Play the phone keypad: a sunday project.
I read a science informativ article on time and perception in psicological ordering. It say we normally do not perceive the sequence of a phone keypad. That does not convince me, so I wrote this code to ear it.
https://crates.io/crates/rodio I take crate rodio, basic examples are easy, I produce some sounds with SineWave generator.
I was convinced phone keypad produce one SineWave for each key, so I can write it easily. Search for frequencies ...
wikipedia: https://en.wikipedia.org/wiki/Telephone_keypad#Key_tones
A cleaner article:
https://www.sigidwiki.com/wiki/Dual_Tone_Multi_Frequency_%28DTMF%29
So, no. I was wrong: a key produces 2 SineWave.
rodio has a mixer created by
rodio::dynamic_mixer::mixer(channel, sample_rate)
So 2 channel is exactly what I need.
SineWave produce sound at 48_000 sample rate, and this is ok.
But a sequence of keypad keys must be sequenced then splitted in two channel.
source::from_iter() accepts an iterator and create a Source.
So it take the ownership, I use
https://doc.rust-lang.org/nightly/std/iter/trait.Iterator.html#method.unzip
Ok this is the code.
(I mean, not "Rust Future"). I admit that this tool is very annoying, also it is not possible to make it interactive.
Rodio provides 2 utilities for crafting a source:
from_iter()from_factory()
from_factory() take a function. To make it interactive it must exists 2 function
that produce void SineWave (volume 0.0) until there is a input key.
A maybe future.