SqrtPriceMath

Contains the math that uses square root of price as a Q64.96 and liquidity to compute deltas

Functions​

getNextSqrtPriceFromAmount0RoundingUp​

  function getNextSqrtPriceFromAmount0RoundingUp(
    uint160 sqrtPX96,
    uint128 liquidity,
    uint256 amount,
    bool add
  ) internal pure returns (uint160)

Gets the next sqrt price given a delta of token0

Always rounds up, because in the exact output case (increasing price) we need to move the price at least far enough to get the desired output amount, and in the exact input case (decreasing price) we need to move the price less in order to not send too much output. The most precise formula for this is liquidity * sqrtPX96 / (liquidity +- amount * sqrtPX96), if this is impossible because of overflow, we calculate liquidity / (liquidity / sqrtPX96 +- amount).

Parameters:​

Name	Type	Description
sqrtPX96	uint160	The starting price, i.e. before accounting for the token0 delta
liquidity	uint128	The amount of usable liquidity
amount	uint256	How much of token0 to add or remove from virtual reserves
add	bool	Whether to add or remove the amount of token0

Return Values:​

Type	Description
uint160	price after adding or removing amount, depending on add

getNextSqrtPriceFromAmount1RoundingDown​

  function getNextSqrtPriceFromAmount1RoundingDown(
    uint160 sqrtPX96,
    uint128 liquidity,
    uint256 amount,
    bool add
  ) internal pure returns (uint160)

Gets the next sqrt price given a delta of token1

Always rounds down, because in the exact output case (decreasing price) we need to move the price at least far enough to get the desired output amount, and in the exact input case (increasing price) we need to move the price less in order to not send too much output. The formula we compute is within <1 wei of the lossless version: sqrtPX96 +- amount / liquidity

Parameters:​

Name	Type	Description
sqrtPX96	uint160	The starting price, i.e., before accounting for the token1 delta
liquidity	uint128	The amount of usable liquidity
amount	uint256	How much of token1 to add, or remove, from virtual reserves
add	bool	Whether to add, or remove, the amount of token1

Return Values:​

Type	Description
uint160	price after adding or removing amount

getNextSqrtPriceFromInput​

  function getNextSqrtPriceFromInput(
    uint160 sqrtPX96,
    uint128 liquidity,
    uint256 amountIn,
    bool zeroForOne
  ) internal pure returns (uint160 sqrtQX96)

Gets the next sqrt price given an input amount of token0 or token1

Throws if price or liquidity are 0, or if the next price is out of bounds

Parameters:​

Name	Type	Description
sqrtPX96	uint160	The starting price, i.e., before accounting for the input amount
liquidity	uint128	The amount of usable liquidity
amountIn	uint256	How much of token0, or token1, is being swapped in
zeroForOne	bool	Whether the amount in is token0 or token1

Return Values:​

Name	Type	Description
sqrtQX96	uint160	The price after adding the input amount to token0 or token1

getNextSqrtPriceFromOutput​

  function getNextSqrtPriceFromOutput(
    uint160 sqrtPX96,
    uint128 liquidity,
    uint256 amountOut,
    bool zeroForOne
  ) internal pure returns (uint160 sqrtQX96)

Gets the next sqrt price given an output amount of token0 or token1

Throws if price or liquidity are 0 or the next price is out of bounds

Parameters:​

Name	Type	Description
sqrtPX96	uint160	The starting price before accounting for the output amount
liquidity	uint128	The amount of usable liquidity
amountOut	uint256	How much of token0, or token1, is being swapped out
zeroForOne	bool	Whether the amount out is token0 or token1

Return Values:​

Name	Type	Description
sqrtQX96	uint160	The price after removing the output amount of token0 or token1

getAmount0Delta​

  function getAmount0Delta(
    uint160 sqrtRatioAX96,
    uint160 sqrtRatioBX96,
    uint128 liquidity,
    bool roundUp
  ) internal pure returns (uint256 amount0)

Gets the amount0 delta between two prices

Calculates liquidity / sqrt(lower) - liquidity / sqrt(upper), i.e. liquidity * (sqrt(upper) - sqrt(lower)) / (sqrt(upper) * sqrt(lower))

Parameters:​

Name	Type	Description
sqrtRatioAX96	uint160	A sqrt price
sqrtRatioBX96	uint160	Another sqrt price
liquidity	uint128	The amount of usable liquidity
roundUp	bool	Whether to round the amount up or down

Return Values:​

Name	Type	Description
amount0	uint256	Amount of token0 required to cover a position of size liquidity between the two passed prices

getAmount1Delta​

  function getAmount1Delta(
    uint160 sqrtRatioAX96,
    uint160 sqrtRatioBX96,
    uint128 liquidity,
    bool roundUp
  ) internal pure returns (uint256 amount1)

Gets the amount1 delta between two prices

Calculates liquidity * (sqrt(upper) - sqrt(lower))

Parameters:​

Name	Type	Description
sqrtRatioAX96	uint160	A sqrt price
sqrtRatioBX96	uint160	Another sqrt price
liquidity	uint128	The amount of usable liquidity
roundUp	bool	Whether to round the amount up, or down

Return Values:​

Name	Type	Description
amount1	uint256	Amount of token1 required to cover a position of size liquidity between the two passed prices

getAmount0Delta​

  function getAmount0Delta(
    uint160 sqrtRatioAX96,
    uint160 sqrtRatioBX96,
    int128 liquidity
  ) internal pure returns (int256 amount0)

Helper that gets signed token0 delta

Parameters:​

Name	Type	Description
sqrtRatioAX96	uint160	A sqrt price
sqrtRatioBX96	uint160	Another sqrt price
liquidity	int128	The change in liquidity for which to compute the amount0 delta

Return Values:​

Name	Type	Description
amount0	int256	Amount of token0 corresponding to the passed liquidityDelta between the two prices

getAmount1Delta​

  function getAmount1Delta(
    uint160 sqrtRatioAX96,
    uint160 sqrtRatioBX96,
    int128 liquidity
  ) internal pure returns (int256 amount1)

Helper that gets signed token1 delta

Parameters:​

Name	Type	Description
sqrtRatioAX96	uint160	A sqrt price
sqrtRatioBX96	uint160	Another sqrt price
liquidity	int128	The change in liquidity for which to compute the amount1 delta

Return Values:​

Name	Type	Description
amount1	int256	Amount of token1 corresponding to the passed liquidityDelta between the two prices