osu-native-napi

N-API bindings and TypeScript wrapper for osu-native. Primary use is calculating future pp in tosu, but it is also handy for inspecting rebalance changes based on pull requests from ppy/osu.

Requirements

• Windows x64 (current packages target win32/x64)
• .NET SDK 10
• MSVC C++ build tools
• Node.js 20 LTS
• pnpm v10

Monorepo structure

• packages/cpp-binding - native N-API binding built with CMake; outputs the .node addon and osu.Native.dll
• packages/wrapper - TypeScript API layer that depends on @tosuapp/osu-native-napi

Install and build

pnpm install

pnpm install runs pnpm -r build via the root postinstall script. You can also run it manually:

pnpm -r build

Development

Common local workflows:

pnpm -r build

pnpm -C packages/wrapper dev

If you only need the native addon:

pnpm -C packages/cpp-binding run build

Usage

See packages/wrapper/examples/usage.ts for a full example. Minimal flow:

import {
  Beatmap,
  DifficultyCalculatorFactory,
  Mod,
  ModsCollection,
  PerformanceCalculatorFactory,
  Ruleset,
} from "@tosuapp/osu-native-wrapper";

const beatmap = Beatmap.fromText("osu file format v14\n...\n");
const ruleset = Ruleset.fromId(0);

const diffCalculator = DifficultyCalculatorFactory.create(ruleset, beatmap);
const perfCalculator = PerformanceCalculatorFactory.create(ruleset);

const mods = ModsCollection.create();
mods.add(Mod.create("HD"));
mods.add(Mod.create("DT"));

const attributes = diffCalculator.calculateWithModsTimed(mods);
const last = attributes[attributes.length - 1].attributes;

const result = perfCalculator.calculate(
  {
    ruleset,
    beatmap,
    mods,
    maxCombo: 589,
    countOk: 4,
    countMiss: 1,
    countGreat: 395,
    countGood: 3,
    countPerfect: 117,
    accuracy: 0.9908333333333332,
    legacyScore: 8577684,
  },
  last,
);

console.log("Total PP:", result.total);

Links

• osu-native: https://github.com/minisbett/osu-native
• tosu: https://github.com/tosuapp/tosu
• ppy/osu PRs: https://github.com/ppy/osu/pulls