diff --git a/src/logic/DrumUtils.ts b/src/logic/DrumUtils.ts index b9917c79..788774a4 100644 --- a/src/logic/DrumUtils.ts +++ b/src/logic/DrumUtils.ts @@ -1,3 +1,5 @@ +import * as Tone from 'tone' + /** * Shared DSP utilities for drum synthesis based on research specs. */ @@ -40,3 +42,47 @@ export function applyVariance(base: number, variance: number = 0.02): number { // Math.random() * 0.04 - 0.02 gives range [-0.02, 0.02] return base * (1 + (Math.random() * (variance * 2) - variance)); } + +/** + * Generates an AudioBuffer of 15-bit LFSR noise (pseudo-random sequence). + * Characteristic polynomial: x^15 + x^14 + 1. + * @param context - Tone.BaseContext + * @param duration - Duration in seconds (default 2.0s) + */ +export function generateLFSRNoise(context: Tone.BaseContext, duration: number = 2.0): AudioBuffer { + const sampleRate = context.sampleRate; + const bufferSize = Math.floor(sampleRate * duration); + const buffer = context.createBuffer(1, bufferSize, sampleRate); + const data = buffer.getChannelData(0); + + let lfsr = 0x7FFF; // 15-bit register, non-zero start + + for (let i = 0; i < bufferSize; i++) { + // x^15 + x^14 + 1 => bits 14 and 13 (0-indexed) + const bit = ((lfsr >> 14) ^ (lfsr >> 13)) & 1; + lfsr = ((lfsr << 1) | bit) & 0x7FFF; + + // Convert to range [-1.0, 1.0] + data[i] = (bit * 2) - 1; + } + + return buffer; +} + +/** + * Generates an AudioBuffer of standard white noise. + * @param context - Tone.BaseContext + * @param duration - Duration in seconds (default 2.0s) + */ +export function generateWhiteNoise(context: Tone.BaseContext, duration: number = 2.0): AudioBuffer { + const sampleRate = context.sampleRate; + const bufferSize = Math.floor(sampleRate * duration); + const buffer = context.createBuffer(1, bufferSize, sampleRate); + const data = buffer.getChannelData(0); + + for (let i = 0; i < bufferSize; i++) { + data[i] = Math.random() * 2 - 1; + } + + return buffer; +} diff --git a/src/logic/drums/TR808Clap.ts b/src/logic/drums/TR808Clap.ts index 3334a6fe..ee0913eb 100644 --- a/src/logic/drums/TR808Clap.ts +++ b/src/logic/drums/TR808Clap.ts @@ -1,17 +1,17 @@ import * as Tone from 'tone' -import { applyVariance } from '../DrumUtils' +import { applyVariance, generateWhiteNoise } from '../DrumUtils' export class TR808Clap { private noiseBuffer: AudioBuffer; constructor(private destination: Tone.ToneAudioNode) { - const sampleRate = Tone.getContext().sampleRate; - this.noiseBuffer = Tone.getContext().createBuffer(1, sampleRate * 0.5, sampleRate); - const data = this.noiseBuffer.getChannelData(0); - for (let i = 0; i < data.length; i++) data[i] = Math.random() * 2 - 1; + this.noiseBuffer = generateWhiteNoise(Tone.getContext(), 0.5); } trigger(time: number, pitch: number, decay: number, velocity: number = 0.8) { + // Early exit if velocity is zero to optimize CPU + if (velocity <= 0) return; + const noiseSrc = new Tone.BufferSource(this.noiseBuffer); const bpfFreq = (1000 + pitch * 1000); const bpf = new Tone.Filter(applyVariance(bpfFreq, 0.02), "bandpass"); @@ -20,6 +20,8 @@ export class TR808Clap { noiseSrc.connect(bpf); bpf.connect(gain); + const safeVelocity = Math.max(0.001, velocity); + // Triple attack "snaps" const snapCount = 3; const snapIntervalBase = 0.01; @@ -27,8 +29,8 @@ export class TR808Clap { for (let i = 0; i < snapCount; i++) { const snapTime = time + i * snapInterval; - gain.gain.setValueAtTime(velocity, snapTime); - gain.gain.exponentialRampToValueAtTime(velocity * 0.1, snapTime + snapInterval * 0.8); + gain.gain.setValueAtTime(safeVelocity, snapTime); + gain.gain.exponentialRampToValueAtTime(safeVelocity * 0.1, snapTime + snapInterval * 0.8); } // Final decay @@ -36,10 +38,13 @@ export class TR808Clap { const decayTimeBase = 0.1 + decay * 0.5; const decayTime = applyVariance(decayTimeBase, 0.02); - gain.gain.setValueAtTime(velocity, finalDecayStart); + // Use random offset within noise buffer for unique hits + const randomStart = Math.random() * (this.noiseBuffer.duration - decayTime - 0.1); + + gain.gain.setValueAtTime(safeVelocity, finalDecayStart); gain.gain.exponentialRampToValueAtTime(0.001, finalDecayStart + decayTime); - noiseSrc.start(time).stop(finalDecayStart + decayTime); + noiseSrc.start(time, randomStart).stop(finalDecayStart + decayTime); noiseSrc.onended = () => { noiseSrc.dispose(); diff --git a/src/logic/drums/TR808Cowbell.ts b/src/logic/drums/TR808Cowbell.ts index 3dd1d4fd..bf30615b 100644 --- a/src/logic/drums/TR808Cowbell.ts +++ b/src/logic/drums/TR808Cowbell.ts @@ -7,6 +7,9 @@ export class TR808Cowbell { constructor(private destination: Tone.ToneAudioNode) { } trigger(time: number, pitch: number, decay: number, velocity: number = 0.8) { + // Early exit if velocity is zero to optimize CPU + if (velocity <= 0) return; + // Core: Dual square wave oscillators from Schmitt trigger matrix // Standard frequencies: 540Hz and 800Hz const pitchMultiplier = 0.5 + pitch; // Range approx 0.5x to 1.5x @@ -29,8 +32,9 @@ export class TR808Cowbell { vca.connect(this.destination); const decayTime = applyVariance(0.1 + decay * 0.4, 0.02); + const safeVelocity = Math.max(0.001, velocity); - vca.gain.setValueAtTime(velocity, time); + vca.gain.setValueAtTime(safeVelocity, time); vca.gain.exponentialRampToValueAtTime(0.001, time + decayTime); this.activeGains.add(vca); diff --git a/src/logic/drums/TR808HiHat.ts b/src/logic/drums/TR808HiHat.ts index acd1216d..a2f3447b 100644 --- a/src/logic/drums/TR808HiHat.ts +++ b/src/logic/drums/TR808HiHat.ts @@ -8,6 +8,9 @@ export class TR808HiHat { constructor(private destination: Tone.ToneAudioNode) { } trigger(time: number, isOpen: boolean, pitch: number, decay: number, velocity: number = 0.8) { + // Early exit if velocity is zero to optimize CPU + if (velocity <= 0) return; + // Create nodes const mixGain = new Tone.Gain(0.15); const bpf1 = new Tone.Filter(3440, "bandpass"); @@ -46,9 +49,10 @@ export class TR808HiHat { // Decay: Closed Hat (40-60ms), Open Hat (300-500ms) const decayBase = isOpen ? (0.3 + decay * 0.2) : (0.04 + decay * 0.02); const decayTime = applyVariance(decayBase, 0.02); + const safeVelocity = Math.max(0.001, velocity); // VCA Envelope - envGain.gain.setValueAtTime(velocity, time); + envGain.gain.setValueAtTime(safeVelocity, time); envGain.gain.exponentialRampToValueAtTime(0.001, time + decayTime); this.activeGains.add(envGain); diff --git a/src/logic/drums/TR808Kick.ts b/src/logic/drums/TR808Kick.ts index 461f73fd..e8dba6e3 100644 --- a/src/logic/drums/TR808Kick.ts +++ b/src/logic/drums/TR808Kick.ts @@ -5,6 +5,9 @@ export class TR808Kick { constructor(private destination: Tone.ToneAudioNode) { } trigger(time: number, pitch: number, decay: number, velocity: number = 0.8) { + // Early exit if velocity is zero to optimize CPU + if (velocity <= 0) return; + // pitch: 0.5 -> 52.5Hz, maps to 45-60Hz range const tune = 45 + pitch * 15; // decay: 0.5 -> 1.7s, maps to 0.4-3.0s range @@ -23,18 +26,24 @@ export class TR808Kick { const finalDecay = applyVariance(decayTime, 0.02); // Pitch Envelope: Start high (Tune * 2.5) and drop quickly (50ms) to simulate the membrane hit ('tonk') - // This rapid sweep generates the punch without needing a separate click oscillator const startFreq = tuneDrift * 2.5; const endFreq = tuneDrift; osc.frequency.setValueAtTime(startFreq, time); osc.frequency.exponentialRampToValueAtTime(endFreq, time + 0.05); - // VCA Amp Envelope: Instant attack, adjustable exponential decay - masterGain.gain.setValueAtTime(velocity, time); - masterGain.gain.exponentialRampToValueAtTime(0.001, time + finalDecay); + // VCA Amp Envelope: Two-stage decay for diode damping emulation + // Stage 1: fast 20ms initial decay to 50% volume + // Stage 2: long adjustable exponential decay + const safeVelocity = Math.max(0.001, velocity); + masterGain.gain.setValueAtTime(safeVelocity, time); + masterGain.gain.exponentialRampToValueAtTime(safeVelocity * 0.5, time + 0.02); + + // Ensure the final decay is always longer than the damping stage + const safeFinalDecay = Math.max(0.03, finalDecay); + masterGain.gain.exponentialRampToValueAtTime(0.001, time + safeFinalDecay); - osc.start(time).stop(time + finalDecay); + osc.start(time).stop(time + safeFinalDecay); osc.onstop = () => { osc.dispose(); diff --git a/src/logic/drums/TR808Snare.ts b/src/logic/drums/TR808Snare.ts index 23f8f2ac..a12d0dd1 100644 --- a/src/logic/drums/TR808Snare.ts +++ b/src/logic/drums/TR808Snare.ts @@ -1,20 +1,17 @@ import * as Tone from 'tone' -import { applyPitchDrift, applyVariance } from '../DrumUtils' +import { applyPitchDrift, applyVariance, generateWhiteNoise } from '../DrumUtils' export class TR808Snare { private noiseBuffer: AudioBuffer; constructor(private destination: Tone.ToneAudioNode) { - const sampleRate = Tone.getContext().sampleRate; - const bufferSize = sampleRate * 0.5; // 500ms - this.noiseBuffer = Tone.getContext().createBuffer(1, bufferSize, sampleRate); - const data = this.noiseBuffer.getChannelData(0); - for (let i = 0; i < data.length; i++) { - data[i] = Math.random() * 2 - 1; - } + this.noiseBuffer = generateWhiteNoise(Tone.getContext(), 0.5); } trigger(time: number, pitch: number, snappy: number, velocity: number = 0.8) { + // Early exit if velocity is zero to optimize CPU + if (velocity <= 0) return; + // pitch maps to tone balance here (balance between low and high modes) const toneBalance = pitch; @@ -38,12 +35,14 @@ export class TR808Snare { gainLow.connect(this.destination); gainHigh.connect(this.destination); + const safeVelocity = Math.max(0.001, velocity); + // Independent envelopes for maximum authenticity as per research // High mode decays faster (approx 75% of low mode decay) - gainLow.gain.setValueAtTime(velocity * (1 - toneBalance), time); + gainLow.gain.setValueAtTime(safeVelocity * (1 - toneBalance), time); gainLow.gain.exponentialRampToValueAtTime(0.001, time + vcaDecay); - gainHigh.gain.setValueAtTime(velocity * toneBalance, time); + gainHigh.gain.setValueAtTime(safeVelocity * toneBalance, time); gainHigh.gain.exponentialRampToValueAtTime(0.001, time + vcaDecay * 0.75); // Snappy Layer @@ -61,12 +60,15 @@ export class TR808Snare { noiseFilter.connect(snappyGain); snappyGain.connect(this.destination); - snappyGain.gain.setValueAtTime(velocity * 0.8, time); + // Use random offset within noise buffer for unique hits + const randomStart = Math.random() * (this.noiseBuffer.duration - snappyDecay - 0.1); + + snappyGain.gain.setValueAtTime(safeVelocity * 0.8, time); snappyGain.gain.exponentialRampToValueAtTime(0.001, time + snappyDecay); oscLow.start(time).stop(time + vcaDecay); oscHigh.start(time).stop(time + vcaDecay); - noiseSrc.start(time).stop(time + snappyDecay + 0.1); + noiseSrc.start(time, randomStart).stop(time + snappyDecay + 0.1); // Cleanup oscLow.onstop = () => { diff --git a/src/logic/drums/TR909Kick.ts b/src/logic/drums/TR909Kick.ts index dd2582ed..2a64a63f 100644 --- a/src/logic/drums/TR909Kick.ts +++ b/src/logic/drums/TR909Kick.ts @@ -1,5 +1,5 @@ import * as Tone from 'tone' -import { makeDistortionCurve, applyPitchDrift, applyVariance } from '../DrumUtils' +import { makeDistortionCurve, applyPitchDrift, applyVariance, generateWhiteNoise } from '../DrumUtils' export class TR909Kick { private noiseBuffer: AudioBuffer; @@ -8,17 +8,13 @@ export class TR909Kick { constructor(private destination: Tone.ToneAudioNode) { // Soft Clipping curve from research this.bodyCurve = makeDistortionCurve(10); - - const sampleRate = Tone.getContext().sampleRate; - const bufferSize = sampleRate * 0.05; // 50ms click - this.noiseBuffer = Tone.getContext().createBuffer(1, bufferSize, sampleRate); - const data = this.noiseBuffer.getChannelData(0); - for (let i = 0; i < bufferSize; i++) { - data[i] = Math.random() * 2 - 1; - } + this.noiseBuffer = generateWhiteNoise(Tone.getContext(), 0.05); } trigger(time: number, pitch: number, decay: number, velocity: number = 0.8) { + // Early exit if velocity is zero to optimize CPU + if (velocity <= 0) return; + // 909 Kick base frequency is fixed around 50Hz const tune = 50; // The 'Pitch' parameter on 909 maps to the frequency sweep duration @@ -53,7 +49,8 @@ export class TR909Kick { bodyOsc.frequency.exponentialRampToValueAtTime(endFreq, time + sweepDuration); // VCA Envelope - bodyGain.gain.setValueAtTime(velocity, time); + const safeVelocity = Math.max(0.001, velocity); + bodyGain.gain.setValueAtTime(safeVelocity, time); bodyGain.gain.exponentialRampToValueAtTime(0.001, time + vcaDecay); // Click Layer (Noise) @@ -67,7 +64,10 @@ export class TR909Kick { // Ultra short envelope (10-20ms) for the click const clickDecay = applyVariance(0.02, 0.02); - noiseGain.gain.setValueAtTime(velocity * 0.7, time); + // Use random offset within noise buffer for unique hits + const randomStart = Math.random() * (this.noiseBuffer.duration - clickDecay - 0.01); + + noiseGain.gain.setValueAtTime(safeVelocity * 0.7, time); noiseGain.gain.exponentialRampToValueAtTime(0.001, time + clickDecay); // Rectangular Pulse Click: Short 5ms impulse for attack articulation @@ -76,11 +76,11 @@ export class TR909Kick { pulseOsc.connect(pulseGain); pulseGain.connect(this.destination); - pulseGain.gain.setValueAtTime(velocity * 0.5, time); + pulseGain.gain.setValueAtTime(safeVelocity * 0.5, time); pulseGain.gain.exponentialRampToValueAtTime(0.001, time + 0.005); bodyOsc.start(time).stop(time + vcaDecay); - noiseSrc.start(time).stop(time + clickDecay); + noiseSrc.start(time, randomStart).stop(time + clickDecay); pulseOsc.start(time).stop(time + 0.005); bodyOsc.onstop = () => { diff --git a/src/logic/drums/TR909Snare.ts b/src/logic/drums/TR909Snare.ts index 4841f055..916ad1b6 100644 --- a/src/logic/drums/TR909Snare.ts +++ b/src/logic/drums/TR909Snare.ts @@ -1,5 +1,5 @@ import * as Tone from 'tone' -import { makeDistortionCurve, applyPitchDrift, applyVariance } from '../DrumUtils' +import { makeDistortionCurve, applyPitchDrift, applyVariance, generateLFSRNoise } from '../DrumUtils' export class TR909Snare { private noiseBuffer: AudioBuffer; @@ -9,17 +9,14 @@ export class TR909Snare { // Soft Clipping curve from research this.bodyCurve = makeDistortionCurve(15); - const sampleRate = Tone.getContext().sampleRate; - const bufferSize = sampleRate * 0.5; - this.noiseBuffer = Tone.getContext().createBuffer(1, bufferSize, sampleRate); - const data = this.noiseBuffer.getChannelData(0); - // While original used LFSR, research says Math.random() is sufficient for Web Audio API context - for (let i = 0; i < data.length; i++) { - data[i] = Math.random() * 2 - 1; - } + // Authentic 15-bit LFSR noise for 909 'Snappy' component + this.noiseBuffer = generateLFSRNoise(Tone.getContext(), 0.5); } trigger(time: number, pitch: number, snappy: number, velocity: number = 0.8) { + // Early exit if velocity is zero to optimize CPU + if (velocity <= 0) return; + // 909 Snare Body: 2 triangle oscillators fixed at ~160Hz and ~220Hz const freq1 = 160; const freq2 = 220; @@ -36,6 +33,7 @@ export class TR909Snare { const osc2 = new Tone.Oscillator(toneDrift2 * 2, "triangle"); osc1.phase = Math.random() * 360; osc2.phase = Math.random() * 360; + // Routing with gain compensation to prevent clipping before the shaper const preShaperGain = new Tone.Gain(0.5); const bodyShaper = new Tone.WaveShaper(this.bodyCurve); @@ -60,12 +58,14 @@ export class TR909Snare { osc2.frequency.setValueAtTime(startFreq2, time); osc2.frequency.exponentialRampToValueAtTime(toneDrift2, time + sweepTime); - tonalGain.gain.setValueAtTime(velocity, time); + const safeVelocity = Math.max(0.001, velocity); + tonalGain.gain.setValueAtTime(safeVelocity, time); tonalGain.gain.exponentialRampToValueAtTime(0.001, time + vcaDecay); // Snappy Layer const noiseSrc = new Tone.BufferSource(this.noiseBuffer); const hpf = new Tone.Filter(noiseHPFFreq, "highpass"); // HPF to protect fundamental + // LPF controlled by 'Tone' (pitch parameter here), range 4kHz to 8kHz (research: toneCutoff) const toneCutoff = 4000 + pitch * 4000; const lpf = new Tone.Filter(applyVariance(toneCutoff, 0.02), "lowpass"); @@ -76,12 +76,15 @@ export class TR909Snare { lpf.connect(noiseGain); noiseGain.connect(this.destination); - noiseGain.gain.setValueAtTime(velocity * 0.7, time); + // Use random offset within noise buffer for unique hits + const randomStart = Math.random() * (this.noiseBuffer.duration - snappyDecay - 0.1); + + noiseGain.gain.setValueAtTime(safeVelocity * 0.7, time); noiseGain.gain.exponentialRampToValueAtTime(0.001, time + snappyDecay); osc1.start(time).stop(time + vcaDecay); osc2.start(time).stop(time + vcaDecay); - noiseSrc.start(time).stop(time + snappyDecay + 0.1); + noiseSrc.start(time, randomStart).stop(time + snappyDecay + 0.1); osc1.onstop = () => { osc1.dispose();