For more information about the examples, such as how the Python and Mojo files interact with each other, see the Examples Overview

DattorroReverbExample

This example demonstrates the Dattorro Reverb graph, which is a reverb algorithm created by Jon Dattorro in his paper "Effect Design Part 1: Reverberator and Other Filters".

Python Code

import sys
from pathlib import Path

sys.path.insert(0, str(Path(__file__).parent.parent))

from mmm_python.GUI import Handle, ControlSpec
from PySide6.QtWidgets import QApplication, QWidget, QVBoxLayout, QCheckBox

from mmm_python import *

def add_handle(layout, mmm_audio, name: str, min: float, max: float, exp: float, default: float, resolution: float, display_resolution: int):
    """Create a slider and connect it to the audio graph."""
    slider = Handle(name, ControlSpec(min, max, exp), default, callback=lambda v: mmm_audio.send_float(name, v), resolution = resolution, display_resolution = display_resolution)
    layout.addWidget(slider)
    mmm_audio.send_float(name, default)

def main():
    # instantiate and load the graph
    m_a = MMMAudio(128, 18, graph_name="DattorroReverbExample", package_name="examples")
    m_a.send_int("in_chan", 0)
    m_a.start_audio()

    app = QApplication([])

    # Create the main window
    window = QWidget()
    window.setWindowTitle("Dattorro Reverb")
    window.resize(300, 100)
    # stop audio when window is closed
    window.closeEvent = lambda event: (m_a.exit_all(), event.accept())

    # Create layout
    layout = QVBoxLayout()
    # Add all the controls
    add_handle(layout, m_a, "pre_delay_time", 0.0, 0.5, 1.0, 0.00, 10000, 6)
    add_handle(layout, m_a, "decay", 0.001, 1.0, 1.0, 0.83, 10000, 6)
    add_handle(layout, m_a, "input_diffusion1", 0.0, 1.0, 1.0, 0.81, 10000, 6)
    add_handle(layout, m_a, "input_diffusion2", 0.0, 1.0, 1.0, 0.66, 10000, 6)
    add_handle(layout, m_a, "decay_diffusion1", 0.0, 1.0, 1.0, 0.43, 10000, 6)
    add_handle(layout, m_a, "decay_diffusion2", 0.0, 1.0, 1.0, 0.81, 10000, 6)
    add_handle(layout, m_a, "bandwidth", 0.0, 1.0, 1.0, 0.3, 10000, 6)
    add_handle(layout, m_a, "damping", 0.0, 1.0, 1.0, 0.004, 10000, 6)

    # Set the layout for the main window
    window.setLayout(layout)

    # Show the window
    window.show()

    # Start the application's event loop
    sys.exit(app.exec())

if __name__ == "__main__":
    main()

Mojo Code

from mmm_audio import *

struct DattorroReverbExample(Movable, Copyable):
        var world: World
        var m: Messenger
        var reverb: DattorroReverb[Interp.none] #the original uses Interp.none on the non-modulated delay lines
        var in_chan: Int

        fn __init__(out self, world: World):
                self.world = world
                self.m = Messenger(world)
                self.reverb = DattorroReverb[Interp.none](world)
                self.in_chan = 0

        fn next(mut self) -> MFloat[2]:
                self.m.update(self.in_chan, "in_chan")
                input = MFloat[2](self.world[].sound_in[self.in_chan])

                self.m.update(self.reverb.pre_delay_time, "pre_delay_time")
                self.m.update(self.reverb.decay, "decay")
                self.m.update(self.reverb.bandwidth, "bandwidth")
                self.m.update(self.reverb.damping, "damping")
                self.m.update(self.reverb.decay_diffusion1, "decay_diffusion1")
                self.m.update(self.reverb.decay_diffusion2, "decay_diffusion2")
                self.m.update(self.reverb.input_diffusion1, "input_diffusion1")
                self.m.update(self.reverb.input_diffusion2, "input_diffusion2")

                return self.reverb.next(input)