/
DyDxMath.sol
67 lines (62 loc) · 2.29 KB
/
DyDxMath.sol
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// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity >=0.8.0;
import "./FullMath.sol";
import "./UnsafeMath.sol";
/// @notice Math library that facilitates ranged liquidity calculations.
library DyDxMath {
function getDy(
uint256 liquidity,
uint256 priceLower,
uint256 priceUpper,
bool roundUp
) internal pure returns (uint256 dy) {
unchecked {
if (roundUp) {
dy = FullMath.mulDivRoundingUp(liquidity, priceUpper - priceLower, 0x1000000000000000000000000);
} else {
dy = FullMath.mulDiv(liquidity, priceUpper - priceLower, 0x1000000000000000000000000);
}
}
}
function getDx(
uint256 liquidity,
uint256 priceLower,
uint256 priceUpper,
bool roundUp
) internal pure returns (uint256 dx) {
unchecked {
if (roundUp) {
dx = UnsafeMath.divRoundingUp(FullMath.mulDivRoundingUp(liquidity << 96, priceUpper - priceLower, priceUpper), priceLower);
} else {
dx = FullMath.mulDiv(liquidity << 96, priceUpper - priceLower, priceUpper) / priceLower;
}
}
}
function getLiquidityForAmounts(
uint256 priceLower,
uint256 priceUpper,
uint256 currentPrice,
uint256 dy,
uint256 dx
) internal pure returns (uint256 liquidity) {
unchecked {
if (priceUpper <= currentPrice) {
liquidity = FullMath.mulDiv(dy, 0x1000000000000000000000000, priceUpper - priceLower);
} else if (currentPrice <= priceLower) {
liquidity = FullMath.mulDiv(
dx,
FullMath.mulDiv(priceLower, priceUpper, 0x1000000000000000000000000),
priceUpper - priceLower
);
} else {
uint256 liquidity0 = FullMath.mulDiv(
dx,
FullMath.mulDiv(priceUpper, currentPrice, 0x1000000000000000000000000),
priceUpper - currentPrice
);
uint256 liquidity1 = FullMath.mulDiv(dy, 0x1000000000000000000000000, currentPrice - priceLower);
liquidity = liquidity0 < liquidity1 ? liquidity0 : liquidity1;
}
}
}
}