint256 ID of the token to be minted | |
*/ | |
function _mint(address to, uint256 tokenId) internal { | |
super._mint(to, tokenId); | |
_addTokenToOwnerEnumeration(to, tokenId); | |
_addTokenToAllTokensEnumeration(tokenId); | |
} | |
/** | |
* @dev Internal function to burn a specific token. | |
* Reverts if the token does not exist. | |
* Deprecated, use {ERC721-_burn} instead. | |
* @param owner owner of the token to burn | |
* @param tokenId uint256 ID of the token being burned | |
*/ | |
function _burn(address owner, uint256 tokenId) internal { | |
super._burn(owner, tokenId); | |
_removeTokenFromOwnerEnumeration(owner, tokenId); | |
// Since tokenId will be deleted, we can clear its slot in _ownedTokensIndex to trigger a gas refund | |
_ownedTokensIndex[tokenId] = 0; | |
_removeTokenFromAllTokensEnumeration(tokenId); | |
} | |
/** | |
* @dev Gets the list of token IDs of the requested owner. | |
* @param owner address owning the tokens | |
* @return uint256[] List of token IDs owned by the requested address | |
*/ | |
function _tokensOfOwner(address owner) internal view returns (uint256[] storage) { | |
return _ownedTokens[owner]; | |
} | |
/** | |
* @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 { | |
_ownedTokensIndex[tokenId] = _ownedTokens[to].length; | |
_ownedTokens[to].push(tokenId); | |
} | |
/** | |
* @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 = _ownedTokens[from].length.sub(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 | |
_ownedTokens[from].length--; | |
// Note that _ownedTokensIndex[tokenId] hasn't been cleared: it still points to the old slot (now occupied by | |
// lastTokenId, or just over the end of the array if the token was the last one). | |
} | |
/** | |
* @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.sub(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 | |
_allTokens.length--; | |
_allTokensIndex[tokenId] = 0; | |
} | |
} | |
/** | |
* @title ERC-721 Non-Fungible Token Standard, optional metadata extension | |
* @dev See https://eips.ethereum.org/EIPS/eip-721 | |
*/ | |
contract IERC721Metadata is IERC721 { | |
function name() external view returns (string memory); | |
function symbol() external view returns (string memory); | |
function tokenURI(uint256 tokenId) external view returns (string memory); | |
} | |
contract ERC721Metadata is Context, ERC165, ERC721, IERC721Metadata { | |
// Token name | |
string private _name; | |
// Token symbol | |
string private _symbol; | |
// Optional mapping for token URIs | |
mapping(uint256 => string) private _tokenURIs; | |
/* | |
* bytes4(keccak256('name()')) == 0x06fdde03 | |
* bytes4(keccak256('symbol()')) == 0x95d89b41 | |
* bytes4(keccak256('tokenURI(uint256)')) == 0xc87b56dd | |
* | |
* => 0x06fdde03 ^ 0x95d89b41 ^ 0xc87b56dd == 0x5b5e139f | |
*/ | |
bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f; | |
/** | |
* @dev Constructor function | |
*/ | |
constructor (string memory name, string memory symbol) public { | |
_name = name; | |
_symbol = symbol; | |
// register the supported interfaces to conform to ERC721 via ERC165 | |
_registerInterface(_INTERFACE_ID_ERC721_METADATA); | |
} | |
/** | |
* @dev Gets the token name. | |
* @return string representing the token name | |
*/ | |
function name() external view returns (string memory) { | |
return _name; | |
} | |
/** | |
* @dev Gets the token symbol. | |
* @return string representing the token symbol | |
*/ | |
function symbol() external view returns (string memory) { | |
return _symbol; | |
} | |
/** | |
* @dev Returns an URI for a given token ID. | |
* Throws if the token ID does not exist. May return an empty string. | |
* @param tokenId uint256 ID of the token to query | |
*/ | |
/* | |
function tokenURI(uint256 tokenId) external view returns (string memory) { | |
require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token"); | |
// return _tokenURIs[tokenId]; | |
return string(abi.encodePacked("https://chainfacesrinkeby.azurewebsites.net/api/HttpTrigger?id=", id_to_value[tokenId])); | |
} | |
*/ | |
/** | |
* @dev Internal function to set the token URI for a given token. | |
* Reverts if the token ID does not exist. | |
* @param tokenId uint256 ID of the token to set its URI | |
* @param uri string URI to assign | |
*/ | |
function _setTokenURI(uint256 tokenId, string memory uri) internal { | |
require(_exists(tokenId), "ERC721Metadata: URI set of nonexistent token"); | |
_tokenURIs[tokenId] = uri; | |
} | |
/** | |
* @dev Internal function to burn a specific token. | |
* Reverts if the token does not exist. | |
* Deprecated, use _burn(uint256) instead. | |
* @param owner owner of the token to burn | |
* @param tokenId uint256 ID of the token being burned by the msg.sender | |
*/ | |
function _burn(address owner, uint256 tokenId) internal { | |
super._burn(owner, tokenId); | |
// Clear metadata (if any) | |
if (bytes(_tokenURIs[tokenId]).length != 0) { | |
delete _tokenURIs[tokenId]; | |
} | |
} | |
} | |
/** | |
* @title Full ERC721 Token | |
* @dev This implementation includes all the required and some optional functionality of the ERC721 standard | |
* Moreover, it includes approve all functionality using operator terminology. | |
* | |
* See https://eips.ethereum.org/EIPS/eip-721 | |
*/ | |
contract ERC721Full is ERC721, ERC721Enumerable, ERC721Metadata { | |
constructor (string memory name, string memory symbol) public ERC721Metadata(name, symbol) { | |
// solhint-disable-previous-line no-empty-blocks | |
} | |
} | |
library Random | |
{ | |
/** | |
* Initialize the pool with the entropy of the blockhashes of the blocks in the closed interval [earliestBlock, latestBlock] | |
* The argument "seed" is optional and can be left zero in most cases. | |
* This extra seed allows you to select a different sequence of random numbers for the same block range. | |
*/ | |
function init(uint256 earliestBlock, uint256 latestBlock, uint256 seed) internal view returns (bytes32[] memory) { | |
//require(block.number-1 >= latestBlock && latestBlock >= earliestBlock && earliestBlock >= block.number-256, "Random.init: invalid block interval"); | |
require(block.number-1 >= latestBlock && latestBlock >= earliestBlock, "Random.init: invalid block interval"); | |
bytes32[] memory pool = new bytes32[](latestBlock-earliestBlock+2); | |
bytes32 salt = keccak256(abi.encodePacked(block.number,seed)); | |
for(uint256 i=0; i<=latestBlock-earliestBlock; i++) { | |
// Add some salt to each blockhash so that we don't reuse those hash chains | |
// when this function gets called again in another block. | |
pool[i+1] = keccak256(abi.encodePacked(blockhash(earliestBlock+i),salt)); | |
} | |
return pool; | |
} | |
/** | |
* Initialize the pool from the latest "num" blocks. | |
*/ | |
function initLatest(uint256 num, uint256 seed) internal view returns (bytes32[] memory) { | |
return init(block.number-num, block.number-1, seed); | |
} | |
/** | |
* Advances to the next 256-bit random number in the pool of hash chains. | |
*/ | |
function next(bytes32[] memory pool) internal pure returns (uint256) { | |
require(pool.length > 1, "Random.next: invalid pool"); | |
uint256 roundRobinIdx = uint256(pool[0]) % (pool.length-1) + 1; | |
bytes32 hash = keccak256(abi.encodePacked(pool[roundRobinIdx])); | |
pool[0] = bytes32(uint256(pool[0])+1); | |
pool[roundRobinIdx] = hash; | |
return uint256(hash); | |
} | |
/** | |
* Produces random integer values, uniformly distributed on the closed interval [a, b] | |
*/ | |
function uniform(bytes32[] memory pool, int256 a, int256 b) internal pure returns (int256) { | |
require(a <= b, "Random.uniform: invalid interval"); | |
return int256(next(pool)%uint256(b-a+1))+a; | |
} | |
} | |
contract ChainFaces is ERC721Full { | |
using SafeMath for uint256; | |
mapping(string => uint256) value_to_id; | |
mapping(uint256 => string) id_to_value; | |
mapping (uint256 => uint) internal idToGolfScore; | |
mapping (uint256 => uint) internal idToPercentBear; | |
mapping (uint256 => uint) internal idToFaceSymmetry; | |
mapping (uint256 => uint) internal idToTextColor; | |
mapping (uint256 => uint) internal idToBackgroundColor; | |
constructor() ERC721Full("ChainFaces", "ʕ◕ᴥ◕ʔ") public { | |
string memory alpha1 = "ʕ◕ᴥ◕ʔ"; | |
string memory alpha2 = "(▀̿Ĺ̯▀̿ ̿)"; | |
string memory alpha3 = "(◣_◢)"; | |
string memory alpha4 = "щ(ಠ益ಠщ)"; | |
string memory alpha5 = "( ͡° ͜ʖ ͡°)"; | |
string memory alpha6 = "(;´༎ຶД༎ຶ`)"; | |
string memory alpha7 = "(●´ω`●)"; | |
string memory alpha8 = "(╯°◡°)╯"; | |
_registerToken(alpha1, 0, 100, 100, 16736095, 0); //alpha1 face | |
_registerToken(alpha2, 5, 0, 100, 16777215, 0); //alpha2 face | |
_registerToken(alpha3, 5, 0, 100, 16777215, 0); //alpha3 face | |
_registerToken(alpha4, 5, 0, 100, 16777215, 0); //alpha4 face | |
_registerToken(alpha5, 5, 0, 100, 16777215, 0); //alpha5 face | |
_registerToken(alpha6, 5, 0, 100, 16777215, 0); //alpha6 face | |
_registerToken(alpha7, 5, 0, 100, 16777215, 0); //alpha7 face | |
_registerToken(alpha8, 5, 0, 100, 16777215, 0); //alpha8 face | |
} | |
function getLeftFace(uint256 seed) internal view returns (uint256 leftFacePartID){ | |
bytes32[] memory pool = Random.initLatest(4, seed); | |
uint256 leftFaceRNG = uint256(Random.uniform(pool, 1, 70)); | |
if (leftFaceRNG <= 1) { | |
leftFacePartID = 0; | |
} else if (leftFaceRNG <= 3) { | |
leftFacePartID = 1; | |
} else if (leftFaceRNG <= 6) { | |
leftFacePartID = 2; | |
} else if (leftFaceRNG <= 13) { | |
leftFacePartID = 3; | |
} else if (leftFaceRNG <= 25) { | |
leftFacePartID = 4; | |
} else if (leftFaceRNG <= 40) { | |
leftFacePartID = 5; | |
} else if (leftFaceRNG <= 55) { | |
leftFacePartID = 6; | |
} else { | |
leftFacePartID = 7; | |
} | |
} | |
function getLeftEye(uint256 seed) internal view returns (uint256 leftEyePartID){ | |
bytes32[] memory pool = Random.initLatest(5, seed); | |
uint256 leftEyeRNG = uint256(Random.uniform(pool, 1, 143)); | |
if (leftEyeRNG <= 1) { | |
leftEyePartID = 0; | |
} else if (leftEyeRNG <= 3) { | |
leftEyePartID = 1; | |
} else if (leftEyeRNG <= 6) { | |
leftEyePartID = 2; | |
} else if (leftEyeRNG <= 11) { | |
leftEyePartID = 3; | |
} else if (leftEyeRNG <= 18) { | |
leftEyePartID = 4; | |
} else if (leftEyeRNG <= 26) { | |
leftEyePartID = 5; | |
} else if (leftEyeRNG <= 38) { | |
leftEyePartID = 6; | |
} else if (leftEyeRNG <= 53) { | |
leftEyePartID = 7; | |
} else if (leftEyeRNG <= 68) { | |
leftEyePartID = 8; | |
} else if (leftEyeRNG <= 83) { | |
leftEyePartID = 9; | |
} else if (leftEyeRNG <= 103) { | |
leftEyePartID = 10; | |
} else if (leftEyeRNG <= 123) { | |
leftEyePartID = 11; | |
} else { | |
leftEyePartID = 12; | |
} | |
} | |
function getMouth(uint256 seed) internal view returns (uint256 mouthPartID){ | |
bytes32[] memory pool = Random.initLatest(6, seed); | |
uint256 mouthRNG = uint256(Random.uniform(pool, 1, 121)); | |
if (mouthRNG <= 1) { | |
mouthPartID = 0; | |
} else if (mouthRNG <= 3) { | |
mouthPartID = 1; | |
} else if (mouthRNG <= 6) { | |
mouthPartID = 2; | |
} else if (mouthRNG <= 11) { | |
mouthPartID = 3; | |
} else if (mouthRNG <= 19) { | |
mouthPartID = 4; | |
} else if (mouthRNG <= 31) { | |
mouthPartID = 5; | |
} else if (mouthRNG <= 46) { | |
mouthPartID = 5; | |
} else if (mouthRNG <= 61) { | |
mouthPartID = 5; | |
} else if (mouthRNG <= 81) { | |
mouthPartID = 5; | |
} else if (mouthRNG <= 101) { | |
mouthPartID = 5; | |
} else { | |
mouthPartID = 6; | |
} | |
} | |
function getRightEye(uint256 seed) internal view returns (uint256 rightEyePartID){ | |
bytes32[] memory pool = Random.initLatest(7, seed); | |
uint256 rightEyeRNG = uint256(Random.uniform(pool, 1, 143)); | |
if (rightEyeRNG <= 1) { | |
rightEyePartID = 0; | |
} else if (rightEyeRNG <= 3) { | |
rightEyePartID = 1; | |
} else if (rightEyeRNG <= 6) { | |
rightEyePartID = 2; | |
} else if (rightEyeRNG <= 11) { | |
rightEyePartID = 3; | |
} else if (rightEyeRNG <= 18) { | |
rightEyePartID = 4; | |
} else if (rightEyeRNG <= 26) { | |
rightEyePartID = 5; | |
} else if (rightEyeRNG <= 38) { | |
rightEyePartID = 6; | |
} else if (rightEyeRNG <= 53) { | |
rightEyePartID = 7; | |
} else if (rightEyeRNG <= 68) { | |
rightEyePartID = 8; | |
} else if (rightEyeRNG <= 83) { | |
rightEyePartID = 9; | |
} else if (rightEyeRNG <= 103) { | |
rightEyePartID = 10; | |
} else if (rightEyeRNG <= 123) { | |
rightEyePartID = 11; | |
} else { | |
rightEyePartID = 12; | |
} | |
} | |
function getRightFace(uint256 seed) internal view returns (uint256 rightFacePartID){ | |
bytes32[] memory pool = Random.initLatest(8, seed); | |
uint256 rightFaceRNG = uint256(Random.uniform(pool, 1, 70)); | |
if (rightFaceRNG <= 1) { | |
rightFacePartID = 0; | |
} else if (rightFaceRNG <= 3) { | |
rightFacePartID = 1; | |
} else if (rightFaceRNG <= 6) { | |
rightFacePartID = 2; | |
} else if (rightFaceRNG <= 13) { | |
rightFacePartID = 3; | |
} else if (rightFaceRNG <= 25) { | |
rightFacePartID = 4; | |
} else if (rightFaceRNG <= 40) { | |
rightFacePartID = 4; | |
} else if (rightFaceRNG <= 55) { | |
rightFacePartID = 4; | |
} else { | |
rightFacePartID = 5; | |
} | |
} | |
function _registerToken(string memory value, uint256 faceGolfScore, uint256 percentBear, uint256 faceSymmetry, uint256 textColor, uint256 backgroundColor) private { | |
uint256 tokenId = totalSupply(); | |
id_to_value[tokenId] = value; | |
value_to_id[value] = tokenId; | |
idToGolfScore[tokenId] = faceGolfScore; | |
idToPercentBear[tokenId] = percentBear; | |
idToFaceSymmetry[tokenId] = faceSymmetry; | |
idToTextColor[tokenId] = textColor; | |
idToBackgroundColor[tokenId] = backgroundColor; | |
_mint(msg.sender, tokenId); | |
} | |
uint public constant tokenLimit = 9999; | |
function createFace(uint256 seed) public payable { | |
if (totalSupply() < 2000) { | |
require(msg.value == 6 finney); | |
} | |
else if (totalSupply() < 4000) { | |
require(msg.value == 8 finney); | |
} | |
else if (totalSupply() < 6000) { | |
require(msg.value == 10 finney); | |
} | |
else if (totalSupply() < 8000) { | |
require(msg.value == 12 finney); | |
} | |
else { | |
require(msg.value == 14 finney); | |
} | |
// require(block.timestamp < 1574711999, "ChainFaces sale has completed. They are now only available on the secondary market. "); | |
require(totalSupply() <= tokenLimit, "ChainFaces sale has completed. They are now only available on the secondary market. "); | |
address(0x63a9dbCe75413036B2B778E670aaBd4493aAF9F3).transfer(msg.value/5*4); | |
address(0x027Fb48bC4e3999DCF88690aEbEBCC3D1748A0Eb).transfer(msg.value/5); | |
string[8] memory leftFaceCharacters = [ "ʕ" , "✿" ,"꒰" , ":" , "{" , "|" , "[" , "(" ]; | |
string[13] memory eyeCharacters = ["◕" , "👁" , "ಥ" , "♥" , "ʘ̚", "X", "⊙" , "˘" , "ಠ" , "◉" , "⚆" , "¬" , "^" ]; | |
string[11] memory mouthCharacters = [ "ᴥ" , "益" , "෴" , "ʖ" , "ᆺ" , "." , "o", "◡" , "_" , "╭╮" , "‿" ]; | |
string[8] memory rightFaceCharacters = [ "ʔ" , "✿" ,"꒱" , ":" , "}" , "|" , "]" , ")" ]; | |
uint256 leftFacePartID = getLeftFace(seed + totalSupply()); | |
uint256 leftEyePartID = getLeftEye(seed + totalSupply()); | |
uint256 mouthPartID = getMouth(seed + totalSupply()); | |
uint256 rightEyePartID = getRightEye(seed + totalSupply()); | |
uint256 rightFacePartID = getRightFace(seed + totalSupply()); | |
string memory faceAssembly = string(abi.encodePacked(leftFaceCharacters[leftFacePartID], eyeCharacters[leftEyePartID], mouthCharacters[mouthPartID], eyeCharacters[rightEyePartID], rightFaceCharacters[rightFacePartID])); | |
uint256 percentBear; | |
uint256 faceSymmetry; | |
if (totalSupply() == 77) { | |
faceAssembly = "ฅ^•ﻌ•^ฅ"; | |
} | |
if (totalSupply() == 80) { | |
faceAssembly = "( ● Y ● )"; | |
} | |
bytes32[] memory pool = Random.initLatest(3, seed); | |
percentBear = uint256(Random.uniform(pool, 0, 20)); | |
if (leftFacePartID == 0) { | |
percentBear = percentBear + 16; | |
} | |
if (leftEyePartID == 0) { | |
percentBear = percentBear + 16; | |
} | |
if (mouthPartID == 0) { | |
percentBear = percentBear + 16; | |
} | |
if (rightEyePartID == 0) { | |
percentBear = percentBear + 16; | |
} | |
if (rightFacePartID == 0) { | |
percentBear = percentBear + 16; | |
} | |
if (leftFacePartID == rightFacePartID) { | |
faceSymmetry = faceSymmetry + 50; | |
} | |
if (leftEyePartID == rightEyePartID) { | |
faceSymmetry = faceSymmetry + 50; | |
} | |
uint256 faceGolfScore = leftFacePartID + leftEyePartID + mouthPartID + rightEyePartID + rightFacePartID; | |
uint256 textColor = (8*(30-faceGolfScore))+(256*(8*(30-faceGolfScore))); | |
uint256 backgroundColor = (2*(100-percentBear))+(256*(2*(100-percentBear)+20))+(65536*(2*(100-percentBear)+56)); | |
if (totalSupply() == 77) { | |
backgroundColor = 0; | |
} | |
if (totalSupply() == 80) { | |
backgroundColor = 0; | |
} | |
_registerToken(faceAssembly, faceGolfScore, percentBear, faceSymmetry, textColor, backgroundColor); | |
} | |
function integerToString(uint _i) internal pure | |
returns (string memory) { | |
if (_i == 0) { | |
return "0"; | |
} | |
uint j = _i; | |
uint len; | |
while (j != 0) { | |
len++; | |
j /= 10; | |
} | |
bytes memory bstr = new bytes(len); | |
uint k = len - 1; | |
while (_i != 0) { | |
bstr[k--] = byte(uint8(48 + _i % 10)); | |
_i /= 10; | |
} | |
return string(bstr); | |
} | |
function tokenURI(uint256 id) external view returns (string memory) { | |
require(_exists(id), "ERC721Metadata: URI query for nonexistent token"); | |
return string(abi.encodePacked("https://chainfacesrinkeby.azurewebsites.net/api/HttpTrigger?id=", integerToString(id))); | |
} | |
function getFace(uint256 id) public view returns (string memory face) { | |
return id_to_value[id]; | |
} | |
function getGolfScore(uint id) public view returns (uint256 golfScore) { | |
return idToGolfScore[id]; | |
} | |
function getPercentBear(uint id) public view returns (uint256 percentBear) { | |
return idToPercentBear[id]; | |
} | |
function getFaceSymmetry(uint id) public view returns (uint256 faceSymmetry) { | |
return idToFaceSymmetry[id]; | |
} | |
function getTextColor(uint id) public view returns (uint256 textColor) { | |
return idToTextColor[id]; | |
} | |
function getBackgroundColor(uint id) public view returns (uint256 backgroundColor) { | |
return idToBackgroundColor[id]; | |
} | |
} |
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/** | |
*Submitted for verification at Etherscan.io on 2020-02-29 | |
*/ | |
/** | |
*Submitted for verification at Etherscan.io on 2020-02-25 | |
*/ | |
/** | |
*Submitted for verification at Etherscan.io on 2020-02-02 | |
*/ | |
pragma solidity ^0.5.14; | |
/* | |
* @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 GSN 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. | |
*/ | |
contract Context { | |
// Empty internal constructor, to prevent people from mistakenly deploying | |
// an instance of this contract, which should be used via inheritance. | |
constructor () internal { } | |
// solhint-disable-previous-line no-empty-blocks | |
function _msgSender() internal view returns (address payable) { | |
return msg.sender; | |
} | |
function _msgData() internal view returns (bytes memory) { | |
this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691 | |
return msg.data; | |
} | |
} | |
/** | |
* @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); | |
} | |
/** | |
* @dev Required interface of an ERC721 compliant contract. | |
*/ | |
contract IERC721 is IERC165 { | |
event Transfer(address indexed from, address indexed to, uint256 indexed tokenId); | |
event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId); | |
event ApprovalForAll(address indexed owner, address indexed operator, bool approved); | |
/** | |
* @dev Returns the number of NFTs in `owner`'s account. | |
*/ | |
function balanceOf(address owner) public view returns (uint256 balance); | |
/** | |
* @dev Returns the owner of the NFT specified by `tokenId`. | |
*/ | |
function ownerOf(uint256 tokenId) public view returns (address owner); | |
/** | |
* @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to | |
* another (`to`). | |
* | |
* | |
* | |
* Requirements: | |
* - `from`, `to` cannot be zero. | |
* - `tokenId` must be owned by `from`. | |
* - If the caller is not `from`, it must be have been allowed to move this | |
* NFT by either {approve} or {setApprovalForAll}. | |
*/ | |
function safeTransferFrom(address from, address to, uint256 tokenId) public; | |
/** | |
* @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to | |
* another (`to`). | |
* | |
* Requirements: | |
* - If the caller is not `from`, it must be approved to move this NFT by | |
* either {approve} or {setApprovalForAll}. | |
*/ | |
function transferFrom(address from, address to, uint256 tokenId) public; | |
function approve(address to, uint256 tokenId) public; | |
function getApproved(uint256 tokenId) public view returns (address operator); | |
function setApprovalForAll(address operator, bool _approved) public; | |
function isApprovedForAll(address owner, address operator) public view returns (bool); | |
function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public; | |
} | |
/** | |
* @title ERC721 token receiver interface | |
* @dev Interface for any contract that wants to support safeTransfers | |
* from ERC721 asset contracts. | |
*/ | |
contract IERC721Receiver { | |
/** | |
* @notice Handle the receipt of an NFT | |
* @dev The ERC721 smart contract calls this function on the recipient | |
* after a {IERC721-safeTransferFrom}. This function MUST return the function selector, | |
* otherwise the caller will revert the transaction. The selector to be | |
* returned can be obtained as `this.onERC721Received.selector`. This | |
* function MAY throw to revert and reject the transfer. | |
* Note: the ERC721 contract address is always the message sender. | |
* @param operator The address which called `safeTransferFrom` function | |
* @param from The address which previously owned the token | |
* @param tokenId The NFT identifier which is being transferred | |
* @param data Additional data with no specified format | |
* @return bytes4 `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))` | |
*/ | |
function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data) | |
public returns (bytes4); | |
} | |
/** | |
* @dev Wrappers over Solidity's arithmetic operations with added overflow | |
* checks. | |
* | |
* Arithmetic operations in Solidity wrap on overflow. This can easily result | |
* in bugs, because programmers usually assume that an overflow raises an | |
* error, which is the standard behavior in high level programming languages. | |
* `SafeMath` restores this intuition by reverting the transaction when an | |
* operation overflows. | |
* | |
* Using this library instead of the unchecked operations eliminates an entire | |
* class of bugs, so it's recommended to use it always. | |
*/ | |
library SafeMath { | |
/** | |
* @dev Returns the addition of two unsigned integers, reverting on | |
* overflow. | |
* | |
* Counterpart to Solidity's `+` operator. | |
* | |
* Requirements: | |
* - Addition cannot overflow. | |
*/ | |
function add(uint256 a, uint256 b) internal pure returns (uint256) { | |
uint256 c = a + b; | |
require(c >= a, "SafeMath: addition overflow"); | |
return c; | |
} | |
/** | |
* @dev Returns the subtraction of two unsigned integers, reverting on | |
* overflow (when the result is negative). | |
* | |
* Counterpart to Solidity's `-` operator. | |
* | |
* Requirements: | |
* - Subtraction cannot overflow. | |
*/ | |
function sub(uint256 a, uint256 b) internal pure returns (uint256) { | |
return sub(a, b, "SafeMath: subtraction overflow"); | |
} | |
/** | |
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on | |
* overflow (when the result is negative). | |
* | |
* Counterpart to Solidity's `-` operator. | |
* | |
* Requirements: | |
* - Subtraction cannot overflow. | |
* | |
* _Available since v2.4.0._ | |
*/ | |
function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { | |
require(b <= a, errorMessage); | |
uint256 c = a - b; | |
return c; | |
} | |
/** | |
* @dev Returns the multiplication of two unsigned integers, reverting on | |
* overflow. | |
* | |
* Counterpart to Solidity's `*` operator. | |
* | |
* Requirements: | |
* - Multiplication cannot overflow. | |
*/ | |
function mul(uint256 a, uint256 b) internal pure returns (uint256) { | |
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the | |
// benefit is lost if 'b' is also tested. | |
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522 | |
if (a == 0) { | |
return 0; | |
} | |
uint256 c = a * b; | |
require(c / a == b, "SafeMath: multiplication overflow"); | |
return c; | |
} | |
/** | |
* @dev Returns the integer division of two unsigned integers. Reverts on | |
* division by zero. The result is rounded towards zero. | |
* | |
* Counterpart to Solidity's `/` operator. Note: this function uses a | |
* `revert` opcode (which leaves remaining gas untouched) while Solidity | |
* uses an invalid opcode to revert (consuming all remaining gas). | |
* | |
* Requirements: | |
* - The divisor cannot be zero. | |
*/ | |
function div(uint256 a, uint256 b) internal pure returns (uint256) { | |
return div(a, b, "SafeMath: division by zero"); | |
} | |
/** | |
* @dev Returns the integer division of two unsigned integers. Reverts with custom message on | |
* division by zero. The result is rounded towards zero. | |
* | |
* Counterpart to Solidity's `/` operator. Note: this function uses a | |
* `revert` opcode (which leaves remaining gas untouched) while Solidity | |
* uses an invalid opcode to revert (consuming all remaining gas). | |
* | |
* Requirements: | |
* - The divisor cannot be zero. | |
* | |
* _Available since v2.4.0._ | |
*/ | |
function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { | |
// Solidity only automatically asserts when dividing by 0 | |
require(b > 0, errorMessage); | |
uint256 c = a / b; | |
// assert(a == b * c + a % b); // There is no case in which this doesn't hold | |
return c; | |
} | |
/** | |
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo), | |
* Reverts when dividing by zero. | |
* | |
* Counterpart to Solidity's `%` operator. This function uses a `revert` | |
* opcode (which leaves remaining gas untouched) while Solidity uses an | |
* invalid opcode to revert (consuming all remaining gas). | |
* | |
* Requirements: | |
* - The divisor cannot be zero. | |
*/ | |
function mod(uint256 a, uint256 b) internal pure returns (uint256) { | |
return mod(a, b, "SafeMath: modulo by zero"); | |
} | |
/** | |
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo), | |
* Reverts with custom message when dividing by zero. | |
* | |
* Counterpart to Solidity's `%` operator. This function uses a `revert` | |
* opcode (which leaves remaining gas untouched) while Solidity uses an | |
* invalid opcode to revert (consuming all remaining gas). | |
* | |
* Requirements: | |
* - The divisor cannot be zero. | |
* | |
* _Available since v2.4.0._ | |
*/ | |
function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { | |
require(b != 0, errorMessage); | |
return a % b; | |
} | |
} | |
/** | |
* @dev Collection of functions related to the address type | |
*/ | |
library Address { | |
/** | |
* @dev Returns true if `account` is a contract. | |
* | |
* This test is non-exhaustive, and there may be false-negatives: during the | |
* execution of a contract's constructor, its address will be reported as | |
* not containing 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. | |
*/ | |
function isContract(address account) internal view returns (bool) { | |
// This method relies in extcodesize, which returns 0 for contracts in | |
// construction, since the code is only stored at the end of the | |
// constructor execution. | |
// According to EIP-1052, 0x0 is the value returned for not-yet created accounts | |
// and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned | |
// for accounts without code, i.e. `keccak256('')` | |
bytes32 codehash; | |
bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470; | |
// solhint-disable-next-line no-inline-assembly | |
assembly { codehash := extcodehash(account) } | |
return (codehash != 0x0 && codehash != accountHash); | |
} | |
/** | |
* @dev Converts an `address` into `address payable`. Note that this is | |
* simply a type cast: the actual underlying value is not changed. | |
* | |
* _Available since v2.4.0._ | |
*/ | |
function toPayable(address account) internal pure returns (address payable) { | |
return address(uint160(account)); | |
} | |
/** | |
* @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]. | |
* | |
* _Available since v2.4.0._ | |
*/ | |
function sendValue(address payable recipient, uint256 amount) internal { | |
require(address(this).balance >= amount, "Address: insufficient balance"); | |
// solhint-disable-next-line avoid-call-value | |
(bool success, ) = recipient.call.value(amount)(""); | |
require(success, "Address: unable to send value, recipient may have reverted"); | |
} | |
} | |
/** | |
* @title Counters | |
* @author Matt Condon (@shrugs) | |
* @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number | |
* of elements in a mapping, issuing ERC721 ids, or counting request ids. | |
* | |
* Include with `using Counters for Counters.Counter;` | |
* Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the {SafeMath} | |
* overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never | |
* directly accessed. | |
*/ | |
library Counters { | |
using SafeMath for uint256; | |
struct Counter { | |
// This variable should never be directly accessed by users of the library: interactions must be restricted to | |
// the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add | |
// this feature: see https://github.com/ethereum/solidity/issues/4637 | |
uint256 _value; // default: 0 | |
} | |
function current(Counter storage counter) internal view returns (uint256) { | |
return counter._value; | |
} | |
function increment(Counter storage counter) internal { | |
counter._value += 1; | |
} | |
function decrement(Counter storage counter) internal { | |
counter._value = counter._value.sub(1); | |
} | |
} | |
/** | |
* @dev Implementation of the {IERC165} interface. | |
* | |
* Contracts may inherit from this and call {_registerInterface} to declare | |
* their support of an interface. | |
*/ | |
contract ERC165 is IERC165 { | |
/* | |
* bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7 | |
*/ | |
bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7; | |
/** | |
* @dev Mapping of interface ids to whether or not it's supported. | |
*/ | |
mapping(bytes4 => bool) private _supportedInterfaces; | |
constructor () internal { | |
// Derived contracts need only register support for their own interfaces, | |
// we register support for ERC165 itself here | |
_registerInterface(_INTERFACE_ID_ERC165); | |
} | |
/** | |
* @dev See {IERC165-supportsInterface}. | |
* | |
* Time complexity O(1), guaranteed to always use less than 30 000 gas. | |
*/ | |
function supportsInterface(bytes4 interfaceId) external view returns (bool) { | |
return _supportedInterfaces[interfaceId]; | |
} | |
/** | |
* @dev Registers the contract as an implementer of the interface defined by | |
* `interfaceId`. Support of the actual ERC165 interface is automatic and | |
* registering its interface id is not required. | |
* | |
* See {IERC165-supportsInterface}. | |
* | |
* Requirements: | |
* | |
* - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`). | |
*/ | |
function _registerInterface(bytes4 interfaceId) internal { | |
require(interfaceId != 0xffffffff, "ERC165: invalid interface id"); | |
_supportedInterfaces[interfaceId] = true; | |
} | |
} | |
/** | |
* @title ERC721 Non-Fungible Token Standard basic implementation | |
* @dev see https://eips.ethereum.org/EIPS/eip-721 | |
*/ | |
contract ERC721 is Context, ERC165, IERC721 { | |
using SafeMath for uint256; | |
using Address for address; | |
using Counters for Counters.Counter; | |
// Equals to `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))` | |
// which can be also obtained as `IERC721Receiver(0).onERC721Received.selector` | |
bytes4 private constant _ERC721_RECEIVED = 0x150b7a02; | |
// Mapping from token ID to owner | |
mapping (uint256 => address) private _tokenOwner; | |
// Mapping from token ID to approved address | |
mapping (uint256 => address) private _tokenApprovals; | |
// Mapping from owner to number of owned token | |
mapping (address => Counters.Counter) private _ownedTokensCount; | |
// Mapping from owner to operator approvals | |
mapping (address => mapping (address => bool)) private _operatorApprovals; | |
/* | |
* bytes4(keccak256('balanceOf(address)')) == 0x70a08231 | |
* bytes4(keccak256('ownerOf(uint256)')) == 0x6352211e | |
* bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3 | |
* bytes4(keccak256('getApproved(uint256)')) == 0x081812fc | |
* bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465 | |
* bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c5 | |
* bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd | |
* bytes4(keccak256('safeTransferFrom(address,address,uint256)')) == 0x42842e0e | |
* bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)')) == 0xb88d4fde | |
* | |
* => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^ | |
* 0xa22cb465 ^ 0xe985e9c ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd | |
*/ | |
bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd; | |
constructor () public { | |
// register the supported interfaces to conform to ERC721 via ERC165 | |
_registerInterface(_INTERFACE_ID_ERC721); | |
} | |
/** | |
* @dev Gets the balance of the specified address. | |
* @param owner address to query the balance of | |
* @return uint256 representing the amount owned by the passed address | |
*/ | |
function balanceOf(address owner) public view returns (uint256) { | |
require(owner != address(0), "ERC721: balance query for the zero address"); | |
return _ownedTokensCount[owner].current(); | |
} | |
/** | |
* @dev Gets the owner of the specified token ID. | |
* @param tokenId uint256 ID of the token to query the owner of | |
* @return address currently marked as the owner of the given token ID | |
*/ | |
function ownerOf(uint256 tokenId) public view returns (address) { | |
address owner = _tokenOwner[tokenId]; | |
require(owner != address(0), "ERC721: owner query for nonexistent token"); | |
return owner; | |
} | |
/** | |
* @dev Approves another address to transfer the given token ID | |
* The zero address indicates there is no approved address. | |
* There can only be one approved address per token at a given time. | |
* Can only be called by the token owner or an approved operator. | |
* @param to address to be approved for the given token ID | |
* @param tokenId uint256 ID of the token to be approved | |
*/ | |
function approve(address to, uint256 tokenId) public { | |
address owner = 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" | |
); | |
_tokenApprovals[tokenId] = to; | |
emit Approval(owner, to, tokenId); | |
} | |
/** | |
* @dev Gets the approved address for a token ID, or zero if no address set | |
* Reverts if the token ID does not exist. | |
* @param tokenId uint256 ID of the token to query the approval of | |
* @return address currently approved for the given token ID | |
*/ | |
function getApproved(uint256 tokenId) public view returns (address) { | |
require(_exists(tokenId), "ERC721: approved query for nonexistent token"); | |
return _tokenApprovals[tokenId]; | |
} | |
/** | |
* @dev Sets or unsets the approval of a given operator | |
* An operator is allowed to transfer all tokens of the sender on their behalf. | |
* @param to operator address to set the approval | |
* @param approved representing the status of the approval to be set | |
*/ | |
function setApprovalForAll(address to, bool approved) public { | |
require(to != _msgSender(), "ERC721: approve to caller"); | |
_operatorApprovals[_msgSender()][to] = approved; | |
emit ApprovalForAll(_msgSender(), to, approved); | |
} | |
/** | |
* @dev Tells whether an operator is approved by a given owner. | |
* @param owner owner address which you want to query the approval of | |
* @param operator operator address which you want to query the approval of | |
* @return bool whether the given operator is approved by the given owner | |
*/ | |
function isApprovedForAll(address owner, address operator) public view returns (bool) { | |
return _operatorApprovals[owner][operator]; | |
} | |
/** | |
* @dev Transfers the ownership of a given token ID to another address. | |
* Usage of this method is discouraged, use {safeTransferFrom} whenever possible. | |
* Requires the msg.sender to be the owner, approved, or operator. | |
* @param from current owner of the token | |
* @param to address to receive the ownership of the given token ID | |
* @param tokenId uint256 ID of the token to be transferred | |
*/ | |
function transferFrom(address from, address to, uint256 tokenId) public { | |
//solhint-disable-next-line max-line-length | |
require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved"); | |
_transferFrom(from, to, tokenId); | |
} | |
/** | |
* @dev Safely transfers the ownership of a given token ID to another address | |
* If the target address is a contract, it must implement {IERC721Receiver-onERC721Received}, | |
* which is called upon a safe transfer, and return the magic value | |
* `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise, | |
* the transfer is reverted. | |
* Requires the msg.sender to be the owner, approved, or operator | |
* @param from current owner of the token | |
* @param to address to receive the ownership of the given token ID | |
* @param tokenId uint256 ID of the token to be transferred | |
*/ | |
function safeTransferFrom(address from, address to, uint256 tokenId) public { | |
safeTransferFrom(from, to, tokenId, ""); | |
} | |
/** | |
* @dev Safely transfers the ownership of a given token ID to another address | |
* If the target address is a contract, it must implement {IERC721Receiver-onERC721Received}, | |
* which is called upon a safe transfer, and return the magic value | |
* `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise, | |
* the transfer is reverted. | |
* Requires the _msgSender() to be the owner, approved, or operator | |
* @param from current owner of the token | |
* @param to address to receive the ownership of the given token ID | |
* @param tokenId uint256 ID of the token to be transferred | |
* @param _data bytes data to send along with a safe transfer check | |
*/ | |
function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public { | |
require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved"); | |
_safeTransferFrom(from, to, tokenId, _data); | |
} | |
/** | |
* @dev Safely transfers the ownership of a given token ID to another address | |
* If the target address is a contract, it must implement `onERC721Received`, | |
* which is called upon a safe transfer, and return the magic value | |
* `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise, | |
* the transfer is reverted. | |
* Requires the msg.sender to be the owner, approved, or operator | |
* @param from current owner of the token | |
* @param to address to receive the ownership of the given token ID | |
* @param tokenId uint256 ID of the token to be transferred | |
* @param _data bytes data to send along with a safe transfer check | |
*/ | |
function _safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) internal { | |
_transferFrom(from, to, tokenId); | |
require(_checkOnERC721Received(from, to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer"); | |
} | |
/** | |
* @dev Returns whether the specified token exists. | |
* @param tokenId uint256 ID of the token to query the existence of | |
* @return bool whether the token exists | |
*/ | |
function _exists(uint256 tokenId) internal view returns (bool) { | |
address owner = _tokenOwner[tokenId]; | |
return owner != address(0); | |
} | |
/** | |
* @dev Returns whether the given spender can transfer a given token ID. | |
* @param spender address of the spender to query | |
* @param tokenId uint256 ID of the token to be transferred | |
* @return bool whether the msg.sender is approved for the given token ID, | |
* is an operator of the owner, or is the owner of the token | |
*/ | |
function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) { | |
require(_exists(tokenId), "ERC721: operator query for nonexistent token"); | |
address owner = ownerOf(tokenId); | |
return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender)); | |
} | |
/** | |
* @dev Internal function to safely mint a new token. | |
* Reverts if the given token ID already exists. | |
* If the target address is a contract, it must implement `onERC721Received`, | |
* which is called upon a safe transfer, and return the magic value | |
* `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise, | |
* the transfer is reverted. | |
* @param to The address that will own the minted token | |
* @param tokenId uint256 ID of the token to be minted | |
*/ | |
function _safeMint(address to, uint256 tokenId) internal { | |
_safeMint(to, tokenId, ""); | |
} | |
/** | |
* @dev Internal function to safely mint a new token. | |
* Reverts if the given token ID already exists. | |
* If the target address is a contract, it must implement `onERC721Received`, | |
* which is called upon a safe transfer, and return the magic value | |
* `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise, | |
* the transfer is reverted. | |
* @param to The address that will own the minted token | |
* @param tokenId uint256 ID of the token to be minted | |
* @param _data bytes data to send along with a safe transfer check | |
*/ | |
function _safeMint(address to, uint256 tokenId, bytes memory _data) internal { | |
_mint(to, tokenId); | |
require(_checkOnERC721Received(address(0), to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer"); | |
} | |
/** | |
* @dev Internal function to mint a new token. | |
* Reverts if the given token ID already exists. | |
* @param to The address that will own the minted token | |
* @param tokenId uint256 ID of the token to be minted | |
*/ | |
function _mint(address to, uint256 tokenId) internal { | |
require(to != address(0), "ERC721: mint to the zero address"); | |
require(!_exists(tokenId), "ERC721: token already minted"); | |
_tokenOwner[tokenId] = to; | |
_ownedTokensCount[to].increment(); | |
emit Transfer(address(0), to, tokenId); | |
} | |
/** | |
* @dev Internal function to burn a specific token. | |
* Reverts if the token does not exist. | |
* Deprecated, use {_burn} instead. | |
* @param owner owner of the token to burn | |
* @param tokenId uint256 ID of the token being burned | |
*/ | |
function _burn(address owner, uint256 tokenId) internal { | |
require(ownerOf(tokenId) == owner, "ERC721: burn of token that is not own"); | |
_clearApproval(tokenId); | |
_ownedTokensCount[owner].decrement(); | |
_tokenOwner[tokenId] = address(0); | |
emit Transfer(owner, address(0), tokenId); | |
} | |
/** | |
* @dev Internal function to burn a specific token. | |
* Reverts if the token does not exist. | |
* @param tokenId uint256 ID of the token being burned | |
*/ | |
function _burn(uint256 tokenId) internal { | |
_burn(ownerOf(tokenId), tokenId); | |
} | |
/** | |
* @dev Internal function to transfer ownership of a given token ID to another address. | |
* As opposed to {transferFrom}, this imposes no restrictions on msg.sender. | |
* @param from current owner of the token | |
* @param to address to receive the ownership of the given token ID | |
* @param tokenId uint256 ID of the token to be transferred | |
*/ | |
function _transferFrom(address from, address to, uint256 tokenId) internal { | |
require(ownerOf(tokenId) == from, "ERC721: transfer of token that is not own"); | |
require(to != address(0), "ERC721: transfer to the zero address"); | |
_clearApproval(tokenId); | |
_ownedTokensCount[from].decrement(); | |
_ownedTokensCount[to].increment(); | |
_tokenOwner[tokenId] = to; | |
emit Transfer(from, 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. | |
* | |
* This function is deprecated. | |
* @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) | |
internal returns (bool) | |
{ | |
if (!to.isContract()) { | |
return true; | |
} | |
bytes4 retval = IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data); | |
return (retval == _ERC721_RECEIVED); | |
} | |
/** | |
* @dev Private function to clear current approval of a given token ID. | |
* @param tokenId uint256 ID of the token to be transferred | |
*/ | |
function _clearApproval(uint256 tokenId) private { | |
if (_tokenApprovals[tokenId] != address(0)) { | |
_tokenApprovals[tokenId] = address(0); | |
} | |
} | |
} | |
/** | |
* @title ERC-721 Non-Fungible Token Standard, optional enumeration extension | |
* @dev See https://eips.ethereum.org/EIPS/eip-721 | |
*/ | |
contract IERC721Enumerable is IERC721 { | |
function totalSupply() public view returns (uint256); | |
function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256 tokenId); | |
function tokenByIndex(uint256 index) public view returns (uint256); | |
} | |
/** | |
* @title ERC-721 Non-Fungible Token with optional enumeration extension logic | |
* @dev See https://eips.ethereum.org/EIPS/eip-721 | |
*/ | |
contract ERC721Enumerable is Context, ERC165, ERC721, IERC721Enumerable { | |
// Mapping from owner to list of owned token IDs | |
mapping(address => 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; | |
/* | |
* bytes4(keccak256('totalSupply()')) == 0x18160ddd | |
* bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) == 0x2f745c59 | |
* bytes4(keccak256('tokenByIndex(uint256)')) == 0x4f6ccce7 | |
* | |
* => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63 | |
*/ | |
bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63; | |
/** | |
* @dev Constructor function. | |
*/ | |
constructor () public { | |
// register the supported interface to conform to ERC721Enumerable via ERC165 | |
_registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE); | |
} | |
/** | |
* @dev Gets the token ID at a given index of the tokens list of the requested owner. | |
* @param owner address owning the tokens list to be accessed | |
* @param index uint256 representing the index to be accessed of the requested tokens list | |
* @return uint256 token ID at the given index of the tokens list owned by the requested address | |
*/ | |
function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256) { | |
require(index < balanceOf(owner), "ERC721Enumerable: owner index out of bounds"); | |
return _ownedTokens[owner][index]; | |
} | |
/** | |
* @dev Gets the total amount of tokens stored by the contract. | |
* @return uint256 representing the total amount of tokens | |
*/ | |
function totalSupply() public view returns (uint256) { | |
return _allTokens.length; | |
} | |
/** | |
* @dev Gets the token ID at a given index of all the tokens in this contract | |
* Reverts if the index is greater or equal to the total number of tokens. | |
* @param index uint256 representing the index to be accessed of the tokens list | |
* @return uint256 token ID at the given index of the tokens list | |
*/ | |
function tokenByIndex(uint256 index) public view returns (uint256) { | |
require(index < totalSupply(), "ERC721Enumerable: global index out of bounds"); | |
return _allTokens[index]; | |
} | |
/** | |
* @dev Internal function to transfer ownership of a given token ID to another address. | |
* As opposed to transferFrom, this imposes no restrictions on msg.sender. | |
* @param from current owner of the token | |
* @param to address to receive the ownership of the given token ID | |
* @param tokenId uint256 ID of the token to be transferred | |
*/ | |
function _transferFrom(address from, address to, uint256 tokenId) internal { | |
super._transferFrom(from, to, tokenId); | |
_removeTokenFromOwnerEnumeration(from, tokenId); | |
_addTokenToOwnerEnumeration(to, tokenId); | |
} | |
/** | |
* @dev Internal function to mint a new token. | |
* Reverts if the given token ID already exists. | |
* @param to address the beneficiary that will own the minted token | |
* @param tokenId uint256 ID of the token to be minted | |
*/ | |
function _mint(address to, uint256 tokenId) internal { | |
super._mint(to, tokenId); | |
_addTokenToOwnerEnumeration(to, tokenId); | |
_addTokenToAllTokensEnumeration(tokenId); | |
} | |
/** | |
* @dev Internal function to burn a specific token. | |
* Reverts if the token does not exist. | |
* Deprecated, use {ERC721-_burn} instead. | |
* @param owner owner of the token to burn | |
* @param tokenId uint256 ID of the token being burned | |
*/ | |
function _burn(address owner, uint256 tokenId) internal { | |
super._burn(owner, tokenId); | |
_removeTokenFromOwnerEnumeration(owner, tokenId); | |
// Since tokenId will be deleted, we can clear its slot in _ownedTokensIndex to trigger a gas refund | |
_ownedTokensIndex[tokenId] = 0; | |
_removeTokenFromAllTokensEnumeration(tokenId); | |
} | |
/** | |
* @dev Gets the list of token IDs of the requested owner. | |
* @param owner address owning the tokens | |
* @return uint256[] List of token IDs owned by the requested address | |
*/ | |
function _tokensOfOwner(address owner) internal view returns (uint256[] storage) { | |
return _ownedTokens[owner]; | |
} | |
/** | |
* @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 { | |
_ownedTokensIndex[tokenId] = _ownedTokens[to].length; | |
_ownedTokens[to].push(tokenId); | |
} | |
/** | |
* @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 = _ownedTokens[from].length.sub(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 | |
_ownedTokens[from].length--; | |
// Note that _ownedTokensIndex[tokenId] hasn't been cleared: it still points to the old slot (now occupied by | |
// lastTokenId, or just over the end of the array if the token was the last one). | |
} | |
/** | |
* @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.sub(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 | |
_allTokens.length--; | |
_allTokensIndex[tokenId] = 0; | |
} | |
} | |
/** | |
* @title ERC-721 Non-Fungible Token Standard, optional metadata extension | |
* @dev See https://eips.ethereum.org/EIPS/eip-721 | |
*/ | |
contract IERC721Metadata is IERC721 { | |
function name() external view returns (string memory); | |
function symbol() external view returns (string memory); | |
function tokenURI(uint256 tokenId) external view returns (string memory); | |
} | |
contract ERC721Metadata is Context, ERC165, ERC721, IERC721Metadata { | |
// Token name | |
string private _name; | |
// Token symbol | |
string private _symbol; | |
// Optional mapping for token URIs | |
mapping(uint256 => string) private _tokenURIs; | |
/* | |
* bytes4(keccak256('name()')) == 0x06fdde03 | |
* bytes4(keccak256('symbol()')) == 0x95d89b41 | |
* bytes4(keccak256('tokenURI(uint256)')) == 0xc87b56dd | |
* | |
* => 0x06fdde03 ^ 0x95d89b41 ^ 0xc87b56dd == 0x5b5e139f | |
*/ | |
bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f; | |
/** | |
* @dev Constructor function | |
*/ | |
constructor (string memory name, string memory symbol) public { | |
_name = name; | |
_symbol = symbol; | |
// register the supported interfaces to conform to ERC721 via ERC165 | |
_registerInterface(_INTERFACE_ID_ERC721_METADATA); | |
} | |
/** | |
* @dev Gets the token name. | |
* @return string representing the token name | |
*/ | |
function name() external view returns (string memory) { | |
return _name; | |
} | |
/** | |
* @dev Gets the token symbol. | |
* @return string representing the token symbol | |
*/ | |
function symbol() external view returns (string memory) { | |
return _symbol; | |
} | |
/** | |
* @dev Returns an URI for a given token ID. | |
* Throws if the token ID does not exist. May return an empty string. | |
* @param tokenId uint256 ID of the token to query | |
*/ | |
/* | |
function tokenURI(uint256 tokenId) external view returns (string memory) { | |
require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token"); | |
// return _tokenURIs[tokenId]; | |
return string(abi.encodePacked("https://chainfacesrinkeby.azurewebsites.net/api/HttpTrigger?id=", id_to_value[tokenId])); | |
} | |
*/ | |
/** | |
* @dev Internal function to set the token URI for a given token. | |
* Reverts if the token ID does not exist. | |
* @param tokenId uint256 ID of the token to set its URI | |
* @param uri string URI to assign | |
*/ | |
function _setTokenURI(uint256 tokenId, string memory uri) internal { | |
require(_exists(tokenId), "ERC721Metadata: URI set of nonexistent token"); | |
_tokenURIs[tokenId] = uri; | |
} | |
/** | |
* @dev Internal function to burn a specific token. | |
* Reverts if the token does not exist. | |
* Deprecated, use _burn(uint256) instead. | |
* @param owner owner of the token to burn | |
* @param tokenId uint256 ID of the token being burned by the msg.sender | |
*/ | |
function _burn(address owner, uint256 tokenId) internal { | |
super._burn(owner, tokenId); | |
// Clear metadata (if any) | |
if (bytes(_tokenURIs[tokenId]).length != 0) { | |
delete _tokenURIs[tokenId]; | |
} | |
} | |
} | |
/** | |
* @title Full ERC721 Token | |
* @dev This implementation includes all the required and some optional functionality of the ERC721 standard | |
* Moreover, it includes approve all functionality using operator terminology. | |
* | |
* See https://eips.ethereum.org/EIPS/eip-721 | |
*/ | |
contract ERC721Full is ERC721, ERC721Enumerable, ERC721Metadata { | |
constructor (string memory name, string memory symbol) public ERC721Metadata(name, symbol) { | |
// solhint-disable-previous-line no-empty-blocks | |
} | |
} | |
library Random | |
{ | |
/** | |
* Initialize the pool with the entropy of the blockhashes of the blocks in the closed interval [earliestBlock, latestBlock] | |
* The argument "seed" is optional and can be left zero in most cases. | |
* This extra seed allows you to select a different sequence of random numbers for the same block range. | |
*/ | |
function init(uint256 earliestBlock, uint256 latestBlock, uint256 seed) internal view returns (bytes32[] memory) { | |
//require(block.number-1 >= latestBlock && latestBlock >= earliestBlock && earliestBlock >= block.number-256, "Random.init: invalid block interval"); | |
require(block.number-1 >= latestBlock && latestBlock >= earliestBlock, "Random.init: invalid block interval"); | |
bytes32[] memory pool = new bytes32[](latestBlock-earliestBlock+2); | |
bytes32 salt = keccak256(abi.encodePacked(block.number,seed)); | |
for(uint256 i=0; i<=latestBlock-earliestBlock; i++) { | |
// Add some salt to each blockhash so that we don't reuse those hash chains | |
// when this function gets called again in another block. | |
pool[i+1] = keccak256(abi.encodePacked(blockhash(earliestBlock+i),salt)); | |
} | |
return pool; | |
} | |
/** | |
* Initialize the pool from the latest "num" blocks. | |
*/ | |
function initLatest(uint256 num, uint256 seed) internal view returns (bytes32[] memory) { | |
return init(block.number-num, block.number-1, seed); | |
} | |
/** | |
* Advances to the next 256-bit random number in the pool of hash chains. | |
*/ | |
function next(bytes32[] memory pool) internal pure returns (uint256) { | |
require(pool.length > 1, "Random.next: invalid pool"); | |
uint256 roundRobinIdx = uint256(pool[0]) % (pool.length-1) + 1; | |
bytes32 hash = keccak256(abi.encodePacked(pool[roundRobinIdx])); | |
pool[0] = bytes32(uint256(pool[0])+1); | |
pool[roundRobinIdx] = hash; | |
return uint256(hash); | |
} | |
/** | |
* Produces random integer values, uniformly distributed on the closed interval [a, b] | |
*/ | |
function uniform(bytes32[] memory pool, int256 a, int256 b) internal pure returns (int256) { | |
require(a <= b, "Random.uniform: invalid interval"); | |
return int256(next(pool)%uint256(b-a+1))+a; | |
} | |
} | |
contract faceGolfBalls { | |
function transfer(address _to, uint256 _tokenId) external; | |
function transferFrom(address _from, address _to, uint256 _tokenId) external; | |
} | |
contract chainFaces { | |
function ownerOf(uint256 _tokenId) public view returns (address owner); | |
function getFaceSymmetry(uint id) public view returns (uint256 faceSymmetry); | |
function getPercentBear(uint id) public view returns (uint256 percentBear); | |
function getGolfScore(uint id) public view returns (uint256 golfScore); | |
} | |
contract FaceGolf is ERC721Full { | |
using SafeMath for uint256; | |
mapping(uint256 => uint256) value_to_id; | |
mapping(uint256 => uint256[9]) id_to_value; | |
mapping (uint256 => uint) internal idToGolfScore; | |
mapping (uint256 => uint) internal idToTotalScore; | |
mapping(uint256 => uint) internal idToGolferBestScore; | |
mapping(uint256 => uint) internal idToGolferWorstScore; | |
mapping(uint256 => uint) internal idToGolferRoundsTotal; | |
mapping (uint256 => uint) internal idToFaceSymmetry; | |
mapping (uint256 => uint) internal idToTextColor; | |
mapping (uint256 => uint) internal idToBackgroundColor; | |
mapping (uint256 => uint) internal idToGolferID; | |
// mapping (uint256 => uint256[10000]) internal golferBestScore; | |
// mapping (uint256 => uint256[10000]) internal golferWorstScore; | |
// mapping(uint256 => uint256) golferBestScore; | |
// mapping(uint256 => uint256) golferWorstScore; | |
constructor() ERC721Full("FaceGolf Score Card v0", "SCORE") public { | |
faceGolfBallsERC20 = faceGolfBalls(FaceGolfERC20Address); | |
chainFacesERC721 = chainFaces(ChainFacesAddress); | |
} | |
function getPar3(uint256 seed, uint256 golfBoost) internal view returns (uint256 par3Result){ | |
bytes32[] memory pool = Random.initLatest(1, seed); | |
uint256 par3RNG = uint256(Random.uniform(pool, 1, 1000 - int256(golfBoost))); | |
if (par3RNG <= 10) { | |
par3Result = 1; | |
} else if (par3RNG <= 100) { | |
par3Result = 2; | |
} else if (par3RNG <= 400) { | |
par3Result = 3; | |
} else if (par3RNG <= 750) { | |
par3Result = 4; | |
} else if (par3RNG <= 950) { | |
par3Result = 5; | |
} else { | |
par3Result = 6; | |
} | |
} | |
function getPar4(uint256 seed, uint256 golfBoost) internal view returns (uint256 par4Result){ | |
bytes32[] memory pool = Random.initLatest(2, seed); | |
uint256 par4RNG = uint256(Random.uniform(pool, 1, 1000 - int256(golfBoost))); | |
if (par4RNG <= 1) { | |
par4Result = 1; | |
} else if (par4RNG <= 20) { | |
par4Result = 2; | |
} else if (par4RNG <= 150) { | |
par4Result = 3; | |
} else if (par4RNG <= 400) { | |
par4Result = 4; | |
} else if (par4RNG <= 750) { | |
par4Result = 5; | |
} else if (par4RNG <= 950) { | |
par4Result = 6; | |
} else { | |
par4Result = 7; | |
} | |
} | |
function getPar5(uint256 seed, uint256 golfBoost) internal view returns (uint256 par5Result){ | |
bytes32[] memory pool = Random.initLatest(3, seed); | |
uint256 par5RNG = uint256(Random.uniform(pool, 1, 1000 - int256(golfBoost))); | |
if (par5RNG <= 5) { | |
par5Result = 2; | |
} else if (par5RNG <= 25) { | |
par5Result = 3; | |
} else if (par5RNG <= 225) { | |
par5Result = 4; | |
} else if (par5RNG <= 625) { | |
par5Result = 5; | |
} else if (par5RNG <= 825) { | |
par5Result = 6; | |
} else if (par5RNG <= 950) { | |
par5Result = 7; | |
} else { | |
par5Result = 8; | |
} | |
} | |
function getLostBalls(uint256 seed, uint256 lostBoost) internal view returns (uint256 ballLost){ | |
bytes32[] memory pool = Random.initLatest(4, seed); | |
uint256 lostBallRNG = uint256(Random.uniform(pool, 1, 1000 - int256(lostBoost))); | |
if (lostBallRNG <= 500) { | |
ballLost = 0; | |
} else { | |
ballLost = 10; | |
} | |
} | |
function sendLostBalls(uint256 seed) internal view returns (address ballFinderAddress){ | |
bytes32[] memory pool = Random.initLatest(4, seed); | |
uint256 ballFinder = uint256(Random.uniform(pool, 0, 99)); | |
ballFinderAddress = chainFacesERC721.ownerOf(ballFinder); | |
} | |
function chainFaceBoosts(uint256 golferID) internal view returns (uint256 lostBoost, uint256 golfBoost){ | |
lostBoost = 0; | |
golfBoost = 0; | |
if (chainFacesERC721.getFaceSymmetry(golferID) == 100) { | |
lostBoost = 200; | |
golfBoost = 200; | |
} | |
if (chainFacesERC721.getPercentBear(golferID) > 28) { | |
lostBoost = 400; | |
} | |
if (chainFacesERC721.getGolfScore(golferID) < 20) { | |
golfBoost = 400; | |
} | |
} | |
function _registerToken(uint256[9] memory scoreCard, uint256 totalScore, uint256 backgroundColor, uint256 golferID) private { | |
uint256 tokenId = totalSupply(); | |
id_to_value[tokenId] = scoreCard; | |
value_to_id[totalSupply()] = tokenId; | |
idToTotalScore[tokenId] = totalScore; | |
idToBackgroundColor[tokenId] = backgroundColor; | |
idToGolferID[tokenId] = golferID; | |
idToGolferRoundsTotal[golferID] = idToGolferRoundsTotal[golferID] + 1; | |
if (idToGolferBestScore[golferID] < 1){ | |
idToGolferBestScore[golferID] = totalScore; | |
} | |
if (idToGolferBestScore[golferID] > totalScore){ | |
idToGolferBestScore[golferID] = totalScore; | |
} | |
if (idToGolferWorstScore[golferID] < 1){ | |
idToGolferWorstScore[golferID] = totalScore; | |
} | |
if (idToGolferWorstScore[golferID] < totalScore){ | |
idToGolferWorstScore[golferID] = totalScore; | |
} | |
_mint(msg.sender, tokenId); | |
} | |
uint public constant tokenLimit = 9999; | |
uint256 hole1; | |
uint256 hole2; | |
uint256 hole3; | |
uint256 hole4; | |
uint256 hole5; | |
uint256 hole6; | |
uint256 hole7; | |
uint256 hole8; | |
uint256 hole9; | |
uint256 roundBalls = 90; | |
address public FaceGolfERC20Address = 0x39F2A4b3F8428932c5f09d89653148468f42B5A2; | |
address public ChainFacesAddress = 0xE6Da1E491a9442a2A91453d1C15719b3666fd8d3; | |
faceGolfBalls faceGolfBallsERC20; | |
chainFaces chainFacesERC721; | |
function playGolf(uint256 seed, uint256 golferID) public { | |
require(msg.sender == chainFacesERC721.ownerOf(golferID), 'you do not own this chainface'); | |
// require(msg.value == 0 finney); | |
// require(value >= roundBalls); | |
faceGolfBallsERC20.transferFrom(msg.sender, address(this), roundBalls); | |
// require(block.timestamp < 1574711999, "ChainFaces sale has completed. They are now only available on the secondary market. "); | |
require(totalSupply() <= tokenLimit, "Maximum golf rounds on genesis course have been played. Score cards available on secondary market"); | |
// address(0x63a9dbCe75413036B2B778E670aaBd4493aAF9F3).transfer(msg.value); | |
(uint256 lostBoost, uint256 golfBoost) = chainFaceBoosts(golferID); | |
uint256 holeCount = 0; | |
hole1 = getPar4(seed + totalSupply() + holeCount, golfBoost); | |
holeCount = holeCount + 1; | |
hole2 = getPar3(seed + totalSupply() + holeCount, golfBoost); | |
holeCount = holeCount + 1; | |
hole3 = getPar4(seed + totalSupply() + holeCount, golfBoost); | |
holeCount = holeCount + 1; | |
hole4 = getPar4(seed + totalSupply() + holeCount, golfBoost); | |
holeCount = holeCount + 1; | |
hole5 = getPar4(seed + totalSupply() + holeCount, golfBoost); | |
holeCount = holeCount + 1; | |
hole6 = getPar3(seed + totalSupply() + holeCount, golfBoost); | |
holeCount = holeCount + 1; | |
hole7 = getPar4(seed + totalSupply() + holeCount, golfBoost); | |
holeCount = holeCount + 1; | |
hole8 = getPar5(seed + totalSupply() + holeCount, golfBoost); | |
holeCount = holeCount + 1; | |
hole9 = getPar5(seed + totalSupply() + holeCount, golfBoost); | |
holeCount = holeCount + 1; | |
uint256 totalLostBalls = 0; | |
for (uint256 i=0; i<9; i++) { | |
totalLostBalls = totalLostBalls + getLostBalls(seed + i, lostBoost); | |
} | |
faceGolfBallsERC20.transfer(msg.sender, roundBalls - totalLostBalls); | |
faceGolfBallsERC20.transfer(sendLostBalls(seed), totalLostBalls); | |
uint256[9] memory scoreCard = [hole1,hole2,hole3,hole4,hole5,hole6,hole7,hole8,hole9]; | |
uint256 totalScore = hole1+hole2+hole3+hole4+hole5+hole6+hole7+hole8+hole9; | |
uint256 backgroundColor; | |
if (totalScore < 36) { | |
backgroundColor = 0; | |
} | |
else if (totalScore == 36) { | |
backgroundColor = 1; | |
} | |
else { | |
backgroundColor = 2; | |
} | |
_registerToken(scoreCard, totalScore, backgroundColor, golferID); | |
} | |
function integerToString(uint _i) internal pure | |
returns (string memory) { | |
if (_i == 0) { | |
return "0"; | |
} | |
uint j = _i; | |
uint len; | |
while (j != 0) { | |
len++; | |
j /= 10; | |
} | |
bytes memory bstr = new bytes(len); | |
uint k = len - 1; | |
while (_i != 0) { | |
bstr[k--] = byte(uint8(48 + _i % 10)); | |
_i /= 10; | |
} | |
return string(bstr); | |
} | |
function tokenURI(uint256 id) external view returns (string memory) { | |
require(_exists(id), "ERC721Metadata: URI query for nonexistent token"); | |
return string(abi.encodePacked("https://chainfacesrinkeby.azurewebsites.net/api/HttpTrigger?id=", integerToString(id))); | |
} | |
function getScoreCard(uint256 id) public view returns (uint256[9] memory scoreCard) { | |
return id_to_value[id]; | |
} | |
function getTotalScore(uint id) public view returns (uint256 totalScore) { | |
return idToTotalScore[id]; | |
} | |
function getGolferID(uint id) public view returns (uint256 golferID) { | |
return idToGolferID[id]; | |
} | |
function getGolferRoundsTotal(uint golferID) public view returns (uint256 golferRoundsTotal) { | |
return idToGolferRoundsTotal[golferID]; | |
} | |
function getGolferScoreBest(uint golferID) public view returns (uint256 golferBestScore) { | |
return idToGolferBestScore[golferID]; | |
} | |
function getGolferScoreWorst(uint golferID) public view returns (uint256 golferWorstScore) { | |
return idToGolferWorstScore[golferID]; | |
} | |
function getBackgroundColor(uint id) public view returns (uint256 backgroundColor) { | |
return idToBackgroundColor[id]; | |
} | |
/* | |
function getFace(uint256 id) public view returns (uint256 hole1Par4, uint256 hole2Par3, uint256 hole3Par4, uint256 hole4Par4, uint256 hole5Par4, | |
uint256 hole6Par3, uint256 hole7Par4, uint256 hole8Par5, uint256 hole9Par5) { | |
return (hole1(id),hole2(id),hole3(id),hole4(id),hole5(id),hole6(id),hole7(id),hole8(id),hole9(id)); | |
} | |
*/ | |
} |
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/** | |
*Submitted for verification at Etherscan.io on 2020-02-29 | |
*/ | |
/** | |
*Submitted for verification at Etherscan.io on 2020-02-25 | |
*/ | |
/** | |
*Submitted for verification at Etherscan.io on 2020-02-02 | |
*/ | |
pragma solidity ^0.5.14; | |
/* | |
* @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 GSN 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. | |
*/ | |
contract Context { | |
// Empty internal constructor, to prevent people from mistakenly deploying | |
// an instance of this contract, which should be used via inheritance. | |
constructor () internal { } | |
// solhint-disable-previous-line no-empty-blocks | |
function _msgSender() internal view returns (address payable) { | |
return msg.sender; | |
} | |
function _msgData() internal view returns (bytes memory) { | |
this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691 | |
return msg.data; | |
} | |
} | |
/** | |
* @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); | |
} | |
/** | |
* @dev Required interface of an ERC721 compliant contract. | |
*/ | |
contract IERC721 is IERC165 { | |
event Transfer(address indexed from, address indexed to, uint256 indexed tokenId); | |
event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId); | |
event ApprovalForAll(address indexed owner, address indexed operator, bool approved); | |
/** | |
* @dev Returns the number of NFTs in `owner`'s account. | |
*/ | |
function balanceOf(address owner) public view returns (uint256 balance); | |
/** | |
* @dev Returns the owner of the NFT specified by `tokenId`. | |
*/ | |
function ownerOf(uint256 tokenId) public view returns (address owner); | |
/** | |
* @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to | |
* another (`to`). | |
* | |
* | |
* | |
* Requirements: | |
* - `from`, `to` cannot be zero. | |
* - `tokenId` must be owned by `from`. | |
* - If the caller is not `from`, it must be have been allowed to move this | |
* NFT by either {approve} or {setApprovalForAll}. | |
*/ | |
function safeTransferFrom(address from, address to, uint256 tokenId) public; | |
/** | |
* @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to | |
* another (`to`). | |
* | |
* Requirements: | |
* - If the caller is not `from`, it must be approved to move this NFT by | |
* either {approve} or {setApprovalForAll}. | |
*/ | |
function transferFrom(address from, address to, uint256 tokenId) public; | |
function approve(address to, uint256 tokenId) public; | |
function getApproved(uint256 tokenId) public view returns (address operator); | |
function setApprovalForAll(address operator, bool _approved) public; | |
function isApprovedForAll(address owner, address operator) public view returns (bool); | |
function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public; | |
} | |
/** | |
* @title ERC721 token receiver interface | |
* @dev Interface for any contract that wants to support safeTransfers | |
* from ERC721 asset contracts. | |
*/ | |
contract IERC721Receiver { | |
/** | |
* @notice Handle the receipt of an NFT | |
* @dev The ERC721 smart contract calls this function on the recipient | |
* after a {IERC721-safeTransferFrom}. This function MUST return the function selector, | |
* otherwise the caller will revert the transaction. The selector to be | |
* returned can be obtained as `this.onERC721Received.selector`. This | |
* function MAY throw to revert and reject the transfer. | |
* Note: the ERC721 contract address is always the message sender. | |
* @param operator The address which called `safeTransferFrom` function | |
* @param from The address which previously owned the token | |
* @param tokenId The NFT identifier which is being transferred | |
* @param data Additional data with no specified format | |
* @return bytes4 `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))` | |
*/ | |
function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data) | |
public returns (bytes4); | |
} | |
/** | |
* @dev Wrappers over Solidity's arithmetic operations with added overflow | |
* checks. | |
* | |
* Arithmetic operations in Solidity wrap on overflow. This can easily result | |
* in bugs, because programmers usually assume that an overflow raises an | |
* error, which is the standard behavior in high level programming languages. | |
* `SafeMath` restores this intuition by reverting the transaction when an | |
* operation overflows. | |
* | |
* Using this library instead of the unchecked operations eliminates an entire | |
* class of bugs, so it's recommended to use it always. | |
*/ | |
library SafeMath { | |
/** | |
* @dev Returns the addition of two unsigned integers, reverting on | |
* overflow. | |
* | |
* Counterpart to Solidity's `+` operator. | |
* | |
* Requirements: | |
* - Addition cannot overflow. | |
*/ | |
function add(uint256 a, uint256 b) internal pure returns (uint256) { | |
uint256 c = a + b; | |
require(c >= a, "SafeMath: addition overflow"); | |
return c; | |
} | |
/** | |
* @dev Returns the subtraction of two unsigned integers, reverting on | |
* overflow (when the result is negative). | |
* | |
* Counterpart to Solidity's `-` operator. | |
* | |
* Requirements: | |
* - Subtraction cannot overflow. | |
*/ | |
function sub(uint256 a, uint256 b) internal pure returns (uint256) { | |
return sub(a, b, "SafeMath: subtraction overflow"); | |
} | |
/** | |
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on | |
* overflow (when the result is negative). | |
* | |
* Counterpart to Solidity's `-` operator. | |
* | |
* Requirements: | |
* - Subtraction cannot overflow. | |
* | |
* _Available since v2.4.0._ | |
*/ | |
function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { | |
require(b <= a, errorMessage); | |
uint256 c = a - b; | |
return c; | |
} | |
/** | |
* @dev Returns the multiplication of two unsigned integers, reverting on | |
* overflow. | |
* | |
* Counterpart to Solidity's `*` operator. | |
* | |
* Requirements: | |
* - Multiplication cannot overflow. | |
*/ | |
function mul(uint256 a, uint256 b) internal pure returns (uint256) { | |
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the | |
// benefit is lost if 'b' is also tested. | |
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522 | |
if (a == 0) { | |
return 0; | |
} | |
uint256 c = a * b; | |
require(c / a == b, "SafeMath: multiplication overflow"); | |
return c; | |
} | |
/** | |
* @dev Returns the integer division of two unsigned integers. Reverts on | |
* division by zero. The result is rounded towards zero. | |
* | |
* Counterpart to Solidity's `/` operator. Note: this function uses a | |
* `revert` opcode (which leaves remaining gas untouched) while Solidity | |
* uses an invalid opcode to revert (consuming all remaining gas). | |
* | |
* Requirements: | |
* - The divisor cannot be zero. | |
*/ | |
function div(uint256 a, uint256 b) internal pure returns (uint256) { | |
return div(a, b, "SafeMath: division by zero"); | |
} | |
/** | |
* @dev Returns the integer division of two unsigned integers. Reverts with custom message on | |
* division by zero. The result is rounded towards zero. | |
* | |
* Counterpart to Solidity's `/` operator. Note: this function uses a | |
* `revert` opcode (which leaves remaining gas untouched) while Solidity | |
* uses an invalid opcode to revert (consuming all remaining gas). | |
* | |
* Requirements: | |
* - The divisor cannot be zero. | |
* | |
* _Available since v2.4.0._ | |
*/ | |
function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { | |
// Solidity only automatically asserts when dividing by 0 | |
require(b > 0, errorMessage); | |
uint256 c = a / b; | |
// assert(a == b * c + a % b); // There is no case in which this doesn't hold | |
return c; | |
} | |
/** | |
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo), | |
* Reverts when dividing by zero. | |
* | |
* Counterpart to Solidity's `%` operator. This function uses a `revert` | |
* opcode (which leaves remaining gas untouched) while Solidity uses an | |
* invalid opcode to revert (consuming all remaining gas). | |
* | |
* Requirements: | |
* - The divisor cannot be zero. | |
*/ | |
function mod(uint256 a, uint256 b) internal pure returns (uint256) { | |
return mod(a, b, "SafeMath: modulo by zero"); | |
} | |
/** | |
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo), | |
* Reverts with custom message when dividing by zero. | |
* | |
* Counterpart to Solidity's `%` operator. This function uses a `revert` | |
* opcode (which leaves remaining gas untouched) while Solidity uses an | |
* invalid opcode to revert (consuming all remaining gas). | |
* | |
* Requirements: | |
* - The divisor cannot be zero. | |
* | |
* _Available since v2.4.0._ | |
*/ | |
function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { | |
require(b != 0, errorMessage); | |
return a % b; | |
} | |
} | |
/** | |
* @dev Collection of functions related to the address type | |
*/ | |
library Address { | |
/** | |
* @dev Returns true if `account` is a contract. | |
* | |
* This test is non-exhaustive, and there may be false-negatives: during the | |
* execution of a contract's constructor, its address will be reported as | |
* not containing 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. | |
*/ | |
function isContract(address account) internal view returns (bool) { | |
// This method relies in extcodesize, which returns 0 for contracts in | |
// construction, since the code is only stored at the end of the | |
// constructor execution. | |
// According to EIP-1052, 0x0 is the value returned for not-yet created accounts | |
// and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned | |
// for accounts without code, i.e. `keccak256('')` | |
bytes32 codehash; | |
bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470; | |
// solhint-disable-next-line no-inline-assembly | |
assembly { codehash := extcodehash(account) } | |
return (codehash != 0x0 && codehash != accountHash); | |
} | |
/** | |
* @dev Converts an `address` into `address payable`. Note that this is | |
* simply a type cast: the actual underlying value is not changed. | |
* | |
* _Available since v2.4.0._ | |
*/ | |
function toPayable(address account) internal pure returns (address payable) { | |
return address(uint160(account)); | |
} | |
/** | |
* @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]. | |
* | |
* _Available since v2.4.0._ | |
*/ | |
function sendValue(address payable recipient, uint256 amount) internal { | |
require(address(this).balance >= amount, "Address: insufficient balance"); | |
// solhint-disable-next-line avoid-call-value | |
(bool success, ) = recipient.call.value(amount)(""); | |
require(success, "Address: unable to send value, recipient may have reverted"); | |
} | |
} | |
/** | |
* @title Counters | |
* @author Matt Condon (@shrugs) | |
* @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number | |
* of elements in a mapping, issuing ERC721 ids, or counting request ids. | |
* | |
* Include with `using Counters for Counters.Counter;` | |
* Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the {SafeMath} | |
* overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never | |
* directly accessed. | |
*/ | |
library Counters { | |
using SafeMath for uint256; | |
struct Counter { | |
// This variable should never be directly accessed by users of the library: interactions must be restricted to | |
// the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add | |
// this feature: see https://github.com/ethereum/solidity/issues/4637 | |
uint256 _value; // default: 0 | |
} | |
function current(Counter storage counter) internal view returns (uint256) { | |
return counter._value; | |
} | |
function increment(Counter storage counter) internal { | |
counter._value += 1; | |
} | |
function decrement(Counter storage counter) internal { | |
counter._value = counter._value.sub(1); | |
} | |
} | |
/** | |
* @dev Implementation of the {IERC165} interface. | |
* | |
* Contracts may inherit from this and call {_registerInterface} to declare | |
* their support of an interface. | |
*/ | |
contract ERC165 is IERC165 { | |
/* | |
* bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7 | |
*/ | |
bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7; | |
/** | |
* @dev Mapping of interface ids to whether or not it's supported. | |
*/ | |
mapping(bytes4 => bool) private _supportedInterfaces; | |
constructor () internal { | |
// Derived contracts need only register support for their own interfaces, | |
// we register support for ERC165 itself here | |
_registerInterface(_INTERFACE_ID_ERC165); | |
} | |
/** | |
* @dev See {IERC165-supportsInterface}. | |
* | |
* Time complexity O(1), guaranteed to always use less than 30 000 gas. | |
*/ | |
function supportsInterface(bytes4 interfaceId) external view returns (bool) { | |
return _supportedInterfaces[interfaceId]; | |
} | |
/** | |
* @dev Registers the contract as an implementer of the interface defined by | |
* `interfaceId`. Support of the actual ERC165 interface is automatic and | |
* registering its interface id is not required. | |
* | |
* See {IERC165-supportsInterface}. | |
* | |
* Requirements: | |
* | |
* - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`). | |
*/ | |
function _registerInterface(bytes4 interfaceId) internal { | |
require(interfaceId != 0xffffffff, "ERC165: invalid interface id"); | |
_supportedInterfaces[interfaceId] = true; | |
} | |
} | |
/** | |
* @title ERC721 Non-Fungible Token Standard basic implementation | |
* @dev see https://eips.ethereum.org/EIPS/eip-721 | |
*/ | |
contract ERC721 is Context, ERC165, IERC721 { | |
using SafeMath for uint256; | |
using Address for address; | |
using Counters for Counters.Counter; | |
// Equals to `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))` | |
// which can be also obtained as `IERC721Receiver(0).onERC721Received.selector` | |
bytes4 private constant _ERC721_RECEIVED = 0x150b7a02; | |
// Mapping from token ID to owner | |
mapping (uint256 => address) private _tokenOwner; | |
// Mapping from token ID to approved address | |
mapping (uint256 => address) private _tokenApprovals; | |
// Mapping from owner to number of owned token | |
mapping (address => Counters.Counter) private _ownedTokensCount; | |
// Mapping from owner to operator approvals | |
mapping (address => mapping (address => bool)) private _operatorApprovals; | |
/* | |
* bytes4(keccak256('balanceOf(address)')) == 0x70a08231 | |
* bytes4(keccak256('ownerOf(uint256)')) == 0x6352211e | |
* bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3 | |
* bytes4(keccak256('getApproved(uint256)')) == 0x081812fc | |
* bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465 | |
* bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c5 | |
* bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd | |
* bytes4(keccak256('safeTransferFrom(address,address,uint256)')) == 0x42842e0e | |
* bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)')) == 0xb88d4fde | |
* | |
* => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^ | |
* 0xa22cb465 ^ 0xe985e9c ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd | |
*/ | |
bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd; | |
constructor () public { | |
// register the supported interfaces to conform to ERC721 via ERC165 | |
_registerInterface(_INTERFACE_ID_ERC721); | |
} | |
/** | |
* @dev Gets the balance of the specified address. | |
* @param owner address to query the balance of | |
* @return uint256 representing the amount owned by the passed address | |
*/ | |
function balanceOf(address owner) public view returns (uint256) { | |
require(owner != address(0), "ERC721: balance query for the zero address"); | |
return _ownedTokensCount[owner].current(); | |
} | |
/** | |
* @dev Gets the owner of the specified token ID. | |
* @param tokenId uint256 ID of the token to query the owner of | |
* @return address currently marked as the owner of the given token ID | |
*/ | |
function ownerOf(uint256 tokenId) public view returns (address) { | |
address owner = _tokenOwner[tokenId]; | |
require(owner != address(0), "ERC721: owner query for nonexistent token"); | |
return owner; | |
} | |
/** | |
* @dev Approves another address to transfer the given token ID | |
* The zero address indicates there is no approved address. | |
* There can only be one approved address per token at a given time. | |
* Can only be called by the token owner or an approved operator. | |
* @param to address to be approved for the given token ID | |
* @param tokenId uint256 ID of the token to be approved | |
*/ | |
function approve(address to, uint256 tokenId) public { | |
address owner = 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" | |
); | |
_tokenApprovals[tokenId] = to; | |
emit Approval(owner, to, tokenId); | |
} | |
/** | |
* @dev Gets the approved address for a token ID, or zero if no address set | |
* Reverts if the token ID does not exist. | |
* @param tokenId uint256 ID of the token to query the approval of | |
* @return address currently approved for the given token ID | |
*/ | |
function getApproved(uint256 tokenId) public view returns (address) { | |
require(_exists(tokenId), "ERC721: approved query for nonexistent token"); | |
return _tokenApprovals[tokenId]; | |
} | |
/** | |
* @dev Sets or unsets the approval of a given operator | |
* An operator is allowed to transfer all tokens of the sender on their behalf. | |
* @param to operator address to set the approval | |
* @param approved representing the status of the approval to be set | |
*/ | |
function setApprovalForAll(address to, bool approved) public { | |
require(to != _msgSender(), "ERC721: approve to caller"); | |
_operatorApprovals[_msgSender()][to] = approved; | |
emit ApprovalForAll(_msgSender(), to, approved); | |
} | |
/** | |
* @dev Tells whether an operator is approved by a given owner. | |
* @param owner owner address which you want to query the approval of | |
* @param operator operator address which you want to query the approval of | |
* @return bool whether the given operator is approved by the given owner | |
*/ | |
function isApprovedForAll(address owner, address operator) public view returns (bool) { | |
return _operatorApprovals[owner][operator]; | |
} | |
/** | |
* @dev Transfers the ownership of a given token ID to another address. | |
* Usage of this method is discouraged, use {safeTransferFrom} whenever possible. | |
* Requires the msg.sender to be the owner, approved, or operator. | |
* @param from current owner of the token | |
* @param to address to receive the ownership of the given token ID | |
* @param tokenId uint256 ID of the token to be transferred | |
*/ | |
function transferFrom(address from, address to, uint256 tokenId) public { | |
//solhint-disable-next-line max-line-length | |
require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved"); | |
_transferFrom(from, to, tokenId); | |
} | |
/** | |
* @dev Safely transfers the ownership of a given token ID to another address | |
* If the target address is a contract, it must implement {IERC721Receiver-onERC721Received}, | |
* which is called upon a safe transfer, and return the magic value | |
* `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise, | |
* the transfer is reverted. | |
* Requires the msg.sender to be the owner, approved, or operator | |
* @param from current owner of the token | |
* @param to address to receive the ownership of the given token ID | |
* @param tokenId uint256 ID of the token to be transferred | |
*/ | |
function safeTransferFrom(address from, address to, uint256 tokenId) public { | |
safeTransferFrom(from, to, tokenId, ""); | |
} | |
/** | |
* @dev Safely transfers the ownership of a given token ID to another address | |
* If the target address is a contract, it must implement {IERC721Receiver-onERC721Received}, | |
* which is called upon a safe transfer, and return the magic value | |
* `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise, | |
* the transfer is reverted. | |
* Requires the _msgSender() to be the owner, approved, or operator | |
* @param from current owner of the token | |
* @param to address to receive the ownership of the given token ID | |
* @param tokenId uint256 ID of the token to be transferred | |
* @param _data bytes data to send along with a safe transfer check | |
*/ | |
function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public { | |
require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved"); | |
_safeTransferFrom(from, to, tokenId, _data); | |
} | |
/** | |
* @dev Safely transfers the ownership of a given token ID to another address | |
* If the target address is a contract, it must implement `onERC721Received`, | |
* which is called upon a safe transfer, and return the magic value | |
* `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise, | |
* the transfer is reverted. | |
* Requires the msg.sender to be the owner, approved, or operator | |
* @param from current owner of the token | |
* @param to address to receive the ownership of the given token ID | |
* @param tokenId uint256 ID of the token to be transferred | |
* @param _data bytes data to send along with a safe transfer check | |
*/ | |
function _safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) internal { | |
_transferFrom(from, to, tokenId); | |
require(_checkOnERC721Received(from, to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer"); | |
} | |
/** | |
* @dev Returns whether the specified token exists. | |
* @param tokenId uint256 ID of the token to query the existence of | |
* @return bool whether the token exists | |
*/ | |
function _exists(uint256 tokenId) internal view returns (bool) { | |
address owner = _tokenOwner[tokenId]; | |
return owner != address(0); | |
} | |
/** | |
* @dev Returns whether the given spender can transfer a given token ID. | |
* @param spender address of the spender to query | |
* @param tokenId uint256 ID of the token to be transferred | |
* @return bool whether the msg.sender is approved for the given token ID, | |
* is an operator of the owner, or is the owner of the token | |
*/ | |
function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) { | |
require(_exists(tokenId), "ERC721: operator query for nonexistent token"); | |
address owner = ownerOf(tokenId); | |
return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender)); | |
} | |
/** | |
* @dev Internal function to safely mint a new token. | |
* Reverts if the given token ID already exists. | |
* If the target address is a contract, it must implement `onERC721Received`, | |
* which is called upon a safe transfer, and return the magic value | |
* `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise, | |
* the transfer is reverted. | |
* @param to The address that will own the minted token | |
* @param tokenId uint256 ID of the token to be minted | |
*/ | |
function _safeMint(address to, uint256 tokenId) internal { | |
_safeMint(to, tokenId, ""); | |
} | |
/** | |
* @dev Internal function to safely mint a new token. | |
* Reverts if the given token ID already exists. | |
* If the target address is a contract, it must implement `onERC721Received`, | |
* which is called upon a safe transfer, and return the magic value | |
* `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise, | |
* the transfer is reverted. | |
* @param to The address that will own the minted token | |
* @param tokenId uint256 ID of the token to be minted | |
* @param _data bytes data to send along with a safe transfer check | |
*/ | |
function _safeMint(address to, uint256 tokenId, bytes memory _data) internal { | |
_mint(to, tokenId); | |
require(_checkOnERC721Received(address(0), to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer"); | |
} | |
/** | |
* @dev Internal function to mint a new token. | |
* Reverts if the given token ID already exists. | |
* @param to The address that will own the minted token | |
* @param tokenId uint256 ID of the token to be minted | |
*/ | |
function _mint(address to, uint256 tokenId) internal { | |
require(to != address(0), "ERC721: mint to the zero address"); | |
require(!_exists(tokenId), "ERC721: token already minted"); | |
_tokenOwner[tokenId] = to; | |
_ownedTokensCount[to].increment(); | |
emit Transfer(address(0), to, tokenId); | |
} | |
/** | |
* @dev Internal function to burn a specific token. | |
* Reverts if the token does not exist. | |
* Deprecated, use {_burn} instead. | |
* @param owner owner of the token to burn | |
* @param tokenId uint256 ID of the token being burned | |
*/ | |
function _burn(address owner, uint256 tokenId) internal { | |
require(ownerOf(tokenId) == owner, "ERC721: burn of token that is not own"); | |
_clearApproval(tokenId); | |
_ownedTokensCount[owner].decrement(); | |
_tokenOwner[tokenId] = address(0); | |
emit Transfer(owner, address(0), tokenId); | |
} | |
/** | |
* @dev Internal function to burn a specific token. | |
* Reverts if the token does not exist. | |
* @param tokenId uint256 ID of the token being burned | |
*/ | |
function _burn(uint256 tokenId) internal { | |
_burn(ownerOf(tokenId), tokenId); | |
} | |
/** | |
* @dev Internal function to transfer ownership of a given token ID to another address. | |
* As opposed to {transferFrom}, this imposes no restrictions on msg.sender. | |
* @param from current owner of the token | |
* @param to address to receive the ownership of the given token ID | |
* @param tokenId uint256 ID of the token to be transferred | |
*/ | |
function _transferFrom(address from, address to, uint256 tokenId) internal { | |
require(ownerOf(tokenId) == from, "ERC721: transfer of token that is not own"); | |
require(to != address(0), "ERC721: transfer to the zero address"); | |
_clearApproval(tokenId); | |
_ownedTokensCount[from].decrement(); | |
_ownedTokensCount[to].increment(); | |
_tokenOwner[tokenId] = to; | |
emit Transfer(from, 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. | |
* | |
* This function is deprecated. | |
* @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) | |
internal returns (bool) | |
{ | |
if (!to.isContract()) { | |
return true; | |
} | |
bytes4 retval = IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data); | |
return (retval == _ERC721_RECEIVED); | |
} | |
/** | |
* @dev Private function to clear current approval of a given token ID. | |
* @param tokenId uint256 ID of the token to be transferred | |
*/ | |
function _clearApproval(uint256 tokenId) private { | |
if (_tokenApprovals[tokenId] != address(0)) { | |
_tokenApprovals[tokenId] = address(0); | |
} | |
} | |
} | |
/** | |
* @title ERC-721 Non-Fungible Token Standard, optional enumeration extension | |
* @dev See https://eips.ethereum.org/EIPS/eip-721 | |
*/ | |
contract IERC721Enumerable is IERC721 { | |
function totalSupply() public view returns (uint256); | |
function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256 tokenId); | |
function tokenByIndex(uint256 index) public view returns (uint256); | |
} | |
/** | |
* @title ERC-721 Non-Fungible Token with optional enumeration extension logic | |
* @dev See https://eips.ethereum.org/EIPS/eip-721 | |
*/ | |
contract ERC721Enumerable is Context, ERC165, ERC721, IERC721Enumerable { | |
// Mapping from owner to list of owned token IDs | |
mapping(address => 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; | |
/* | |
* bytes4(keccak256('totalSupply()')) == 0x18160ddd | |
* bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) == 0x2f745c59 | |
* bytes4(keccak256('tokenByIndex(uint256)')) == 0x4f6ccce7 | |
* | |
* => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63 | |
*/ | |
bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63; | |
/** | |
* @dev Constructor function. | |
*/ | |
constructor () public { | |
// register the supported interface to conform to ERC721Enumerable via ERC165 | |
_registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE); | |
} | |
/** | |
* @dev Gets the token ID at a given index of the tokens list of the requested owner. | |
* @param owner address owning the tokens list to be accessed | |
* @param index uint256 representing the index to be accessed of the requested tokens list | |
* @return uint256 token ID at the given index of the tokens list owned by the requested address | |
*/ | |
function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256) { | |
require(index < balanceOf(owner), "ERC721Enumerable: owner index out of bounds"); | |
return _ownedTokens[owner][index]; | |
} | |
/** | |
* @dev Gets the total amount of tokens stored by the contract. | |
* @return uint256 representing the total amount of tokens | |
*/ | |
function totalSupply() public view returns (uint256) { | |
return _allTokens.length; | |
} | |
/** | |
* @dev Gets the token ID at a given index of all the tokens in this contract | |
* Reverts if the index is greater or equal to the total number of tokens. | |
* @param index uint256 representing the index to be accessed of the tokens list | |
* @return uint256 token ID at the given index of the tokens list | |
*/ | |
function tokenByIndex(uint256 index) public view returns (uint256) { | |
require(index < totalSupply(), "ERC721Enumerable: global index out of bounds"); | |
return _allTokens[index]; | |
} | |
/** | |
* @dev Internal function to transfer ownership of a given token ID to another address. | |
* As opposed to transferFrom, this imposes no restrictions on msg.sender. | |
* @param from current owner of the token | |
* @param to address to receive the ownership of the given token ID | |
* @param tokenId uint256 ID of the token to be transferred | |
*/ | |
function _transferFrom(address from, address to, uint256 tokenId) internal { | |
super._transferFrom(from, to, tokenId); | |
_removeTokenFromOwnerEnumeration(from, tokenId); | |
_addTokenToOwnerEnumeration(to, tokenId); | |
} | |
/** | |
* @dev Internal function to mint a new token. | |
* Reverts if the given token ID already exists. | |
* @param to address the beneficiary that will own the minted token | |
* @param tokenId uint256 ID of the token to be minted | |
*/ | |
function _mint(address to, uint256 tokenId) internal { | |
super._mint(to, tokenId); | |
_addTokenToOwnerEnumeration(to, tokenId); | |
_addTokenToAllTokensEnumeration(tokenId); | |
} | |
/** | |
* @dev Internal function to burn a specific token. | |
* Reverts if the token does not exist. | |
* Deprecated, use {ERC721-_burn} instead. | |
* @param owner owner of the token to burn | |
* @param tokenId uint256 ID of the token being burned | |
*/ | |
function _burn(address owner, uint256 tokenId) internal { | |
super._burn(owner, tokenId); | |
_removeTokenFromOwnerEnumeration(owner, tokenId); | |
// Since tokenId will be deleted, we can clear its slot in _ownedTokensIndex to trigger a gas refund | |
_ownedTokensIndex[tokenId] = 0; | |
_removeTokenFromAllTokensEnumeration(tokenId); | |
} | |
/** | |
* @dev Gets the list of token IDs of the requested owner. | |
* @param owner address owning the tokens | |
* @return uint256[] List of token IDs owned by the requested address | |
*/ | |
function _tokensOfOwner(address owner) internal view returns (uint256[] storage) { | |
return _ownedTokens[owner]; | |
} | |
/** | |
* @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 { | |
_ownedTokensIndex[tokenId] = _ownedTokens[to].length; | |
_ownedTokens[to].push(tokenId); | |
} | |
/** | |
* @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 = _ownedTokens[from].length.sub(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 | |
_ownedTokens[from].length--; | |
// Note that _ownedTokensIndex[tokenId] hasn't been cleared: it still points to the old slot (now occupied by | |
// lastTokenId, or just over the end of the array if the token was the last one). | |
} | |
/** | |
* @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.sub(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 | |
_allTokens.length--; | |
_allTokensIndex[tokenId] = 0; | |
} | |
} | |
/** | |
* @title ERC-721 Non-Fungible Token Standard, optional metadata extension | |
* @dev See https://eips.ethereum.org/EIPS/eip-721 | |
*/ | |
contract IERC721Metadata is IERC721 { | |
function name() external view returns (string memory); | |
function symbol() external view returns (string memory); | |
function tokenURI(uint256 tokenId) external view returns (string memory); | |
} | |
contract ERC721Metadata is Context, ERC165, ERC721, IERC721Metadata { | |
// Token name | |
string private _name; | |
// Token symbol | |
string private _symbol; | |
// Optional mapping for token URIs | |
mapping(uint256 => string) private _tokenURIs; | |
/* | |
* bytes4(keccak256('name()')) == 0x06fdde03 | |
* bytes4(keccak256('symbol()')) == 0x95d89b41 | |
* bytes4(keccak256('tokenURI(uint256)')) == 0xc87b56dd | |
* | |
* => 0x06fdde03 ^ 0x95d89b41 ^ 0xc87b56dd == 0x5b5e139f | |
*/ | |
bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f; | |
/** | |
* @dev Constructor function | |
*/ | |
constructor (string memory name, string memory symbol) public { | |
_name = name; | |
_symbol = symbol; | |
// register the supported interfaces to conform to ERC721 via ERC165 | |
_registerInterface(_INTERFACE_ID_ERC721_METADATA); | |
} | |
/** | |
* @dev Gets the token name. | |
* @return string representing the token name | |
*/ | |
function name() external view returns (string memory) { | |
return _name; | |
} | |
/** | |
* @dev Gets the token symbol. | |
* @return string representing the token symbol | |
*/ | |
function symbol() external view returns (string memory) { | |
return _symbol; | |
} | |
/** | |
* @dev Returns an URI for a given token ID. | |
* Throws if the token ID does not exist. May return an empty string. | |
* @param tokenId uint256 ID of the token to query | |
*/ | |
/* | |
function tokenURI(uint256 tokenId) external view returns (string memory) { | |
require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token"); | |
// return _tokenURIs[tokenId]; | |
return string(abi.encodePacked("https://chainfacesrinkeby.azurewebsites.net/api/HttpTrigger?id=", id_to_value[tokenId])); | |
} | |
*/ | |
/** | |
* @dev Internal function to set the token URI for a given token. | |
* Reverts if the token ID does not exist. | |
* @param tokenId uint256 ID of the token to set its URI | |
* @param uri string URI to assign | |
*/ | |
function _setTokenURI(uint256 tokenId, string memory uri) internal { | |
require(_exists(tokenId), "ERC721Metadata: URI set of nonexistent token"); | |
_tokenURIs[tokenId] = uri; | |
} | |
/** | |
* @dev Internal function to burn a specific token. | |
* Reverts if the token does not exist. | |
* Deprecated, use _burn(uint256) instead. | |
* @param owner owner of the token to burn | |
* @param tokenId uint256 ID of the token being burned by the msg.sender | |
*/ | |
function _burn(address owner, uint256 tokenId) internal { | |
super._burn(owner, tokenId); | |
// Clear metadata (if any) | |
if (bytes(_tokenURIs[tokenId]).length != 0) { | |
delete _tokenURIs[tokenId]; | |
} | |
} | |
} | |
/** | |
* @title Full ERC721 Token | |
* @dev This implementation includes all the required and some optional functionality of the ERC721 standard | |
* Moreover, it includes approve all functionality using operator terminology. | |
* | |
* See https://eips.ethereum.org/EIPS/eip-721 | |
*/ | |
contract ERC721Full is ERC721, ERC721Enumerable, ERC721Metadata { | |
constructor (string memory name, string memory symbol) public ERC721Metadata(name, symbol) { | |
// solhint-disable-previous-line no-empty-blocks | |
} | |
} | |
library Random | |
{ | |
/** | |
* Initialize the pool with the entropy of the blockhashes of the blocks in the closed interval [earliestBlock, latestBlock] | |
* The argument "seed" is optional and can be left zero in most cases. | |
* This extra seed allows you to select a different sequence of random numbers for the same block range. | |
*/ | |
function init(uint256 earliestBlock, uint256 latestBlock, uint256 seed) internal view returns (bytes32[] memory) { | |
//require(block.number-1 >= latestBlock && latestBlock >= earliestBlock && earliestBlock >= block.number-256, "Random.init: invalid block interval"); | |
require(block.number-1 >= latestBlock && latestBlock >= earliestBlock, "Random.init: invalid block interval"); | |
bytes32[] memory pool = new bytes32[](latestBlock-earliestBlock+2); | |
bytes32 salt = keccak256(abi.encodePacked(block.number,seed)); | |
for(uint256 i=0; i<=latestBlock-earliestBlock; i++) { | |
// Add some salt to each blockhash so that we don't reuse those hash chains | |
// when this function gets called again in another block. | |
pool[i+1] = keccak256(abi.encodePacked(blockhash(earliestBlock+i),salt)); | |
} | |
return pool; | |
} | |
/** | |
* Initialize the pool from the latest "num" blocks. | |
*/ | |
function initLatest(uint256 num, uint256 seed) internal view returns (bytes32[] memory) { | |
return init(block.number-num, block.number-1, seed); | |
} | |
/** | |
* Advances to the next 256-bit random number in the pool of hash chains. | |
*/ | |
function next(bytes32[] memory pool) internal pure returns (uint256) { | |
require(pool.length > 1, "Random.next: invalid pool"); | |
uint256 roundRobinIdx = uint256(pool[0]) % (pool.length-1) + 1; | |
bytes32 hash = keccak256(abi.encodePacked(pool[roundRobinIdx])); | |
pool[0] = bytes32(uint256(pool[0])+1); | |
pool[roundRobinIdx] = hash; | |
return uint256(hash); | |
} | |
/** | |
* Produces random integer values, uniformly distributed on the closed interval [a, b] | |
*/ | |
function uniform(bytes32[] memory pool, int256 a, int256 b) internal pure returns (int256) { | |
require(a <= b, "Random.uniform: invalid interval"); | |
return int256(next(pool)%uint256(b-a+1))+a; | |
} | |
} | |
contract faceGolfBalls { | |
function transfer(address _to, uint256 _tokenId) external; | |
function transferFrom(address _from, address _to, uint256 _tokenId) external; | |
} | |
contract chainFaces { | |
function ownerOf(uint256 _tokenId) public view returns (address owner); | |
function getFaceSymmetry(uint id) public view returns (uint256 faceSymmetry); | |
function getPercentBear(uint id) public view returns (uint256 percentBear); | |
function getGolfScore(uint id) public view returns (uint256 golfScore); | |
} | |
contract FaceGolf is ERC721Full { | |
using SafeMath for uint256; | |
mapping(uint256 => uint256) value_to_id; | |
mapping(uint256 => uint256[9]) id_to_value; | |
mapping (uint256 => uint) internal idToGolfScore; | |
mapping (uint256 => uint) internal idToTotalScore; | |
mapping(uint256 => uint) internal idToGolferBestScore; | |
mapping(uint256 => uint) internal idToGolferWorstScore; | |
mapping(uint256 => uint) internal idToGolferRoundsTotal; | |
mapping (uint256 => uint) internal idToFaceSymmetry; | |
mapping (uint256 => uint) internal idToTextColor; | |
mapping (uint256 => uint) internal idToBackgroundColor; | |
mapping (uint256 => uint) internal idToGolferID; | |
// mapping (uint256 => uint256[10000]) internal golferBestScore; | |
// mapping (uint256 => uint256[10000]) internal golferWorstScore; | |
// mapping(uint256 => uint256) golferBestScore; | |
// mapping(uint256 => uint256) golferWorstScore; | |
constructor() ERC721Full("FaceGolf Score Card v0", "SCORE") public { | |
faceGolfBallsERC20 = faceGolfBalls(FaceGolfERC20Address); | |
chainFacesERC721 = chainFaces(ChainFacesAddress); | |
} | |
function getPar(uint8 holePar, uint256 seed, uint16 golfBoost) internal view returns (uint8 parResult){ | |
bytes32[] memory pool = Random.initLatest(holePar-2, seed); | |
uint256 RNG = uint256(Random.uniform(pool, 1, 1000 - int256(golfBoost))); | |
uint8[3] memory thresholdCounts = [5,6,6]; | |
uint16[6][3] memory parThresholds = [ | |
[10,100,400,750,950,1000], | |
[1,20,150,400,750,950], | |
[5,25,225,625,825,950] | |
]; | |
parResult = 0; | |
for (uint8 i = 0; i < thresholdCounts[i]; i++) { | |
if (parResult == 0 && RNG <= parThresholds[holePar-3][i]) parResult = i + 1; | |
} | |
// add one to result on par 5 holes | |
if (holePar == 5) parResult++; | |
} | |
function getLostBalls(uint256 seed, uint256 lostBoost) internal view returns (uint8 ballLost){ | |
bytes32[] memory pool = Random.initLatest(4, seed); | |
uint16 lostBallRNG = uint16(Random.uniform(pool, 1, 1000 - int256(lostBoost))); | |
ballLost = lostBallRNG <= 500 ? 0 : 10; | |
} | |
function sendLostBalls(uint256 seed) internal view returns (address ballFinderAddress){ | |
bytes32[] memory pool = Random.initLatest(4, seed); | |
uint8 ballFinder = uint8(Random.uniform(pool, 0, 99)); | |
ballFinderAddress = chainFacesERC721.ownerOf(ballFinder); | |
} | |
function chainFaceBoosts(uint256 golferID) internal view returns (uint16 lostBoost, uint16 golfBoost){ | |
bool perfectSymetry = chainFacesERC721.getFaceSymmetry(golferID) == 100; | |
bool highBear = chainFacesERC721.getPercentBear(golferID) > 28; | |
bool lowGolf = chainFacesERC721.getGolfScore(golferID) < 20; | |
lostBoost = highBear ? 400 : (perfectSymetry ? 200 : 0); | |
golfBoost = lowGolf ? 400 : (perfectSymetry ? 200 : 0); | |
} | |
function _registerToken(uint8[9] memory scoreCard, uint8 totalScore, uint256 backgroundColor, uint256 golferID) private { | |
uint256 tokenId = totalSupply(); | |
id_to_value[tokenId] = scoreCard; | |
value_to_id[totalSupply()] = tokenId; | |
idToTotalScore[tokenId] = totalScore; | |
idToBackgroundColor[tokenId] = backgroundColor; | |
idToGolferID[tokenId] = golferID; | |
idToGolferRoundsTotal[golferID]++; | |
if (idToGolferBestScore[golferID] < 1 || idToGolferBestScore[golferID] > totalScore) idToGolferBestScore[golferID] = totalScore; | |
if (idToGolferWorstScore[golferID] < 1 || idToGolferWorstScore[golferID] < totalScore) idToGolferWorstScore[golferID] = totalScore; | |
_mint(msg.sender, tokenId); | |
} | |
uint public constant tokenLimit = 9999; | |
uint256 roundBalls = 90; | |
address public FaceGolfERC20Address = 0xaa3e8737aA7F893ACb86650d81B10e1630217303; | |
address public ChainFacesAddress = 0xE6Da1E491a9442a2A91453d1C15719b3666fd8d3; | |
faceGolfBalls faceGolfBallsERC20; | |
chainFaces chainFacesERC721; | |
function playGolf(uint256 seed, uint256 golferID) public { | |
require(msg.sender == chainFacesERC721.ownerOf(golferID), 'you do not own this chainface'); | |
// require(msg.value == 0 finney); | |
// require(value >= roundBalls); | |
faceGolfBallsERC20.transferFrom(msg.sender, address(this), roundBalls); | |
// require(block.timestamp < 1574711999, "ChainFaces sale has completed. They are now only available on the secondary market. "); | |
require(totalSupply() <= tokenLimit, "Maximum golf rounds on genesis course have been played. Score cards available on secondary market"); | |
// address(0x63a9dbCe75413036B2B778E670aaBd4493aAF9F3).transfer(msg.value); | |
(uint16 lostBoost, uint16 golfBoost) = chainFaceBoosts(golferID); | |
uint8 totalLostBalls = 0; | |
uint8[9] memory holePar = [4,3,4,4,4,3,4,5,5]; | |
uint8[9] memory scoreCard; | |
uint8 totalScore = 0; | |
for (uint8 i=0; i<9; i++) { | |
scoreCard[i] = getPar(holePar[i], seed + totalSupply() + i, golfBoost); | |
totalScore += scoreCard[i]; | |
totalLostBalls += getLostBalls(seed + i, lostBoost); | |
} | |
faceGolfBallsERC20.transfer(msg.sender, roundBalls - totalLostBalls); | |
faceGolfBallsERC20.transfer(sendLostBalls(seed), totalLostBalls); | |
uint256 backgroundColor; | |
if (totalScore < 36) { | |
backgroundColor = 0; | |
} | |
else if (totalScore == 36) { | |
backgroundColor = 1; | |
} | |
else { | |
backgroundColor = 2; | |
} | |
_registerToken(scoreCard, totalScore, backgroundColor, golferID); | |
} | |
function integerToString(uint _i) internal pure | |
returns (string memory) { | |
if (_i == 0) { | |
return "0"; | |
} | |
uint j = _i; | |
uint len; | |
while (j != 0) { | |
len++; | |
j /= 10; | |
} | |
bytes memory bstr = new bytes(len); | |
uint k = len - 1; | |
while (_i != 0) { | |
bstr[k--] = byte(uint8(48 + _i % 10)); | |
_i /= 10; | |
} | |
return string(bstr); | |
} | |
function tokenURI(uint256 id) external view returns (string memory) { | |
require(_exists(id), "ERC721Metadata: URI query for nonexistent token"); | |
return string(abi.encodePacked("https://chainfacesrinkeby.azurewebsites.net/api/HttpTrigger?id=", integerToString(id))); | |
} | |
function getScoreCard(uint256 id) public view returns (uint256[9] memory scoreCard) { | |
return id_to_value[id]; | |
} | |
function getTotalScore(uint id) public view returns (uint256 totalScore) { | |
return idToTotalScore[id]; | |
} | |
function getGolferID(uint id) public view returns (uint256 golferID) { | |
return idToGolferID[id]; | |
} | |
function getGolferRoundsTotal(uint golferID) public view returns (uint256 golferRoundsTotal) { | |
return idToGolferRoundsTotal[golferID]; | |
} | |
function getGolferScoreBest(uint golferID) public view returns (uint256 golferBestScore) { | |
return idToGolferBestScore[golferID]; | |
} | |
function getGolferScoreWorst(uint golferID) public view returns (uint256 golferWorstScore) { | |
return idToGolferWorstScore[golferID]; | |
} | |
function getBackgroundColor(uint id) public view returns (uint256 backgroundColor) { | |
return idToBackgroundColor[id]; | |
} | |
/* | |
function getFace(uint256 id) public view returns (uint8[9] scoreCard) { | |
return (scoreCard(id)); | |
} | |
*/ | |
} |
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/** | |
*Submitted for verification at Etherscan.io on 2020-02-02 | |
*/ | |
/** | |
*Submitted for verification at Etherscan.io on 2019-05-31 | |
*/ | |
pragma solidity ^0.5.11; | |
/** | |
* @title ERC20 interface | |
* @dev see https://github.com/ethereum/EIPs/issues/20 | |
*/ | |
interface IERC20 { | |
function transfer(address to, uint256 value) external returns (bool); | |
function approve(address spender, uint256 value) external returns (bool); | |
function transferFrom(address from, address to, uint256 value) external returns (bool); | |
function totalSupply() external view returns (uint256); | |
function balanceOf(address who) external view returns (uint256); | |
function allowance(address owner, address spender) external view returns (uint256); | |
event Transfer(address indexed from, address indexed to, uint256 value); | |
event Approval(address indexed owner, address indexed spender, uint256 value); | |
} | |
/** | |
* @title SafeMath | |
* @dev Unsigned math operations with safety checks that revert on error | |
*/ | |
library SafeMath { | |
/** | |
* @dev Multiplies two unsigned integers, reverts on overflow. | |
*/ | |
function mul(uint256 a, uint256 b) internal pure returns (uint256) { | |
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the | |
// benefit is lost if 'b' is also tested. | |
// See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522 | |
if (a == 0) { | |
return 0; | |
} | |
uint256 c = a * b; | |
require(c / a == b); | |
return c; | |
} | |
/** | |
* @dev Integer division of two unsigned integers truncating the quotient, reverts on division by zero. | |
*/ | |
function div(uint256 a, uint256 b) internal pure returns (uint256) { | |
// Solidity only automatically asserts when dividing by 0 | |
require(b > 0); | |
uint256 c = a / b; | |
// assert(a == b * c + a % b); // There is no case in which this doesn't hold | |
return c; | |
} | |
/** | |
* @dev Subtracts two unsigned integers, reverts on overflow (i.e. if subtrahend is greater than minuend). | |
*/ | |
function sub(uint256 a, uint256 b) internal pure returns (uint256) { | |
require(b <= a); | |
uint256 c = a - b; | |
return c; | |
} | |
/** | |
* @dev Adds two unsigned integers, reverts on overflow. | |
*/ | |
function add(uint256 a, uint256 b) internal pure returns (uint256) { | |
uint256 c = a + b; | |
require(c >= a); | |
return c; | |
} | |
/** | |
* @dev Divides two unsigned integers and returns the remainder (unsigned integer modulo), | |
* reverts when dividing by zero. | |
*/ | |
function mod(uint256 a, uint256 b) internal pure returns (uint256) { | |
require(b != 0); | |
return a % b; | |
} | |
} | |
/** | |
* @title Standard ERC20 token | |
* | |
* @dev Implementation of the basic standard token. | |
* https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20.md | |
* Originally based on code by FirstBlood: | |
* https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol | |
* | |
* This implementation emits additional Approval events, allowing applications to reconstruct the allowance status for | |
* all accounts just by listening to said events. Note that this isn't required by the specification, and other | |
* compliant implementations may not do it. | |
*/ | |
contract ERC20 is IERC20 { | |
using SafeMath for uint256; | |
mapping (address => uint256) private _balances; | |
mapping (address => mapping (address => uint256)) private _allowed; | |
uint256 private _totalSupply; | |
/** | |
* @dev Total number of tokens in existence | |
*/ | |
function totalSupply() public view returns (uint256) { | |
return _totalSupply; | |
} | |
/** | |
* @dev Gets the balance of the specified address. | |
* @param owner The address to query the balance of. | |
* @return An uint256 representing the amount owned by the passed address. | |
*/ | |
function balanceOf(address owner) public view returns (uint256) { | |
return _balances[owner]; | |
} | |
/** | |
* @dev Function to check the amount of tokens that an owner allowed to a spender. | |
* @param owner address The address which owns the funds. | |
* @param spender address The address which will spend the funds. | |
* @return A uint256 specifying the amount of tokens still available for the spender. | |
*/ | |
function allowance(address owner, address spender) public view returns (uint256) { | |
return _allowed[owner][spender]; | |
} | |
/** | |
* @dev Transfer token for a specified address | |
* @param to The address to transfer to. | |
* @param value The amount to be transferred. | |
*/ | |
function transfer(address to, uint256 value) public returns (bool) { | |
_transfer(msg.sender, to, value); | |
return true; | |
} | |
/** | |
* @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender. | |
* Beware that changing an allowance with this method brings the risk that someone may use both the old | |
* and the new allowance by unfortunate transaction ordering. One possible solution to mitigate this | |
* race condition is to first reduce the spender's allowance to 0 and set the desired value afterwards: | |
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729 | |
* @param spender The address which will spend the funds. | |
* @param value The amount of tokens to be spent. | |
*/ | |
function approve(address spender, uint256 value) public returns (bool) { | |
require(spender != address(0)); | |
_allowed[msg.sender][spender] = value; | |
emit Approval(msg.sender, spender, value); | |
return true; | |
} | |
/** | |
* @dev Transfer tokens from one address to another. | |
* Note that while this function emits an Approval event, this is not required as per the specification, | |
* and other compliant implementations may not emit the event. | |
* @param from address The address which you want to send tokens from | |
* @param to address The address which you want to transfer to | |
* @param value uint256 the amount of tokens to be transferred | |
*/ | |
function transferFrom(address from, address to, uint256 value) public returns (bool) { | |
_allowed[from][msg.sender] = _allowed[from][msg.sender].sub(value); | |
_transfer(from, to, value); | |
emit Approval(from, msg.sender, _allowed[from][msg.sender]); | |
return true; | |
} | |
/** | |
* @dev Increase the amount of tokens that an owner allowed to a spender. | |
* approve should be called when allowed_[_spender] == 0. To increment | |
* allowed value is better to use this function to avoid 2 calls (and wait until | |
* the first transaction is mined) | |
* From MonolithDAO Token.sol | |
* Emits an Approval event. | |
* @param spender The address which will spend the funds. | |
* @param addedValue The amount of tokens to increase the allowance by. | |
*/ | |
function increaseAllowance(address spender, uint256 addedValue) public returns (bool) { | |
require(spender != address(0)); | |
_allowed[msg.sender][spender] = _allowed[msg.sender][spender].add(addedValue); | |
emit Approval(msg.sender, spender, _allowed[msg.sender][spender]); | |
return true; | |
} | |
/** | |
* @dev Decrease the amount of tokens that an owner allowed to a spender. | |
* approve should be called when allowed_[_spender] == 0. To decrement | |
* allowed value is better to use this function to avoid 2 calls (and wait until | |
* the first transaction is mined) | |
* From MonolithDAO Token.sol | |
* Emits an Approval event. | |
* @param spender The address which will spend the funds. | |
* @param subtractedValue The amount of tokens to decrease the allowance by. | |
*/ | |
function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) { | |
require(spender != address(0)); | |
_allowed[msg.sender][spender] = _allowed[msg.sender][spender].sub(subtractedValue); | |
emit Approval(msg.sender, spender, _allowed[msg.sender][spender]); | |
return true; | |
} | |
/** | |
* @dev Transfer token for a specified addresses | |
* @param from The address to transfer from. | |
* @param to The address to transfer to. | |
* @param value The amount to be transferred. | |
*/ | |
function _transfer(address from, address to, uint256 value) internal { | |
require(to != address(0)); | |
_balances[from] = _balances[from].sub(value); | |
_balances[to] = _balances[to].add(value); | |
emit Transfer(from, to, value); | |
} | |
/** | |
* @dev Internal function that mints an amount of the token and assigns it to | |
* an account. This encapsulates the modification of balances such that the | |
* proper events are emitted. | |
* @param account The account that will receive the created tokens. | |
* @param value The amount that will be created. | |
*/ | |
function _mint(address account, uint256 value) internal { | |
require(account != address(0)); | |
_totalSupply = _totalSupply.add(value); | |
_balances[account] = _balances[account].add(value); | |
emit Transfer(address(0), account, value); | |
} | |
/** | |
* @dev Internal function that burns an amount of the token of a given | |
* account. | |
* @param account The account whose tokens will be burnt. | |
* @param value The amount that will be burnt. | |
*/ | |
function _burn(address account, uint256 value) internal { | |
require(account != address(0)); | |
_totalSupply = _totalSupply.sub(value); | |
_balances[account] = _balances[account].sub(value); | |
emit Transfer(account, address(0), value); | |
} | |
/** | |
* @dev Internal function that burns an amount of the token of a given | |
* account, deducting from the sender's allowance for said account. Uses the | |
* internal burn function. | |
* Emits an Approval event (reflecting the reduced allowance). | |
* @param account The account whose tokens will be burnt. | |
* @param value The amount that will be burnt. | |
*/ | |
function _burnFrom(address account, uint256 value) internal { | |
_allowed[account][msg.sender] = _allowed[account][msg.sender].sub(value); | |
_burn(account, value); | |
emit Approval(account, msg.sender, _allowed[account][msg.sender]); | |
} | |
} | |
/** | |
* @title Helps contracts guard against reentrancy attacks. | |
* @author Remco Bloemen <remco@2π.com>, Eenae <alexey@mixbytes.io> | |
* @dev If you mark a function `nonReentrant`, you should also | |
* mark it `external`. | |
*/ | |
contract ReentrancyGuard { | |
/// @dev counter to allow mutex lock with only one SSTORE operation | |
uint256 private _guardCounter; | |
constructor() public { | |
// The counter starts at one to prevent changing it from zero to a non-zero | |
// value, which is a more expensive operation. | |
_guardCounter = 1; | |
} | |
/** | |
* @dev Prevents a contract from calling itself, directly or indirectly. | |
* Calling a `nonReentrant` function from another `nonReentrant` | |
* function is not supported. It is possible to prevent this from happening | |
* by making the `nonReentrant` function external, and make it call a | |
* `private` function that does the actual work. | |
*/ | |
modifier nonReentrant() { | |
_guardCounter += 1; | |
uint256 localCounter = _guardCounter; | |
_; | |
require(localCounter == _guardCounter); | |
} | |
} | |
contract Context { | |
// Empty internal constructor, to prevent people from mistakenly deploying | |
// an instance of this contract, which should be used via inheritance. | |
constructor () internal { } | |
// solhint-disable-previous-line no-empty-blocks | |
function _msgSender() internal view returns (address payable) { | |
return msg.sender; | |
} | |
function _msgData() internal view returns (bytes memory) { | |
this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691 | |
return msg.data; | |
} | |
} | |
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 () internal { | |
_owner = _msgSender(); | |
emit OwnershipTransferred(address(0), _owner); | |
} | |
/** | |
* @dev Returns the address of the current owner. | |
*/ | |
function owner() public view returns (address) { | |
return _owner; | |
} | |
/** | |
* @dev Throws if called by any account other than the owner. | |
*/ | |
modifier onlyOwner() { | |
require(isOwner(), "Ownable: caller is not the owner"); | |
_; | |
} | |
/** | |
* @dev Returns true if the caller is the current owner. | |
*/ | |
function isOwner() public view returns (bool) { | |
return _msgSender() == _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 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 onlyOwner { | |
_transferOwnership(newOwner); | |
} | |
/** | |
* @dev Transfers ownership of the contract to a new account (`newOwner`). | |
*/ | |
function _transferOwnership(address newOwner) internal { | |
require(newOwner != address(0), "Ownable: new owner is the zero address"); | |
emit OwnershipTransferred(_owner, newOwner); | |
_owner = newOwner; | |
} | |
} | |
contract FaceGolfBalls is ERC20, Ownable, ReentrancyGuard { | |
// OpenZeppelin's SafeMath library is used for all arithmetic operations to avoid overflows/underflows. | |
using SafeMath for uint256; | |
/// @dev The metadata details about the "Wrapped CryptoKitties" WCK ERC20 token. | |
uint8 constant public decimals = 1; | |
string constant public name = "ChainFace Golf Balls v0"; | |
string constant public symbol = "GOLF0"; | |
uint256 constant public maxTokens = 10000; | |
/* ********* */ | |
/* FUNCTIONS */ | |
/* ********* */ | |
function mintTokens() public onlyOwner{ | |
if (totalSupply() <= maxTokens){ | |
_mint(msg.sender, (maxTokens).mul(10**1)); | |
} | |
} | |
} |
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