We need chart statistics APIs for each game type

[ListenerJubatus]

The RadarCategory/PaneCategory APIs that are often used for displaying statistics about charts is too dance-centric in regards to the types of values it offers. We should be able to calculate and cache other types of data about charts that are mode-specific, so themes can display relevant data not tied to DDR paradigms. Such as, for instance;

beat and related

• notes (only key notes)
• scratches
• note holds
• turntable holds
• chords (calculated like hands, but only on key notes)
• NPS
• Beatmania actually added its own groove radar on IIDX 27, which is based on Average density, Peak density, Scratch density, Holds, Chords, and BPM changes

drum-related

• Notes in each column, mainly because current drummania actually shows this on a graph on their music wheel
• A chart parameter we can use to mark double-bass charts?

guitar-related

• strum notes
• hammer-ons and pull offs
• tap sections
• chords
• NPS

You can see where I'm going here. Does anyone have further ideas/suggestions in this realm?