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User:Pailiaq/common.js: Difference between revisions

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Line 5: Line 5:
     var activeNodes = [];
     var activeNodes = [];
     var activeBtn = null;
     var activeBtn = null;
    var STORAGE_KEY = 'edoChordPlayTimbre';
    var TIMBRES = ['triangle', 'sawtooth', 'square', 'sine'];
    var TIMBRE_LABELS = { triangle: 'Triangle', sawtooth: 'Sawtooth', square: 'Square', sine: 'Sine' };
    var LOOK_AHEAD = 0.00;    // 50ms buffer so the audio thread can schedule
    var BASE_FREQ = 261.63;  // middle C; pitch is set via detune (cents) on top
    var timbre = (function () {
        try {
            var saved = localStorage.getItem(STORAGE_KEY);
            return TIMBRES.indexOf(saved) >= 0 ? saved : 'triangle';
        } catch (e) { return 'triangle'; }
    })();
    function setTimbre(t) {
        if (TIMBRES.indexOf(t) < 0) return;
        timbre = t;
        try { localStorage.setItem(STORAGE_KEY, t); } catch (e) {}
        document.querySelectorAll('.edo-chord-timbre').forEach(function (sel) {
            sel.value = t;
        });
    }


     function getCtx() {
     function getCtx() {
         if (!ctx) ctx = new (window.AudioContext || window.webkitAudioContext)();
         if (!ctx) ctx = new (window.AudioContext || window.webkitAudioContext)();
         return ctx;
         return ctx;
    }
    function disposeNode(node) {
        try { node.osc.disconnect(); } catch (e) {}
        try { node.gain.disconnect(); } catch (e) {}
        var idx = activeNodes.indexOf(node);
        if (idx >= 0) activeNodes.splice(idx, 1);
     }
     }


     function stopAll() {
     function stopAll() {
         if (!ctx) return;
         if (!ctx) return;
         var now = ctx.currentTime;
         var now = ctx.currentTime + LOOK_AHEAD;
         activeNodes.forEach(function (n) {
         // Snapshot and clear before stopping, so onended handlers find no matches and just dispose
        var toStop = activeNodes;
        activeNodes = [];
        toStop.forEach(function (n) {
             try {
             try {
                 n.gain.gain.cancelScheduledValues(now);
                 n.gain.gain.cancelScheduledValues(now);
Line 22: Line 53:
             } catch (e) {}
             } catch (e) {}
         });
         });
        activeNodes = [];
         if (activeBtn) { activeBtn.classList.remove('playing'); activeBtn = null; }
         if (activeBtn) { activeBtn.classList.remove('playing'); activeBtn = null; }
     }
     }
Line 30: Line 60:
         var c = getCtx();
         var c = getCtx();
         if (c.state === 'suspended') c.resume();
         if (c.state === 'suspended') c.resume();
         var now = c.currentTime;
         var now = c.currentTime + LOOK_AHEAD;
        var base = 261.63;                  // middle C
         var attack = 0.02, sustain = 0.2, release = 5;
         var attack = 0.02, sustain = 0.05, release = 2.5;
         var totalDur = attack + sustain + release;
         var totalDur = attack + sustain + release;
         var peak = 0.18 / Math.sqrt(centsArr.length);
         var peak = 0.18 / Math.sqrt(centsArr.length);
Line 39: Line 68:
             var osc = c.createOscillator();
             var osc = c.createOscillator();
             var gain = c.createGain();
             var gain = c.createGain();
             osc.type = 'triangle';
             osc.type = timbre;
             osc.frequency.value = base * Math.pow(2, cents / 1200);
             osc.frequency.value = BASE_FREQ;
            osc.detune.value = cents;
             gain.gain.setValueAtTime(0, now);
             gain.gain.setValueAtTime(0, now);
             gain.gain.linearRampToValueAtTime(peak, now + attack);
             gain.gain.linearRampToValueAtTime(peak, now + attack);
Line 48: Line 78:
             osc.start(now);
             osc.start(now);
             osc.stop(now + totalDur + 0.1);
             osc.stop(now + totalDur + 0.1);
             activeNodes.push({ osc: osc, gain: gain });
 
             var node = { osc: osc, gain: gain };
            activeNodes.push(node);
            osc.onended = function () { disposeNode(node); };
         });
         });


Line 58: Line 91:
             }, totalDur * 1000);
             }, totalDur * 1000);
         }
         }
    }
    function injectSelectors() {
        var tables = new Set();
        document.querySelectorAll('.edo-chord-play').forEach(function (btn) {
            var table = btn.closest('table');
            if (table) tables.add(table);
        });
        tables.forEach(function (table) {
            var firstTh = table.querySelector('th');
            if (!firstTh || firstTh.querySelector('.edo-chord-timbre')) return;
            var sel = document.createElement('select');
            sel.className = 'edo-chord-timbre';
            sel.title = 'Synth timbre';
            TIMBRES.forEach(function (t) {
                var opt = document.createElement('option');
                opt.value = t;
                opt.textContent = TIMBRE_LABELS[t];
                if (t === timbre) opt.selected = true;
                sel.appendChild(opt);
            });
            sel.addEventListener('change', function () { setTimbre(sel.value); });
            sel.addEventListener('click', function (e) { e.stopPropagation(); });
            firstTh.innerHTML = '';
            firstTh.appendChild(sel);
        });
     }
     }


Line 64: Line 123:
         if (!btn) return;
         if (!btn) return;
         e.preventDefault();
         e.preventDefault();
         if (btn === activeBtn) { stopAll(); return; }   // click again to stop
         if (btn === activeBtn) { stopAll(); return; }
         var edo = parseInt(btn.dataset.edo, 10);
 
        var steps = (btn.dataset.steps || '').split(',').map(Number);
        var cents;
        if (!edo || !steps.length) return;
        if (btn.dataset.cents) {
        var stepSize = 1200 / edo;
            cents = btn.dataset.cents.split(',').map(Number);
        playChord(steps.map(function (s) { return s * stepSize; }), btn);
         } else {
            var edo = parseInt(btn.dataset.edo, 10);
            var steps = (btn.dataset.steps || '').split(',').map(Number);
            if (!edo || !steps.length) return;
            var stepSize = 1200 / edo;
            cents = steps.map(function (s) { return s * stepSize; });
        }
        if (!cents.length || cents.some(isNaN)) return;
        playChord(cents, btn);
     }
     }


Line 78: Line 145:
         }
         }
     });
     });
    if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded', injectSelectors);
    } else {
        injectSelectors();
    }
}());
}());
Retrieved from "https://en.xen.wiki/w/User:Pailiaq/common.js"