# 18. Input Buckets

In this chapter, we will set up input buckets for notes.

# Input Buckets

Input buckets are categories of notes which notes can feed judgment distance values into, and at the result screen a probability graph will be shown for each bucket.

While it's not necessary, it is very useful for players to calibrate their input offset or improve on their accuracy.

# Setup Buckets

Our engine only has one type of note, so one bucket will do.

At the result screen each bucket will be represented by a graphic composed of skin sprites, so we should make it as close to the in game visual of the note as possible:

export const buckets = defineBuckets({
    note: {
        sprites: [
            {
                id: SkinSprite.NoteHeadCyan,
                x: 0,
                y: 0,
                w: 2,
                h: 2,
                rotation: 0,
            },
        ],
    },
})

export const buckets = defineBuckets({
    note: {
        sprites: [
            {
                id: SkinSprite.NoteHeadCyan,
                x: 0,
                y: 0,
                w: 2,
                h: 2,
                rotation: 0,
            },
        ],
    },
})

What bucket value to report is up to the engine, however it is mostly commonly the timing difference in milliseconds.

In initialization script we set up the bucket windows:

const preprocess = [
    // ...
    LevelBucket.of(buckets.noteIndex).setBucket(50, 100, 200),
]

const preprocess = [
    // ...
    LevelBucket.of(buckets.noteIndex).setBucket(50, 100, 200),
]

# Bucket and Bucket Value

Similar to how we tell Sonolus about judgment result, we write to Entity Input block for bucket and bucket value in note script.

Since we want InputBucketValue to be timing difference in milliseconds while we already have InputAccuracy which is timing difference in seconds, we can simply multiply that by 1000.

const touch = And(
    // ...
    [
        // ...
        InputBucket.set(buckets.noteIndex),
        InputBucketValue.set(Multiply(1000, InputAccuracy)),
    ]
)

const touch = And(
    // ...
    [
        // ...
        InputBucket.set(buckets.noteIndex),
        InputBucketValue.set(Multiply(1000, InputAccuracy)),
    ]
)