modularity

src/domain/audio/effects/ReverbEffect.ts

@@ -0,0 +1,70 @@
+import type { Effect } from './Effect.interface'
+
+export class ReverbEffect implements Effect {
+  readonly id = 'reverb'
+
+  private audioContext: AudioContext
+  private inputNode: GainNode
+  private outputNode: GainNode
+  private convolverNode: ConvolverNode
+  private wetNode: GainNode
+  private dryNode: GainNode
+
+  constructor(audioContext: AudioContext) {
+    this.audioContext = audioContext
+    this.inputNode = audioContext.createGain()
+    this.outputNode = audioContext.createGain()
+    this.convolverNode = audioContext.createConvolver()
+    this.wetNode = audioContext.createGain()
+    this.dryNode = audioContext.createGain()
+
+    this.wetNode.gain.value = 0
+    this.dryNode.gain.value = 1
+
+    this.inputNode.connect(this.dryNode)
+    this.inputNode.connect(this.convolverNode)
+    this.convolverNode.connect(this.wetNode)
+    this.dryNode.connect(this.outputNode)
+    this.wetNode.connect(this.outputNode)
+
+    this.generateImpulseResponse()
+  }
+
+  private generateImpulseResponse(): void {
+    const length = this.audioContext.sampleRate * 2
+    const impulse = this.audioContext.createBuffer(2, length, this.audioContext.sampleRate)
+    const left = impulse.getChannelData(0)
+    const right = impulse.getChannelData(1)
+
+    for (let i = 0; i < length; i++) {
+      left[i] = (Math.random() * 2 - 1) * Math.pow(1 - i / length, 2)
+      right[i] = (Math.random() * 2 - 1) * Math.pow(1 - i / length, 2)
+    }
+
+    this.convolverNode.buffer = impulse
+  }
+
+  getInputNode(): AudioNode {
+    return this.inputNode
+  }
+
+  getOutputNode(): AudioNode {
+    return this.outputNode
+  }
+
+  updateParams(values: Record<string, number>): void {
+    if (values.reverbWetDry !== undefined) {
+      const wet = values.reverbWetDry / 100
+      this.wetNode.gain.value = wet
+      this.dryNode.gain.value = 1 - wet
+    }
+  }
+
+  dispose(): void {
+    this.inputNode.disconnect()
+    this.outputNode.disconnect()
+    this.convolverNode.disconnect()
+    this.wetNode.disconnect()
+    this.dryNode.disconnect()
+  }
+}