滑点与价格影响

p_before = pool.spot_price()
p_after  = pool.spot_price_if_trade(Δin) applied
impact   = (p_before − p_after) / p_before       // 可以是有符号的

quoted_out = 报价时计算的 amount_out
actual_out = 链上观察到的 amount_out
slippage   = (quoted_out − actual_out) / quoted_out

// AMM v4 — 唯一有字面上叫 computeAmountOut 的方法的模块
const computed = raydium.liquidity.computeAmountOut({
  poolInfo,            // 需要 baseReserve/quoteReserve/version/status 拼接进去
  amountIn,            // BN
  mintIn,
  mintOut,
  slippage: 0.005,     // 0.5% 容差，一个普通数字
});
// -> { amountOut, minAmountOut, currentPrice, executionPrice, priceImpact, fee }
//    所有金额都是普通 BN

// CPMM
const { computePoolInfo } = await raydium.cpmm.getPoolInfoFromRpc(POOL_ID);
const cpmmQuote = raydium.cpmm.computeSwapAmount({
  pool: computePoolInfo, amountIn, outputMint: mintOut, slippage: 0.005,
});
// -> { amountIn, amountOut, minAmountOut, fee, executionPrice, priceImpact, swapResult, allTrade }

// CLMM — 一个 PoolUtils 静态方法，需要位图扩展 + 区块时间戳
const clmmQuote = PoolUtils.computeAmountOutFormat({
  poolInfo: computeClmmPoolInfo, tickarrayBitmapExtension, tickArrayCache,
  amountIn, tokenOut, slippage: 0.005,
  epochInfo: await raydium.fetchEpochInfo(),
  blockTimestamp: Math.floor(Date.now() / 1000),
});
// -> { amountOut, minAmountOut, fee, priceImpact, remainingAccounts, ... }

// 不好：0.5% 仅在末尾应用，所以任何中间跳滑动都会导致第二跳失败。
const finalMin = finalAmount * (1 - 0.005);

// 更好：每跳强制执行自己的边界。
const hop1Min  = hop1Amount * (1 - 0.005);
const hop2Min  = hop2Amount * (1 - 0.005);
// 端到端这更紧凑（复合），但是原子的——如果任何跳降级，交易早期回滚。