tek/src/sequence/midi.rs

use crate::sequence::{Frame, Time};

/// Pulses per quarter note
pub const PPQ: usize = 96;

pub struct Message {
    bytes: Vec<u8>
}

pub struct MIDISequence {
    name:   String,
    length: usize,
    events: Vec<(Frame, MIDIEvent)>,
    notes:  Vec<u8>,
}

impl MIDISequence {
    pub fn new (name: &str, length: usize) -> Self {
        Self {
            name: name.to_string(),
            length,
            events: vec![],
            notes:  vec![],
        }
    }
    pub fn add (&mut self, time: usize, event: MIDIEvent) -> &mut Self {
        let mut sort = false;
        match &event {
            MIDIEvent::NoteOn(pitch, _velocity) => {
                if !self.notes.contains(pitch) {
                    self.notes.push(*pitch);
                    sort = true;
                }
            }
        }
        if sort {
            self.notes.sort();
        }
        self.events.push((time, event));
        self
    }
    pub fn render (&self, stdout: &mut std::io::Stdout, resolution: usize)
        -> Result<(), Box<dyn std::error::Error>>
    {
        use crossterm::{*, style::Stylize};
        let (col, row) = cursor::position()?;
        let unit = PPQ / resolution;
        let length = self.length / unit;
        let mut header = String::from("     ");
        for i in 0..length {
            if i % 8 == 0 {
                header.push('┍');
            } else {
                header.push('━');
            }
        }
        header.push('┑');
        let mut tracks: Vec<(String, String)> = vec![];
        for note in self.notes.iter().rev() {
            let mut row_header = format!(" {note:3} ");
            let mut row = String::new();
            for beat in 0..length {
                let mut active = false;
                for (frame, event) in self.events.iter() {
                    match event {
                        MIDIEvent::NoteOn(pitch, _) => {
                            if pitch == note
                                && *frame >= beat * unit
                                && *frame < (beat + 1) * unit
                            {
                                active = true;
                                continue
                            }
                        }
                    }
                }
                if active {
                    row.push('⯀')
                } else if beat == 0 {
                    row.push('│');
                } else if beat % 8 == 0 {
                    row.push('┆');
                } else {
                    row.push('·');
                }
            }
            tracks.push((row_header, row));
        }
        stdout.queue(style::PrintStyledContent(header.grey()))?;
        for (row_header, row) in tracks.into_iter() {
            stdout
                .queue(cursor::MoveDown(1))?
                .queue(cursor::MoveToColumn(col))?
                .queue(style::PrintStyledContent(row_header.grey()))?
                .queue(style::PrintStyledContent(row.clone().white()))?
                .queue(style::PrintStyledContent(row.clone().yellow()))?
                .queue(style::PrintStyledContent(row.white()))?;
        }
        //stdout
            //.queue(cursor::MoveDown(1))?
            //.queue(cursor::MoveToColumn(col))?
            //.queue(style::PrintStyledContent(footer.grey()))?;
            //.queue(style::PrintStyledContent("················".grey()))?
            //.queue(style::PrintStyledContent("│".yellow()))?
            //.queue(cursor::MoveDown(1))?
            //.queue(cursor::MoveLeft(18))?
            //.queue(style::PrintStyledContent("└────────────────┘".yellow()))?;
        Ok(())
    }
}

pub enum MIDIEvent {
    NoteOn(u8, u8)
}