implement basic typing via midi

Cargo.toml

@@ -6,8 +6,8 @@ edition = "2021"
 [dependencies]
 anyhow = "1.0.86"
 crossbeam = "0.8.4"
-eframe = "0.29.1"
+eframe = "0"
-egui = "0.29.1"
+egui = "0"
 enigo = { version = "0.2.1", features = ["serde"] }
 hex = "0.4.3"
 midir = "0.10.0"

doc/typing.md

@@ -0,0 +1,61 @@
+
+# Typing system design
+
+
+This document talks about how data flows through the system, and how it's
+displayed, so that users can enter text using a MIDI device.
+
+There are a few distinct pieces:
+- **data flow**: how do we get from MIDI to the display and to the typing portion?
+- **encoding**: how do we represent text so that we can enter it?
+- **parsing**: how do we read a MIDI stream to convert it into our text encoding?
+- **display**: how do we present the state to a user so that they can see what they're doing?
+
+
+## Data flow and architecture
+
+We already have the ability for data to flow in, and for devices to be added
+and removed. What we need here is another piece that will keep track of state
+for the typing daemon.
+
+The typing daemon will be a state machine, with state transitions for entering
+new bits and for emitting text (which will then move back to a clear state).
+
+It will be subscribed to all incoming MIDI messages, and it will store a
+separate state for each connection ID, so things you enter on the drums will
+not alter what you're entering on the wind synth, for example.
+
+It will emit text directly, via `enigo` (or, in debug mode, to the console).
+And it will emit its current state on another queue, which can be used to
+display the characters which can be typed.
+
+
+## Encoding
+
+Each MIDI device will be in a given *base*. Wind synth will be in base 11 by
+default, so we can read the semitone and ignore which octave it's in. We could
+expand this to use a wider range, or narrow it to belong to a particular key,
+but this is the starting point. Drums will be in base 2 by default, with the
+snare and kick drum providing the bits and everything else being ignored.
+
+We will support a given range of characters, and some modifiers as well. Other
+keys can be added, but this is where we'll start: just text! the characters
+supported initially will be 'a'..'z', 'A'..'Z', '0'..'9', '.', and ','.
+
+Each of these will be assigned a number, which will then be converted to base 2
+for entry.
+
+
+
+## Display
+
+Given a list of
+
+
+
+
+
+
+
+
+

src/bin/main.rs

@@ -4,20 +4,17 @@ use std::{
 };
 
 use anyhow::{anyhow, Result};
+use enigo::{Enigo, Keyboard, Settings};
 use midi_keys::{
     log::load_raw_log,
     midi::daemon::Category,
     parser::parse_message,
+    typing::{base_values, encode, midi_to_scale_degree, TypingState},
     ui::{display_state_daemon, DisplayQueues, DisplayState},
 };
-//use enigo::{Direction, Enigo, Key, Keyboard, Settings};
 use midir::{MidiInput, MidiInputPort};
 
 fn main() {
-    //let mut enigo = Enigo::new(&Settings::default()).unwrap();
-    //enigo.text("echo \"hello world\"").unwrap();
-    //enigo.key(Key::Return, Direction::Press).unwrap();
-
     let (dbg_send, dbg_recv) = crossbeam::channel::unbounded();
     let (ws_send, ws_recv) = crossbeam::channel::unbounded();
     let (drum_send, drum_recv) = crossbeam::channel::unbounded();
@@ -37,17 +34,47 @@ fn main() {
     let _handle = display_state_daemon(queues, state.clone());
     println!("started daemon");
 
-    std::thread::spawn(move || loop {
+    for c in "hello, world".chars() {
-        match dbg_recv.recv() {
+        let v = encode(c).unwrap();
-            Ok(m) => println!("debug: {m:?}"),
+        println!("{c}: {:?} - {:?}", v, base_values(v, 7, 3));
-            Err(err) => println!("err: {err:?}"),
     }
-    });
+    for c in "Hello, WORLD!".chars() {
-    std::thread::spawn(move || loop {
+        let v = encode(c).unwrap();
+        println!("{c}: {:?} - {:?}", v, base_values(v, 7, 3));
+    }
+
+    //std::thread::spawn(move || loop {
+    //    match dbg_recv.recv() {
+    //        Ok(m) => println!("debug: {m:?}"),
+    //        Err(err) => println!("err: {err:?}"),
+    //    }
+    //});
+    std::thread::spawn(move || {
+        let mut steps = 0;
+        let mut state = TypingState::new(7);
+        let mut enigo = Enigo::new(&Settings::default()).unwrap();
+        loop {
             match ws_recv.recv() {
-            Ok(m) => println!("windsynth: {m:?}"),
+                Ok((_cid, _ts, m)) => {
+                    if let Some((note, _velocity)) = m.note_on_values() {
+                        if let Some(degree) = midi_to_scale_degree(60, note) {
+                            steps += 1;
+                            println!("got degree: {degree}, steps: {steps}, state: {state:?}");
+                            state.enter(degree);
+
+                            if steps % 3 == 0 {
+                                let (b, c) = state.emit();
+                                println!("got {b}, {c:?}");
+                                if let Some(c) = c {
+                                    enigo.text(&format!("{c}"));
+                                }
+                            }
+                        }
+                    }
+                }
                 Err(err) => println!("err(ws): {err:?}"),
             }
+        }
     });
     std::thread::spawn(move || loop {
         match drum_recv.recv() {

src/lib.rs

@@ -1,4 +1,5 @@
 pub mod log;
 pub mod midi;
 pub mod parser;
+pub mod typing;
 pub mod ui;

src/midi.rs

@@ -10,6 +10,19 @@ impl Message {
     pub fn new(raw: Vec<u8>, parsed: ParsedMessage) -> Self {
         Message { raw, parsed }
     }
+
+    /// Extracts the note value and velocity for any NoteOn messages.
+    /// This is a convenience function to let us avoid a match in all the places
+    /// we need to extract this.
+    pub fn note_on_values(&self) -> Option<(u8, u8)> {
+        match &self.parsed {
+            ParsedMessage::Voice(VoiceMessage {
+                category: VoiceCategory::NoteOn { note, velocity },
+                ..
+            }) => Some((*note, *velocity)),
+            _ => None,
+        }
+    }
 }
 
 #[derive(PartialEq, Eq, Debug, Clone)]

src/parser.rs

@@ -149,11 +149,11 @@ mod tests {
 
         let note = 0x24;
         let velocity = 0x51;
-        let expected = Message::Voice(VoiceMessage::new(
+        let expected = ParsedMessage::Voice(VoiceMessage::new(
             VoiceCategory::NoteOn { note, velocity },
             0,
         ));
-        assert_eq!(parsed, expected,);
+        assert_eq!(parsed.parsed, expected,);
         assert_eq!(remainder.len(), 0);
     }
 

src/typing.rs

@@ -0,0 +1,169 @@
+#[derive(Debug, Copy, Clone)]
+pub struct TypingState {
+    base: u8,
+    current: u8,
+}
+
+impl TypingState {
+    pub fn new(base: u8) -> TypingState {
+        TypingState { base, current: 0 }
+    }
+
+    /// Add the value into the current accumulator.
+    pub fn enter(&mut self, value: u8) {
+        self.current = self.current.saturating_mul(self.base).saturating_add(value);
+    }
+
+    /// Decode the current accumulator as a character, or None if it's invalid.
+    /// This resets the accumulator to 0!
+    pub fn emit(&mut self) -> (u8, Option<char>) {
+        let x = self.current;
+        let c = decode(x);
+
+        self.current = 0;
+
+        (x, c)
+    }
+}
+
+/// Chunks a u8 into a sequence of values in a given base.
+pub fn base_values(mut x: u8, base: u8, len: usize) -> Vec<u8> {
+    let mut vals = vec![];
+    for _ in 0..len {
+        vals.push(x % base);
+        x = x / base;
+    }
+    vals.reverse();
+
+    vals
+}
+
+/// Determines the scale degree of a given MIDI note relative to the provided
+/// scale root.
+pub fn midi_to_scale_degree(root: u8, note: u8) -> Option<u8> {
+    let semitones = (note as i32 - root as i32).rem_euclid(12);
+    Some(match semitones {
+        0 => 0,
+        2 => 1,
+        4 => 2,
+        5 => 3,
+        7 => 4,
+        9 => 5,
+        11 => 6,
+        _ => return None,
+    })
+}
+
+/// Converts a character to its assigned number for use in text entry. This is
+/// stores them as u8 to keep things simple and fixed length. If we want to
+/// support the full Unicode space, we can have expand this to u32.
+pub fn encode(c: char) -> Option<u8> {
+    Some(match c {
+        'a'..='z' => c as u8 - 'a' as u8,
+        'A'..='Z' => c as u8 - 'A' as u8 + 26,
+        '0'..='9' => c as u8 - '0' as u8 + 26 * 2,
+        '.' => 62,
+        ',' => 63,
+        '!' => 64,
+        ' ' => 65,
+        _ => return None,
+    })
+}
+
+/// Converts a number to its corresponding character for use in text entry.
+/// If a character isn't implemented, it will return None.
+pub fn decode(x: u8) -> Option<char> {
+    let c = match x {
+        0..=25 => 'a' as u8 + x,
+        26..=51 => 'A' as u8 + x - 26,
+        52..=61 => '0' as u8 + x - 26 * 2,
+        62 => '.' as u8,
+        63 => ',' as u8,
+        64 => '!' as u8,
+        65 => ' ' as u8,
+        _ => return None,
+    };
+    Some(char::from(c))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn encodes_lowercase() {
+        assert_eq!(encode('a'), Some(0));
+        assert_eq!(encode('b'), Some(1));
+        assert_eq!(encode('z'), Some(25));
+    }
+
+    #[test]
+    fn encodes_uppercase() {
+        assert_eq!(encode('A'), Some(26));
+        assert_eq!(encode('B'), Some(27));
+        assert_eq!(encode('Z'), Some(51));
+    }
+
+    #[test]
+    fn encodes_numbers() {
+        assert_eq!(encode('0'), Some(52));
+        assert_eq!(encode('1'), Some(53));
+        assert_eq!(encode('9'), Some(61));
+    }
+
+    #[test]
+    fn encodes_punctuation() {
+        assert_eq!(encode('.'), Some(62));
+        assert_eq!(encode(','), Some(63));
+        assert_eq!(encode('!'), Some(64));
+    }
+
+    #[test]
+    fn decodes_lowercase() {
+        assert_eq!(decode(0), Some('a'));
+        assert_eq!(decode(1), Some('b'));
+        assert_eq!(decode(25), Some('z'));
+    }
+
+    #[test]
+    fn decodes_uppercase() {
+        assert_eq!(decode(26), Some('A'));
+        assert_eq!(decode(27), Some('B'));
+        assert_eq!(decode(51), Some('Z'));
+    }
+
+    #[test]
+    fn decodes_numbers() {
+        assert_eq!(decode(52), Some('0'));
+        assert_eq!(decode(53), Some('1'));
+        assert_eq!(decode(61), Some('9'));
+    }
+
+    #[test]
+    fn decodes_punctuation() {
+        assert_eq!(decode(62), Some('.'));
+        assert_eq!(decode(63), Some(','));
+        assert_eq!(decode(64), Some('!'));
+    }
+
+    #[test]
+    fn converts_to_scale_degree() {
+        assert_eq!(midi_to_scale_degree(60, 58), None);
+        assert_eq!(midi_to_scale_degree(60, 59), Some(6));
+        assert_eq!(midi_to_scale_degree(60, 60), Some(0));
+        assert_eq!(midi_to_scale_degree(60, 61), None);
+        assert_eq!(midi_to_scale_degree(60, 62), Some(1));
+        assert_eq!(midi_to_scale_degree(60, 63), None);
+        assert_eq!(midi_to_scale_degree(60, 64), Some(2));
+        assert_eq!(midi_to_scale_degree(60, 65), Some(3));
+        assert_eq!(midi_to_scale_degree(60, 66), None);
+        assert_eq!(midi_to_scale_degree(60, 67), Some(4));
+        assert_eq!(midi_to_scale_degree(60, 68), None);
+        assert_eq!(midi_to_scale_degree(60, 69), Some(5));
+        assert_eq!(midi_to_scale_degree(60, 70), None);
+        assert_eq!(midi_to_scale_degree(60, 71), Some(6));
+        assert_eq!(midi_to_scale_degree(60, 72), Some(0));
+        assert_eq!(midi_to_scale_degree(60, 73), None);
+        assert_eq!(midi_to_scale_degree(60, 74), Some(1));
+    }
+}

src/ui.rs

@@ -232,7 +232,7 @@ impl eframe::App for MidiKeysApp {
 
                             frame.content_ui.label(RichText::new(port_name).strong());
 
-                            display_midi_message(idx, msg, &mut frame.content_ui, show_raw);
+                            //display_midi_message(idx, msg, &mut frame.content_ui, show_raw);
                             frame.end(ui);
                         }
                     });