Method process

wasm/browser/src/workers/old-spn.worker.js:183–302

({ inputBuffer, outputBuffer })

  // try to do the same here as in Vanilla+Worklet
  process({ inputBuffer, outputBuffer }) {
    if (this.workerMessagePort.vanillaWorkerState === "realtimePerformanceEnded") {
      setPlayState({ contextUid: this.contextUid, newPlayState: "realtimePerformanceEnded" });
      return true;
    }

    if (!this.vanillaInitialized) {
      // this minimizes startup glitches
      const firstTransferSize = this.softwareBufferSize * PERIODS;

      this.requestPort.postMessage({
        readIndex: 0,
        numFrames: firstTransferSize,
      });

      this.pendingFrames += firstTransferSize;
      this.vanillaInitialized = true;
      return true;
    }

    if (!this.vanillaFirstTransferDone) {
      return true;
    }

    const writeableInputChannels = range(0, this.inputsCount).map((index) =>
      inputBuffer.getChannelData(index),
    );
    const writeableOutputChannels = range(0, this.outputsCount).map((index) =>
      outputBuffer.getChannelData(index),
    );

    const hasWriteableInputChannels = writeableInputChannels.length > 0;

    const nextOutputReadIndex =
      (this.vanillaOutputReadIndex + writeableOutputChannels[0].length) % this.hardwareBufferSize;

    const nextInputReadIndex = hasWriteableInputChannels
      ? (this.vanillaInputReadIndex + writeableInputChannels[0].length) % this.hardwareBufferSize
      : 0;

    if (
      this.workerMessagePort.vanillaWorkerState !== "realtimePerformanceStarted" &&
      this.workerMessagePort.vanillaWorkerState !== "realtimePerformanceResumed"
    ) {
      writeableOutputChannels.forEach((channelBuffer) => {
        channelBuffer.fill(0);
      });
      return true;
    } else if (this.vanillaAvailableFrames >= writeableOutputChannels[0].length) {
      writeableOutputChannels.forEach((channelBuffer, channelIndex) => {
        channelBuffer.set(
          this.vanillaOutputChannels[channelIndex].subarray(
            this.vanillaOutputReadIndex,
            nextOutputReadIndex < this.vanillaOutputReadIndex
              ? this.hardwareBufferSize
              : nextOutputReadIndex,
          ),
        );