Oscillioscope in Unity using the Shapes plugin. (Can also be used with the default Line Renderer)

Oscillator.cs

// Created by Starpelly, based on the FL STUDIO oscillator
using UnityEngine;
using Shapes;

public class Oscillator : MonoBehaviour
{
    public int lengthOfLineRenderer = 16384;
    public float thickness;
    public float strength;
    private Polyline polyline;
    public AudioSource source;

    [Header("Testing")]
    public bool testing;
    public double frequency = 400.0;

    private double increment;
    private double phase;
    private readonly double sampleRate = 48000.0;

    [Range(0, 32)]
    public double gain = 0.5;

    [Range(0, 32)]
    public double c = 32;

    [Range(-32, 32)]
    public double ind = 1;

    public double z = 5;

    [Range(0, 8)]
    public byte choice = 0;

    void Start()
    {
        polyline = transform.GetChild(0).GetComponent<Polyline>();
        polyline.Closed = false;
        for (int i = 0; i < lengthOfLineRenderer; i++)
        {
            PolylinePoint polylinePoint = new PolylinePoint();
            polylinePoint.color = Color.white;
            polylinePoint.thickness = thickness;
            polyline.points.Add(polylinePoint);
        }
    }

    void LateUpdate()
    {
        float[] samples = new float[lengthOfLineRenderer];
        source.GetOutputData(samples, 0);

        for (int i = 0; i < lengthOfLineRenderer; i++)
        {
            polyline.SetPointPosition(i, new Vector3(i * 0.5f, samples[i] * strength, 0.0f));
        }
    }

    private void OnAudioFilterRead(float[] data, int channels)
    {
        if (!testing) return;

        increment = frequency * 2.0 * Mathf.PI / sampleRate;
        for (int i = 0; i < data.Length - 1; i += channels)
        {
            switch (choice)
            {
                case 0: //sawtooth
                    for (float j = Mathf.Floor((float)ind); j < c; j++)
                    {
                        data[i] += (float)(gain * (Mathf.Sin((float)(phase * j)) / j));
                    }
                    break;
                case 1: //square
                    for (float j = Mathf.Floor((float)ind); j < c; j++)
                    {
                        data[i] += (float)(gain * (Mathf.Sin((float)(phase * (2 * j - 1))) / (2 * j - 1)));
                    }
                    break;
                case 2: //triangle
                    for (float j = Mathf.Floor((float)ind); j < c; j++)
                    {
                        data[i] += (float)(gain * (Mathf.Sin((float)(phase * (2 * j - 1) + Mathf.PI * ((j + 1) % 2)))) / Mathf.Pow((2 * j - 1), 2));
                    }
                    break;
                case 3: //harmonics
                    for (int j = (int)Mathf.Floor((float)ind); j < c; j++)
                    {
                        data[i] += (float)(gain * (Mathf.Cos((float)(j * phase + z))));
                    }
                    break;
                default: //sine
                    data[i] = (float)(gain * Mathf.Sin((float)phase));
                    break;
            }

            phase += increment;

            if (channels == 2)
            {
                data[i + 1] = data[i];
                // ring mod: Mathf.Sin((float)((Mathf.Pow((float)(phase * j), 3)) * frequency / sampleRate)); data[i] += (float)(gain * (Mathf.Sin((float)((Mathf.Pow((float)(phase * j), 3))))));
                // sawtooth: data[i] += (float)(gain * (Mathf.Sin((float)(phase * j)) / j));
                // square: data[i] += (float)(gain * (Mathf.Sin((float)(phase * (2 * j - 1))) / (2* j - 1)));
                // triangle: data[i] += (float)(gain * (Mathf.Sin((float)(phase * (2 * j - 1) + Mathf.PI * ((j + 1) % 2)))) / Mathf.Pow((2 * j - 1), 2));
                // accidental bitcrushed sine: data[i] += (float)(gain * (Mathf.Cos((float)(2 * Mathf.PI * frequency * phase + Mathf.Pow((float)1.618034, j - 1)))));
                // harsh squares depending on frequency: data[i] += (float)(gain * (Mathf.Cos((float)(2 * Mathf.PI * frequency * phase + z))));
            }
        }
    }
}