You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
82 lines
2.3 KiB
82 lines
2.3 KiB
const VF = Vex.Flow;
|
|
|
|
// Create an SVG renderer and attach it to the DIV element named "boo".
|
|
const div = document.querySelector("body")
|
|
const renderer = new VF.Renderer(div, VF.Renderer.Backends.SVG);
|
|
|
|
// Size our SVG:
|
|
renderer.resize(1200, 1200);
|
|
|
|
// And get a drawing context:
|
|
const context = renderer.getContext();
|
|
|
|
const randomNote = () => {
|
|
const pitches = ['a', 'b', 'c', 'd', 'e', 'f', 'g'];
|
|
const randomPitchIndex = Math.floor(Math.random()*pitches.length);
|
|
const pitch = pitches[randomPitchIndex];
|
|
|
|
const octaves = ['4', '5'];
|
|
const randomOctaveIndex = Math.floor(Math.random()*octaves.length);
|
|
const octave = octaves[randomOctaveIndex];
|
|
|
|
return `${pitch}/${octave}`;
|
|
}
|
|
|
|
const returnNewNote = () => {
|
|
const newNote = new VF.StaveNote({clef: "treble", keys: [randomNote()], duration: "8" })
|
|
if(Math.random() > 0.5){
|
|
const accidentals = ['b', '#']
|
|
const randomAccidentalIndex = Math.floor(Math.random()*accidentals.length);
|
|
const accidental = accidentals[randomAccidentalIndex];
|
|
newNote.addAccidental(0, new VF.Accidental(accidental));
|
|
}
|
|
|
|
return newNote;
|
|
}
|
|
|
|
const drawNotes = (measureNum) => {
|
|
const staveWidth = 550;
|
|
// Create a stave at position 10, 40 of width 400 on the canvas.
|
|
const stave = new VF.Stave(10+(measureNum*staveWidth), 40, staveWidth);
|
|
|
|
// Add a clef and time signature.
|
|
if(measureNum === 0){
|
|
stave.addClef("treble").addTimeSignature("7/8");
|
|
}
|
|
|
|
// Connect it to the rendering context and draw!
|
|
stave.setContext(context).draw();
|
|
|
|
const notes = [
|
|
returnNewNote(),
|
|
returnNewNote(),
|
|
];
|
|
const notes2 = [
|
|
returnNewNote(),
|
|
returnNewNote(),
|
|
];
|
|
const notes3 = [
|
|
returnNewNote(),
|
|
returnNewNote(),
|
|
returnNewNote(),
|
|
];
|
|
const allNotes = notes.concat(notes2).concat(notes3);
|
|
|
|
const beams = [
|
|
new VF.Beam(notes),
|
|
new VF.Beam(notes2),
|
|
new VF.Beam(notes3)
|
|
]
|
|
|
|
// Create a voice in 4/4 and add the notes from above
|
|
const voice = new VF.Voice({num_beats: 7, beat_value: 8});
|
|
voice.addTickables(notes);
|
|
|
|
// Format and justify the notes to 400 pixels.
|
|
Vex.Flow.Formatter.FormatAndDraw(context, stave, allNotes);
|
|
beams.forEach(function(b) {b.setContext(context).draw()})
|
|
}
|
|
|
|
drawNotes(0);
|
|
drawNotes(1);
|