A large part of rosu-pp is a port of osu!lazer's difficulty and performance calculation with emphasis on a precise translation to Rust for the most accurate results.

Another important factor is the calculation speed. Optimizations and an accurate translation unfortunately don't always go hand-in-hand. Nonetheless, performance improvements are still snuck in wherever possible, providing a significantly faster runtime than the native C# code.

TODO: values to compare

Additionally, rosu-pp allows previous values to be re-used so that they don't need to be calculated again. For example, a beatmap needs to be decoded only once and can then be used for any amount of attribute calculations. Similarly, previous attributes can be re-used for later calculations (with some limitations, see the example).

Last commits of the ported code:

osu!lazer : 7342fb7f51b34533a42bffda89c3d6c569cc69ce (2022-10-11)
osu!tools : 146d5916937161ef65906aa97f85d367035f3712 (2022-10-08)

News posts of the latest gamemode updates:

Usage

// Decode the map
let map = rosu_pp::Beatmap::from_path("./resources/2785319.osu").unwrap();

// Calculate difficulty attributes
let diff_attrs = map.difficulty()
    .mods(8 + 16) // HDHR
    .calculate();

let stars = diff_attrs.stars();

// Calculate performance attributes
let perf_attrs = map.performance()
    // To speed up the calculation, we can use the previous attributes.
    // **Note** that this should only be done if the map, mode, mods, 
    // clock rate, and amount of passed objects stay the same.
    // Otherwise, the final attributes will be incorrect.
    .attributes(diff_attrs)
    .mods(24) // HDHR, must be the same as before
    .combo(789)
    .accuracy(99.2)
    .misses(2)
    .calculate();

let pp = perf_attrs.pp();

// Again, we re-use the previous attributes for maximum efficiency.
// This time we do it directly instead of through the map.
let max_pp = perf_attrs.performance()
    .mods(24) // Still the same
    .calculate()
    .pp();

println!("Stars: {stars} | PP: {pp}/{max_pp}");

Gradual calculation

TODO

Features

Flag	Description	Dependencies
`default`	No features
`tracing`	Any error encountered during beatmap decoding will be logged through `tracing::error`. If this feature is not enabled, errors will be ignored.	`tracing`

Bindings

Using rosu-pp from other languages than Rust:

JavaScript: rosu-pp-js
Python: rosu-pp-py