HexoDSP/src/dsp/node_midip.rs

// Copyright (c) 2022 Weird Constructor <weirdconstructor@gmail.com>
// This file is a part of HexoDSP. Released under GPL-3.0-or-later.
// See README.md and COPYING for details.

use crate::dsp::{
    at, denorm, inp, out_idx, DspNode, LedPhaseVals, NodeContext, NodeId, ProcBuf, SAtom,
};
use crate::nodes::{HxMidiEvent, MidiEventPointer, NodeAudioContext, NodeExecContext};
use synfx_dsp::{GateSignal, TrigSignal};

#[macro_export]
macro_rules! fa_midip_chan {
    ($formatter: expr, $v: expr, $denorm_v: expr) => {{
        write!($formatter, "{}", $v.round() as usize)
    }};
}

#[macro_export]
macro_rules! fa_midip_gmode {
    ($formatter: expr, $v: expr, $denorm_v: expr) => {{
        let s = match ($v.round() as usize) {
            0 => "MIDI",
            1 => "Trigger",
            2 => "Gate Len",
            _ => "?",
        };
        write!($formatter, "{}", s)
    }};
}

/// The (stereo) output port of the plugin
#[derive(Debug, Clone)]
pub struct MidiP {
    next_gate: i8,
    cur_note: u8,
    cur_gate: u8,
    cur_vel: f32,
    trig_sig: TrigSignal,
    gate_sig: GateSignal,
}

impl MidiP {
    pub fn new(_nid: &NodeId) -> Self {
        Self {
            next_gate: 0,
            cur_note: 0,
            cur_gate: 0,
            cur_vel: 0.0,
            trig_sig: TrigSignal::new(),
            gate_sig: GateSignal::new(),
        }
    }

    pub const chan: &'static str = "MidiP chan\nMIDI Channel 0 to 15\n";
    pub const gmode: &'static str = "MidiP gmode\nMIDI gate mode.\n- 'MIDI' gate same as MIDI input\n- 'Trigger' output only triggers on 'gate' output\n- 'Gate Len' output gate with the length of the 'glen' parameter\n";
    pub const glen: &'static str = "MidiP glen\nMIDI gate length\n\
        If 'gmode' is set to 'Gate Len' this controls and overrides the gate length on a MIDI \
        note event. 'Trigger' will just send a short trigger when a note event is received. \
        'MIDI' means the gate reflects the note on/off duration.";
    pub const det: &'static str = "MidiP det\nDetune input pitch a bit\nRange: (-1..1)";
    pub const freq: &'static str =
        "MidiP freq\nMIDI note frequency, detuned by 'det'.\nRange: (-1..1)";
    pub const gate: &'static str = "MidiP gate\nMIDI note gate\nRange: (0..1)";
    pub const vel: &'static str = "MidiP vel\nMIDI note velocity\nRange: (0..1)";

    pub const DESC: &'static str = "MIDI Pitch/Note Input\n\n\
        This node is an input of MIDI note events into the DSP graph. \
        You get 3 outputs: frequency of the note, gate signal for the length of the note and the velocity.";
    pub const HELP: &'static str = r#"MIDI Pitch/Note Input

This node is an input of MIDI note events into the DSP graph.
You get 3 outputs: frequency of the note, gate signal for the length of
the note and the velocity.

You can modify the gate length using the 'gmode' and 'glen' settings.
Setting 'gmode' to 'Trigger' allows you to get only a short trigger
signal, which might be helpful in some situations.
The 'Gate Len' setting allows you to overwrite the gate length with a
custom and fixed gate length. However, if new note is played on this
MIDI channel, the gate will restart after a very short pause.
"#;
}

impl DspNode for MidiP {
    fn outputs() -> usize {
        0
    }

    fn set_sample_rate(&mut self, srate: f32) {
        self.trig_sig.set_sample_rate(srate);
        self.gate_sig.set_sample_rate(srate);
    }
    fn reset(&mut self) {
        self.trig_sig.reset();
        self.gate_sig.reset();
    }

    #[inline]
    fn process<T: NodeAudioContext>(
        &mut self,
        ctx: &mut T,
        ectx: &mut NodeExecContext,
        _nctx: &NodeContext,
        atoms: &[SAtom],
        inputs: &[ProcBuf],
        outputs: &mut [ProcBuf],
        ctx_vals: LedPhaseVals,
    ) {
        let det = inp::MidiP::det(inputs);
        let glen = inp::MidiP::glen(inputs);
        let chan = at::MidiP::chan(atoms);
        let gmode = at::MidiP::gmode(atoms);
        let out_i = out_idx::MidiP::gate();
        let (freq, r) = outputs.split_at_mut(out_i);
        let (gate, vel) = r.split_at_mut(1);
        let freq = &mut freq[0];
        let gate = &mut gate[0];
        let vel = &mut vel[0];

        let midip_channel = (chan.i() as usize % 16) as u8;

        let mut ptr = MidiEventPointer::new(&ectx.midi_notes[..]);

        let gmode = gmode.i();

        for frame in 0..ctx.nframes() {
            let gate_len = denorm::MidiP::glen(glen, frame);

            if self.next_gate > 0 {
                self.cur_gate = 1;
            } else if self.next_gate < 0 {
                self.cur_gate = 0;
            }
            self.next_gate = 0;

            while let Some(ev) = ptr.next_at(frame) {
                match ev {
                    HxMidiEvent::NoteOn { channel, note, vel } => {
                        if channel != midip_channel {
                            continue;
                        }

                        if self.cur_gate > 0 {
                            self.next_gate = 1;
                            self.cur_gate = 0;
                        } else {
                            self.cur_gate = 1;
                        }
                        self.trig_sig.trigger();
                        self.gate_sig.trigger();
                        self.cur_note = note;
                        self.cur_vel = vel;
                    }
                    HxMidiEvent::NoteOff { channel, note } => {
                        if channel != midip_channel {
                            continue;
                        }

                        if self.cur_note == note {
                            self.next_gate = -1;
                        }
                    }
                    _ => (),
                }
            }

            match gmode {
                1 => {
                    gate.write(frame, self.trig_sig.next());
                }
                2 => {
                    if self.next_gate > 0 {
                        gate.write(frame, 0.0);
                        self.cur_gate = 0;
                    } else {
                        let gsig = self.gate_sig.next(gate_len);
                        self.cur_gate = gsig.ceil() as u8;
                        gate.write(frame, gsig);
                    }
                }
                _ => {
                    gate.write(frame, if self.cur_gate > 0 { 1.0 } else { 0.0 });
                }
            }

            let note = (self.cur_note as f32 - 69.0) / 120.0;
            let note = note + det.read(frame);
            //d// println!("FRAME: {} => gate={}, freq={}, next_gate={}", frame, self.cur_gate, note, self.next_gate);
            freq.write(frame, note);
            vel.write(frame, self.cur_vel as f32);
        }

        let last_val = gate.read(ctx.nframes() - 1);
        ctx_vals[0].set(last_val);
    }
}