HexoDSP/src/dsp/node_bosc.rs

// Copyright (c) 2021 Weird Constructor <weirdconstructor@gmail.com>
// This is a part of HexoDSP. Released under (A)GPLv3 or any later.
// See README.md and COPYING for details.

use crate::nodes::{NodeAudioContext, NodeExecContext};
use crate::dsp::{
    NodeId, SAtom, ProcBuf, DspNode, LedPhaseVals, NodeContext,
    GraphAtomData, GraphFun,
};
use crate::dsp::helpers::{PolyBlepOscillator, lerp};

#[macro_export]
macro_rules! fa_bosc_wtype { ($formatter: expr, $v: expr, $denorm_v: expr) => { {
    let s =
        match ($v.round() as usize) {
            0  => "Sin",
            1  => "Tri",
            2  => "Saw",
            3  => "Pulse",
            _  => "?",
        };
    write!($formatter, "{}", s)
} } }

/// A simple amplifier
#[derive(Debug, Clone)]
pub struct BOsc {
    osc: PolyBlepOscillator,
    israte: f32,
}

impl BOsc {
    pub fn new(nid: &NodeId) -> Self {
        let init_phase = nid.init_phase();

        Self {
            osc: PolyBlepOscillator::new(init_phase),
            israte: 1.0 / 44100.0,
        }
    }

    pub const freq : &'static str =
        "BOsc freq\nBase frequency of the oscillator.\n\nRange: (-1..1)\n";
    pub const det : &'static str =
        "BOsc det\nDetune the oscillator in semitones and cents. \
         the input of this value is rounded to semitones on coarse input. \
         Fine input lets you detune in cents (rounded). \
         A signal sent to this port is not rounded.\n\
         Note: The signal input allows detune +-10 octaves.\
         \nRange: (Knob -0.2 .. 0.2) / (Signal -1.0 .. 1.0)\n";
    pub const pw : &'static str =
        "BOsc pw\n\nRange: (0..1)\n";
    pub const wtype : &'static str =
        "BOsc wtype\nWaveform type\nAvailable waveforms:\n\
            Sin   - Sine Waveform\n\
            Tri   - Triangle Waveform\n\
            Saw   - Sawtooth Waveform\n\
            Pulse - Pulse Waveform with configurable pulse width";
    pub const sig : &'static str =
        "BOsc sig\nOscillator output\nRange: (-1..1)\n";
    pub const DESC : &'static str =
r#"Basic Oscillator

A very basic oscillator with a sine, triangle, pulse and sawtooth waveform.
"#;
    pub const HELP : &'static str =
r#"BOsc - Basic Waveform Oscillator

A very basic oscillator with a sine, triangle, pulse and sawtooth waveform.
The pulse width `pw` parameter only has an effect for the `Pulse` waveform.
"#;

}

impl DspNode for BOsc {
    fn outputs() -> usize { 1 }

    fn set_sample_rate(&mut self, srate: f32) {
        self.israte = 1.0 / srate;
    }

    fn reset(&mut self) {
        self.osc.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)
    {
        use crate::dsp::{out, inp, denorm, denorm_offs, at};

        let freq = inp::BOsc::freq(inputs);
        let det  = inp::BOsc::det(inputs);
        let pw   = inp::BOsc::pw(inputs);
        let out  = out::BOsc::sig(outputs);

        let wtype = at::BOsc::wtype(atoms);

        let israte = self.israte;

        match wtype.i() {
            0 => { // sin
                for frame in 0..ctx.nframes() {
                    let freq =
                        denorm_offs::BOsc::freq(
                            freq, det.read(frame), frame);
                    out.write(
                        frame,
                        self.osc.next_sin(freq, israte));
                }
            },
            1 => { // tri
                for frame in 0..ctx.nframes() {
                    let freq =
                        denorm_offs::BOsc::freq(
                            freq, det.read(frame), frame);
                    out.write(
                        frame,
                        self.osc.next_tri(freq, israte));
                }
            },
            2 => { // saw
                for frame in 0..ctx.nframes() {
                    let freq =
                        denorm_offs::BOsc::freq(
                            freq, det.read(frame), frame);
                    out.write(
                        frame,
                        self.osc.next_saw(freq, israte));
                }
            },
            3 | _ => { // pulse
                for frame in 0..ctx.nframes() {
                    let freq =
                        denorm_offs::BOsc::freq(
                            freq, det.read(frame), frame);
                    let pw = denorm::BOsc::pw(pw, frame);
                    out.write(
                        frame,
                        self.osc.next_pulse(freq, israte, pw));
                }
            }
        }

        ctx_vals[0].set(out.read(ctx.nframes() - 1));
    }

    fn graph_fun() -> Option<GraphFun> {
        let mut osc = Box::new(PolyBlepOscillator::new(0.0));
        let israte = 1.0 / 128.0;

        Some(Box::new(move |gd: &dyn GraphAtomData, init: bool, x: f32, xn: f32| -> f32 {
            let wtype = NodeId::BOsc(0).inp_param("wtype").unwrap().inp();
            let pw    = NodeId::BOsc(0).inp_param("pw").unwrap().inp();
            let det   = NodeId::BOsc(0).inp_param("det").unwrap().inp();

            let wtype = gd.get(wtype as u32).map(|a| a.i()).unwrap_or(0);
            let pw    = gd.get_denorm(pw as u32);
            let det   = gd.get_norm(det as u32);

            // the detune scaling with lerp is wrong...
            // let pow = lerp((det + 0.2) * (1.0 / 0.4), 0.25, 4.0);
            // let freq = (2.0_f32).powf(pow);
            let freq = 2.0;

            if init {
                osc.reset();
                if wtype == 1 {
                    // we need to initialize the leaky integrator
                    // in the triangle wave form, or it would look
                    // a bit weird.
                    for _ in 0..256 { osc.next_tri(freq, israte); }
                }
            }

            let s =
                match wtype {
                    0     => (osc.next_sin(freq, israte)       + 1.0) * 0.5,
                    1     => (osc.next_tri(freq, israte)       + 1.0) * 0.5,
                    2     => (osc.next_saw(freq, israte)       + 1.0) * 0.5,
                    3 | _ => (osc.next_pulse_no_dc(freq, israte, pw)
                                                               + 1.0) * 0.5,
                };

            s * 0.9 + 0.05
        }))
    }
}