A basic, cross platform CLI metronome. Uses OS-native frameworks to play audio. Mostly meant as an exercise to see what it takes to create a cross-platform application with C++.

The program takes milliseconds passed since Jan 1, 1970 (a "Unix Timestamp"), and sets the next click to be at the next multiple of the BPM interval in milliseconds. Example: The BPM is 120, which means the BPM interval is 500 milliseconds. If the current Unix Timestamp is 2100 milliseconds, then the next beat is at 2500 milliseconds, since that is the next multiple of 500.

Therefore, if two computers share the same system time, then the metronome click will occur at exactly the same time (barring any audio latency).

1. Make sure metro exists in your PATH variable.

2. Within your terminal/command prompt:

metro <bpm>

Quit using Ctrl+C.

Please ensure the sounds folder that came with the executable is in the same directory as the executable.

Linux users: You may need to install the libao and libsndfile packages. On Debian-based distros, you can do this with: sudo apt install libao-dev libsndfile1-dev

graph TD
    A["main.cc"] --> B["Metronome.h"]
    B --> C["MetronomeMac.mm"]
    B --> D["MetronomeWin.cc"]
    B --> E["MetronomeLinux.cc"]

main.cc: The cross platform logic of the program. Creates and stores a Metronome instance for playing audio.

Metronome.h: Defines the Metronome class: the abstraction layer for playing audio. Includes functions init and playClick.

MetronomeMac.mm, MetronomeWin.cc, MetronomeLinux.cc: Platform specific implementations of the Metronome class.