bass-foundry/plugins/common/params/src/lib.rs

//! Host parameters shared by every tracked plugin: Note mode's note, the key lock and
//! Follow bends. Plugins nest [`PitchParams`] in their own parameter struct.
use common_dsp::tracker::{Pitch, Scale, NOTE_MAX, NOTE_MIN};
use common_dsp::note_name;
use nih_plug::prelude::*;
use std::sync::Arc;

#[derive(Enum, Debug, PartialEq, Eq, Clone, Copy)]
pub enum ScaleParam {
    #[id = "free"]
    #[name = "Off"]
    Free,
    #[id = "minor"]
    Minor,
    #[id = "major"]
    Major,
    #[id = "root"]
    #[name = "Root only"]
    Root,
}
impl From<ScaleParam> for Scale {
    fn from(s: ScaleParam) -> Self {
        match s {
            ScaleParam::Free => Scale::Free,
            ScaleParam::Minor => Scale::Minor,
            ScaleParam::Major => Scale::Major,
            ScaleParam::Root => Scale::Root,
        }
    }
}
impl From<Scale> for ScaleParam {
    fn from(s: Scale) -> Self {
        match s {
            Scale::Free => ScaleParam::Free,
            Scale::Minor => ScaleParam::Minor,
            Scale::Major => ScaleParam::Major,
            Scale::Root => ScaleParam::Root,
        }
    }
}

#[derive(Params)]
pub struct PitchParams {
    /// The note played in Note mode; its pitch class is the key root.
    #[id = "note"]
    pub note: IntParam,
    #[id = "scale"]
    pub scale: EnumParam<ScaleParam>,
    #[id = "bends"]
    pub bends: BoolParam,
}
impl Default for PitchParams {
    fn default() -> Self {
        let d = Pitch::default();
        Self {
            note: IntParam::new(
                "Note",
                d.note as i32,
                IntRange::Linear {
                    min: NOTE_MIN as i32,
                    max: NOTE_MAX as i32,
                },
            )
            .with_value_to_string(Arc::new(|v| note_name(v.clamp(0, 127) as u8)))
            .with_string_to_value(Arc::new(|s| parse_note(s).map(i32::from))),
            scale: EnumParam::new("Key lock", ScaleParam::Free),
            bends: BoolParam::new("Follow bends", d.bends),
        }
    }
}
impl PitchParams {
    pub fn pitch(&self) -> Pitch {
        Pitch {
            note: (self.note.value().clamp(NOTE_MIN as i32, NOTE_MAX as i32)) as u8,
            scale: self.scale.value().into(),
            bends: self.bends.value(),
        }
    }
    /// Pushes editor changes to the host, one gesture per change.
    pub fn apply(&self, setter: &ParamSetter, old: &Pitch, new: &Pitch) {
        if old.note != new.note {
            setter.begin_set_parameter(&self.note);
            setter.set_parameter(&self.note, new.note as i32);
            setter.end_set_parameter(&self.note);
        }
        if old.scale != new.scale {
            setter.begin_set_parameter(&self.scale);
            setter.set_parameter(&self.scale, new.scale.into());
            setter.end_set_parameter(&self.scale);
        }
        if old.bends != new.bends {
            setter.begin_set_parameter(&self.bends);
            setter.set_parameter(&self.bends, new.bends);
            setter.end_set_parameter(&self.bends);
        }
    }
}

/// Reads a note name such as "F1" within the Note range.
pub fn parse_note(text: &str) -> Option<u8> {
    common_dsp::parse_note(text).filter(|n| (NOTE_MIN..=NOTE_MAX).contains(n))
}

#[cfg(test)]
mod tests {
    use super::*;
    #[test]
    fn note_names_round_trip() {
        for n in NOTE_MIN..=NOTE_MAX {
            assert_eq!(parse_note(&note_name(n)), Some(n));
        }
        assert_eq!(parse_note("f1"), Some(29));
        assert_eq!(parse_note("H2"), None);
    }
    #[test]
    fn scale_maps_both_ways() {
        for s in [Scale::Free, Scale::Minor, Scale::Major, Scale::Root] {
            assert_eq!(Scale::from(ScaleParam::from(s)), s);
        }
    }
}