Merge pull request 'feat: procedural sound engine (Web Audio API) — epic #57' (#81) from burn/20260412-1227-sound into main

index.html

@@ -227,6 +227,7 @@ The light is on. The room is empty."
     <script src="js/data.js"></script>
     <script src="js/utils.js"></script>
     <script src="js/strategy.js"></script>
+    <script src="js/sound.js"></script>
     <script src="js/engine.js"></script>
     <script src="js/render.js"></script>
     <script src="js/main.js"></script>

js/engine.js

@@ -283,6 +283,7 @@ function checkMilestones() {
                 G.milestones.push(m.flag);
                 log(m.msg, true);
                 showToast(m.msg, 'milestone', 5000);
+                if (typeof Sound !== 'undefined') Sound.playMilestone();
 
                 // Check phase advancement
                 if (m.at) {
@@ -296,6 +297,10 @@ function checkMilestones() {
                             if (pNum > _shownPhaseTransition) {
                                 _shownPhaseTransition = pNum;
                                 showPhaseTransition(pNum);
+                                if (typeof Sound !== 'undefined') {
+                                    Sound.playFanfare();
+                                    Sound.updateAmbientPhase(pNum);
+                                }
                             }
                         }
                     }
@@ -356,6 +361,7 @@ function buyBuilding(id) {
     log(`Built ${def.name} ${label} (total: ${totalBuilt})`);
     // Particle burst on purchase
     const btn = document.querySelector('[onclick="buyBuilding(\'' + id + '\')"]');
+    if (typeof Sound !== 'undefined') Sound.playBuild();
     if (btn) {
         const rect = btn.getBoundingClientRect();
         const cx = rect.left + rect.width / 2;
@@ -396,6 +402,7 @@ function buyProject(id) {
 
     updateRates();
     // Gold particle burst on project completion
+    if (typeof Sound !== 'undefined') Sound.playProject();
     const pBtn = document.querySelector('[onclick="buyProject(\'' + id + '\')"]');
     if (pBtn) {
         const rect = pBtn.getBoundingClientRect();
@@ -437,6 +444,7 @@ function renderDriftEnding() {
     // Fade-in animation
     el.classList.add('fade-in');
     el.classList.add('active');
+    if (typeof Sound !== 'undefined') Sound.playDriftEnding();
 
     // Log the ending text with delays for dramatic effect
     const lines = [
@@ -479,8 +487,7 @@ function renderBeaconEnding() {
         </button>
     `;
     document.body.appendChild(overlay);
-
-    // Create particle/light ray container
+    if (typeof Sound !== 'undefined') Sound.playBeaconEnding();
     const particleContainer = document.createElement('div');
     particleContainer.id = 'beacon-ending-particles';
     document.body.appendChild(particleContainer);
@@ -762,6 +769,7 @@ function writeCode() {
     }
     // Float a number at the click position
     showClickNumber(amount, comboMult);
+    if (typeof Sound !== 'undefined') Sound.playClick();
     updateRates();
     checkMilestones();
     render();

js/main.js

@@ -42,6 +42,18 @@ window.addEventListener('load', function () {
     // Game loop at 10Hz (100ms tick)
     setInterval(tick, 100);
 
+    // Start ambient drone on first interaction
+    if (typeof Sound !== 'undefined') {
+        const startAmbientOnce = () => {
+            Sound.startAmbient();
+            Sound.updateAmbientPhase(G.phase);
+            document.removeEventListener('click', startAmbientOnce);
+            document.removeEventListener('keydown', startAmbientOnce);
+        };
+        document.addEventListener('click', startAmbientOnce);
+        document.addEventListener('keydown', startAmbientOnce);
+    }
+
     // Auto-save every 30 seconds
     setInterval(saveGame, CONFIG.AUTO_SAVE_INTERVAL);
 
@@ -69,6 +81,7 @@ function toggleMute() {
     }
     // Save preference
     try { localStorage.setItem('the-beacon-muted', _muted ? '1' : '0'); } catch(e) {}
+    if (typeof Sound !== 'undefined') Sound.onMuteChanged(_muted);
 }
 // Restore mute state on load
 try {

js/sound.js

@@ -0,0 +1,401 @@
+// ============================================================
+// THE BEACON - Sound Engine
+// Procedural audio via Web Audio API (no audio files)
+// ============================================================
+
+const Sound = (function () {
+    let ctx = null;
+    let masterGain = null;
+    let ambientGain = null;
+    let ambientOsc1 = null;
+    let ambientOsc2 = null;
+    let ambientOsc3 = null;
+    let ambientLfo = null;
+    let ambientStarted = false;
+    let currentPhase = 0;
+
+    function ensureCtx() {
+        if (!ctx) {
+            ctx = new (window.AudioContext || window.webkitAudioContext)();
+            masterGain = ctx.createGain();
+            masterGain.gain.value = 0.3;
+            masterGain.connect(ctx.destination);
+        }
+        if (ctx.state === 'suspended') {
+            ctx.resume();
+        }
+        return ctx;
+    }
+
+    function isMuted() {
+        return typeof _muted !== 'undefined' && _muted;
+    }
+
+    // --- Noise buffer helper ---
+    function createNoiseBuffer(duration) {
+        const c = ensureCtx();
+        const len = c.sampleRate * duration;
+        const buf = c.createBuffer(1, len, c.sampleRate);
+        const data = buf.getChannelData(0);
+        for (let i = 0; i < len; i++) {
+            data[i] = Math.random() * 2 - 1;
+        }
+        return buf;
+    }
+
+    // --- playClick: mechanical keyboard sound ---
+    function playClick() {
+        if (isMuted()) return;
+        const c = ensureCtx();
+        const now = c.currentTime;
+
+        // Short noise burst (mechanical key)
+        const noise = c.createBufferSource();
+        noise.buffer = createNoiseBuffer(0.03);
+
+        const noiseGain = c.createGain();
+        noiseGain.gain.setValueAtTime(0.4, now);
+        noiseGain.gain.exponentialRampToValueAtTime(0.001, now + 0.03);
+
+        const hpFilter = c.createBiquadFilter();
+        hpFilter.type = 'highpass';
+        hpFilter.frequency.value = 3000;
+
+        noise.connect(hpFilter);
+        hpFilter.connect(noiseGain);
+        noiseGain.connect(masterGain);
+        noise.start(now);
+        noise.stop(now + 0.03);
+
+        // Click tone
+        const osc = c.createOscillator();
+        osc.type = 'square';
+        osc.frequency.setValueAtTime(1800, now);
+        osc.frequency.exponentialRampToValueAtTime(600, now + 0.02);
+
+        const oscGain = c.createGain();
+        oscGain.gain.setValueAtTime(0.15, now);
+        oscGain.gain.exponentialRampToValueAtTime(0.001, now + 0.025);
+
+        osc.connect(oscGain);
+        oscGain.connect(masterGain);
+        osc.start(now);
+        osc.stop(now + 0.03);
+    }
+
+    // --- playBuild: purchase thud + chime ---
+    function playBuild() {
+        if (isMuted()) return;
+        const c = ensureCtx();
+        const now = c.currentTime;
+
+        // Low thud
+        const thud = c.createOscillator();
+        thud.type = 'sine';
+        thud.frequency.setValueAtTime(150, now);
+        thud.frequency.exponentialRampToValueAtTime(60, now + 0.12);
+
+        const thudGain = c.createGain();
+        thudGain.gain.setValueAtTime(0.35, now);
+        thudGain.gain.exponentialRampToValueAtTime(0.001, now + 0.15);
+
+        thud.connect(thudGain);
+        thudGain.connect(masterGain);
+        thud.start(now);
+        thud.stop(now + 0.15);
+
+        // Bright chime on top
+        const chime = c.createOscillator();
+        chime.type = 'sine';
+        chime.frequency.setValueAtTime(880, now + 0.05);
+        chime.frequency.exponentialRampToValueAtTime(1200, now + 0.2);
+
+        const chimeGain = c.createGain();
+        chimeGain.gain.setValueAtTime(0, now);
+        chimeGain.gain.linearRampToValueAtTime(0.2, now + 0.06);
+        chimeGain.gain.exponentialRampToValueAtTime(0.001, now + 0.25);
+
+        chime.connect(chimeGain);
+        chimeGain.connect(masterGain);
+        chime.start(now + 0.05);
+        chime.stop(now + 0.25);
+    }
+
+    // --- playProject: ascending chime ---
+    function playProject() {
+        if (isMuted()) return;
+        const c = ensureCtx();
+        const now = c.currentTime;
+
+        const notes = [523, 659, 784]; // C5, E5, G5
+        notes.forEach((freq, i) => {
+            const osc = c.createOscillator();
+            osc.type = 'sine';
+            osc.frequency.value = freq;
+
+            const gain = c.createGain();
+            const t = now + i * 0.1;
+            gain.gain.setValueAtTime(0, t);
+            gain.gain.linearRampToValueAtTime(0.22, t + 0.03);
+            gain.gain.exponentialRampToValueAtTime(0.001, t + 0.35);
+
+            osc.connect(gain);
+            gain.connect(masterGain);
+            osc.start(t);
+            osc.stop(t + 0.35);
+        });
+    }
+
+    // --- playMilestone: bright arpeggio ---
+    function playMilestone() {
+        if (isMuted()) return;
+        const c = ensureCtx();
+        const now = c.currentTime;
+
+        const notes = [523, 659, 784, 1047]; // C5, E5, G5, C6
+        notes.forEach((freq, i) => {
+            const osc = c.createOscillator();
+            osc.type = 'triangle';
+            osc.frequency.value = freq;
+
+            const gain = c.createGain();
+            const t = now + i * 0.08;
+            gain.gain.setValueAtTime(0, t);
+            gain.gain.linearRampToValueAtTime(0.25, t + 0.02);
+            gain.gain.exponentialRampToValueAtTime(0.001, t + 0.4);
+
+            osc.connect(gain);
+            gain.connect(masterGain);
+            osc.start(t);
+            osc.stop(t + 0.4);
+        });
+    }
+
+    // --- playFanfare: 8-note scale for phase transitions ---
+    function playFanfare() {
+        if (isMuted()) return;
+        const c = ensureCtx();
+        const now = c.currentTime;
+
+        const scale = [262, 294, 330, 349, 392, 440, 494, 523]; // C4 to C5
+        scale.forEach((freq, i) => {
+            const osc = c.createOscillator();
+            osc.type = 'sawtooth';
+            osc.frequency.value = freq;
+
+            const filter = c.createBiquadFilter();
+            filter.type = 'lowpass';
+            filter.frequency.value = 2000;
+
+            const gain = c.createGain();
+            const t = now + i * 0.1;
+            gain.gain.setValueAtTime(0, t);
+            gain.gain.linearRampToValueAtTime(0.15, t + 0.03);
+            gain.gain.exponentialRampToValueAtTime(0.001, t + 0.3);
+
+            osc.connect(filter);
+            filter.connect(gain);
+            gain.connect(masterGain);
+            osc.start(t);
+            osc.stop(t + 0.3);
+        });
+
+        // Final chord
+        const chordNotes = [523, 659, 784];
+        chordNotes.forEach((freq) => {
+            const osc = c.createOscillator();
+            osc.type = 'sine';
+            osc.frequency.value = freq;
+
+            const gain = c.createGain();
+            const t = now + 0.8;
+            gain.gain.setValueAtTime(0, t);
+            gain.gain.linearRampToValueAtTime(0.2, t + 0.05);
+            gain.gain.exponentialRampToValueAtTime(0.001, t + 1.2);
+
+            osc.connect(gain);
+            gain.connect(masterGain);
+            osc.start(t);
+            osc.stop(t + 1.2);
+        });
+    }
+
+    // --- playDriftEnding: descending dissonance ---
+    function playDriftEnding() {
+        if (isMuted()) return;
+        const c = ensureCtx();
+        const now = c.currentTime;
+
+        const notes = [440, 415, 392, 370, 349, 330, 311, 294]; // A4 descending, slightly detuned
+        notes.forEach((freq, i) => {
+            const osc = c.createOscillator();
+            osc.type = 'sawtooth';
+            osc.frequency.value = freq;
+
+            // Slight detune for dissonance
+            const osc2 = c.createOscillator();
+            osc2.type = 'sawtooth';
+            osc2.frequency.value = freq * 1.02;
+
+            const filter = c.createBiquadFilter();
+            filter.type = 'lowpass';
+            filter.frequency.setValueAtTime(1500, now + i * 0.2);
+            filter.frequency.exponentialRampToValueAtTime(200, now + i * 0.2 + 0.5);
+
+            const gain = c.createGain();
+            const t = now + i * 0.2;
+            gain.gain.setValueAtTime(0, t);
+            gain.gain.linearRampToValueAtTime(0.1, t + 0.05);
+            gain.gain.exponentialRampToValueAtTime(0.001, t + 0.8);
+
+            osc.connect(filter);
+            osc2.connect(filter);
+            filter.connect(gain);
+            gain.connect(masterGain);
+            osc.start(t);
+            osc.stop(t + 0.8);
+            osc2.start(t);
+            osc2.stop(t + 0.8);
+        });
+    }
+
+    // --- playBeaconEnding: warm chord ---
+    function playBeaconEnding() {
+        if (isMuted()) return;
+        const c = ensureCtx();
+        const now = c.currentTime;
+
+        // Warm major chord: C3, E3, G3, C4, E4
+        const chord = [131, 165, 196, 262, 330];
+        chord.forEach((freq, i) => {
+            const osc = c.createOscillator();
+            osc.type = 'sine';
+            osc.frequency.value = freq;
+
+            // Add subtle harmonics
+            const osc2 = c.createOscillator();
+            osc2.type = 'sine';
+            osc2.frequency.value = freq * 2;
+
+            const gain = c.createGain();
+            const gain2 = c.createGain();
+            const t = now + i * 0.15;
+            gain.gain.setValueAtTime(0, t);
+            gain.gain.linearRampToValueAtTime(0.15, t + 0.3);
+            gain.gain.setValueAtTime(0.15, t + 2);
+            gain.gain.exponentialRampToValueAtTime(0.001, t + 4);
+
+            gain2.gain.setValueAtTime(0, t);
+            gain2.gain.linearRampToValueAtTime(0.05, t + 0.3);
+            gain2.gain.setValueAtTime(0.05, t + 2);
+            gain2.gain.exponentialRampToValueAtTime(0.001, t + 4);
+
+            osc.connect(gain);
+            osc2.connect(gain2);
+            gain.connect(masterGain);
+            gain2.connect(masterGain);
+            osc.start(t);
+            osc.stop(t + 4);
+            osc2.start(t);
+            osc2.stop(t + 4);
+        });
+    }
+
+    // --- Ambient drone system ---
+    function startAmbient() {
+        if (ambientStarted) return;
+        if (isMuted()) return;
+        const c = ensureCtx();
+        ambientStarted = true;
+
+        ambientGain = c.createGain();
+        ambientGain.gain.value = 0;
+        ambientGain.gain.linearRampToValueAtTime(0.06, c.currentTime + 3);
+        ambientGain.connect(masterGain);
+
+        // Base drone
+        ambientOsc1 = c.createOscillator();
+        ambientOsc1.type = 'sine';
+        ambientOsc1.frequency.value = 55; // A1
+        ambientOsc1.connect(ambientGain);
+        ambientOsc1.start();
+
+        // Second voice (fifth above)
+        ambientOsc2 = c.createOscillator();
+        ambientOsc2.type = 'sine';
+        ambientOsc2.frequency.value = 82.4; // E2
+        const g2 = c.createGain();
+        g2.gain.value = 0.5;
+        ambientOsc2.connect(g2);
+        g2.connect(ambientGain);
+        ambientOsc2.start();
+
+        // Third voice (high shimmer)
+        ambientOsc3 = c.createOscillator();
+        ambientOsc3.type = 'triangle';
+        ambientOsc3.frequency.value = 220; // A3
+        const g3 = c.createGain();
+        g3.gain.value = 0.15;
+        ambientOsc3.connect(g3);
+        g3.connect(ambientGain);
+        ambientOsc3.start();
+
+        // LFO for subtle movement
+        ambientLfo = c.createOscillator();
+        ambientLfo.type = 'sine';
+        ambientLfo.frequency.value = 0.2;
+        const lfoGain = c.createGain();
+        lfoGain.gain.value = 3;
+        ambientLfo.connect(lfoGain);
+        lfoGain.connect(ambientOsc1.frequency);
+        ambientLfo.start();
+    }
+
+    function updateAmbientPhase(phase) {
+        if (!ambientStarted || !ambientOsc1 || !ambientOsc2 || !ambientOsc3) return;
+        if (phase === currentPhase) return;
+        currentPhase = phase;
+        const c = ensureCtx();
+        const now = c.currentTime;
+        const rampTime = 2;
+
+        // Phase determines the drone's character
+        const phases = {
+            1: { base: 55,  fifth: 82.4,  shimmer: 220,  shimmerVol: 0.15 },
+            2: { base: 65.4, fifth: 98,    shimmer: 262,  shimmerVol: 0.2 },
+            3: { base: 73.4, fifth: 110,   shimmer: 294,  shimmerVol: 0.25 },
+            4: { base: 82.4, fifth: 123.5, shimmer: 330,  shimmerVol: 0.3 },
+            5: { base: 98,   fifth: 147,   shimmer: 392,  shimmerVol: 0.35 },
+            6: { base: 110,  fifth: 165,   shimmer: 440,  shimmerVol: 0.4 }
+        };
+
+        const p = phases[phase] || phases[1];
+        ambientOsc1.frequency.linearRampToValueAtTime(p.base, now + rampTime);
+        ambientOsc2.frequency.linearRampToValueAtTime(p.fifth, now + rampTime);
+        ambientOsc3.frequency.linearRampToValueAtTime(p.shimmer, now + rampTime);
+    }
+
+    // --- Mute integration ---
+    function onMuteChanged(muted) {
+        if (ambientGain) {
+            ambientGain.gain.linearRampToValueAtTime(
+                muted ? 0 : 0.06,
+                (ctx ? ctx.currentTime : 0) + 0.3
+            );
+        }
+    }
+
+    // Public API
+    return {
+        playClick,
+        playBuild,
+        playProject,
+        playMilestone,
+        playFanfare,
+        playDriftEnding,
+        playBeaconEnding,
+        startAmbient,
+        updateAmbientPhase,
+        onMuteChanged
+    };
+})();