midiviz/005_keyboard.html at gh-pages · zz85/midiviz · GitHub

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<!DOCTYPE HTML>
<html>
	<head>
		<script src="MidiConvert.js"></script>
        <script src="soundfont-player.js"></script>
        <script src="audio.js"></script>
        <script src="player.js"></script>
        <script src="keyboard.js"></script>

		<!--
			Vendor sources:
			https://raw.githubusercontent.com/Tonejs/MidiConvert/master/build/MidiConvert.js
		-->
	</head>
	<body>
		<style>
			body { background: #000; color: #eee; }
			#controls {
				position: absolute;
				z-index: 10;
			}

			input {
				width: 50px;
			}
		</style>
		<div id="controls">
			Size: <input type="range" value="1" min="0" max="8" step="0.1" onchange="BALL_MULTIPLIER = this.value"></input>

            Time: <span id="playing_time"></span>

			Progress: <input id="progress" type="range" value="0" min="0" max="1" step="0.0001"
				onmousedown="PROGRESS_CHANGE = true"
				onmouseup="player.seek(this.value * duration); lastPlayed = -1; PROGRESS_CHANGE = false"
				onchange="this.value"></input>
			Speed: <input type="range" value="1" min="0.2" max="4" step="0.2" onchange="player.speed(this.value)"></input>

			<button onclick="player.pause()">Pause</button>
		</div>
		<script>

            keyboard = new Keyboard(1, 10);
            // transform-origin: center;
            // transform: rotate(90deg)
            /*
            position: absolute;
            top: 0;
            left: -100px;
            transform: scale(0.5, 0.5);
            */

			canvas = document.createElement('canvas')
			ctx = canvas.getContext('2d')
			canvas.width = innerWidth
			canvas.height = innerHeight
			document.body.appendChild(canvas)
            ctx.globalCompositeOperation = 'lighter' // lighter

			min = 100000
			max = 0
			m = null
			lastPlayed = -1
			allNotes = []

			NOTE_HEIGHT = 8
			NOTE_RANGE = 110

			// PARAMETERS
			TIME_IN_Y = 40
			START_X = 400 // + 400
			BALL_MULTIPLIER = 1

			DISPLAY_GRID = false
			DISPLAY_HIT_GRID = false
            PROGRESS_CHANGE = false


			// move prepTime etc...

			// bigger
            NOTE_HEIGHT = 10; TIME_IN_Y = 200

            buffer = 50

            // defaults https://github.com/danigb/sample-player/blob/ebe9f25cf512f78cd338965ba524d6b47ccece38/lib/player.js#L8
            _attack = 0.01 // 0.01
            _decay = 0.1 // 0.01
            _sustain = 0.9 // 4
            _release = 0.3 // 0.01
            _velMul = 1.5
            _durMul = 1.5

			// file = 'Prelude1.mid'
			file = 'rachmaninov3.mid'
			// file = 'minute_waltz.mid'
			// file = 'chpn-p15.mid' // http://www.piano-midi.de/chopin.htm

			// minute_waltz.mid rachmaninov3
            // 0 &&

			const startup = () => MidiConvert.load(file, function(midi) {
				console.log(midi)
				m = midi
				colors = {}

				const c = 0.35
				const len = midi.tracks.length

				midi.tracks.forEach((track, trackNo) => {
					track.notes.forEach((note) => {
						const { midi, time, duration, velocity } = note;
						min = Math.min(midi, min)
						max = Math.max(midi, max)
						allNotes.push(Object.assign({ trackNo }, note))
					})

					const color = ((trackNo / len / 1.2 + c) * 0xffffff | 0).toString(16)
					colors[trackNo] = `#${color}`
				})

				allNotes.sort((an, bn) => {
					const a = an.time
					const b = bn.time
					return a < b ? -1 : a > b ? 1 : 0
				})

				endNote = allNotes[allNotes.length - 1]
				duration = endNote.time + endNote.duration

				player.play()

				console.log(`${min} -> ${max}`)
            })

            instrument = null
            // ac = new AudioContext()
            // Soundfont.instrument(ac, 'acoustic_grand_piano', { soundfont: 'MusyngKite' })
            // .then(function (instrument) {
            //     window.instrument = instrument
            // })
            // .then(startup)
            startup();

			const easings = {
				easeOut(t) {
					return t*(2-t)
				},

				easeIn(t) {
					return t*t
				},

				cubicIn(k) {
					return k * k * k;
				},

				cubicOut(k) {
					return --k * k * k + 1;
				},

				linear(t) {
					return t;
				},

				easeInOut(t) {
					// quad
					return t<.5 ? 2*t*t : -1+(4-2*t)*t
				},

				cubicInOut(t) {
					return t <.5 ? 4*t*t*t : (t-1)*(2*t-2)*(2*t-2)+1
				},

				exponentialOut(k) {
					return k === 1 ? 1 : 1 - Math.pow(2, - 10 * k)
				},

				exponentialIn(k) {
					return k === 0 ? 0 : Math.pow(1024, k - 1);
				},

				sinInOut(k) {
					return 0.5 * (1 - Math.cos(Math.PI * k))
				}


			};

            var PREP_EASE = easings.linear;
            PREP_EASE = easings.easeIn


			function formatSeconds(s) {
				var min = s / 60 | 0;
				var secs = (s % 60).toFixed(2);

				return min + ':' + secs;
			}

			function render() {
                requestAnimationFrame(render)

                keyboard.paint();
				ctx.save()

				// background
				ctx.clearRect(0, 0, canvas.width, canvas.height)

				if (typeof duration !== 'undefined') {
					playing_time.innerHTML = formatSeconds(lapse) + ' ' + speed.toFixed(1) + 'x'
					if (!PROGRESS_CHANGE) progress.value = lapse / duration
				}

				// proceed after midi is loaded
				if (!playing) return ctx.restore()

				const midi = m
				player.update()

				translateY = -lapse * TIME_IN_Y + START_X

				// Math.max(lastPlayed - 50, 0)
				for (let i = 0; i < allNotes.length; i++) {
					const note = allNotes[i];
					if (
						i > lastPlayed && note.time <= lapse + 0.00) {
							// allow scheduling up to
						if (note.time >= lapse - 0.05) { // up until missed by 100ms, we drop it.
                            var drift = note.time - lapse;
                            setTimeout(() => keyboard.toggleNote(note.midi, true), drift * 1000)
                            setTimeout(() => {
                                keyboard.toggleNote(note.midi, false)
                            }, note.duration * 1000 + drift)

                            if (!instrument)
                                noteOn(note.midi, note.velocity, drift)
                            else
                            instrument.play(note.midi, ac.currentTime + drift, {
                                gain: note.velocity * _velMul,
                                duration: note.duration * _durMul,
                                attack: _attack,
                                decay: _decay,
                                sustain: _sustain,
                                release: _release
                            })
                        }
						lastPlayed = i;
					}

					var bufferTime = 4;
					// if (note.time >= lapse - 0.05 && note.time <= lapse)
					// if (note.time >= lapse - 0.05 && note.time <= lapse + 0.05)
					if (note.time >= lapse - bufferTime && note.time <= lapse + bufferTime)
						drawNote(note)

					if (i > lastPlayed + buffer) break;
				}

				ctx.restore()
			}

			player.init()
			render()

			function trackInY(midi) {
				return NOTE_HEIGHT * (NOTE_RANGE - midi)
			}

			function frac(t, unit) {
				return t / unit;
			}

			function reverseFrac(t, unit) {
				return 1 - t / unit;
			}

			var easeInTime = 4;
			var prepTime = 0.4;


			function drawNote(note) {
				const { midi, time, duration, velocity } = note;
				// Math.max(...allNotes.map(({ velocity }) => velocity))

				// quick optimization by filtering
				if (time < lapse - 60 * 2 || time > lapse + 60 * 2) return

				ctx.fillStyle = colors[note.trackNo]
				ctx.save()
				// ctx.globalAlpha = velocity


				var diff = time - lapse
				const f = diff > 0 ? (1 - PREP_EASE(1 - diff / easeInTime)) * easeInTime : diff
				const x0 = f * TIME_IN_Y + START_X

				const y0 = trackInY(midi)
				const w = duration * TIME_IN_Y

				// Impact 1 + size
				let h = diff <= 0 ?
					// on note on
					velocity * 2 *
					(Math.max(duration * 4, 0.1)) *
					NOTE_HEIGHT * Math.min(Math.max(easings.easeIn(2 + diff / 0.5), 0), 4) :
						diff < prepTime ?
							// prep time
							(easings.easeIn(reverseFrac(diff, prepTime)) + 1) * NOTE_HEIGHT
						:
						NOTE_HEIGHT

				h *= BALL_MULTIPLIER

				if (diff < 0) {
					ctx.globalAlpha = Math.max(easings.easeIn(1 + diff / 1.4), 0);
				}

				// Circles
				ctx.beginPath()
				ctx.arc(x0, y0 + NOTE_HEIGHT / 2, h /2, 0, Math.PI * 2)
				ctx.fill()

				ctx.restore()
			}
		</script>
	</body>
</html>