djminus/index.html at main · pierrevedel/djminus · GitHub

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<!DOCTYPE html>
<html lang="fr">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Test MIDI Web App avec Réverb</title>
    <style>
        body {
            font-family: monospace;
            margin: 20px;
        }
        #console {
            height: 300px;
            overflow-y: scroll;
            border: 1px solid #ccc;
            padding: 10px;
            background: #f9f9f9;
            margin-bottom: 20px;
        }
        button {
            padding: 8px 16px;
            font-family: monospace;
        }
    </style>
</head>
<body>
    <h1>Test MIDI Web App avec Réverb</h1>
    <button id="start">Démarrer MIDI</button>
    <div id="console"></div>
    <script>
        // Variables globales
        let midiAccess;
        const sounds = {};
        let audioContext;
        let masterGain;
        let reverb;
        let dryGain;
        let wetGain;
        let globalVolume = 0.7;
        let globalPitch = 1.0;
        let reverbAmount = 0.3; // Niveau de réverb (0 à 1)

        // Fonction pour ajouter un message à la console
        function log(message) {
            const consoleEl = document.getElementById('console');
            consoleEl.innerHTML += message + "<br>";
            consoleEl.scrollTop = consoleEl.scrollHeight;
        }

        // Fonction pour précharger les sons
        async function loadSounds() {
            for (let note = 36; note <= 51; note++) {
                const num = (note - 35).toString().padStart(4, '0');
                const url = `https://lasonotheque.org/UPLOAD/mp3/${num}.mp3`;
                sounds[note] = new Audio(url);
            }
            log("Sons chargés !");
        }

        // Fonction pour initialiser l'AudioContext et les effets
        function initAudioContext() {
            audioContext = new (window.AudioContext || window.webkitAudioContext)();

            // Nœud de gain principal
            masterGain = audioContext.createGain();
            masterGain.gain.value = globalVolume;
            masterGain.connect(audioContext.destination);

            // Création de la réverb (convolution)
            const impulseResponseUrl = "https://raw.githubusercontent.com/mohayonao/web-audio-api-samples/master/samples/impulse/impulse-rev.wav";
            fetch(impulseResponseUrl)
                .then(response => response.arrayBuffer())
                .then(buffer => audioContext.decodeAudioData(buffer))
                .then(impulse => {
                    reverb = audioContext.createConvolver();
                    reverb.buffer = impulse;
                    reverb.connect(masterGain);

                    // Gains dry/wet pour mélanger son original et réverbéré
                    dryGain = audioContext.createGain();
                    wetGain = audioContext.createGain();
                    dryGain.gain.value = 1 - reverbAmount;
                    wetGain.gain.value = reverbAmount;
                    dryGain.connect(masterGain);
                    wetGain.connect(reverb);
                })
                .catch(err => log(`Erreur chargement réverb : ${err}`));
        }

        // Fonction pour démarrer MIDI
        async function startMIDI() {
            try {
                midiAccess = await navigator.requestMIDIAccess();
                log("MIDI démarré avec succès !");
                initAudioContext();
                await loadSounds();
                for (const input of midiAccess.inputs.values()) {
                    input.onmidimessage = handleMIDIMessage;
                    log(`Écoute sur : ${input.name}`);
                }
            } catch (err) {
                log(`Erreur MIDI : ${err}`);
            }
        }

        // Fonction pour gérer les messages MIDI
        function handleMIDIMessage(message) {
            const [status, data1, data2] = message.data;
            const command = status >> 4;
            const channel = status & 0xf;
            const note = data1;
            const velocity = data2;
            log(`Message MIDI : command=${command}, channel=${channel}, note=${note}, velocity=${velocity}`);

            // Note On (144 = 0x90)
            if (command === 9 && velocity > 0) {
                log(`Note ON : ${note} (vélocité: ${velocity})`);
                if (note >= 36 && note <= 51) {
                    if (sounds[note]) {
                        const source = audioContext.createMediaElementSource(sounds[note]);
                        source.connect(dryGain);
                        if (wetGain) source.connect(wetGain);
                        sounds[note].currentTime = 0;
                        sounds[note].volume = (velocity / 127) * globalVolume;
                        sounds[note].playbackRate = globalPitch;
                        sounds[note].play();
                    }
                }
            }
            // Control Change (176 = 0xB0)
            else if (command === 11) {
                log(`Control Change : CC#${data1} (valeur: ${data2})`);
                // CC#7 = Volume global
                if (data1 === 7) {
                    globalVolume = data2 / 127;
                    masterGain.gain.value = globalVolume;
                    log(`Volume global : ${Math.round(globalVolume * 100)}%`);
                }
                // CC#1 = Pitch
                else if (data1 === 1) {
                    globalPitch = 0.5 + (data2 / 127) * 1.5;
                    log(`Pitch : ${globalPitch.toFixed(2)}`);
                }
                // CC#30 = Réverb
                else if (data1 === 30) {
                    reverbAmount = data2 / 127;
                    if (dryGain) dryGain.gain.value = 1 - reverbAmount;
                    if (wetGain) wetGain.gain.value = reverbAmount;
                    log(`Réverb : ${Math.round(reverbAmount * 100)}%`);
                }
            }
        }

        // Événements
        document.getElementById('start').addEventListener('click', startMIDI);
    </script>
</body>
</html>