Limitations

piuGBA has the following limitations:

• Maximum on-screen arrows:
  • 50 arrow sprites
  • 10 hold arrows per player
• Maximum songs per ROM: 99
• Maximum ROM size: 32MB
• Numeric difficulty range: 0~99
• Maximum song duration:
  • Single player:
    • 60 minutes (23 bits for event timestamps, but limited to 1 hour by the importer)
  • Multiplayer:
    • 4 minutes and 33 seconds (2 audio chunks per frame, 15-bit value for audio sync)
• Maximum # of events per chart:
  • Rythm events: 500 (BPM changes and Tick counts)
  • Regular events: 3000
• Unsupported SSC features:
  • Negative timing segments (e.g. negative speed or bpm)
    • Negative bpm/scroll will make the importer fail, but negative speeds are just ignored.
  • Progressive scrolls (#SCROLLS segments with a value != from 0 or 1)
    • These are emulated as regular speed changes. It doesn't have the same effect, but it works better than ignoring them.
    • Real scroll support is out of the scope for this project, as it would be very resource-intensive for the GBA.
  • Weird event types like:
    • L/4 (lift/roll head)
      • These will make the importer fail and ignore the entire chart.
    • M/K/S/V/H (mines/auto keysound/sudden/vanish/hidden)
      • These are ignored and interpreted as 0.
    • {1|v|1|0}{1|v|1|0}{1|v|1|0}{1|v|1|0}1 (advanced syntax) -> {note type|appearance|fake flag|reserved flag}
      • This is partially supported. If the fake flag is 1, the note will be F, otherwise it'll be {note type}.
    • 00{10a}0{10a}{10a}0{10a}00 / 00{207}00 (wtf)
      • These will make the importer fail and ignore the entire chart.