RXYO: A simple XY oscilloscope implemented with Raylib and Miniaudio

Logo as a .wav file

What?

This is a simple implementation of a xy oscilloscope using raylib and miniaudio that showcases the following:

• Capture of audio from the user's microphone to an internal ring buffer
• Plot it into the screen using the audio's left channel for the x coordinate and the right channel for the y coordinate.
• Interpolate it using cubic interpolation to simulate upsampling+lowpassing

Why?

I did it as an excercise in Raylib and because I like oscilloscope music but oscilloscopes are too heavy to carry and I move a lot. There is also a specific challenge in implementing a XY oscilloscope:

• The audio rate and the display refresh rate are different.

How?

The code should be self-documented. If something is not clear feel free to recommend changes. The main idea is this:

• Have two ring buffers and an index which points to which buffer to write to.
• When capturing, write to one of the buffers.
• When plotting, switch the index to the other buffer, and plot from the current buffer.

Requirements

• Raylib
• A C compiler

Compilation

cc -g -o rxyo rxyo.c -lraylib -lGL -lm -lpthread -ldl -lrt -lX11

Usage

Just start it with ./rxyo. You can then choose from the inputs shown on screen by pressing one of the numbers corresponding to the system's input. Press m to turn off the shortcuts' menu and esc to exit.