perf: stream propagation working sets

packages/acoustics-core/fractional-delay.js

@@ -32,19 +32,36 @@ export function addFrequencyDomainPaths(options) {
     frequencyResponse,
     sampleRate,
     workspace,
+    outputOffsetSamples = 0,
+    pathDelaySampleRate,
   } = options;
   if (!Array.isArray(paths) || paths.length === 0) {
     throw new Error("frequency-domain path가 하나 이상 필요합니다.");
   }
+  const delaySamplesForPath = (path) => {
+    if (path.delaySamples !== undefined) return path.delaySamples;
+    if (
+      path.delaySeconds !== undefined &&
+      pathDelaySampleRate > 0 &&
+      Number.isFinite(pathDelaySampleRate)
+    ) {
+      return path.delaySeconds * pathDelaySampleRate;
+    }
+    return undefined;
+  };
   for (const path of paths) {
-    if (!(path.delaySamples >= 0) || !Number.isFinite(path.delaySamples)) {
-      throw new Error("유효하지 않은 delay: " + path.delaySamples);
+    const delaySamples = delaySamplesForPath(path);
+    if (!(delaySamples >= 0) || !Number.isFinite(delaySamples)) {
+      throw new Error("유효하지 않은 delay: " + delaySamples);
     }
     if (!Number.isFinite(path.gain)) throw new Error("path gain은 유한한 숫자여야 합니다.");
   }
   if (workspace.real.length !== spectrum.fftSize || workspace.imaginary.length !== spectrum.fftSize) {
     throw new Error("fractional-delay workspace 크기가 spectrum과 다릅니다.");
   }
+  if (!Number.isSafeInteger(outputOffsetSamples) || outputOffsetSamples < 0) {
+    throw new RangeError("outputOffsetSamples must be a non-negative safe integer.");
+  }
   const hasFrequencyResponse = Array.isArray(frequencyResponse) && frequencyResponse.length > 0;
   if (hasFrequencyResponse && (!(sampleRate > 0) || !Number.isFinite(sampleRate))) {
     throw new Error("frequencyResponse 적용에는 유효한 sampleRate가 필요합니다.");
@@ -58,7 +75,7 @@ export function addFrequencyDomainPaths(options) {
   const halfSize = size / 2;
   const phaseReanchorInterval = 1024;
   for (const path of paths) {
-    const phaseStep = (-TAU * path.delaySamples) / size;
+    const phaseStep = (-TAU * delaySamplesForPath(path)) / size;
     const stepReal = Math.cos(phaseStep);
     const stepImaginary = Math.sin(phaseStep);
     let phaseReal = 1;
@@ -118,9 +135,12 @@ export function addFrequencyDomainPaths(options) {
   // bin back to the real axis preserves Hermitian symmetry for fractional delays.
   workspace.imaginary[size / 2] = 0;
   fftInPlace(workspace.real, workspace.imaginary, true);
-  const outputLength = Math.min(output.length, workspace.real.length);
+  const outputLength = Math.min(
+    output.length,
+    Math.max(0, workspace.real.length - outputOffsetSamples),
+  );
   for (let sampleIndex = 0; sampleIndex < outputLength; sampleIndex += 1) {
-    output[sampleIndex] += workspace.real[sampleIndex];
+    output[sampleIndex] += workspace.real[outputOffsetSamples + sampleIndex];
   }
 }