13 Test Level

This chapter builds a playable test level from the prepared chart and assets.

Level Assets

The template includes a cover image and background music (BGM) under resources/levels/patience:

• cover.jpg is the image shown for the level.
• bgm.mp3 is the music played during the level.

Chart

A test chart is also prepared in guide/chart.py. It contains BPMS, NOTE_BEATS, and TIMESCALES, which chapter 20 will use.

Now we can generate the BPM change and Note entities from BPMS and NOTE_BEATS. A Sonolus.py level stores typed archetype instances in its entity list, so we can construct them directly. Replace the contents of guide/level.py with:

from sonolus.script.level import BpmChange, Level, LevelData

from guide.chart import BPMS, NOTE_BEATS
from guide.play.initialization import Initialization
from guide.play.note import Note
from guide.play.stage import Stage

guide_level = Level(
    name="guide",
    title="Patience",
    artists="More Plastic & VinDon",
    author="ntsu",
    description=(
        "Song: More Plastic & VinDon - Patience\n"
        "Music provided by NoCopyrightSounds\n"
        "Free Download/Stream: http://NCS.io/Patience\n"
        "Watch: https://youtu.be/Lxf65uhlR6s"
    ),
    cover="levels/patience/cover.jpg",
    bgm="levels/patience/bgm.mp3",
    data=LevelData(
        bgm_offset=0,
        entities=[
            Initialization(),
            Stage(),
            *(BpmChange(beat=beat, bpm=bpm) for beat, bpm in BPMS),
            *(Note(beat=beat) for beat in NOTE_BEATS),
        ],
    ),
)


def load_levels():
    yield guide_level

Because Note.beat uses StandardImport.BEAT, constructing Note(beat=beat) writes the standard beat field that Sonolus expects. The note drawing code places every note in the center lane.

Checkpoint

Open Patience. Its cover should appear in the level list. During play, the BGM should play and the center lane should contain notes from the test chart.